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Beckett HAA, Bryant C, Neeman T, Mencuccini M, Ball MC. Plasticity in branch water relations and stem hydraulic vulnerability enhances hydraulic safety in mangroves growing along a salinity gradient. PLANT, CELL & ENVIRONMENT 2024; 47:854-870. [PMID: 37975319 DOI: 10.1111/pce.14764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
Coping with water stress depends on maintaining cellular function and hydraulic conductance. Yet measurements of vulnerability to drought and salinity do not often focus on capacitance in branch organs that buffer hydraulic function during water stress. The relationships between branch water relations, stem hydraulic vulnerability and stem anatomy were investigated in two co-occurring mangroves Aegiceras corniculatum and Rhizophora stylosa growing at low and high salinity. The dynamics of branch water release acted to conserve water content in the stem at the expense of the foliage during extended drying. Hydraulic redistribution from the foliage to the stem increased stem relative water content by up to 21%. The water potentials at which 12% and 50% loss of stem hydraulic conductivity occurred decreased by ~1.7 MPa in both species between low and high salinity sites. These coordinated tissue adjustments increased hydraulic safety despite declining turgor safety margins at higher salinity sites. Our results highlight the complex interplay of plasticity in organ-level water relations with hydraulic vulnerability in the maintenance of stem hydraulic function in mangroves distributed along salinity gradients. These results emphasise the importance of combining water relations and hydraulic vulnerability parameters to understand vulnerability to water stress across the whole plant.
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Affiliation(s)
- Holly A A Beckett
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
| | - Callum Bryant
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
| | - Teresa Neeman
- Biological Data Science Institute, Australian National University, Canberra, Australia
| | - Maurizio Mencuccini
- Ecological and Forestry Applications Research Centre (CREAF), Barcelona, Bellaterra, Spain
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
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Li Z, Luo D, Ibrahim MM, Hou E, Wang C. Adaptive strategies to freeze-thaw cycles in branch hydraulics of tree species coexisting in a temperate forest. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 206:108223. [PMID: 38043252 DOI: 10.1016/j.plaphy.2023.108223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/04/2023] [Accepted: 11/21/2023] [Indexed: 12/05/2023]
Abstract
Freeze-thaw cycles (FTCs) limit the distribution and survival of temperate tree species. Tree species with different wood types coexist in temperate forests and are subjected to the same FTCs. It is essential to understand how these trees differentially cope with xylem hydraulic failure induced by FTCs in the field. The branch hydraulic traits and nonstructural carbohydrate concentration of six coexisting tree species in a temperate forest were measured from mid-winter to early spring when the FTCs occurred from January to April. The percentage loss of hydraulic conductivity (PLC) was lower, and the water potential inducing a 50% loss of hydraulic conductivity (P50) was more negative in tracheid trees than in ring- and diffuse-porous trees, suggesting tracheid trees with narrow tracheid diameters showed less vulnerable to embolism and provided a lower degree of hydraulic failure during FTCs (stronger resistance). Ring-porous trees always showed lower hydraulic conductivity and higher PLC and P50, and these traits did not change during FTCs, suggesting that they might lose the hydraulic functions in winter and abandon the last year xylem. The P50 in diffuse-porous increased after several FTCs (frost fatigue), but that in tracheid species continued to increase (or even decrease) until the end of FTCs (69 cycles), suggesting that tracheid trees were less sensitive to frost fatigue than diffuse-porous trees. Soluble sugar concentration in deciduous trees negatively correlated with PLC at the end of FTCs, indicating that the effect of soluble sugar on refilling embolism occurred in early spring. While the soluble sugar concentration of deciduous trees decreased, that of two evergreen tracheid trees gradually increased, possibly due to the winter photosynthesis of evergreen leaves. Our results suggest temperate trees adopt different strategies to cope with the same FTCs. These findings enrich the understanding of plant hydraulics and carbon physiology in winter and provide insights into the response of different species coexisting in temperate forests under climate change.
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Affiliation(s)
- Zhimin Li
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
| | - Dandan Luo
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Muhammed Mustapha Ibrahim
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Enqing Hou
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Chuankuan Wang
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China.
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Chen L, Li M, Li C, Zheng W, Liu R. Different Physiological Responses to Continuous Drought between Seedlings and Younger Individuals of Haloxylon ammodendron. PLANTS (BASEL, SWITZERLAND) 2023; 12:3683. [PMID: 37960040 PMCID: PMC10647405 DOI: 10.3390/plants12213683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 11/15/2023]
Abstract
Drought is an important environmental factor that influences physiological processes in plants; however, few studies have examined the physiological mechanisms underlying plants' responses to continuous drought. In this study, the seedlings and younger individuals of Haloxylon ammodendron were experimentally planted in the southern part of the Gurbantunggut Desert. We measured their photosynthetic traits, functional traits and non-structural carbohydrate contents (NSCs) in order to assess the effects of continuous drought (at 15-day and 30-day drought points) on the plants' physiological responses. The results showed that at the 15-day (15 d) drought point, the leaf light-saturated net photosynthetic rate (An) values of both the seedlings and the younger individuals were decreased (by -68.9% and -45.2%, respectively). The intrinsic water use efficiency (iWUE) of the seedlings was significantly lower than that of the control group (-52.2%), but there was no diffenrence of iWUE observed in younger individuals. At the 30-day (30 d) drought point, a decrease in the An (-129.8%) of the seedlings was induced via biochemical inhibition, with a lower potential maximum photochemical rate (Fv/Fm, 0.42) compared with the control group, while a decrease in the An (-52.3%) of the younger individuals was induced due to lower stomatal conductance (gs, -50.5%). Our results indicated that prolonged drought induced a greater risk of seedling mortality as the relatively limited ability of stomatal regulation may increase the possibility of massive embolism, resulting in hydraulic failure.
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Affiliation(s)
- Lidan Chen
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; (L.C.); (M.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Fukang National Station of Observation and Research for Desert Ecosystem, Fukang 831505, China
| | - Minqing Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; (L.C.); (M.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Fukang National Station of Observation and Research for Desert Ecosystem, Fukang 831505, China
| | - Congjuan Li
- National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
| | - Weihua Zheng
- Institute of Agricultural Quality Standards and Testing Technology, Xinjiang Academy of Agricultural Sciecnes, Urumuqi 830091, China;
| | - Ran Liu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; (L.C.); (M.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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Carluccio G, Greco D, Sabella E, Vergine M, De Bellis L, Luvisi A. Xylem Embolism and Pathogens: Can the Vessel Anatomy of Woody Plants Contribute to X. fastidiosa Resistance? Pathogens 2023; 12:825. [PMID: 37375515 DOI: 10.3390/pathogens12060825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
The maintenance of an intact water column in the xylem lumen several meters above the ground is essential for woody plant viability. In fact, abiotic and biotic factors can lead to the formation of emboli in the xylem, interrupting sap flow and causing consequences on the health status of the plant. Anyway, the tendency of plants to develop emboli depends on the intrinsic features of the xylem, while the cyto-histological structure of the xylem plays a role in resistance to vascular pathogens, as in the case of the pathogenic bacterium Xylella fastidiosa. Analysis of the scientific literature suggests that on grapevine and olive, some xylem features can determine plant tolerance to vascular pathogens. However, the same trend was not reported in citrus, indicating that X. fastidiosa interactions with host plants differ by species. Unfortunately, studies in this area are still limited, with few explaining inter-cultivar insights. Thus, in a global context seriously threatened by X. fastidiosa, a deeper understanding of the relationship between the physical and mechanical characteristics of the xylem and resistance to stresses can be useful for selecting cultivars that may be more resistant to environmental changes, such as drought and vascular pathogens, as a way to preserve agricultural productions and ecosystems.
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Affiliation(s)
- Giambattista Carluccio
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Davide Greco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Erika Sabella
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Marzia Vergine
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Luigi De Bellis
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Andrea Luvisi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
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Zhao N, Sun X, Hou S, Ma S, Chen G, Chen Z, Wang X, Zhang Z. Festuca coelestis Increases Drought Tolerance and Nitrogen Use via Nutrient Supply-Demand Relationship on the Qinghai-Tibet Plateau. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091773. [PMID: 37176832 PMCID: PMC10181188 DOI: 10.3390/plants12091773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 05/15/2023]
Abstract
Drought and nutrient deficiency pose great challenges to the successful establishment of native plants on the Qinghai-Tibet Plateau. The dominant factors and strategies that affect the adaptation of alpine herbs to dry and nutrient-deficient environments remain unclear. Three water gradients were established using two-factor controlled experiments: low water (WL), medium water (WM), and high water (WH). The field water-holding capacities were 35%, 55%, and 75%, respectively. Nitrogen fertilizer (N) was applied at four levels: control (CK), low (FL), medium (FM), and high (FH) at 0, 110, 330, and 540 mg/kg, respectively. The results revealed that N was the main limiting factor, rather than phosphorous (P), in Festuca coelestis under drought stress. Under water shortage conditions, F. coelestis accumulated more proline and non-structural carbohydrates, especially in the aboveground parts of the leaves and stems; however, the root diameter and aboveground nitrogen use efficiency were reduced. Appropriate N addition could mitigate the adverse effects by increasing the release of N, P, and enzyme activity in the bulk soil and rhizosphere to balance their ratio, and was mainly transferred to the aboveground parts, which optimized the supply uptake relationship. The effects of water and fertilizer on the physiological adaptability and nutrient utilization of F. coelestis were verified using structural equation modeling. Based on their different sensitivities to water and nitrogen, the WHFM treatment was more suitable for F. coelestis establishment. Our results demonstrated that the disproportionate nutrient supply ability and preferential supply aboveground compared to below ground were the main factors influencing F. coelestis seedling establishment under drought conditions. This study provides evidence for a better understanding of herbaceous plants living in high mountain regions and offers important information for reducing the risk of ecological restoration failure in similar alpine regions.
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Affiliation(s)
- Ningning Zhao
- College of Resources and Environment, Tibet Agriculture and Animal Husbandry University, Nyingchi 860000, China
- Qiangtang Alpine Grassland Ecosystem Research Station (Jointly Built with Lanzhou University), Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
| | - Xingrong Sun
- Qiangtang Alpine Grassland Ecosystem Research Station (Jointly Built with Lanzhou University), Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
| | - Shuai Hou
- Qiangtang Alpine Grassland Ecosystem Research Station (Jointly Built with Lanzhou University), Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
| | - Sujie Ma
- Qiangtang Alpine Grassland Ecosystem Research Station (Jointly Built with Lanzhou University), Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
| | - Guohao Chen
- College of Grassland Agriculture, Northwest A & F University, Yangling 712100, China
| | - Zelin Chen
- College of Grassland Agriculture, Northwest A & F University, Yangling 712100, China
| | - Xiangtao Wang
- Qiangtang Alpine Grassland Ecosystem Research Station (Jointly Built with Lanzhou University), Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, China
| | - Zhixin Zhang
- College of Grassland Agriculture, Northwest A & F University, Yangling 712100, China
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Bianchi D, Ricciardi V, Pozzoli C, Grossi D, Caramanico L, Pindo M, Stefani E, Cestaro A, Brancadoro L, De Lorenzis G. Physiological and Transcriptomic Evaluation of Drought Effect on Own-Rooted and Grafted Grapevine Rootstock (1103P and 101-14MGt). PLANTS (BASEL, SWITZERLAND) 2023; 12:1080. [PMID: 36903939 PMCID: PMC10005690 DOI: 10.3390/plants12051080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Grapevines worldwide are grafted onto Vitis spp. rootstocks in order to improve their tolerance to biotic and abiotic stresses. Thus, the response of vines to drought is the result of the interaction between the scion variety and the rootstock genotype. In this work, the responses of genotypes to drought were evaluated on 1103P and 101-14MGt plants, own-rooted and grafted with Cabernet Sauvignon, in three different water deficit conditions (80, 50, and 20% soil water content, SWC). Gas exchange parameters, stem water potential, root and leaf ABA content, and root and leaf transcriptomic response were investigated. Under well-watered conditions, gas exchange and stem water potential were mainly affected by the grafting condition, whereas under sever water deficit they were affected by the rootstock genotype. Under severe stress conditions (20% SWC), 1103P showed an "avoidance" behavior. It reduced stomatal conductance, inhibited photosynthesis, increased ABA content in the roots, and closed the stomata. The 101-14MGt maintained a high photosynthetic rate, limiting the reduction of soil water potential. This behavior results in a "tolerance" strategy. An analysis of the transcriptome showed that most of the differentially expressed genes were detected at 20% SWC, and more significantly in roots than in leaves. A core set of genes has been highlighted on the roots as being related to the root response to drought that are not affected by genotype nor grafting. Genes specifically regulated by grafting and genes specifically regulated by genotype under drought conditions have been identified as well. The 1103P, more than the 101-14MGt, regulated a high number of genes in both own-rooted and grafted conditions. This different regulation revealed that 1103P rootstock readily perceived the water scarcity and rapidly faced the stress, in agreement with its avoidance strategy.
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Affiliation(s)
- Davide Bianchi
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
| | - Valentina Ricciardi
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
| | - Carola Pozzoli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Daniele Grossi
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
| | - Leila Caramanico
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
| | - Massimo Pindo
- Fondazione E. Mach, Centro Ricerca e Innovazione, Via E. Mach 1, 38010 San Michele all’Adige, TN, Italy
| | - Erika Stefani
- Fondazione E. Mach, Centro Ricerca e Innovazione, Via E. Mach 1, 38010 San Michele all’Adige, TN, Italy
| | - Alessandro Cestaro
- Fondazione E. Mach, Centro Ricerca e Innovazione, Via E. Mach 1, 38010 San Michele all’Adige, TN, Italy
| | - Lucio Brancadoro
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
| | - Gabriella De Lorenzis
- Dipartimento di Scienze Agrarie e Ambientali-Produzione Territorio e Agroenergia, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milano, Italy
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Dimitrova A, Sferra G, Scippa GS, Trupiano D. Network-Based Analysis to Identify Hub Genes Involved in Spatial Root Response to Mechanical Constrains. Cells 2022; 11:cells11193121. [PMID: 36231084 PMCID: PMC9564363 DOI: 10.3390/cells11193121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/16/2022] Open
Abstract
Previous studies report that the asymmetric response, observed along the main poplar woody bent root axis, was strongly related to both the type of mechanical forces (compression or tension) and the intensity of force displacement. Despite a large number of targets that have been proposed to trigger this asymmetry, an understanding of the comprehensive and synergistic effect of the antistress spatially related pathways is still lacking. Recent progress in the bioinformatics area has the potential to fill these gaps through the use of in silico studies, able to investigate biological functions and pathway overlaps, and to identify promising targets in plant responses. Presently, for the first time, a comprehensive network-based analysis of proteomic signatures was used to identify functions and pivotal genes involved in the coordinated signalling pathways and molecular activities that asymmetrically modulate the response of different bent poplar root sectors and sides. To accomplish this aim, 66 candidate proteins, differentially represented across the poplar bent root sides and sectors, were grouped according to their abundance profile patterns and mapped, together with their first neighbours, on a high-confidence set of interactions from STRING to compose specific cluster-related subnetworks (I–VI). Successively, all subnetworks were explored by a functional gene set enrichment analysis to identify enriched gene ontology terms. Subnetworks were then analysed to identify the genes that are strongly interconnected with other genes (hub gene) and, thus, those that have a pivotal role in the bent root asymmetric response. The analysis revealed novel information regarding the response coordination, communication, and potential signalling pathways asymmetrically activated along the main root axis, delegated mainly to Ca2+ (for new lateral root formation) and ROS (for gravitropic response and lignin accumulation) signatures. Furthermore, some of the data indicate that the concave side of the bent sector, where the mechanical forces are most intense, communicates to the other (neighbour and distant) sectors, inducing spatially related strategies to ensure water uptake and accompanying cell modification. This information could be critical for understanding how plants maintain and improve their structural integrity—whenever and wherever it is necessary—in natural mechanical stress conditions.
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Duan H, Wang D, Zhao N, Huang G, Resco de Dios V, Tissue DT. Limited hydraulic recovery in seedlings of six tree species with contrasting leaf habits in subtropical China. FRONTIERS IN PLANT SCIENCE 2022; 13:967187. [PMID: 36035730 PMCID: PMC9403191 DOI: 10.3389/fpls.2022.967187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Subtropical tree species may experience severe drought stress due to variable rainfall under future climates. However, the capacity to restore hydraulic function post-drought might differ among co-occurring species with contrasting leaf habits (e.g., evergreen and deciduous) and have implications for future forest composition. Moreover, the links between hydraulic recovery and physiological and morphological traits related to water-carbon availability are still not well understood. Here, potted seedlings of six tree species (four evergreen and two deciduous) were grown outdoors under a rainout shelter. They grew under favorable water conditions until they were experimentally subjected to a soil water deficit leading to losses of ca. 50% of hydraulic conductivity, and then soils were re-watered to field capacity. Traits related to carbon and water relations were measured. There were differences in drought responses and recovery between species, but not as a function of evergreen or deciduous groups. Sapindus mukorossi exhibited the most rapid drought response, which was associated with a suite of physiological and morphological traits (larger plant size, the lowest hydraulic capacitance (C branch), higher minimum conductance (g min) and lower HV (Huber value)). Upon re-watering, xylem water potential exhibited fast recovery in 1-3 days among species, while photosynthesis at saturating light (A sat) and stomatal conductance (g s) recovery lagged behind water potential recovery depending on species, with g s recovery being more delayed than A sat in most species. Furthermore, none of the six species exhibited significant hydraulic recovery during the 7 days re-watering period, indicating that xylem refilling was apparently limited; in addition, NSC availability had a minimal role in facilitating hydraulic recovery during this short-term period. Collectively, if water supply is limited by insignificant hydraulic recovery post-drought, the observed carbon assimilation recovery of seedlings may not be sustained over the longer term, potentially altering seedling regeneration and shifting forest species composition in subtropical China under climate change.
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Affiliation(s)
- Honglang Duan
- Institute for Forest Resources and Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Defu Wang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Nan Zhao
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Guomin Huang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA Center, Lleida, Spain
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Richmond, NSW, Australia
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Duan H, Resco de Dios V, Wang D, Zhao N, Huang G, Liu W, Wu J, Zhou S, Choat B, Tissue DT. Testing the limits of plant drought stress and subsequent recovery in four provenances of a widely distributed subtropical tree species. PLANT, CELL & ENVIRONMENT 2022; 45:1187-1203. [PMID: 34985807 DOI: 10.1111/pce.14254] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Drought-induced tree mortality may increase with ongoing climate change. Unraveling the links between stem hydraulics and mortality thresholds, and the effects of intraspecific variation, remain important unresolved issues. We conducted a water manipulation experiment in a rain-out shelter, using four provenances of Schima superba originating from a gradient of annual precipitation (1124-1796 mm) and temperature (16.4-22.4°C). Seedlings were droughted to three levels of percentage loss of hydraulic conductivity (i.e., P50 , P88 and P99) and subsequently rewatered to field capacity for 30 days; traits related to water and carbon relations were measured. The lethal water potential associated with incipient mortality was between P50 and P88 . Seedlings exhibited similar drought responses in xylem water potential, hydraulic conductivity and gas exchange. Upon rehydration, patterns of gas exchange differed among provenances but were not related to the climate at the origin. The four provenances exhibited a similar degree of stem hydraulic recovery, which was correlated with the magnitude of antecedent drought and stem soluble sugar at the end of the drought. Results suggest that there were intraspecific differences in the capacity of S. superba seedlings for carbon assimilation during recovery, indicating a decoupling between gas exchange recovery and stem hydraulics across provenances.
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Affiliation(s)
- Honglang Duan
- Institute for Forest Resources and Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- Department of Crop and Forest Sciences, Unversitat de Lleida, Lleida, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA Centre, Lleida, Spain
| | - Defu Wang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Nan Zhao
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Guomin Huang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Wenfei Liu
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Jianping Wu
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Shuangxi Zhou
- Department of Biological Sciences, Macquarie University, New South Wales, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Richmond, New South Wales, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Richmond, New South Wales, Australia
- Global Centre for Land-based Innovation, Western Sydney University, Hawkesbury Campus, Richmond, New South Wales, Australia
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10
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Analysis of Global Gene Expression in Maize (Zea mays) Vegetative and Reproductive Tissues That Differ in Accumulation of Starch and Sucrose. PLANTS 2022; 11:plants11030238. [PMID: 35161219 PMCID: PMC8838981 DOI: 10.3390/plants11030238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 11/17/2022]
Abstract
Carbon allocation between vegetative and reproductive tissues impacts cereal grain production. Despite great agricultural importance, sink–source relationships have not been fully characterized at the early reproductive stages in maize. Here, we quantify the accumulation of non-structural carbohydrates and patterns of gene expression in the top internode of the stem and the female inflorescence of maize at the onset of grain filling (reproductive stage R1). Top internode stem and female inflorescence tissues of the Puma maize inbred line were collected at reproductive stage R1 (without pollination) and non-structural carbohydrates were quantified by spectrophotometry. The female inflorescence accumulated starch at higher levels than the top internode of the stem. Global mRNA transcript levels were then evaluated in both tissues by RNA sequencing. Gene expression analysis identified 491 genes differentially expressed between the female inflorescence and the top stem internode. Gene ontology classification of differentially expressed genes showed enrichment for sucrose synthesis, the light-dependent reactions of photosynthesis, and transmembrane transporters. Our results suggest that sugar transporters play a key role in sugar partitioning in the maize stem and reveal previously uncharacterized differences between the female inflorescence and the top internode of the stem at early reproductive stages.
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11
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Tomasella M, Casolo V, Natale S, Petruzzellis F, Kofler W, Beikircher B, Mayr S, Nardini A. Shade-induced reduction of stem nonstructural carbohydrates increases xylem vulnerability to embolism and impedes hydraulic recovery in Populus nigra. THE NEW PHYTOLOGIST 2021; 231:108-121. [PMID: 33811346 PMCID: PMC9290559 DOI: 10.1111/nph.17384] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 03/28/2021] [Indexed: 05/08/2023]
Abstract
Nonstructural carbohydrates (NSCs) have been suggested to affect xylem transport under fluctuating water availability, but conclusive evidence is still lacking. We tested the effect of shade-induced NSC depletion on xylem vulnerability to embolism and hydraulic recovery on Populus nigra saplings. Vulnerability was assessed in light-exposed (L) and shaded (S) plants with the hydraulic method, and in vivo with the optical method and X-ray micro-computed tomography. Plants were stressed to 80% loss of hydraulic conductance (PLC) and re-irrigated to check for possible recovery. We measured PLC, bark and wood NSC content, as well as xylem sap pH, surface tension (γsap ) and sugar concentration, before, during and after drought. Shading induced depletion of stem NSC (mainly starch) reserves. All methods converged in indicating higher xylem vulnerability in S than in L plants. This difference was not explained by xylem vessel and pit anatomy or by γsap . Shading impeded sap acidification and sugar accumulation during drought in S plants and prevented hydraulic recovery, which was observed in L plants. Our results highlight the importance of stem NSCs to sustain xylem hydraulic functioning during drought and suggest that light and/or adequate stem NSC thresholds are required to trigger xylem sap chemical changes involved in embolism recovery.
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Affiliation(s)
- Martina Tomasella
- Dipartimento di Scienze della VitaUniversità di TriesteVia L. Giorgieri 10Trieste34127Italy
| | - Valentino Casolo
- Dipartimento di Scienze AgroalimentariAmbientali e AnimaliUniversità di UdineVia delle Scienze 91Udine33100Italy
| | - Sara Natale
- Dipartimento di Scienze della VitaUniversità di TriesteVia L. Giorgieri 10Trieste34127Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della VitaUniversità di TriesteVia L. Giorgieri 10Trieste34127Italy
| | - Werner Kofler
- Department of BotanyUniversity of InnsbruckSternwartestraße 15Innsbruck6020Austria
| | - Barbara Beikircher
- Department of BotanyUniversity of InnsbruckSternwartestraße 15Innsbruck6020Austria
| | - Stefan Mayr
- Department of BotanyUniversity of InnsbruckSternwartestraße 15Innsbruck6020Austria
| | - Andrea Nardini
- Dipartimento di Scienze della VitaUniversità di TriesteVia L. Giorgieri 10Trieste34127Italy
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12
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Słupianek A, Dolzblasz A, Sokołowska K. Xylem Parenchyma-Role and Relevance in Wood Functioning in Trees. PLANTS (BASEL, SWITZERLAND) 2021; 10:1247. [PMID: 34205276 PMCID: PMC8235782 DOI: 10.3390/plants10061247] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 12/11/2022]
Abstract
Woody plants are characterised by a highly complex vascular system, wherein the secondary xylem (wood) is responsible for the axial transport of water and various substances. Previous studies have focused on the dead conductive elements in this heterogeneous tissue. However, the living xylem parenchyma cells, which constitute a significant functional fraction of the wood tissue, have been strongly neglected in studies on tree biology. Although there has recently been increased research interest in xylem parenchyma cells, the mechanisms that operate in these cells are poorly understood. Therefore, the present review focuses on selected roles of xylem parenchyma and its relevance in wood functioning. In addition, to elucidate the importance of xylem parenchyma, we have compiled evidence supporting the hypothesis on the significance of parenchyma cells in tree functioning and identified the key unaddressed questions in the field.
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Affiliation(s)
- Aleksandra Słupianek
- Department of Plant Developmental Biology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, 50-328 Wrocław, Poland; (A.D.); (K.S.)
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13
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Rodríguez-Calcerrada J, Rodrigues AM, António C, Perdiguero P, Pita P, Collada C, Li M, Gil L. Stem metabolism under drought stress - a paradox of increasing respiratory substrates and decreasing respiratory rates. PHYSIOLOGIA PLANTARUM 2021; 172:391-404. [PMID: 32671841 DOI: 10.1111/ppl.13145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Metabolic changes underpinning drought-induced variations in stem respiration (Rs ) are unknown. We measured Rs rates and metabolite and gene expression profiles in Ulmus minor Mill. and Quercus ilex L. seedlings subjected to increasing levels of drought stress to better understand how carbon, nitrogen and energy metabolism interact during drought. In both species, only plants showing extreme stress symptoms - i.e. negligible rates of leaf stomatal conductance and photosynthesis, and high stem dehydration (30-50% of maximum water storage) and contraction (50-150 μm week-1 ) - exhibited lower Rs rates than well-watered plants. Abundance of low-molecular weight sugars (e.g. glucose and fructose) and sugar alcohols (e.g. mannitol) increased with drought, at more moderate stress and to a higher extent in Q. ilex than U. minor. Abundance of amino acids increased at more severe stress, more abruptly, and to a higher extent in U. minor, coinciding with leaf senescence, which did not occur in Q. ilex. Organic acids changed less in response to drought: threonate and glycerate increased, and citrate decreased although slightly in both species. Transcripts of genes coding for enzymes of the Krebs cycle decreased in Q. ilex and increased in U. minor in conditions of extreme drought stress. The maintenance of Rs under severe growth and photosynthetic restrictions reveals the importance of stem mitochondrial activity in drought acclimation. The eventual decline in Rs diverts carbon substrates from entering the Krebs cycle that may help to cope with osmotic and oxidative stress during severe drought and to recover hydraulic functionality afterwards.
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Affiliation(s)
- Jesús Rodríguez-Calcerrada
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Ana M Rodrigues
- Plant Metabolomics Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, 2780-157, Portugal
| | - Carla António
- Plant Metabolomics Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, 2780-157, Portugal
| | - Pedro Perdiguero
- Animal Health Research Center, National Institute for Agriculture and Food Research and Technology (CISA-INIA), Valdeolmos, Madrid, 28130, Spain
| | - Pilar Pita
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Carmen Collada
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Meng Li
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Luis Gil
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid, 28040, Spain
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14
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Herrera-Ramírez D, Sierra CA, Römermann C, Muhr J, Trumbore S, Silvério D, Brando PM, Hartmann H. Starch and lipid storage strategies in tropical trees relate to growth and mortality. THE NEW PHYTOLOGIST 2021; 230:139-154. [PMID: 33507548 DOI: 10.1111/nph.17239] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Non-structural carbon (NSC) storage (i.e. starch, soluble sugras and lipids) in tree stems play important roles in metabolism and growth. Their spatial distribution in wood may explain species-specific differences in carbon storage dynamics, growth and survival. However, quantitative information on the spatial distribution of starch and lipids in wood is sparse due to methodological limitations. Here we assessed differences in wood NSC and lipid storage between tropical tree species with different growth and mortality rates and contrasting functional types. We measured starch and soluble sugars in wood cores up to 4 cm deep into the stem using standard chemical quantification methods and histological slices stained with Lugol's iodine. We also detected neutral lipids using histological slices stained with Oil-Red-O. The histological method allowed us to group individuals into two categories according to their starch storage strategy: fiber-storing trees and parenchyma-storing trees. The first group had a bigger starch pool, slower growth and lower mortality rates than the second group. Lipid storage was found in wood parenchyma in five species and was related to low mortality rates. The quantification of the spatial distribution of starch and lipids in wood improves our understanding of NSC dynamics in trees and reveals additional dimensions of tree growth and survival strategies.
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Affiliation(s)
| | - Carlos A Sierra
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str 10, Jena, 07745, Germany
| | - Christine Römermann
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, D-04103, Germany
- Department of Bioclimatology, Georg August University Göttingen, Büsgenweg 2, Göttingen, 37077, Germany
| | - Jan Muhr
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str 10, Jena, 07745, Germany
- Institute of Ecology and Evolution, Friedrich Schiller University Jena, Philosophenweg 16, Jena, 07743, Germany
| | - Susan Trumbore
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str 10, Jena, 07745, Germany
| | - Divino Silvério
- Department of Biology, Universidade Federal Rural da Amazônia - UFRA, Capitão Poço, Pará, 68650-000, Brazil
| | - Paulo M Brando
- Department of Earth System Science, University of California, Irvine, CA, 92697, USA
- Instituto de Pesquisa Ambiental da Amazônia, Brasília, DF, 70863-520, Brazil
- Woodwell Climate Research Center, Falmouth, MA, 02540, USA
| | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str 10, Jena, 07745, Germany
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15
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Rodríguez-Gamir J, Xue J, Meason DF, Clearwater M, Clinton PW, Domec JC. Interclonal variation, coordination, and trade-offs between hydraulic conductance and gas exchange in Pinus radiata: consequences on plant growth and wood density. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2419-2433. [PMID: 33337485 DOI: 10.1093/jxb/eraa587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 12/17/2020] [Indexed: 05/24/2023]
Abstract
Stem growth reflects genetic and phenotypic differences within a tree species. The plant hydraulic system regulates the carbon economy, and therefore variations in growth and wood density. A whole-organism perspective, by partitioning the hydraulic system, is crucial for understanding the physical and physiological processes that coordinately mediate plant growth. The aim of this study was to determine whether the relationships and trade-offs between (i) hydraulic traits and their relative contribution to the whole-plant hydraulic system, (ii) plant water transport, (iii) CO2 assimilation, (iv) plant growth, and (v) wood density are revealed at the interclonal level within a variable population of 10 Pinus radiata (D. Don) clones for these characters. We demonstrated a strong coordination between several plant organs regarding their hydraulic efficiency. Hydraulic efficiency, gas exchange, and plant growth were intimately linked. Small reductions in stem wood density were related to a large increase in sapwood hydraulic efficiency, and thus to plant growth. However, stem growth rate was negatively related to wood density. We discuss insights explaining the relationships and trade-offs of the plant traits examined in this study. These insights provide a better understanding of the existing coordination, likely to be dependent on genetics, between the biophysical structure of wood, plant growth, hydraulic partitioning, and physiological plant functions in P. radiata.
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Affiliation(s)
- Juan Rodríguez-Gamir
- Producción Vegetal en zonas tropicales y subtropicales, Instituto Canario de Investigaciones Agrarias (ICIA), Ctra de El boquerón s/n, 38270 San Cristóbal de La Laguna, Tenerife, Canary Islands, Spain
- Forest Systems, Scion, Christchurch, New Zealand
| | - Jianming Xue
- Forest Systems, Scion, Christchurch, New Zealand
| | - Dean F Meason
- Forest Systems, Scion, Private Bag 3020, Rotorua, New Zealand
| | - Michael Clearwater
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | | | - Jean-Christophe Domec
- Bordeaux Sciences Agro, UMR INRA ISPA 1391, Gradignan, France
- Nicholas School of the Environment, Duke University, Durham, NC, USA
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16
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Sapes G, Demaree P, Lekberg Y, Sala A. Plant carbohydrate depletion impairs water relations and spreads via ectomycorrhizal networks. THE NEW PHYTOLOGIST 2021; 229:3172-3183. [PMID: 33280134 DOI: 10.1111/nph.17134] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Under prolonged drought and reduced photosynthesis, plants consume stored nonstructural carbohydrates (NSCs). Stored NSC depletion may impair the regulation of plant water balance, but the underlying mechanisms are poorly understood, and whether such mechanisms are independent of plant water deficit is not known. If so, carbon costs of fungal symbionts could indirectly influence plant drought tolerance through stored NSC depletion. We connected well-watered Pinus ponderosa seedling pairs via ectomycorrhizal (EM) networks where one seedling was shaded (D) and the other kept illuminated (LD) and compared responses to seedling pairs in full light (L). We measured plant NSCs, osmotic and water potential, and transfer of 13 CO2 through EM to explore mechanisms linking stored NSCs to plant water balance regulation and identify potential tradeoffs between plant water retention and EM fungi under carbon-limiting conditions. NSCs decreased from L to LD to D seedlings. Even without drought, NSC depletion impaired osmoregulation and turgor maintenance, both of which are critical for drought tolerance. Importantly, EM networks propagated NSC depletion and its negative effects on water retention from carbon stressed to nonstressed hosts. We demonstrate that NSC storage depletion influences turgor maintenance independently of plant water deficit and reveal carbon allocation tradeoffs between supporting fungal symbionts and retaining water.
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Affiliation(s)
- Gerard Sapes
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Patrick Demaree
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Ylva Lekberg
- MPG Ranch, Missoula, MT, 59801, USA
- W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, 59812, USA
| | - Anna Sala
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
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17
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Zhang H, Yuan F, Wu J, Jin C, Pivovaroff AL, Tian J, Li W, Guan D, Wang A, McDowell NG. Responses of functional traits to seven-year nitrogen addition in two tree species: coordination of hydraulics, gas exchange and carbon reserves. TREE PHYSIOLOGY 2021; 41:190-205. [PMID: 33313912 DOI: 10.1093/treephys/tpaa120] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 07/25/2020] [Accepted: 09/16/2020] [Indexed: 06/12/2023]
Abstract
Atmospheric nitrogen (N) deposition has been observed to impact plant structure and functional traits in terrestrial ecosystems. Although the effect of N deposition on plant water use has been well-evaluated in laboratories and in experimental forests, the linkages between water and carbon relations under N deposition are unclear. Here, we report on hydraulics, gas exchange and carbon reserves of two broad-leaved tree species (Quercus mongolica and Fraxinus mandshurica) in mature temperate forests after a seven-year experiment with different levels of N addition (control (CK), low (23 kg N ha-1 yr-1), medium (46 kg N ha-1 yr-1) and high (69 kg N ha-1 yr-1)). We investigated variation in hydraulic traits (xylem-specific hydraulic conductivity (Ks), native percentage loss of conductivity (PLC) and leaf water potential), xylem anatomy (vessel diameter and density), gas exchange (maximum net photosynthesis rate and stomatal conductance) and carbon reserves (soluble sugars, starch and total nonstructural carbohydrates (NSC)) with different N addition levels. We found that medium N addition significantly increased Ks and vessel diameter compared to control, but accompanied increasing PLC and decreasing leaf water potential, suggesting that N addition results in a greater hydraulic efficiency and higher risk of embolism. N addition promoted photosynthetic capacity via increasing foliar N concentration but did not change stomatal conductance. In addition, we found increase in foliar soluble sugar concentration and decrease in starch concentration with N addition, and positive correlations between hydraulic traits (vessel diameter and PLC) and soluble sugars. These coupled responses of tree hydraulics and carbon metabolism are consistent with a regulatory role of carbohydrates in maintaining hydraulic integrity. Our study provides an important insight into the relationship of plant water transport and carbon dynamics under increasing N deposition.
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Affiliation(s)
- Hongxia Zhang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fenghui Yuan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jiabing Wu
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Changjie Jin
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Alexandria L Pivovaroff
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Jinyuan Tian
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weibin Li
- State Key Laboratory of Grassland and Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Dexin Guan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Anzhi Wang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Nate G McDowell
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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18
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Precipitation Gradient Drives Divergent Relationship between Non-Structural Carbohydrates and Water Availability in Pinus tabulaeformis of Northern China. FORESTS 2021. [DOI: 10.3390/f12020133] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Seasonal non-structural carbohydrate (NSC) dynamics in different organs can indicate the strategies trees use to cope with water stress; however, these dynamics remain poorly understood along a large precipitation gradient. In this study, we hypothesized that the correlation between water availability and NSC concentrations in different organs might be strengthened by decreasing precipitation in Pinus tabulaeformis Carr. forests in temperate China. Our results show that the concentrations of soluble sugars were lower in stems and coarse roots, and starch was higher in branches in the early growing season at drier sites. Throughout the growing season, the concentrations of soluble sugars increased in drier sites, especially for leaves, and remained stable in wetter sites, while starch concentrations were relatively stable in branches and stems at all sites. The NSC concentrations, mainly starch, decreased in coarse roots along the growing season at drier sites. Trees have a faster growth rate with an earlier cessation in active stem growth at drier sites. Interestingly, we also found a divergent relationship between NSCs in different organs and mean growing season water availability, and a stronger correlation was observed in drier sites. These results show that pine forests in arid and semi-arid regions of northern China exhibit different physiological responses to water availability, improving our understanding of the adaptive mechanisms of trees to water limitations in a warmer and drier climate.
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19
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Zhou XR, Zhang NN, Zhao YM, Dai L, Xu DP, Xu GF, Tian J. Distribution Dynamics and Roles of Starch in Non-photosynthetic Vegetative Organs of Santalum album Linn., a Hemiparasitic Tree. FRONTIERS IN PLANT SCIENCE 2021; 11:532537. [PMID: 33584738 PMCID: PMC7873954 DOI: 10.3389/fpls.2020.532537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Allocation dynamics of stored starch plays essential roles in the development and growth of trees. Previous studies focused on the dynamics and the characteristics of starch in autotrophic trees. However, although starch granules have been detected in the organs or tissues of some parasitic plants, studies on the allocation dynamics and roles of storage starch in them are limited. Therefore, we determined and estimated the allocation dynamics and roles of starch in Santalum album Linn., a hemiparasitic tree, using morphological and physiological methods. Our findings showed abundant starch in the stem and root of S. album at the early seedling stage. Although S. album seedlings attached to the host showed no significant changes in starch levels throughout the experiment, unattached and host-removed seedlings exhibited a gradual decrease in the starch content over time. When the starch content of unattached seedlings was less than 1%, they started to die. Starch accumulated to high levels in developing and active haustoria; however, starch levels were low in the inactive haustoria. The present study suggests that starch may provide energy to seedlings that have no host, allowing them to survive during the unattached phase, thus increasing their chance to attach to host roots by extending their survival duration. In addition, we speculate that storage starch is potentially involved in the development of haustoria and in the physiological processes of S. album related to the absorption and transportation of water and nutrients from its host.
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Affiliation(s)
- Xiu Ren Zhou
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, China
| | - Ning Nan Zhang
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Yi Min Zhao
- Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Lei Dai
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, China
| | - Da Ping Xu
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Gui Fang Xu
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, China
| | - Jing Tian
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, China
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20
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Secchi F, Pagliarani C, Cavalletto S, Petruzzellis F, Tonel G, Savi T, Tromba G, Obertino MM, Lovisolo C, Nardini A, Zwieniecki MA. Chemical inhibition of xylem cellular activity impedes the removal of drought-induced embolisms in poplar stems - new insights from micro-CT analysis. THE NEW PHYTOLOGIST 2021; 229:820-830. [PMID: 32890423 DOI: 10.1111/nph.16912] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
In drought-stressed plants a coordinated cascade of chemical and transcriptional adjustments occurs at the same time as embolism formation. While these processes do not affect embolism formation during stress, they may prime stems for recovery during rehydration by modifying apoplast pH and increasing sugar concentration in the xylem sap. Here we show that in vivo treatments modifying apoplastic pH (stem infiltration with a pH buffer) or reducing stem metabolic activity (infiltration with sodium vanadate and sodium cyanide; plant exposure to carbon monoxide) can reduce sugar accumulation, thus disrupting or delaying the recovery process. Application of the vanadate treatment (NaVO3, an inhibitor of many ATPases) completely halted recovery from drought-induced embolism for up to 24 h after re-irrigation, while partial recovery was observed in vivo in control plants using X-ray microcomputed tomography. Our results suggest that stem hydraulic recovery in poplar is a biological, energy-dependent process that coincides with accumulation of sugars in the apoplast during stress. Recovery and damage are spatially coordinated, with embolism formation occurring from the inside out and refilling from the outside in. The outside-in pattern highlights the importance of xylem proximity to the sugars within the phloem to the embolism recovery process.
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Affiliation(s)
- Francesca Secchi
- Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095, Italy
| | - Chiara Pagliarani
- Institute for Sustainable Plant Protection, National Research Council, Strada delle Cacce 73, Torino, 10135, Italy
| | - Silvia Cavalletto
- Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, University of Trieste, via Giorgieri 10, Trieste, 34127, Italy
| | - Giulia Tonel
- Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095, Italy
| | - Tadeja Savi
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, BOKU, Gregor-Mendel-Straße 33, Vienna, 1180, Austria
| | - Giuliana Tromba
- Elettra-Sincrotrone Trieste, Area Science Park, Basovizza, Trieste, 34149, Italy
| | - Maria Margherita Obertino
- Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095, Italy
| | - Claudio Lovisolo
- Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, University of Trieste, via Giorgieri 10, Trieste, 34127, Italy
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
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21
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Opportunities and Threats of Mediterranean Evergreen Sclerophyllous Woody Species Subjected to Extreme Drought Events. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10238458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Climate change and extreme drought and heat events impact the Mediterranean evergreen sclerophyllous vegetation in South Europe, especially in Iberian and Italian peninsula, where widespread crown defoliation and dieback have been observed since the 90s of the XX century. Field observations and long-term experiments showed different sensitivity of the various woody species, Quercus ilex and Arbutus unedo being prone to drought, whereas Phillyrea latifolia and Pistacia lentiscus appeared to be resistant. The present review aims at exploring the phylogenetic and evolutionary basis of the resistance (or susceptibility) to drought of Mediterranean vegetation and its possible mechanisms of resilience. The main findings are summarized as follows: (1) Mediterranean regions in the world are refuge areas for several plant evolutive lineages and migratory routes. Evergreen sclerophyllous species, currently presented in Mediterranean basin, evolved under different climatic conditions; (2) the evergreen habitus represents an adaptation to mild drought conditions. Deciduous (specially summer deciduous) species are better performing under severe drought and low air relative humidity than evergreen species; (3) severe drought events acts selectively by favouring the species evolved in the Quaternary era and those originated in drier regions; (4) the evergreen trees and shrubs are resilient to the severe drought events and can restore the pre-event condition by resprouting from dormant buds in the cambium tissue. This ability is related to the non-structural carbohydrate content in the parenchyma-rays in woody stems. The amount and availability of these strategic reserve can be compromised by frequent drought events; (5) plant seed regeneration can be affected by drought and seedling establishment may be limited by soil dryness and microenvironment conditions; (6) the role of phenotypic plasticity of the species and epigenetic responses in Mediterranean-type ecosystems, although discussed in few papers, is still poorly known. We hypothesize that instead of latitudinal (South to North) or altitudinal (lowland to upland) plant migrations, Mediterranean forest ecosystems may respond to climate change by modulating their species composition and community structure with genetic resources (i.e., taxonomic diversity) already present in loco. Changes in vegetation assemblages and community structure may lead changes in ecological and landscape ecosystem values, with changes in related ecosystem services. A redefinition of management criteria of natural resources and a pro-active silviculture to make forest ecosystems more resilient are required.
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22
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Brunetti C, Savi T, Nardini A, Loreto F, Gori A, Centritto M. Changes in abscisic acid content during and after drought are related to carbohydrate mobilization and hydraulic recovery in poplar stems. TREE PHYSIOLOGY 2020; 40:1043-1057. [PMID: 32186735 DOI: 10.1093/treephys/tpaa032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 02/26/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Drought compromises plant's ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plant's ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. Young plants of Populus nigra L. were used to investigate possible relationships among ABA, non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 h after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity.
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Affiliation(s)
- Cecilia Brunetti
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - Tadeja Savi
- University of Natural Resources and Life Sciences, Institute of Botany, Department of Integrative Biology and Biodiversity Research, BOKU, Gregor-Mendel-Straße 33, 1190, Vienna, Austria Austria
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Francesco Loreto
- National Research Council of Italy, Department of Biology, Agriculture and Food Sciences, Piazzale Aldo Moro 7, 00185 Roma, Italy
| | - Antonella Gori
- Department of Agri-Food Production and Environmental Sciences, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino (Florence), Italy
| | - Mauro Centritto
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
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23
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Godfrey JM, Riggio J, Orozco J, Guzmán-Delgado P, Chin ARO, Zwieniecki MA. Ray fractions and carbohydrate dynamics of tree species along a 2750 m elevation gradient indicate climate response, not spatial storage limitation. THE NEW PHYTOLOGIST 2020; 225:2314-2330. [PMID: 31808954 DOI: 10.1111/nph.16361] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/03/2019] [Indexed: 06/10/2023]
Abstract
Parenchyma cells in the xylem store nonstructural carbohydrates (NSC), providing reserves of energy that fuel woody perennials through periods of stress and/or limitations to photosynthesis. If the capacity for storage is subject to selection, then the fraction of wood occupied by living parenchyma should increase towards stressful environments. Ray parenchyma fraction (RPF) and seasonal NSC dynamics were quantified for 12 conifers and three oaks along a transect spanning warm dry foothills (500 m above sea level) to cold wet treeline (3250 m asl) in California's central Sierra Nevada. Mean RPF was lower for both conifer and oak species with warmer dryer ranges. RPF variability increased with elevation or in relation to associated climatic variables in conifers - treeline-dominant Pinus albicaulis had the lowest mean RPF measured (c. 3.7%), but the highest environmentally standardized variability index. Conifer RPF variability was explained by environment, increasing predominantly towards cooler wetter range edges. In oaks, NSC was explained by environment - values increasing for evergreen and decreasing for deciduous oaks with elevation. Lastly, all species surveyed appear to prioritize filling available RPF with sugar to achieve molarities that balance reasonable tensions over starch to maximize stored carbon. RPF responds to environment but is unlikely to spatially constrain NSC storage.
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Affiliation(s)
- Jessie M Godfrey
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
| | - Jason Riggio
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, 95616, USA
| | - Jessica Orozco
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
| | | | - Alana R O Chin
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
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24
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Falchi R, Petrussa E, Braidot E, Sivilotti P, Boscutti F, Vuerich M, Calligaro C, Filippi A, Herrera JC, Sabbatini P, Zancani M, Nardini A, Peterlunger E, Casolo V. Analysis of Non-Structural Carbohydrates and Xylem Anatomy of Leaf Petioles Offers New Insights in the Drought Response of Two Grapevine Cultivars. Int J Mol Sci 2020; 21:E1457. [PMID: 32093416 PMCID: PMC7073087 DOI: 10.3390/ijms21041457] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 02/17/2020] [Indexed: 11/16/2022] Open
Abstract
In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.
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Affiliation(s)
- Rachele Falchi
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Elisa Petrussa
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Enrico Braidot
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Paolo Sivilotti
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Francesco Boscutti
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Marco Vuerich
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Carla Calligaro
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Antonio Filippi
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - José Carlos Herrera
- Institute of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz Straβe 24, 3430 Tulln, Austria;
| | - Paolo Sabbatini
- Department of Horticulture, Michigan State University, 1066 Bogue Street, East Lansing, MI 48824, USA;
| | - Marco Zancani
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, via Licio Giorgieri, 5, 34127 Trieste, Italy;
| | - Enrico Peterlunger
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Valentino Casolo
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
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25
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Lu Y, Duursma RA, Farrior CE, Medlyn BE, Feng X. Optimal stomatal drought response shaped by competition for water and hydraulic risk can explain plant trait covariation. THE NEW PHYTOLOGIST 2020; 225:1206-1217. [PMID: 31538667 DOI: 10.1111/nph.16207] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/12/2019] [Indexed: 05/26/2023]
Abstract
The classical theory of stomatal optimization stipulates that stomata should act to maximize photosynthesis while minimizing transpiration. This theory, despite its remarkable success in reproducing empirical patterns, does not account for the fact that the available water to plants is dynamically regulated by plants themselves, and that plants compete for water in most locations. Here, we develop an alternative theory in which plants maximize the expected carbon gain under stochastic rainfall in a competitive environment. We further incorporate xylem hydraulic limitation as an additional constraint to transpiration and evaluate its impacts on stomatal optimization by incorporating the direct carbon cost of xylem recovery and the opportunity cost of reduced future photosynthesis as a result of irrecoverable xylem damage. We predict stomatal behaviour to be more conservative with a higher cost induced by xylem damage. By varying the unit carbon cost and extent of xylem recovery, characterizing the direct and opportunity cost of xylem damage, respectively, our model can reproduce several key patterns of stomatal-hydraulic trait covariations. By addressing the key elements of water limitation in plant gas exchange simultaneously, including plants' self-regulation of water availability, competition for water and hydraulic risk, our study provides a comprehensive theoretical basis for understanding stomatal behaviour.
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Affiliation(s)
- Yaojie Lu
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, MN, 55455, USA
| | - Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Caroline E Farrior
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, MN, 55455, USA
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26
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Traversari S, Neri A, Traversi ML, Giovannelli A, Francini A, Sebastiani L. Daily osmotic adjustments in stem may be good predictors of water stress intensity in poplar. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 146:13-22. [PMID: 31710921 DOI: 10.1016/j.plaphy.2019.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Drought events impair the carbon and water balances in plants. Climate changes highlight the importance to understand the limits of woody species to reallocate carbon in different processes and the mechanisms driving the osmotic adjustments during the day under stress. In this frame, the aim of this work was to investigate the plant capability to shift energy among competing sinks and preserve the osmotic balance during the day under severe short periods of water deficit. The role of carbohydrates as osmolytes as well as energy sources was investigated in poplar plants. Results highlighted that during water deficit soluble sugars, derived both from the new synthetised carbon and starch degradation, were principally convoyed in the bark. This increase in carbohydrates allowed the maintenance of a water reserve used during the day to prevent a water decrease within the xylem. The decrease of xylem sap osmotic potential during the night, driven by an increase of K, Ca, and fructose (+0.46, 0.52, and 0.26 mg ml-1 in water limited plants after 8 days of withholding water, respectively), probably further attracted water into the xylem. This response mechanism increased at higher water deficit intensity. The little variations in carbohydrates and mineral elements within the leaves highlighted the main role of sinks rather than sources in the early response to water deficit.
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Affiliation(s)
- Silvia Traversari
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
| | - Andrea Neri
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
| | - Maria Laura Traversi
- Research Institute on Terrestrial Ecosystems (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto F.no, Florence, Italy
| | - Alessio Giovannelli
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy; Research Institute on Terrestrial Ecosystems (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto F.no, Florence, Italy
| | - Alessandra Francini
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy.
| | - Luca Sebastiani
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
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27
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Tomasella M, Petrussa E, Petruzzellis F, Nardini A, Casolo V. The Possible Role of Non-Structural Carbohydrates in the Regulation of Tree Hydraulics. Int J Mol Sci 2019; 21:E144. [PMID: 31878253 PMCID: PMC6981889 DOI: 10.3390/ijms21010144] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/13/2019] [Accepted: 12/22/2019] [Indexed: 12/29/2022] Open
Abstract
The xylem is a complex system that includes a network of dead conduits ensuring long-distance water transport in plants. Under ongoing climate changes, xylem embolism is a major and recurrent cause of drought-induced tree mortality. Non-structural carbohydrates (NSC) play key roles in plant responses to drought and frost stress, and several studies putatively suggest their involvement in the regulation of xylem water transport. However, a clear picture on the roles of NSCs in plant hydraulics has not been drawn to date. We summarize the current knowledge on the involvement of NSCs during embolism formation and subsequent hydraulic recovery. Under drought, sugars are generally accumulated in xylem parenchyma and in xylem sap. At drought-relief, xylem functionality is putatively restored in an osmotically driven process involving wood parenchyma, xylem sap and phloem compartments. By analyzing the published data on stem hydraulics and NSC contents under drought/frost stress and subsequent stress relief, we found that embolism build-up positively correlated to stem NSC depletion, and that the magnitude of post-stress hydraulic recovery positively correlated to consumption of soluble sugars. These findings suggest a close relationship between hydraulics and carbohydrate dynamics. We call for more experiments on hydraulic and NSC dynamics in controlled and field conditions.
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Affiliation(s)
- Martina Tomasella
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.P.); (A.N.)
| | - Elisa Petrussa
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze 91, 33100 Udine, Italy; (E.P.); (V.C.)
| | - Francesco Petruzzellis
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.P.); (A.N.)
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.P.); (A.N.)
| | - Valentino Casolo
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze 91, 33100 Udine, Italy; (E.P.); (V.C.)
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28
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Tomasella M, Casolo V, Aichner N, Petruzzellis F, Savi T, Trifilò P, Nardini A. Non-structural carbohydrate and hydraulic dynamics during drought and recovery in Fraxinus ornus and Ostrya carpinifolia saplings. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 145:1-9. [PMID: 31665662 DOI: 10.1016/j.plaphy.2019.10.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
The maintenance of hydraulic function during and after a drought event is crucial for tree survival, but the importance of non-structural carbohydrates (NSCs) in the recovery phase is still debated. We tested whether higher NSC availability facilitates post-drought hydraulic recovery, by applying a short-term drought (Sdr) and a long-term drought combined with shading (Ldr+sh) in Fraxinus ornus and Ostrya carpinifolia. Plants were then re-irrigated and recovery was checked 24 h later, by measuring water potential, stem percentage loss of hydraulic conductance (PLC) and NSC content. The relative magnitude of hydraulic and carbon constraints was also assessed in desiccated plants. During drought, PLC increased only in F. ornus, while it was maintained almost constant in O. carpinifolia due to tighter stomatal control of xylem pressure (i.e. more isohydric). In F. ornus, only Sdr plants maintained high NSC contents at the end of drought and, when re-irrigated, recovered PLC to control values. Whereas hydraulic failure was ubiquitous, only F. ornus depleted NSC reserves at mortality. Our results suggest that preserving higher NSC content at the end of a drought can be important for the hydraulic resilience of trees.
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Affiliation(s)
- Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste. Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Valentino Casolo
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Università di Udine. Via delle Scienze 91, 33100, Udine, Italy
| | - Natalie Aichner
- Dipartimento di Scienze della Vita, Università di Trieste. Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste. Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Tadeja Savi
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, BOKU, Gregor-Mendel-Straße 33, Vienna, 1190, Austria
| | - Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste. Via L. Giorgieri 10, 34127, Trieste, Italy.
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29
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Liu J, Gu L, Yu Y, Huang P, Wu Z, Zhang Q, Qian Y, Wan X, Sun Z. Corticular photosynthesis drives bark water uptake to refill embolized vessels in dehydrated branches of Salix matsudana. PLANT, CELL & ENVIRONMENT 2019; 42:2584-2596. [PMID: 31083779 DOI: 10.1111/pce.13578] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
It is well known that xylem embolism can be repaired by bark water uptake and that the sugar required for embolism refilling can be provided by corticular photosynthesis. However, the relationship between corticular photosynthesis and embolism repair by bark water uptake is still poorly understood. In this study, the role of corticular photosynthesis in embolism repair was assessed using Salix matsudana branch segments dehydrated to -1.9 MPa (P50 , water potential at 50% loss of conductivity). The results indicated that corticular photosynthesis significantly promoted water uptake and nonstructural carbohydrate (NSC) accumulation in the bark and xylem during soaking, thereby effectively enhancing the refilling of the embolized vessels and the recovery of hydraulic conductivity. Furthermore, the influence of the extent of dehydration on the embolism refilling enhanced by corticular photosynthesis was investigated. The enhanced refilling effects were much higher in the mildly dehydrated (-1.5 MPa) and moderately dehydrated (-1.9 MPa) branch segments than in the severely dehydrated (-2.2 MPa) branch segments. This study provides evidence that corticular photosynthesis plays a crucial role in xylem embolism repair by bark water uptake for mildly and moderately dehydrated branches.
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Affiliation(s)
- Junxiang Liu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Lin Gu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Yongchang Yu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Ping Huang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Zhigang Wu
- School of Civil Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Qian Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Yongqiang Qian
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, China
| | - Zhenyuan Sun
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
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30
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Smith MS, Centinari M. Young grapevines exhibit interspecific differences in hydraulic response to freeze stress but not in recovery. PLANTA 2019; 250:495-505. [PMID: 31089803 DOI: 10.1007/s00425-019-03183-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
This study demonstrated that freeze-induced hydraulic failure varies between two Vitis species that have different xylem vessel frequency and grouping. However, seasonal recovery of young grapevines was similar between the species. Sub-freezing temperatures after budburst represent a major threat for the cultivation of fruit crops in temperate regions. Freeze stress might disrupt xylem hydraulic functionality and plant growth; however, it is unclear if hydraulic traits influence the ability of woody plants to cope with freeze stress. We investigated if a grapevine species (Vitis hybrid) with earlier budburst had anatomical traits that cause higher freeze-induced hydraulic failure but also confer a greater ability for seasonal recovery compared to a Vitis vinifera species. Two-year-old Vitis hybrid and vinifera grapevines were container-grown outdoors, assigned to either a control (n = 40) or a freeze-stressed (n = 40) treatment and exposed to a controlled-temperature (- 4 °C) freeze stress shortly after budburst. We found that the Vitis hybrid had greater stem-specific hydraulic conductivity (Ks) and was more vulnerable to freeze-induced embolism compared to the V. vinifera species, which exhibited a less efficient but safer water transport strategy. Seventy-two hours after the freeze stress, Ks of freeze-stressed V. vinifera was 77.8% higher than that of the control, indicating hydraulic recovery. While the two species did not differ in xylem vessel diameter, Vitis hybrid exhibited higher vessel frequency and percentage of vessel grouping, which could explain its higher Ks and greater freeze-induced Ks loss compared to the V. vinifera vines. While the two species varied in the short-term hydraulic response, they exhibited similar and full hydraulic and vegetative recovery by midseason, including bud freeze tolerance during the following fall and mid-winter.
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Affiliation(s)
- Maria S Smith
- Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA
| | - Michela Centinari
- Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA.
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Augustine SP, Reinhardt K. Differences in morphological and physiological plasticity in two species of first-year conifer seedlings exposed to drought result in distinct survivorship patterns. TREE PHYSIOLOGY 2019; 39:1446-1460. [PMID: 31181151 DOI: 10.1093/treephys/tpz048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/27/2018] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
First-year tree seedlings represent a critical demographic life stage, functioning as a bottleneck to forest regeneration. Knowledge of how mortality is related to whole-seedling carbon and water relations is deficient and is required to understand how forest compositions will be altered in future climatic conditions. We performed a greenhouse drought experiment using first-year seedlings of two common pine species found in the Intermountain West, USA. Gas exchange, biomass gain, allometry and xylem water potentials were compared between well-watered and droughted seedlings from emergence until drought-induced mortality. In both species, morphological adjustments to confer drought tolerance, such as increased leaf mass per unit area, were not observed in seedlings exposed to drought, and droughted seedlings maintained photosynthesis and whole-seedling carbon gain well into the experiment. Yet, there were important differences between species in terms of carbon budgets, physiological responses and mortality patterns. In Pinus ponderosa P. & C. Lawson, physiological acclimation to drought was much greater, evident through stronger stomatal regulation and increased water-use efficiency. Photosynthesis and carbon budgets in P. ponderosa were greater than in Pinus contorta Dougl. ex. Loud., and survival was 100% until critical hydraulic thresholds in leaf water content and seedling water potentials were crossed. In P. contorta, physiological adjustments to drought were less, and mortality occurred much sooner and well before injurious hydraulic thresholds were approached. First-year conifer seedlings appear canalized for a suite of functional traits that prioritize short-term carbon gain over long-term drought tolerance, suggesting that conifer seedling survival is linked with carbon limitations, even during drought, with survival in species having narrower carbon survival margins being more hampered by carbon limitations.
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Affiliation(s)
- Steven P Augustine
- Department of Biological Sciences, Idaho State University, Pocatello, ID, USA
- Department of Botany, University of Wisconsin - Madison, Madison, WI, USA
| | - Keith Reinhardt
- Department of Biological Sciences, Idaho State University, Pocatello, ID, USA
- Department of Botany, University of Wisconsin - Madison, Madison, WI, USA
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32
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Sabella E, Aprile A, Genga A, Siciliano T, Nutricati E, Nicolì F, Vergine M, Negro C, De Bellis L, Luvisi A. Xylem cavitation susceptibility and refilling mechanisms in olive trees infected by Xylella fastidiosa. Sci Rep 2019; 9:9602. [PMID: 31270378 PMCID: PMC6610111 DOI: 10.1038/s41598-019-46092-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/19/2019] [Indexed: 01/09/2023] Open
Abstract
In olive trees, Xylella fastidiosa colonizes xylem vessels and compromises water transport causing the olive quick decline syndrome (OQDS). The loss of hydraulic conductivity could be attributed to vessel occlusions induced both by the bacteria biofilm and by plant responses (tyloses, gums, etc.) that could trigger embolism. The ability of the infected plants to detect embolism and to respond, by activating mechanisms to restore the hydraulic conductivity, can influence the severity of the disease symptomatology. In order to investigate these mechanisms in the X. fastidiosa-resistant olive cultivar Leccino and in the susceptible Cellina di Nardò, sections of healthy olive stems were analysed by laser scanning microscope to calculate the cavitation vulnerability index. Findings indicated that the cultivar Leccino seems to be constitutively less susceptible to cavitation than the susceptible one. Among the vascular refilling mechanisms, starch hydrolysis is a well-known strategy to refill xylem vessels that suffered cavitation and it is characterized by a dense accumulation of starch grains in the xylem parenchima; SEM-EDX analysis of stem cross-sections of infected plants revealed an aggregation of starch grains in the Leccino xylem vessels. These observations could indicate that this cultivar, as well as being anatomically less susceptible to cavitation, it also could be able to activate more efficient refilling mechanisms, restoring vessel's hydraulic conductivity. In order to verify this hypothesis, we analysed the expression levels of some genes belonging to families involved in embolism sensing and refilling mechanisms: aquaporins, sucrose transporters, carbohydrate metabolism and enzymes related to starch breakdown, alpha and beta-amylase. The obtained genes expression patterns suggested that the infected plants of the cultivar Leccino strongly modulates the genes involved in embolism sensing and refilling.
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Affiliation(s)
- Erika Sabella
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Alessio Aprile
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy.
| | - Alessandra Genga
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Tiziana Siciliano
- Department of Physic and Math, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Eliana Nutricati
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Francesca Nicolì
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Marzia Vergine
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Carmine Negro
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Luigi De Bellis
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
| | - Andrea Luvisi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, via Prov.le Monteroni 165, 73100, Lecce, Italy
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Pagliarani C, Casolo V, Ashofteh Beiragi M, Cavalletto S, Siciliano I, Schubert A, Gullino ML, Zwieniecki MA, Secchi F. Priming xylem for stress recovery depends on coordinated activity of sugar metabolic pathways and changes in xylem sap pH. PLANT, CELL & ENVIRONMENT 2019; 42:1775-1787. [PMID: 30756400 DOI: 10.1111/pce.13533] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
Some plant species are capable of significant reduction of xylem embolism during recovery from drought despite stem water potential remains negative. However, the functional biology underlying this process is elusive. We subjected poplar trees to drought stress followed by a period of recovery. Water potential, hydraulic conductivity, gas exchange, xylem sap pH, and carbohydrate content in sap and woody stems were monitored in combination with an analysis of carbohydrate metabolism, enzyme activity, and expression of genes involved in sugar metabolic and transport pathways. Drought resulted in an alteration of differential partitioning between starch and soluble sugars. Upon stress, an increase in the starch degradation rate and the overexpression of sugar symporter genes promoted the efflux of disaccharides (mostly maltose and sucrose) to the apoplast. In turn, the efflux activity of the sugar-proton cotransporters caused a drop in xylem pH. The newly acidic environment induced the activity of apoplastic invertases leading to the accumulation of monosaccharides in the apoplast, thus providing the main osmoticum necessary for recovery. During drought and recovery, a complex network of coordinated molecular and biochemical signals was activated at the interface between xylem and parenchyma cells that appeared to prime the xylem for hydraulic recovery.
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Affiliation(s)
- Chiara Pagliarani
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
- Institute for Sustainable Plant Protection, National Research Council, Turin, Italy
| | - Valentino Casolo
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Maryam Ashofteh Beiragi
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
| | - Silvia Cavalletto
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
| | - Ilenia Siciliano
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
- AGROINNOVA, Centre for Innovation in the Agro-Environmental Sector, University of Turin, Grugliasco, Italy
| | - Andrea Schubert
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
| | - Maria Lodovica Gullino
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
- AGROINNOVA, Centre for Innovation in the Agro-Environmental Sector, University of Turin, Grugliasco, Italy
| | | | - Francesca Secchi
- Department of Agriculture, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, Italy
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Trifilò P, Kiorapostolou N, Petruzzellis F, Vitti S, Petit G, Lo Gullo MA, Nardini A, Casolo V. Hydraulic recovery from xylem embolism in excised branches of twelve woody species: Relationships with parenchyma cells and non-structural carbohydrates. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 139:513-520. [PMID: 31015090 DOI: 10.1016/j.plaphy.2019.04.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 05/26/2023]
Abstract
Embolism repair ability has been documented in numerous species. Although the actual mechanism driving this phenomenon is still debated, experimental findings suggest that non-structural carbohydrates (NSC) stored in wood parenchyma would provide the osmotic forces to drive the refilling of embolized conduits. We selected 12 broadleaved species differing in vulnerability to xylem embolism (P50) and amount of wood parenchyma in order to check direct evidence about the possible link(s) between parenchyma cells abundance, NSC availability and species-specific capacity to reverse xylem embolism. Branches were dehydrated until ∼50% loss of hydraulic conductivity was recorded (PLC ∼50%). Hydraulic recovery (ΔPLC) and NSC content was, then, assessed after 1h of rehydration. Species showed a different ability to recover their hydraulic conductivity from PLC∼50%. Removing the bark in the species showing hydraulic recovery inhibited the embolism reversal. Strong correlations between the ΔPLC and: a) the amount of parenchyma cells (mainly driven by the pith area), b) the consumption of soluble NSC have been recorded. Our results support the hypothesis that refilling of embolized vessels is mediated by the mobilization of soluble NSC and it is mainly recorded in species with a higher percentage of parenchyma cells that may be important in the hydraulic recovery mechanism as a source of carbohydrates and/or as a source of water.
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Affiliation(s)
- Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy.
| | - Natasa Kiorapostolou
- Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, 35020, Legnaro, PD, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Stefano Vitti
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy; Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, Via delle Scienze 91, 33100, Udine, Italy
| | - Giai Petit
- Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, 35020, Legnaro, PD, Italy
| | - Maria A Lo Gullo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Valentino Casolo
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, Via delle Scienze 91, 33100, Udine, Italy
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35
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Zeppel MJB, Anderegg WRL, Adams HD, Hudson P, Cook A, Rumman R, Eamus D, Tissue DT, Pacala SW. Embolism recovery strategies and nocturnal water loss across species influenced by biogeographic origin. Ecol Evol 2019; 9:5348-5361. [PMID: 31110684 PMCID: PMC6509402 DOI: 10.1002/ece3.5126] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 02/25/2019] [Indexed: 12/28/2022] Open
Abstract
Drought-induced tree mortality is expected to increase in future climates with the potential for significant consequences to global carbon, water, and energy cycles. Xylem embolism can accumulate to lethal levels during drought, but species that can refill embolized xylem and recover hydraulic function may be able to avoid mortality. Yet the potential controls of embolism recovery, including cross-biome patterns and plant traits such as nonstructural carbohydrates (NSCs), hydraulic traits, and nocturnal stomatal conductance, are unknown. We exposed eight plant species, originating from mesic (tropical and temperate) and semi-arid environments, to drought under ambient and elevated CO2 levels, and assessed recovery from embolism following rewatering. We found a positive association between xylem recovery and NSCs, and, surprisingly, a positive relationship between xylem recovery and nocturnal stomatal conductance. Arid-zone species exhibited greater embolism recovery than mesic zone species. Our results indicate that nighttime stomatal conductance often assumed to be a wasteful use of water, may in fact be a key part of plant drought responses, and contribute to drought survival. Findings suggested distinct biome-specific responses that partially depended on species climate-of-origin precipitation or aridity index, which allowed some species to recover from xylem embolism. These findings provide improved understanding required to predict the response of diverse plant communities to drought. Our results provide a framework for predicting future vegetation shifts in response to climate change.
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Affiliation(s)
- Melanie J. B. Zeppel
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | | | - Henry D. Adams
- Department of Plant Biology, Ecology, and EvolutionOklahoma State UniversityStillwaterOklahoma
| | - Patrick Hudson
- Department of BiologyUniversity of New MexicoAlbuquerqueNew Mexico
| | - Alicia Cook
- School of Life SciencesUniversity of Technology SydneySydneyNew South WalesAustralia
| | - Rizwana Rumman
- School of Life SciencesUniversity of Technology SydneySydneyNew South WalesAustralia
| | - Derek Eamus
- School of Life SciencesUniversity of Technology SydneySydneyNew South WalesAustralia
| | - David T. Tissue
- Hawkesbury Institute of the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
| | - Stephen W. Pacala
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNew Jersey
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Vinya R, Malhi Y, Brown ND, Fisher JB, Brodribb T, Aragão LEOC. Seasonal changes in plant-water relations influence patterns of leaf display in Miombo woodlands: evidence of water conservative strategies. TREE PHYSIOLOGY 2019; 39:104-112. [PMID: 29920608 DOI: 10.1093/treephys/tpy062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 05/12/2018] [Indexed: 06/08/2023]
Abstract
Water availability has frequently been linked to seasonal leaf display in seasonally dry ecosystems, but there have been few ecohydrological investigations of this link. Miombo woodland is a dominant seasonally dry tropical forest ecosystem type in southern Africa; however, there are few data on the relationship between seasonal dynamics in plant-water relations and patterns of leaf display for Miombo woodland. Here we investigate this relationship among nine key Miombo woodland tree species differing in drought tolerance ability and leaf phenology. Results of this study showed that seasonal patterns of leaf phenology varied significantly with seasonal changes in stem water relations among the nine species. Leaf shedding coincided with the attainment of seasonal minimum stem water potential. Leaf flush occurred following xylem rehydration at the peak of the dry season suggesting that endogenous plant factors play a pivotal role in seasonal leaf display in this forest type. Drought-tolerant deciduous species suffered significantly higher seasonal losses in xylem hydraulic conductivity than the drought-intolerant semi-evergreen tree species (P < 0.05). There was a significant and positive correlation between species drought tolerance index and species' seasonal loss in hydraulic conductivity (P < 0.05), confirming the ecological role of long-distance xylem transport in this seasonally dry tropical forest. Our results reveal that water stress in seasonally dry tropical forests selects for water conservative traits that protect the vulnerable xylem transport system. Therefore, seasonal rhythms in xylem transport dictate patterns of leaf display in seasonally dry tropical forests.
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Affiliation(s)
- Royd Vinya
- Environmental Change Institute, School of Geography and the Environment, Oxford University Centre for the Environment, South Parks Road, Oxford, UK
- School of Natural Resources, Copperbelt University, Kitwe, Zambia
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, Oxford University Centre for the Environment, South Parks Road, Oxford, UK
| | - Nick D Brown
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - Joshua B Fisher
- School of Plant Sciences, University of Tasmania, Hobart, Australia
| | - Timothy Brodribb
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, USA
| | - Luiz E O C Aragão
- School of Geography, University of Exeter, Amory Building, Rennes Drive, Devon, UK
- National Institute for Space Research, INPE, Avenida dos Astronautas, 1.758, Jd. Granja, CEP 12227-010São José dos Campos, SP, Brazil
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37
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Wang AY, Han SJ, Zhang JH, Wang M, Yin XH, Fang LD, Yang D, Hao GY. The interaction between nonstructural carbohydrate reserves and xylem hydraulics in Korean pine trees across an altitudinal gradient. TREE PHYSIOLOGY 2018; 38:1792-1804. [PMID: 30376119 DOI: 10.1093/treephys/tpy119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 10/05/2018] [Indexed: 05/23/2023]
Abstract
Nonstructural carbohydrates (NSC) have been proposed to play an important role in maintaining the hydraulic integrity of trees, particularly in environments with high risks of embolism formation, but knowledge about the interaction between NSC reserves and xylem hydraulics is still very limited. We studied the variation of NSC reserves and hydraulic traits in Pinus koraiensis Sieb. et Zucc. (Korean pine) in March and June across a relatively large altitudinal gradient in Changbai Mountain of Northeast China. One of the major aims was to investigate the potential role NSC plays in maintaining hydraulic integrity of overwintering stems in facing freezing-induced embolism. Consistent with our hypotheses, substantial variations in both NSC contents and hydraulic traits were observed across altitudes and between the two seasons. In March, when relatively high degrees of winter embolism exist, the percentage loss of conductivity (PLC) showed an exponential increase with altitude. Most notably, positive correlations between branch and trunk soluble sugar content and PLC (P = 0.053 and 0.006) were observed across altitudes during this period. These correlations could indicate that more soluble sugars are required for maintaining stem hydraulic integrity over the winter by resisting or refilling freezing-induced embolism in harsher environments, although more work is needed to establish a direct causal relationship between NSC dynamics and xylem hydraulics. If the correlation is indeed directly associated with varying demands for maintaining hydraulic integrity across environmental gradients, greater carbon demands may compromise tree growth under conditions of higher risk of winter embolism leading to a trade-off between competitiveness and stress resistance, which may be at least partially responsible for the lower dominance of Korean pine trees at higher altitudes.
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Affiliation(s)
- Ai-Ying Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shi-Jie Han
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- School of Life Science, Henan University, Kaifeng, China
| | - Jun-Hui Zhang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Miao Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Xiao-Han Yin
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Li-Dong Fang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Da Yang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Guang-You Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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Klepsch M, Zhang Y, Kotowska MM, Lamarque LJ, Nolf M, Schuldt B, Torres-Ruiz JM, Qin DW, Choat B, Delzon S, Scoffoni C, Cao KF, Jansen S. Is xylem of angiosperm leaves less resistant to embolism than branches? Insights from microCT, hydraulics, and anatomy. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:5611-5623. [PMID: 30184113 PMCID: PMC6255699 DOI: 10.1093/jxb/ery321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 08/28/2018] [Indexed: 05/23/2023]
Abstract
According to the hydraulic vulnerability segmentation hypothesis, leaves are more vulnerable to decline of hydraulic conductivity than branches, but whether stem xylem is more embolism resistant than leaves remains unclear. Drought-induced embolism resistance of leaf xylem was investigated based on X-ray microcomputed tomography (microCT) for Betula pendula, Laurus nobilis, and Liriodendron tulipifera, excluding outside-xylem, and compared with hydraulic vulnerability curves for branch xylem. Moreover, bordered pit characters related to embolism resistance were investigated for both organs. Theoretical P50 values (i.e. the xylem pressure corresponding to 50% loss of hydraulic conductance) of leaves were generally within the same range as hydraulic P50 values of branches. P50 values of leaves were similar to branches for L. tulipifera (-2.01 versus -2.10 MPa, respectively), more negative for B. pendula (-2.87 versus -1.80 MPa), and less negative for L. nobilis (-6.4 versus -9.2 MPa). Despite more narrow conduits in leaves than branches, mean interconduit pit membrane thickness was similar in both organs, but significantly higher in leaves of B. pendula than in branches. This case study indicates that xylem shows a largely similar embolism resistance across leaves and branches, although differences both within and across organs may occur, suggesting interspecific variation with regard to the hydraulic vulnerability segmentation hypothesis.
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Affiliation(s)
- Matthias Klepsch
- Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, Ulm University, Ulm, Germany
| | - Ya Zhang
- Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, Ulm University, Ulm, Germany
| | - Martyna M Kotowska
- Department of Biological Sciences Faculty of Science, Macquarie University, NSW, Australia
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle, Göttingen, Germany
| | - Laurent J Lamarque
- BIOGECO, INRA, University of Bordeaux, Pessac, France
- EGFV, INRA, University of Bordeaux, Villenave d’Ornon, France
| | - Markus Nolf
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia
| | - Bernhard Schuldt
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle, Göttingen, Germany
| | - José M Torres-Ruiz
- BIOGECO, INRA, University of Bordeaux, Pessac, France
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, France
| | - De-Wen Qin
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu, Nanning, Guangxi, PR China
| | - Brendan Choat
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia
| | | | - Christine Scoffoni
- Department of Biological Sciences, California State University, Los Angeles, State University Drive, Los Angeles, CA, USA
| | - Kun-Fang Cao
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu, Nanning, Guangxi, PR China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, Ulm University, Ulm, Germany
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39
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Bianchi D, Grossi D, Tincani DTG, Simone Di Lorenzo G, Brancadoro L, Rustioni L. Multi-parameter characterization of water stress tolerance in Vitis hybrids for new rootstock selection. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 132:333-340. [PMID: 30248519 DOI: 10.1016/j.plaphy.2018.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 05/20/2023]
Abstract
Drought in grapevine could be faced using tolerant rootstocks. The present work aims at the evaluation of 25 new genotypes potentially tolerant to drought by using recent methods of phenotypical screening (thermography and on-solid reaction spectroscopy). Plants were grown in well-watered and stressed field conditions. Proxi for transpiration, wood hydrophobicity and starch content were used to characterize and classify the genotypes. The predominant role of the environment was highlighted, nevertheless genotype and genotype × environment interaction showed significant variations as well. Hybrids were classified based on their steady, susceptible or adaptable behavior. The 14 most promising genotypes were identified, 5 of them showing two tolerance mechanisms. In the future, results from this experiment will support viticulture in water limited areas releasing new drought-tolerant interspecific hybrids to be tested after grafting with different scions.
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Affiliation(s)
- Davide Bianchi
- DISAA, Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Daniele Grossi
- DISAA, Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Davide T G Tincani
- DISAA, Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | | | - Lucio Brancadoro
- DISAA, Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Laura Rustioni
- DISAA, Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy.
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40
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Duan H, Chaszar B, Lewis JD, Smith RA, Huxman TE, Tissue DT. CO2 and temperature effects on morphological and physiological traits affecting risk of drought-induced mortality. TREE PHYSIOLOGY 2018; 38:1138-1151. [PMID: 29701843 DOI: 10.1093/treephys/tpy037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
Despite a wealth of eco-physiological assessments of plant response to extreme drought, few studies have addressed the interactive effects of global change factors on traits driving mortality. To understand the interaction between hydraulic and carbon metabolic traits influencing tree mortality, which may be independently influenced by atmospheric [CO2] and temperature, we grew Eucalyptus sideroxylon A. Cunn. ex Woolls from seed in a full-factorial [CO2] (280, 400 and 640 μmol mol-1, Cp, Ca and Ce, respectively) and temperature (ambient and ambient +4 °C, Ta and Te, respectively) experiment. Prior to drought, growth across treatment combinations resulted in significant variation in physiological and morphological traits, including photosynthesis (Asat), respiration (Rd), stomatal conductance, carbohydrate storage, biomass and leaf area (LA). Ce increased Asat, LA and leaf carbohydrate concentration compared with Ca, while Cp generated the opposite response; Te reduced Rd. However, upon imposition of drought, Te hastened mortality (9 days sooner compared with Ta), while Ce significantly exacerbated drought stress when combined with Te. Across treatments, earlier time-to-mortality was mainly associated with lower (more negative) leaf water potential (Ψl) during the initial drought phase, along with higher water loss across the first 3 weeks of water limitation. Among many variables, Ψl was more important than carbon status in predicting time-to-mortality across treatments, yet leaf starch was associated with residual variation within treatments. These results highlight the need to carefully consider the integration, interaction and hierarchy of traits contributing to mortality, along with their responses to environmental drivers. Both morphological traits, which influence soil resource extraction, and physiological traits, which affect water-for-carbon exchange to the atmosphere, must be considered to adequately predict plant response to drought. Researchers have struggled with assessing the relative importance of hydraulic and carbon metabolic traits in determining mortality, yet an integrated trait, time-dependent framework provides considerable insight into the risk of death from drought for trees.
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Affiliation(s)
- Honglang Duan
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Brian Chaszar
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - James D Lewis
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Louis Calder Center - Biological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY, USA
| | - Renee A Smith
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Travis E Huxman
- School of Biological Sciences, University of California, Irvine, CA, USA
| | - David T Tissue
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
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41
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Traversari S, Francini A, Traversi ML, Emiliani G, Sorce C, Sebastiani L, Giovannelli A. Can sugar metabolism in the cambial region explain the water deficit tolerance in poplar? JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4083-4097. [PMID: 29846657 PMCID: PMC6054210 DOI: 10.1093/jxb/ery195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/16/2018] [Indexed: 05/06/2023]
Abstract
Drought dramatically affects wood production by adversely impacting cambial cells and their derivatives. Photosynthesis and assimilate transport are also affected by drought conditions. Two poplar genotypes, Populus deltoides 'Dvina' and Populus alba 'Marte', demonstrated contrasting growth performance and water-carbon balance strategies; a mechanistic understanding of the water deficit response was provided by these poplar species. 'Marte' was found to be more anisohydric than 'Dvina'. This characteristic was associated with the capacity to reallocate carbohydrates during water deficits. In contrast, 'Dvina' displayed more conservative water management; carbohydrates were preferably stored or used for cellulose production rather than to achieve an osmotic balance between the phloem and the xylem. Data confirmed that the more 'risk-taking' characteristic of 'Marte' allowed a rapid recovery following water deficit and was connected to a different carbohydrate metabolism.
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Affiliation(s)
- Silvia Traversari
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Alessandra Francini
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Maria Laura Traversi
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
| | - Giovanni Emiliani
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
| | - Carlo Sorce
- Department of Biology, University of Pisa, Via Luca Ghini, Pisa, Italy
| | - Luca Sebastiani
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Alessio Giovannelli
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
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Love DM, Sperry JS. In situ embolism induction reveals vessel refilling in a natural aspen stand. TREE PHYSIOLOGY 2018; 38:1006-1015. [PMID: 29509942 DOI: 10.1093/treephys/tpy007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 01/18/2018] [Indexed: 06/08/2023]
Abstract
Little is known about the ability of trees to recover hydraulic conductance (k) within a growing season by regrowth or refilling of embolized conduits. Recovery of k lost to drought or other causes would prevent chronic reductions in gas exchange and productivity. To test recovery ability we conducted a 2-year experiment (2014-15) on a cohort of aspen ramets (Populus tremuloides, Michx.). Whole-tree k was measured from mid-June through September from sapflow (Q) and pre-dawn and mid-day xylem pressure. We induced embolism in the treatment group with high air pressure delivered by a split pressure chamber sealed around the main trunk. Successful treatments reduced k and Q by 50% or more without causing rapid desiccation. The majority of trees recovered following treatment, rising to control levels of k and Q between 12 and 17 days. Failure to recover was correlated with drier climate conditions. The growing-season recovery of k was attributed to refilling of embolized vessels, based on the absence of diameter growth. Pre-dawn xylem pressures during recovery were similar to the threshold needed to passively collapse emboli. Successful recovery during the 2-year study was consistent with no reduction in cumulative Q or canopy area in treatment vs controls. However, non-recovering trees in 2014 exhibited lower basal area growth at the start of the 2015 growing season, suggesting a linkage between recovery ability and productivity. This study provides evidence for the potential of trees to recover xylem function by refilling during the growing season.
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Affiliation(s)
- David M Love
- Department of Biology, University of Utah, 257 S 1400E, Salt Lake City, UT, USA
| | - John S Sperry
- Department of Biology, University of Utah, 257 S 1400E, Salt Lake City, UT, USA
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43
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Hultine KR, Bush SE, Ward JK, Dawson TE. Does sexual dimorphism predispose dioecious riparian trees to sex ratio imbalances under climate change? Oecologia 2018; 187:921-931. [PMID: 29955993 DOI: 10.1007/s00442-018-4190-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 06/05/2018] [Indexed: 11/30/2022]
Abstract
Environmental changes have resulted in significant declines in native riparian forests that are comprised largely of dioecious tree taxa, including boxelder and iconic cottonwood/willow gallery forests. Dioecious species may be especially vulnerable to the effects of climate change given that they often exhibit skewed sex ratios that are reinforced by physiological and morphological specialization of each sex to specific microhabitats. A comprehensive data synthesis suggests that male individuals of boxelder and cottonwood taxa have a higher representation on dry microhabitats than females and are less physiologically sensitive to increased aridity than co-occurring females. Consequently, extreme male-biased sex ratios are possible under future climate conditions that could reduce population fitness below a sustainable threshold. Riparian willows, on the other hand, generally do not express obvious sexual dimorphism in habitat preference or physiological sensitivity to aridity. Thus, it is unclear whether climate change will impact population structure of willows in ways that parallel other dioecious riparian tree taxa. Future riparian tree restoration programs should aim to maintain future sex ratio balance that maximizes population fitness under projected hydro-climatological conditions. Recent advances in genomics will likely provide the critical tools for early sex determination in pre-reproductive trees across riparian tree species such that sex ratio balance could be targeted during initial stages of restoration, along with adaptations for drought tolerance and other key traits that are essential for survival under future conditions.
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Affiliation(s)
- Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA.
| | - Susan E Bush
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - Joy K Ward
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KA, 66045, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California, Berkeley, CA, 94720-3140, USA
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Morris H, Plavcová L, Gorai M, Klepsch MM, Kotowska M, Jochen Schenk H, Jansen S. Vessel-associated cells in angiosperm xylem: Highly specialized living cells at the symplast-apoplast boundary. AMERICAN JOURNAL OF BOTANY 2018; 105:151-160. [PMID: 29578292 DOI: 10.1002/ajb2.1030] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 11/13/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND Vessel-associated cells (VACs) are highly specialized, living parenchyma cells that are in direct contact with water-conducting, dead vessels. The contact may be sparse or in large tight groups of parenchyma that completely surrounds vessels. VACs differ from vessel distant parenchyma in physiology, anatomy, and function and have half-bordered pits at the vessel-parenchyma juncture. The distinct anatomy of VACs is related to the exchange of substances to and from the water-transport system, with the cells long thought to be involved in water transport in woody angiosperms, but where direct experimental evidence is lacking. SCOPE This review focuses on our current knowledge of VACs regarding anatomy and function, including hydraulic capacitance, storage of nonstructural carbohydrates, symplastic and apoplastic interactions, defense against pathogens and frost, osmoregulation, and the novel hypothesis of surfactant production. Based on microscopy, we visually represent how VACs vary in dimensions and general appearance between species, with special attention to the protoplast, amorphous layer, and the vessel-parenchyma pit membrane. CONCLUSIONS An understanding of the relationship between VACs and vessels is crucial to tackling questions related to how water is transported over long distances in xylem, as well as defense against pathogens. New avenues of research show how parenchyma-vessel contact is related to vessel diameter and a new hypothesis may explain how surfactants arising from VAC can allow water to travel under negative pressure. We also reinforce the message of connectivity between VAC and other cells between xylem and phloem.
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Affiliation(s)
- Hugh Morris
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Laboratory for Applied Wood Materials, Empa-Swiss Federal Laboratories for Materials Testing and Research, St. Gallen, Switzerland
| | - Lenka Plavcová
- University of Hradec Králové, Department of Biology, Faculty of Science, Rokitanského 62, 500 03, Hradec Králové, Czech Republic
| | - Mustapha Gorai
- University of Gabes, Higher Institute of Applied Biology of Medenine, Medenine, 4119, Tunisia
| | - Matthias M Klepsch
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Martyna Kotowska
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Macquarie University, Department of Biological Sciences, North Ryde, NSW, 2109, Australia
| | - H Jochen Schenk
- California State University Fullerton, Department of Biological Science, 800 N. State College Blvd., Fullerton, CA, 92831-3599, USA
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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45
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Trapero C, Alcántara E, Jiménez J, Amaro-Ventura MC, Romero J, Koopmann B, Karlovsky P, von Tiedemann A, Pérez-Rodríguez M, López-Escudero FJ. Starch Hydrolysis and Vessel Occlusion Related to Wilt Symptoms in Olive Stems of Susceptible Cultivars Infected by Verticillium dahliae. FRONTIERS IN PLANT SCIENCE 2018; 9:72. [PMID: 29445388 PMCID: PMC5797883 DOI: 10.3389/fpls.2018.00072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/15/2018] [Indexed: 05/25/2023]
Abstract
This study investigated starch content, amount of pathogen DNA and density of occluded vessels in healthy and Verticillium dahliae infected olive shoots and stems. Starch hydrolysis is considered a mechanism to refill xylem vessels that suffered cavitation by either, drought conditions or pathogen infections. The main objective of this work was to evaluate this mechanism in olive plants subjected to V. dahliae infection or to drought conditions, in order to know the importance of cavitation in the development of wilting symptoms. In initial experiments starch content in the shoots was studied in trees of cultivars differing in the level of resistance growing in fields naturally infested with V. dahliae. The starch content, esteemed by microscopic observation of stem transversal sections stained with lugol, decreased with the level of symptom severity. Results were confirmed in a new experiment developed with young plants of cultivars 'Picual' (highly susceptible), 'Arbequina' (moderately susceptible) and 'Frantoio' (resistant), growing in pots under greenhouse conditions, either inoculated or not with V. dahliae. In this experiment, the pathogen DNA content, quantified by real-time PCR, and the density of occluded vessels, recorded by microscopic observations of transversal sections stained with toluidine blue, were related to the symptoms severity caused by the pathogen. Finally, a drought experiment was established with young plants of the cultivar 'Picual' grown in pots under greenhouse conditions in order to compare the effects caused by water deficit with those caused by the pathogen infection. In both cases, results show that starch hydrolysis occurred, what indirectly evidence the importance of xylem cavitation in the development of the symptoms caused by V. dahliae but in the water stressed plants no vessel occlusion was detected.
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Affiliation(s)
- Carlos Trapero
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
- CSIRO-Agriculture and Food, Narrabri, NSW, Australia
| | - Esteban Alcántara
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Jaime Jiménez
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - María C. Amaro-Ventura
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Joaquín Romero
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Birger Koopmann
- Department of Crop Sciences, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Petr Karlovsky
- Department of Crop Sciences, Georg-August-Universität Göttingen, Göttingen, Germany
| | | | - Mario Pérez-Rodríguez
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Francisco J. López-Escudero
- Departamento de Agronomía, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
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Morris H, Gillingham MAF, Plavcová L, Gleason SM, Olson ME, Coomes DA, Fichtler E, Klepsch MM, Martínez-Cabrera HI, McGlinn DJ, Wheeler EA, Zheng J, Ziemińska K, Jansen S. Vessel diameter is related to amount and spatial arrangement of axial parenchyma in woody angiosperms. PLANT, CELL & ENVIRONMENT 2018; 41:245-260. [PMID: 29047119 DOI: 10.1111/pce.13091] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/22/2017] [Accepted: 09/28/2017] [Indexed: 05/13/2023]
Abstract
Parenchyma represents a critically important living tissue in the sapwood of the secondary xylem of woody angiosperms. Considering various interactions between parenchyma and water transporting vessels, we hypothesize a structure-function relationship between both cell types. Through a generalized additive mixed model approach based on 2,332 woody angiosperm species derived from the literature, we explored the relationship between the proportion and spatial distribution of ray and axial parenchyma and vessel size, while controlling for maximum plant height and a range of climatic factors. When factoring in maximum plant height, we found that with increasing mean annual temperatures, mean vessel diameter showed a positive correlation with axial parenchyma proportion and arrangement, but not for ray parenchyma. Species with a high axial parenchyma tissue fraction tend to have wide vessels, with most of the parenchyma packed around vessels, whereas species with small diameter vessels show a reduced amount of axial parenchyma that is not directly connected to vessels. This finding provides evidence for independent functions of axial parenchyma and ray parenchyma in large vesselled species and further supports a strong role for axial parenchyma in long-distance xylem water transport.
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Affiliation(s)
- Hugh Morris
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Laboratory for Applied Wood Materials, Empa-Swiss Federal Laboratories for Materials Testing and Research, St. Gallen, 9014, Switzerland
| | - Mark A F Gillingham
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Albert-Einstein-Allee 11, D-89069, Ulm, Germany
| | - Lenka Plavcová
- Department of Biology, Faculty of Science, University of Hradec Králové, Rokitanského 62, 500 03, Hradec Králové, Czech Republic
| | - Sean M Gleason
- USDA-ARS Water Management and Systems Research Unit, Fort Collins, CO, 80526, USA
| | - Mark E Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de CU, Mexico, DF, 04510, Mexico
| | - David A Coomes
- Forest Ecology and Conservation Group, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Esther Fichtler
- Department of Crop Sciences, Tropical Plant Production and Agricultural Systems Modelling, Göttingen University, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Matthias M Klepsch
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | | | - Daniel J McGlinn
- Department of Biology, College of Charleston, Charleston, SC, 29424, USA
| | - Elisabeth A Wheeler
- Department of Forest Biomaterials, NC State University, Raleigh, NC, 27695-8005, USA
- North Carolina Museum of Natural Sciences, 11 West Jones St., Raleigh, NC, 27601, USA
| | - Jingming Zheng
- Zheng JingminG, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Kasia Ziemińska
- Arnold Arboretum of Harvard University, 1300 Centre St, Boston, MA, 02130, USA
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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Martín-Gómez P, Aguilera M, Pemán J, Gil-Pelegrín E, Ferrio JP. Contrasting ecophysiological strategies related to drought: the case of a mixed stand of Scots pine (Pinus sylvestris) and a submediterranean oak (Quercus subpyrenaica). TREE PHYSIOLOGY 2017; 37:1478-1492. [PMID: 29040771 DOI: 10.1093/treephys/tpx101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
Submediterranean forests are considered an ecotone between Mediterranean and Eurosiberian ecosystems, and are very sensitive to global change. A decline of Scots pine (Pinus sylvestris L.) and a related expansion of oak species (Quercus spp.) have been reported in the Spanish Pre-Pyrenees. Although this has been associated with increasing drought stress, the underlying mechanisms are not fully understood, and suitable monitoring protocols are lacking. The aim of this study is to bring insight into the physiological mechanisms anticipating selective decline of the pines, with particular focus on carbon and water relations. For this purpose, we performed a sampling campaign covering two growing seasons in a mixed stand of P. sylvestris and Quercus subpyrenaica E.H del Villar. We sampled seasonally twig xylem and soil for water isotope composition (δ18O and δ2H), leaves for carbon isotope composition (δ13C) and stems to quantify non-structural carbohydrates (NSC) concentration, and measured water potential and leaf gas exchange. The first summer drought was severe for both species, reaching low predawn water potential (-2.2 MPa), very low stomatal conductance (12 ± 1.0 mmol m-2 s-1) and near-zero or even negative net photosynthesis, particularly in P. sylvestris (-0.6 ± 0.34 μmol m-2 s-1 in oaks, -1.3 ± 0.16 μmol m-2 s-1 in pines). Hence, the tighter stomatal control and more isohydric strategy of P. sylvestris resulted in larger limitations on carbon assimilation, and this was also reflected in carbon storage, showing twofold larger total NSC concentration in oaks than in pines (7.8 ± 2.4% and 4.0 ± 1.3%, respectively). We observed a faster recovery of predawn water potential after summer drought in Q. subpyrenaica than in P. sylvestris (-0.8 MPa and -1.1 MPa, respectively). As supported by the isotopic data, this was probably associated with a deeper and more reliable water supply in Q. subpyrenaica. In line with these short-term observations, we found a more pronounced negative effect of steadily increasing drought stress on long-term growth in pines compared with oaks. All these observations confer evidence of early warning of P. sylvestris decline and indicate the adaptive advantage of Q. subpyrenaica in the area.
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Affiliation(s)
- Paula Martín-Gómez
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Mònica Aguilera
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Eustaquio Gil-Pelegrín
- Unidad de Recursos Forestales, CITA de Aragón, Av. Montañana, 930, 50059 Zaragoza, Spain
| | - Juan Pedro Ferrio
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, 4030000 Concepción, Chile
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48
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Trifilò P, Casolo V, Raimondo F, Petrussa E, Boscutti F, Lo Gullo MA, Nardini A. Effects of prolonged drought on stem non-structural carbohydrates content and post-drought hydraulic recovery in Laurus nobilis L.: The possible link between carbon starvation and hydraulic failure. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 120:232-241. [PMID: 29073538 DOI: 10.1016/j.plaphy.2017.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/15/2017] [Accepted: 10/09/2017] [Indexed: 05/17/2023]
Abstract
Drought-induced tree decline is a complex event, and recent hypotheses suggest that hydraulic failure and carbon starvation are co-responsible for this process. We tested the possible role of non-structural carbohydrates (NSC) content on post-drought hydraulic recovery, to verify the hypothesis that embolism reversal represents a mechanistic link between carbon starvation and stem hydraulics. Measurements were performed in laurel plants subjected to similar water stress levels either over short or long term, to induce comparable embolism levels. Plants subjected to mild and prolonged water shortage (S) showed reduced growth, adjustment of turgor loss point driven by changes in both osmotic potential at full turgor and bulk modulus of elasticity, a lower content of soluble NSC and a higher content of starch with respect to control (C) plants. Moreover, S plants showed a lower ability to recover from xylem embolism than C plants, even after irrigation. Our data suggest that plant carbon status might indirectly influence plant performance during and after drought via effects on xylem hydraulic functioning, supporting the view of a possible mechanistic link between the two processes.
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Affiliation(s)
- Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, salita F. Stagno D'Alcontres 31, 98166 Messina, Italy.
| | - Valentino Casolo
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, via delle Scienze 91, 33100 Udine, Italy
| | - Fabio Raimondo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, salita F. Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Elisa Petrussa
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, via delle Scienze 91, 33100 Udine, Italy
| | - Francesco Boscutti
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, via delle Scienze 91, 33100 Udine, Italy
| | - Maria Assunta Lo Gullo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, salita F. Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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Tomasella M, Häberle KH, Nardini A, Hesse B, Machlet A, Matyssek R. Post-drought hydraulic recovery is accompanied by non-structural carbohydrate depletion in the stem wood of Norway spruce saplings. Sci Rep 2017; 7:14308. [PMID: 29085007 PMCID: PMC5662761 DOI: 10.1038/s41598-017-14645-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/12/2017] [Indexed: 11/30/2022] Open
Abstract
Hydraulic failure and carbon starvation are recognized as main causes of drought-induced forest decline. As water transport and carbon dynamics are strictly interdependent, it is necessary to clarify how dehydration-rehydration cycles are affecting the relations between stem embolism and non-structural carbohydrates (NSC). This is particularly needed for conifers whose embolism repair capability is still controversial. Potted Norway spruce saplings underwent two drought-re-irrigation cycles of same intensity, but performed in two consecutive summers. During the second cycle, stem percent loss of hydraulic conductivity (PLC) and NSC content showed no carry-over effects from the previous drought, indicating complete long-term recovery. The second drought treatment induced moderate PLC (20%) and did not affect total NSCs content, while starch was converted to soluble sugars in the bark. After one week of re-irrigation, PLC recovered to pre-stress values (0%) and NSCs were depleted, only in the wood, by about 30%. Our data suggest that spruce can repair xylem embolism and that, when water is newly available, NSCs stored in xylem parenchyma can be mobilized over short term to sustain respiration and/or for processes involved in xylem transport restoration. This, however, might imply dependency on sapwood NSC reserves for survival, especially if frequent drought spells occur.
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Affiliation(s)
- Martina Tomasella
- Department of Ecology and Ecosystem Management- Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, 85354, Freising, Germany.
| | - Karl-Heinz Häberle
- Department of Ecology and Ecosystem Management- Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, 85354, Freising, Germany
| | - Andrea Nardini
- Department of Life Sciences, Università degli Studi di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Benjamin Hesse
- Department of Ecology and Ecosystem Management- Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, 85354, Freising, Germany
| | - Anna Machlet
- Department of Ecology and Ecosystem Management- Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, 85354, Freising, Germany
| | - Rainer Matyssek
- Department of Ecology and Ecosystem Management- Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, 85354, Freising, Germany
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50
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Prendin AL, Petit G, Fonti P, Rixen C, Dawes MA, Arx G. Axial xylem architecture of
Larix decidua
exposed to CO
2
enrichment and soil warming at the tree line. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12986] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Angela Luisa Prendin
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversità degli Studi di Padova Legnaro PD Italy
| | - Giai Petit
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversità degli Studi di Padova Legnaro PD Italy
| | - Patrick Fonti
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF Davos Switzerland
| | - Melissa Autumn Dawes
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
- WSL Institute for Snow and Avalanche Research SLF Davos Switzerland
| | - Georg Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
- Climatic Change and Climate ImpactsInstitute for Environmental Sciences Geneva Switzerland
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