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Marino G, Guzmán-Delgado P, Santos E, Adaskaveg JA, Blanco-Ulate B, Ferguson L, Zwieniecki MA, Fernández-Suela E. Interactive effect of branch source-sink ratio and leaf aging on photosynthesis in pistachio. FRONTIERS IN PLANT SCIENCE 2023; 14:1194177. [PMID: 37600173 PMCID: PMC10436215 DOI: 10.3389/fpls.2023.1194177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 06/27/2023] [Indexed: 08/22/2023]
Abstract
Tree source-sink ratio has a predominant and complex impact on tree performance and can affect multiple physiological processes including vegetative and reproductive growth, water and nutrient use, photosynthesis, and productivity. In this study, we manipulated the branch level source-sink ratio by reduction of photosynthetic activity (partial branch defoliation) or thinning branch fruit load early in the growing season (after fruit set) in pistachio (Pistacia vera) trees. We then characterized the leaf photosynthetic light response curves through leaf aging. In addition, we determined changes in leaf non-structural carbohydrates (NSC) and nitrogen (N) concentrations. In leaves with high source-sink ratios, there was a gradual decrease in maximum net photosynthetic rate (ANmax) over the growing season, while in branches with low source-sink ratios, there was a sharp decline in ANmax in the first two weeks of August. Branches with high-sink showed an up-regulation (increase) in photosynthesis toward the end of July (at 1,500 growing degree days) during the period of rapid kernel growth rate and increased sink strength, with ANmax being about 7 μmol m-1 s-1 higher than in branches with low-sink. In August, low source-sink ratios precipitated leaf senescence, resulting in a drastic ANmax decline, from 25 to 8 μmol m-1 s-1 (70% drop in two weeks). This reduction was associated with the accumulation of NSC in the leaves from 20 to 30 mg g-1. The mechanisms of ANmax reduction differ between the two treatments. Lower photosynthetic rates of 8-10 μmol m-1 s-1 late in the season were associated with lower N levels in high-sink branches, suggesting N remobilization to the kernels. Lower photosynthesis late in the season was associated with lower respiration rates in low-source branches, indicating prioritization of assimilates to storage. These results can facilitate the adaptation of management practices to tree crop load changes in alternate bearing species.
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Affiliation(s)
- Giulia Marino
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Paula Guzmán-Delgado
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Emily Santos
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Jaclyn A. Adaskaveg
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Bárbara Blanco-Ulate
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Louise Ferguson
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Maciej A. Zwieniecki
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Eduardo Fernández-Suela
- Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario, Madrid, Spain
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2
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Chin ARO, Guzmán-Delgado P, Görlich A, HilleRisLambers J. Towards multivariate functional trait syndromes: Predicting foliar water uptake in trees. Ecology 2023; 104:e4112. [PMID: 37252804 DOI: 10.1002/ecy.4112] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/10/2023] [Accepted: 05/18/2023] [Indexed: 06/01/2023]
Abstract
Analysis of functional traits is a cornerstone of ecology, yet individual traits seldom explain useful amounts of variation in species distribution or climatic tolerance, and their functional significance is rarely validated experimentally. Multivariate suites of interacting traits could build an understanding of ecological processes and improve our ability to make sound predictions of species success in our rapidly changing world. We use foliar water uptake capacity as a case study because it is increasingly considered to be a key functional trait in plant ecology due to its importance for stress-tolerance physiology. However, the traits behind the trait, that is, the features of leaves that determine variation in foliar water uptake rates, have not been assembled into a widely applicable framework for uptake prediction. Focusing on trees, we investigated relationships among 25 structural traits, leaf osmotic potential (a source of free energy to draw water into leaves), and foliar water uptake in 10 diverse angiosperm and conifer species. We identified consistent, multitrait "uptake syndromes" for both angiosperm and conifer trees, with differences in key traits revealing suspected differences in the water entry route between these two clades and an evolutionarily significant divergence in the function of homologous structures. A literature review of uptake-associated functional traits, which largely documents similar univariate relationships, provides additional support for our proposed "uptake syndrome." Importantly, more than half of shared traits had opposite-direction influences on the capacity of leaves to absorb water in angiosperms and conifers. Taxonomically targeted multivariate trait syndromes provide a useful tool for trait selection in ecological research, while highlighting the importance of micro-traits and the physiological verification of their function for advancing trait-based ecology.
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Affiliation(s)
- Alana R O Chin
- Plant Ecology Group, Institute of Integrative Biology, ETH-Zürich, Zürich, Switzerland
| | - Paula Guzmán-Delgado
- Department of Plant Sciences, University of California, Davis, Davis, California, USA
| | - Anna Görlich
- Plant Ecology Group, Institute of Integrative Biology, ETH-Zürich, Zürich, Switzerland
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3
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Composition, metabolism and postharvest function and regulation of fruit cuticle: A review. Food Chem 2023; 411:135449. [PMID: 36669336 DOI: 10.1016/j.foodchem.2023.135449] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/19/2022] [Accepted: 01/07/2023] [Indexed: 01/15/2023]
Abstract
The cuticle of plants, a hydrophobic membrane that covers their aerial organs, is crucial to their ability to withstand biotic and abiotic stressors. Fruit is the reproductive organ of plants, and an important dietary source that can offer a variety of nutrients for the human body, and fruit cuticle performs a crucial protective role in fruit development and postharvest quality. This review discusses the universality and diversity of the fruit cuticle composition, and systematically summarizes the metabolic process of fruit cuticle, including the biosynthesis, transport and regulatory factors (including transcription factors, phytohormones and environmental elements) of fruit cuticle. Additionally, we emphasize the postharvest functions and postharvest regulatory technologies of fruit cuticle, and propose future research directions for fruit cuticle.
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Du Y, Zhao Y, Dong S, Chen G, Wang X, Ma K. The Diversity Distribution and Climatic Niche of Samara Species in China. FRONTIERS IN PLANT SCIENCE 2022; 13:895720. [PMID: 35783943 PMCID: PMC9249021 DOI: 10.3389/fpls.2022.895720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Studying the distribution of samara species is of ecological and economic significance. This information helps us with understanding species dispersal mechanisms, evaluating the risk of invasive species, and the management of ecological forests. However, limited research has explored, on a large scale, the geographic distribution of samara species and their influential abiotic factors. Here, we use the distribution data of 835 vascular samara species and growth form data to explore their geographic patterns in China and the environmental determinants. We divided China into 984 grid cells and examined the relationship between the proportion of samara species and climate variables using both ordinary and spatial linear regressions for each grid cell. Total samara species richness is higher in southern China in low altitude regions and the proportion of woody samara species is significantly higher than that of herbaceous samara species. The proportion of woody samara species is higher in the northeast regions where precipitation is sufficient, winters are dry and mild, and temperature seasonality and land surface relief degree values are high. Annual precipitation and temperature seasonality are the most important climatic drivers for the distribution of woody samara species. In contrast, herbaceous samara species prefer to distribute to the areas where climate is warm and dry but have higher temperature seasonality. Temperature related variables (mean annual temperature, mean diurnal range, and temperature seasonality) are the most important drivers for the distribution of herbaceous samara species. Samara species can better adapt to climatic regions with large temperature fluctuations and dry winters. The present distribution patterns of samara species are formed by the combined adaptation of fruit traits and growth form to climate. This work contributes to predictions of the global distribution of samara species under future climate change scenarios and conservation and management for the samara species.
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Affiliation(s)
- Yanjun Du
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), College of Forestry, Hainan University, Haikou, China
| | - Yuan Zhao
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | | | - Guoke Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xinyang Wang
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), College of Forestry, Hainan University, Haikou, China
| | - Keping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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Bock P, Felhofer M, Mayer K, Gierlinger N. A Guide to Elucidate the Hidden Multicomponent Layered Structure of Plant Cuticles by Raman Imaging. FRONTIERS IN PLANT SCIENCE 2021; 12:793330. [PMID: 34975980 PMCID: PMC8718554 DOI: 10.3389/fpls.2021.793330] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/09/2021] [Indexed: 05/29/2023]
Abstract
The cuticle covers almost all plant organs as the outermost layer and serves as a transpiration barrier, sunscreen, and first line of defense against pathogens. Waxes, fatty acids, and aromatic components build chemically and structurally diverse layers with different functionality. So far, electron microscopy has elucidated structure, while isolation, extraction, and analysis procedures have revealed chemistry. With this method paper, we close the missing link by demonstrating how Raman microscopy gives detailed information about chemistry and structure of the native cuticle on the microscale. We introduce an optimized experimental workflow, covering the whole process of sample preparation, Raman imaging experiment, data analysis, and interpretation and show the versatility of the approach on cuticles of a spruce needle, a tomato peel, and an Arabidopsis stem. We include laser polarization experiments to deduce the orientation of molecules and multivariate data analysis to separate cuticle layers and verify their molecular composition. Based on the three investigated cuticles, we discuss the chemical and structural diversity and validate our findings by comparing models based on our spectroscopic data with the current view of the cuticle. We amend the model by adding the distribution of cinnamic acids and flavonoids within the cuticle layers and their transition to the epidermal layer. Raman imaging proves as a non-destructive and fast approach to assess the chemical and structural variability in space and time. It might become a valuable tool to tackle knowledge gaps in plant cuticle research.
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Affiliation(s)
| | | | | | - Notburga Gierlinger
- Department of Nanobiotechnology, Institute of Biophysics, University of Natural Resources and Life Sciences, Vienna, Austria
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6
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Boanares D, Bueno A, de Souza AX, Kozovits AR, Sousa HC, Pimenta LPS, Isaias RMDS, França MGC. Cuticular wax composition contributes to different strategies of foliar water uptake in six plant species from foggy rupestrian grassland in tropical mountains. PHYTOCHEMISTRY 2021; 190:112894. [PMID: 34364088 DOI: 10.1016/j.phytochem.2021.112894] [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: 04/15/2021] [Revised: 07/21/2021] [Accepted: 07/31/2021] [Indexed: 06/13/2023]
Abstract
The cuticle is the outermost region of the epidermal cell wall of plant aerial organs. The cuticle acts as a two-way lipid barrier for water diffusion; therefore, it plays a vital role in foliar water uptake (FWU). We hypothesised that the chemical composition of the cuticular waxes influences the FWU strategy that plants adopt in a foggy tropical ecosystem. We analysed the leaf cuticular waxes of six plant species known by their different FWU strategies, in both qualitative and quantitative approaches, to test this hypothesis. We also investigated the fine structure of the plant cuticle by scanning electron microscopy. Neither the total wax loads nor the amounts of single wax compound classes correlated to the FWU. In contrast, the qualitative chemical composition of the cuticular waxes was related to the water absorption speed but not to the maximum water absorbed. The presence of wax crystals might interfere with the FWU. Our findings suggest that a complex three-dimensional network of the cuticular compounds contributes to different strategies of FWU in six plant species from foggy tropical mountaintops.
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Affiliation(s)
- Daniela Boanares
- Departamento de Botânica, Universidade Federal de Minas Gerais, Minas Gerais, Brazil.
| | - Amauri Bueno
- University of Würzburg, Julius-von-Sachs Institute of Biological Sciences, Chair of Botany II - Ecophysiology and Vegetation Ecology, Würzburg, Germany.
| | - Aline Xavier de Souza
- University of Würzburg, Julius-von-Sachs Institute of Biological Sciences, Chair of Botany II - Ecophysiology and Vegetation Ecology, Würzburg, Germany
| | | | - Hildeberto Caldas Sousa
- Departamento de Biodiversidade, Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, Minas Gerais, Brazil
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Stem CO2 Efflux as an Indicator of Forests’ Productivity in Relict Juniper Woodlands (Juniperus thurifera L.) of Southern Spain. FORESTS 2021. [DOI: 10.3390/f12101340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There are considerable uncertainties about the C cycle in semi-arid ecosystems. Hence, studies that have focused on Juniperus in Mediterranean woodlands are non-existent. This study provides a survey of the effect of the juniper woodland type (young and mature woodlands; joint effect of maturity and forest productivity) on stem respiration. We checked the seasonal variation of stem respiration, evaluating the effects of stem temperature on stem CO2 efflux. For this, we measured the stem CO2 efflux (µmol CO2 m−2 s−1) over the four seasons on 16 junipers using LI-6400 equipment. The results showed that in the more productive site (young woodland), the stem CO2 efflux was higher. This variable followed a clear seasonal trend, being higher during the spring and progressively decreasing in cold periods. In both juniper woodlands, and especially in the older forests, the Q10 coefficients were low (<2), typical of cold forests and slow-growing species. The exponential model also confirmed that the Q10 was significantly higher in young juniper trees. Thus, stem CO2 efflux was an indicator of the growth in this juniper woodland that is well adapted to a semi-arid climate.
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8
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Amico Roxas A, Orozco J, Guzmán-Delgado P, Zwieniecki MA. Spring phenology is affected by fall non-structural carbohydrate concentration and winter sugar redistribution in three Mediterranean nut tree species. TREE PHYSIOLOGY 2021; 41:1425-1438. [PMID: 34383074 DOI: 10.1093/treephys/tpab014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/26/2021] [Indexed: 06/13/2023]
Abstract
Deciduous trees mostly rely on non-structural carbohydrates (NSC-soluble carbohydrates and starch) stored prior to dormancy to sustain both spring bloom and the initial phase of spring growth prior to the transition of leaves from sink to source. Winter management of NSC, their loss due to respiration, reallocation patterns and remobilization during spring, seems to be key to a timely and synchronous bloom. To assess tree dependence on NSC during dormancy, we tested whether the interruption of local branch NSC accumulation prior to dormancy by defoliation and the interruption of NSC translocation by phloem girdling influence spring phenology in three major deciduous Mediterranean nut crop species: Prunus dulcis (Mill.) D.A Webb, a hybrid between Pistacia integerrima (J. L. Stewart ex Brandis) and P. atlantica Desf. (referred to as P. integerrima), and Juglans regia L. Defoliation treatments had different effects on NSC concentration in different species depending on the time of application. However, despite the significant initial impact (increase or decrease of NSC concentration), with time this impact diminished resulting in overall similar concentrations between control and defoliated branches suggesting the presence of NSC reallocation during dormancy. Phloem girdling in P. dulcis and P. integerrima resulted in reduced export activity and greater NSC concentrations, while in J. regia girdling resulted in lower NSC concentrations, indicating that this species requires a net import of NSC during dormancy. Bud break was distinctly delayed by both defoliation and phloem girdling in all the three species, providing evidence of the significant roles that fall NSC accumulation and winter NSC management play in priming trees for spring growth resumption.
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Affiliation(s)
- Adele Amico Roxas
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Jessica Orozco
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Paula Guzmán-Delgado
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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Guzmán-Delgado P, Laca E, Zwieniecki MA. Unravelling foliar water uptake pathways: The contribution of stomata and the cuticle. PLANT, CELL & ENVIRONMENT 2021; 44:1728-1740. [PMID: 33665817 DOI: 10.1111/pce.14041] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Plants can absorb water through their leaf surfaces, a phenomenon commonly referred to as foliar water uptake (FWU). Despite the physiological importance of FWU, the pathways and mechanisms underlying the process are not well known. Using a novel experimental approach, we parsed out the contribution of the stomata and the cuticle to FWU in two species with Mediterranean (Prunus dulcis) and temperate (Pyrus communis) origin. The hydraulic parameters of FWU were derived by analysing mass and water potential changes of leaves placed in a fog chamber. Leaves were previously treated with abscisic acid to force stomata to remain closed, with fusicoccin to remain open, and with water (control). Leaves with open stomata rehydrated two times faster than leaves with closed stomata and attained approximately three times higher maximum fluxes and hydraulic conductance. Based on FWU rates, we propose that rehydration through stomata occurs primarily via diffusion of water vapour rather than in liquid form even when leaf surfaces are covered with a water film. We discuss the potential mechanisms of FWU and the significance of both stomatal and cuticular pathways for plant productivity and survival.
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Affiliation(s)
- Paula Guzmán-Delgado
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - Emilio Laca
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California Davis, Davis, California, USA
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Sasani N, Bock P, Felhofer M, Gierlinger N. Raman imaging reveals in-situ microchemistry of cuticle and epidermis of spruce needles. PLANT METHODS 2021; 17:17. [PMID: 33557869 PMCID: PMC7871409 DOI: 10.1186/s13007-021-00717-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/28/2021] [Indexed: 05/26/2023]
Abstract
BACKGROUND The cuticle is a protective layer playing an important role in plant defense against biotic and abiotic stresses. So far cuticle structure and chemistry was mainly studied by electron microscopy and chemical extraction. Thus, analysing composition involved sample destruction and the link between chemistry and microstructure remained unclear. In the last decade, Raman imaging showed high potential to link plant anatomical structure with microchemistry and to give insights into orientation of molecules. In this study, we use Raman imaging and polarization experiments to study the native cuticle and epidermal layer of needles of Norway spruce, one of the economically most important trees in Europe. The acquired hyperspectral dataset is the basis to image the chemical heterogeneity using univariate (band integration) as well as multivariate data analysis (cluster analysis and non-negative matrix factorization). RESULTS Confocal Raman microscopy probes the cuticle together with the underlying epidermis in the native state and tracks aromatics, lipids, carbohydrates and minerals with a spatial resolution of 300 nm. All three data analysis approaches distinguish a waxy, crystalline layer on top, in which aliphatic chains and coumaric acid are aligned perpendicular to the surface. Also in the lipidic amorphous cuticle beneath, strong signals of coumaric acid and flavonoids are detected. Even the unmixing algorithm results in mixed endmember spectra and confirms that lipids co-locate with aromatics. The underlying epidermal cell walls are devoid of lipids but show strong aromatic Raman bands. Especially the upper periclinal thicker cell wall is impregnated with aromatics. At the interface between epidermis and cuticle Calcium oxalate crystals are detected in a layer-like fashion. Non-negative matrix factorization gives the purest component spectra, thus the best match with reference spectra and by this promotes band assignments and interpretation of the visualized chemical heterogeneity. CONCLUSIONS Results sharpen our view about the cuticle as the outermost layer of plants and highlight the aromatic impregnation throughout. In the future, developmental studies tracking lipid and aromatic pathways might give new insights into cuticle formation and comparative studies might deepen our understanding why some trees and their needle and leaf surfaces are more resistant to biotic and abiotic stresses than others.
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Affiliation(s)
- Nadia Sasani
- Department of Nanobiotechnology (DNBT), Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11-II, 1190, Vienna, Austria
| | - Peter Bock
- Department of Nanobiotechnology (DNBT), Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11-II, 1190, Vienna, Austria
| | - Martin Felhofer
- Department of Nanobiotechnology (DNBT), Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11-II, 1190, Vienna, Austria
| | - Notburga Gierlinger
- Department of Nanobiotechnology (DNBT), Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11-II, 1190, Vienna, Austria.
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Vega C, González G, Bahamonde HA, Valbuena-Carabaña M, Gil L, Fernández V. Effect of irradiation and canopy position on anatomical and physiological features of Fagus sylvatica and Quercus petraea leaves. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 152:232-242. [PMID: 32449682 DOI: 10.1016/j.plaphy.2020.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Growing conditions at different tree canopy positions may significantly vary and lead to foliar changes even within the same tree. An assessment of foliar anatomy, including also epidermal features, can help us understand how plants respond to environmental factors. Working with two model tree species (i.e., Quercus petraea and Fagus sylvatica) grown at their southernmost European distribution area in Central Spain, the influence of irradiation and canopy height was examined by sampling lower canopy leaves and comparing them with fully irradiated, top canopy leaves and shaded top canopy leaves grown for months within a bag made of shade netting fabric before they sprouted. At the end of the summer, samples were collected, and several parameters were analysed. The results indicate that SLA (specific leaf area) differences are significant both between species and groups. Leaf and cuticle thickness differed significantly between groups while stomatal densities only between species. Regarding mineral concentrations, differences between species were significant for K, Mn, N and N: P ratios. It is concluded that leaf responses to environmental conditions may be variable both within the same tree and between species.
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Affiliation(s)
- Clara Vega
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Guillermo González
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Héctor A Bahamonde
- Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Diagonal 113 Nº 469, 1900, La Plata, Argentina
| | - María Valbuena-Carabaña
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Gil
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Victoria Fernández
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain.
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López-Pozo M, Ballesteros D, Laza JM, García-Plazaola JI, Fernández-Marín B. Desiccation Tolerance in Chlorophyllous Fern Spores: Are Ecophysiological Features Related to Environmental Conditions? FRONTIERS IN PLANT SCIENCE 2019; 10:1130. [PMID: 31616448 PMCID: PMC6764020 DOI: 10.3389/fpls.2019.01130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/15/2019] [Indexed: 05/17/2023]
Abstract
Fern spores of most species are desiccation tolerant (DT) and, in some cases, are photosynthetic at maturation, the so-called chlorophyllous spores (CS). The lifespan of CS in the dry state is very variable among species. The physiological, biochemical, and biophysical mechanisms underpinning this variability remain understudied and their interpretation from an ecophysiological approach virtually unexplored. In this study, we aimed at fulfilling this gap by assessing photochemical, hydric, and biophysical properties of CS from three temperate species with contrasting biological strategies and longevity in the dry state: Equisetum telmateia (spore maturation and release in spring, ultrashort lifespan), Osmunda regalis (spore maturation and release in summer, medium lifespan), Matteuccia struthiopteris (spore maturation and release in winter, medium-long lifespan). After subjection of CS to controlled drying treatments, results showed that the three species displayed different extents of DT. CS of E. telmateia rapidly lost viability after desiccation, while the other two withstood several dehydration-rehydration cycles without compromising viability. The extent of DT was in concordance with water availability in the sporulation season of each species. CS of O. regalis and M. struthiopteris carried out the characteristic quenching of chlorophyll fluorescence, widely displayed by other DT cryptogams during drying, and had higher tocopherol and proline contents. The turgor loss point of CS is also related to the extent of DT and to the sporulation season: lowest values were found in CS of M. struthiopteris and O. regalis. The hydrophobicity of spores in these two species was higher and probably related to the prevention of water absorption under unfavorable conditions. Molecular mobility, estimated by dynamic mechanical thermal analysis, confirmed an unstable glassy state in the spores of E. telmateia, directly related to the low DT, while the DT species entered in a stable glassy state when dried. Overall, our data revealed a DT syndrome related to the season of sporulation that was characterized by higher photoprotective potential, specific hydric properties, and lower molecular mobility in the dry state. Being unicellular haploid structures, CS represent not only a challenge for germplasm preservation (e.g., as these spores are prone to photooxidation) but also an excellent opportunity for studying mechanisms of DT in photosynthetic cells.
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Affiliation(s)
- Marina López-Pozo
- Depatment of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Daniel Ballesteros
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, West Sussex, United Kingdom
| | - José Manuel Laza
- Laboratory of Macromolecular Chemistry (Labquimac), Department of Physical Chemistry, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | | | - Beatriz Fernández-Marín
- Depatment of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Bilbao, Spain
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Gougherty AV, Gougherty SW. Sequence of flower and leaf emergence in deciduous trees is linked to ecological traits, phylogenetics, and climate. THE NEW PHYTOLOGIST 2018; 220:121-131. [PMID: 29900552 DOI: 10.1111/nph.15270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/12/2018] [Indexed: 06/08/2023]
Abstract
While much research has focused on the timing of individual plant phenological events, the sequence of phenological events has received considerably less attention. Here we identify drivers and patterns of flower and leaf emergence sequence (FLS) in deciduous tree species of the Great Lakes region of North America. Five hypotheses related to cold tolerance, water dynamics, seed mass, pollination syndrome, and xylem anatomy type were compared for their ability to explain FLS. Phylogenetic and geographic patterns of FLS were also assessed. We identified additional traits associated with FLS using Random Forest models. Of the hypotheses assessed, those related to species' water dynamics and seed mass had the greatest support. The spatial pattern of FLS was found to be strongly related to minimum monthly temperature and the phylogenetic pattern was clustered among species. Based on results from Random Forest models, species' fruiting characteristics were found to be the most important variables in explaining FLS. Our results show that FLS is related to a suite of plant traits and environmental tolerances. We emphasize the need to expand phenological research to include both the timing and sequence of plant's entire phenology, in particular in relation to plant physiology and global change.
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Affiliation(s)
- Andrew V Gougherty
- Appalachian Lab, University of Maryland Center for Environmental Science, Frostburg, MD, 21532, USA
| | - Steven W Gougherty
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, 49060, USA
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Guzmán-Delgado P, Mason Earles J, Zwieniecki MA. Insight into the physiological role of water absorption via the leaf surface from a rehydration kinetics perspective. PLANT, CELL & ENVIRONMENT 2018; 41:1886-1894. [PMID: 29740843 DOI: 10.1111/pce.13327] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Soil water transported via the petiole is a primary rehydration pathway for leaves of water-stressed plants. Leaves may also rehydrate by absorbing water via their epidermal surfaces. The mechanisms and physiological relevance of this water pathway, however, remain unclear, as the associated hydraulic properties are unknown. To gain insight into the foliar water absorption process, we compared rehydration kinetics via the petiole and surface of Prunus dulcis and Quercus lobata leaves. Petiole rehydration could be described by a double exponential function suggesting that 2 partly isolated water pools exist in leaves of both species. Surface rehydration could be described by a logistic function, suggesting that leaves behave as a single water pool. Whereas full leaf rehydration via the petiole required approximately 20 min, it took over 150 and 300 min via the surface of P. dulcis and Q. lobata, respectively. Such differences were attributed to the high resistance imposed by the leaf surface and especially the cuticle. The minimum resistance to surface rehydration was estimated to be 6.6 × 102 (P. dulcis) and 2.6 × 103 MPa·m2 ·s·g-1 (Q. lobata), which is remarkably higher than estimated for petiole rehydration. These results are discussed in a physiological context.
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Affiliation(s)
- Paula Guzmán-Delgado
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - J Mason Earles
- School of Forestry & Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
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15
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Fernández V, Bahamonde HA, Javier Peguero-Pina J, Gil-Pelegrín E, Sancho-Knapik D, Gil L, Goldbach HE, Eichert T. Physico-chemical properties of plant cuticles and their functional and ecological significance. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5293-5306. [PMID: 28992247 DOI: 10.1093/jxb/erx302] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/03/2017] [Indexed: 05/19/2023]
Abstract
Most aerial plant surfaces are covered with a lipid-rich cuticle, which is a barrier for the bidirectional transport of substances between the plant and the surrounding environment. This review article provides an overview of the significance of the leaf cuticle as a barrier for the deposition and absorption of water and electrolytes. After providing insights into the physico-chemical properties of plant surfaces, the mechanisms of foliar absorption are revised with special emphasis on solutes. Due to the limited information and relative importance of the leaf cuticle of herbaceous and deciduous cultivated plants, an overview of the studies developed with Alpine conifers and treeline species is provided. The significance of foliar water uptake as a phenomenon of ecophysiological relevance in many areas of the world is also highlighted. Given the observed variability in structure and composition among, for example, plant species and organs, it is concluded that it is currently not possible to establish general permeability and wettability models that are valid for predicting liquid-surface interactions and the subsequent transport of water and electrolytes across plant surfaces.
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Affiliation(s)
- Victoria Fernández
- Forest Genetics and Ecophysiology Research Group, School of Forest Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Hector A Bahamonde
- Instituto Nacional de Tecnología Agropecuaria (INTA), cc 332, 9400 Río Gallegos, Santa Cruz, Argentina
| | - José Javier Peguero-Pina
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, 50059 Zaragoza, Spain
| | - Eustaquio Gil-Pelegrín
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, 50059 Zaragoza, Spain
| | - Domingo Sancho-Knapik
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, 50059 Zaragoza, Spain
| | - Luis Gil
- Forest Genetics and Ecophysiology Research Group, School of Forest Engineering, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Heiner E Goldbach
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, 53115 Bonn, Germany
| | - Thomas Eichert
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, 53115 Bonn, Germany
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