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Askanbayeva B, Janová J, Kubásek J, Zeisler-Diehl VV, Schreiber L, Muir CD, Šantrůček J. Amphistomy: stomata patterning inferred from 13C content and leaf-side-specific deposition of epicuticular wax. ANNALS OF BOTANY 2024; 134:437-454. [PMID: 38836501 PMCID: PMC11341673 DOI: 10.1093/aob/mcae082] [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: 12/14/2023] [Accepted: 06/04/2024] [Indexed: 06/06/2024]
Abstract
BACKGROUND AND AIMS The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular wax on the opposite leaf sides is studied. METHODS We suggest that the 13C content of long-chain aliphatic compounds of cuticular wax records the leaf internal CO2 concentration in chloroplasts adjacent to the adaxial and abaxial epidermes. This unique property stems from: (1) wax synthesis being located exclusively in epidermal cells; and (2) ongoing wax renewal over the whole leaf lifespan. Compound-specific and bulk wax 13C abundance (δ) was related to amphistomy level (ASL; as a fraction of adaxial in all stomata) of four AS and five HS species grown under various levels of irradiance. The isotopic polarity of epicuticular wax, i.e. the difference in abaxial and adaxial δ (δab - δad), was used to calculate the leaf dorsiventral CO2 gradient. Leaf-side-specific epicuticular wax deposition (amphiwaxy level) was estimated and related to ASL. KEY RESULTS In HS species, the CO2 concentration in the adaxial epidermis was lower than in the abaxial one, independently of light conditions. In AS leaves grown in high-light and low-light conditions, the isotopic polarity and CO2 gradient varied in parallel with ASL. The AS leaves grown in high-light conditions increased ASL compared with low light, and δab - δad approached near-zero values. Changes in ASL occurred concomitantly with changes in amphiwaxy level. CONCLUSIONS Leaf wax isotopic polarity is a newly identified leaf trait, distinguishing between hypo- and amphistomatous species and indicating that increased ASL in sun-exposed AS leaves reduces the CO2 gradient across the leaf mesophyll. Stomata and epicuticular wax deposition follow similar leaf-side patterning.
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Affiliation(s)
- Balzhan Askanbayeva
- Department of Experimental Plant Biology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Jitka Janová
- Department of Experimental Plant Biology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Jiří Kubásek
- Department of Experimental Plant Biology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Viktoria V Zeisler-Diehl
- Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Lukas Schreiber
- Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Christopher D Muir
- Department of Botany, University of Wisconsin, 143 Lincoln Drive, Madison, WI 53711, USA
| | - Jiří Šantrůček
- Department of Experimental Plant Biology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
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Tulva I, Koolmeister K, Hõrak H. Low relative air humidity and increased stomatal density independently hamper growth in young Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 39072887 DOI: 10.1111/tpj.16944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 06/26/2024] [Accepted: 07/13/2024] [Indexed: 07/30/2024]
Abstract
Stomatal pores in plant leaves mediate CO2 uptake for photosynthesis and water loss via transpiration. Altered stomatal density can affect plant photosynthetic capacity, water use efficiency, and growth, potentially providing either benefits or drawbacks depending on the environment. Here we explore, at different air humidity regimes, gas exchange, stomatal anatomy, and growth of Arabidopsis lines designed to combine increased stomatal density (epf1, epf2) with high stomatal sensitivity (ht1-2, cyp707a1/a3). We show that the stomatal density and sensitivity traits combine as expected: higher stomatal density increases stomatal conductance, whereas the effect is smaller in the high stomatal sensitivity mutant backgrounds than in the epf1epf2 double mutant. Growth under low air humidity increases plant stomatal ratio with relatively more stomata allocated to the adaxial epidermis. Low relative air humidity and high stomatal density both independently impair plant growth. Higher evaporative demand did not punish increased stomatal density, nor did inherently low stomatal conductance provide any protection against low relative humidity. We propose that the detrimental effects of high stomatal density on plant growth at a young age are related to the cost of producing stomata; future experiments need to test if high stomatal densities might pay off in later life stages.
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Affiliation(s)
- Ingmar Tulva
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
| | - Kaspar Koolmeister
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
- Institute of Bioengineering, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
| | - Hanna Hõrak
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
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Ayala-Ramos MA, Montaño-Arias SA, Terrazas T, Grether R. Ecological implications of stomatal density and stomatal index in the adult stage of Mimosa L. (Leguminosae, Caesalpinioideae). PROTOPLASMA 2024; 261:477-486. [PMID: 38030853 DOI: 10.1007/s00709-023-01909-8] [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: 09/23/2023] [Accepted: 11/09/2023] [Indexed: 12/01/2023]
Abstract
Differences in stomatal density (SD) and stomatal index (SI) are associated with the conditions of the environment in which they are distributed. Mimosa species are important elements in different plant communities, yet knowledge of the ecological implications of its stomatal characteristics is scarce. For this reason, SD and SI were determined in seven Mimosa species from different environments in this study. Five individuals per species were selected, and a sample of leaflets was obtained from each. Fifteen mature leaflets per individual were then extracted and observed by optical microscopy. SD, SI, epidermal cell density (ECD), and guard cell length (GCL) values were obtained. Differences between species were analyzed through a balanced analysis of variance test, and the correspondence between the stomatal characteristics and 21 climate variables was determined by canonical correspondence analysis. The species differed in all evaluated characteristics. It should be noted that only M. affinis showed differences between the leaflet surfaces. Both DE and ECD were negatively associated with altitude and solar radiation and positively with temperature and precipitation. SI was explained by temperature and seasonality of precipitation, and GCL by temperature oscillation and seasonality of precipitation. The results suggest that the stomatal characteristics of the leaflets confer resistance in the species to alterations in environmental conditions.
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Affiliation(s)
- Manuel Alberto Ayala-Ramos
- Doctorado en Ciencias Biológicas y de La Salud, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de México, México
| | - Susana Adriana Montaño-Arias
- Universidad Autónoma Metropolitana, Unidad-Iztapalapa, Departamento de Biología, División de Ciencias Biológicas y de La Salud, Apdo. Postal 55-535, 09340, Ciudad de Mexico, México.
| | - Teresa Terrazas
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, Ciudad de México, CP, 04510, México
| | - Rosaura Grether
- Universidad Autónoma Metropolitana, Unidad-Iztapalapa, Departamento de Biología, División de Ciencias Biológicas y de La Salud, Apdo. Postal 55-535, 09340, Ciudad de Mexico, México
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4
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Feng W, Ma X, Yuan Z, Li W, Yan Y, Yang W. An Experimental Investigation of the Precipitation Utilization of Plants in Arid Regions. PLANTS (BASEL, SWITZERLAND) 2024; 13:594. [PMID: 38475440 DOI: 10.3390/plants13050594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/01/2024] [Accepted: 01/12/2024] [Indexed: 03/14/2024]
Abstract
What represents a water source for the ecological restoration of a plant in an arid region is still up to debate. To address this issue, we conducted an in situ experiment in the Ulan Buh Desert of China, to study desert plants absorbing atmospheric water vapor. We selected Tamarisk, a common drought-salt-tolerant species in the desert, for ecological restoration as our research subject, used a newly designed lysimeter to monitor precipitation infiltration, and a sap flow system to track reverse sap flow that occurred in the shoot, branch, and stem during the precipitation event, and observed the precipitation redistribution process of the Tamarisk plot. The results showed that Tamarisk indeed directly absorbs precipitation water: when precipitation occurs, the main stem, lateral branch, and shoot all show the signs of reversed sap flow, and the reversed sap flow accounted for 21.5% of the annual sap flow in the shoot and branch, and 13.6% in the stem. The precipitation event in the desert was dominated by light precipitation events, which accounted for 81% of the annual precipitation events. It was found that light precipitation can be directly absorbed by the Tamarisk leaves, especially during nighttime or cloudy days. Even when the precipitation is absent, it was found that desert plants can still absorb water from the unsaturated atmospheric vapor; even the absorbed atmospheric water vapor was transported from the leaves to the stem, forming a reversed sap flow, as a reversed sap flow was observed when the atmospheric relative humidity reached 75%. This study indicated that the effect of light precipitation on desert plants was significant and should not be overlooked in terms of managing the ecological and hydrological systems in arid regions.
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Affiliation(s)
- Wei Feng
- Department of Livestock, Xilingol Vocational College, Xilinhot 026000, China
- Institute of Ecological Protection and Restoration, China Academy of Forestry, Beijing 100093, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Xiaoxu Ma
- School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Zixuan Yuan
- School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Wei Li
- Institute of Ecological Protection and Restoration, China Academy of Forestry, Beijing 100093, China
| | - Yujie Yan
- School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Wenbin Yang
- Low-Coverage Sand Control Company, Hohhot 010000, China
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Triplett G, Buckley TN, Muir CD. Amphistomy increases leaf photosynthesis more in coastal than montane plants of Hawaiian 'ilima (Sida fallax). AMERICAN JOURNAL OF BOTANY 2024; 111:e16284. [PMID: 38351495 DOI: 10.1002/ajb2.16284] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 02/22/2024]
Abstract
PREMISE The adaptive significance of amphistomy (stomata on both upper and lower leaf surfaces) is unresolved. A widespread association between amphistomy and open, sunny habitats suggests the adaptive benefit of amphistomy may be greatest in these contexts, but this hypothesis has not been tested experimentally. Understanding amphistomy informs its potential as a target for crop improvement and paleoenvironment reconstruction. METHODS We developed a method to quantify "amphistomy advantage" (AA $\text{AA}$ ) as the log-ratio of photosynthesis in an amphistomatous leaf to that of the same leaf but with gas exchange blocked through the upper surface (pseudohypostomy). Humidity modulated stomatal conductance and thus enabled comparing photosynthesis at the same total stomatal conductance. We estimatedAA $\text{AA}$ and leaf traits in six coastal (open, sunny) and six montane (closed, shaded) populations of the indigenous Hawaiian species 'ilima (Sida fallax). RESULTS Coastal 'ilima leaves benefit 4.04 times more from amphistomy than montane leaves. Evidence was equivocal with respect to two hypotheses: (1) that coastal leaves benefit more because they are thicker and have lower CO2 conductance through the internal airspace and (2) that they benefit more because they have similar conductance on each surface, as opposed to most conductance being through the lower surface. CONCLUSIONS This is the first direct experimental evidence that amphistomy increases photosynthesis, consistent with the hypothesis that parallel pathways through upper and lower mesophyll increase CO2 supply to chloroplasts. The prevalence of amphistomatous leaves in open, sunny habitats can partially be explained by the increased benefit of amphistomy in "sun" leaves, but the mechanistic basis remains uncertain.
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Affiliation(s)
- Genevieve Triplett
- School of Life Sciences, University of Hawai'i Mānoa, Honolulu, HI, 96822, USA
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Christopher D Muir
- School of Life Sciences, University of Hawai'i Mānoa, Honolulu, HI, 96822, USA
- Department of Botany, University of Wisconsin, Madison, WI, 53706, USA
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6
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Liu G, Fu P, Mao Q, Xia J, Zhao W. Effect of life cycle and venation pattern on the coordination between stomatal and vein densities of herbs. AOB PLANTS 2024; 16:plae007. [PMID: 38435969 PMCID: PMC10908534 DOI: 10.1093/aobpla/plae007] [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: 07/14/2023] [Accepted: 02/19/2024] [Indexed: 03/05/2024]
Abstract
Life cycle (annual vs perennial) and leaf venation pattern (parallel and reticular) are known to be related to water use strategies in herb species and critical adaptation to certain climatic conditions. However, the effect of these two traits and how they influence the coordination between vein density (vein length per area, VLA) and stomatal density (SD) remains unclear. In this study, we examined the leaves of 53 herb species from a subtropical botanical garden in Guangdong Province, China, including herbs with different life cycles and leaf venation patterns. We assessed 21 leaf water-related functional traits for all species, including leaf area (LA), major and minor VLA, major and minor vein diameter (VD), SD and stomatal length (SL). The results showed no significant differences in mean SD and SL between either functional group (parallel venation vs reticular venation and annual vs perennial). However, parallel vein herbs and perennial herbs displayed a significantly higher mean LA and minor VD, and lower minor VLA compared to reticular vein herbs and annual herbs, respectively. There was a linear correlation between total VLA and SD in perennial and reticular vein herbs, but this kind of correlation was not found in annual and parallel vein herbs. The major VLA and minor VD were significantly affected by the interaction between life cycle and leaf venation pattern. Our findings suggested that VLA, rather than SD, may serve as a more adaptable structure regulated by herbaceous plants to support the coordination between leaf water supply and demand in the context of different life cycles and leaf venation patterns. The results of the present study provide mechanistic understandings of functional advantages of different leaf types, which may involve in species fitness in community assembly and divergent responses to climate changes.
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Affiliation(s)
- Guolan Liu
- Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Shandong University of Aeronautics, Binzhou, Shandong, China
| | - Peili Fu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Jinghong, Yunnan, China
- Ailaoshan Station of Subtropical Forest Ecosystem Studies, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Jingdong, Yunnan, China
| | - Qinggong Mao
- Key Laboratory of Vegetatcion Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Jiangbao Xia
- Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Shandong University of Aeronautics, Binzhou, Shandong, China
| | - Wanli Zhao
- Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Shandong University of Aeronautics, Binzhou, Shandong, China
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7
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Wall S, Lemonnier P, Milliken AL, Davey P, Lawson T. Simultaneous and Independent Abaxial and Adaxial Gas Exchange Measurements. Methods Mol Biol 2024; 2790:63-76. [PMID: 38649566 DOI: 10.1007/978-1-0716-3790-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Stomata can be distributed exclusively on the abaxial or adaxial leaf surface, but they are most commonly found on both leaf surfaces. Variations in stomatal arrangement, patterning, and the impact on photosynthesis can be measured using an infrared gas exchange system. However, when using standard gas exchange techniques, both surfaces are measured together and averaged to provide leaf-level values. Employing an innovative gas exchange apparatus with two infrared gas analyzers, separate gaseous flux from both leaf surfaces can be quantified simultaneously and independently. Here, we provide examples of typical measurements that can be performed using a "split chamber" gas exchange system.
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Affiliation(s)
- Shellie Wall
- School of Life Sciences, University of Essex, Colchester, UK
| | | | | | - Phillip Davey
- School of Life Sciences, University of Essex, Colchester, UK
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK.
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8
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Naz N, Asghar A, Basharat S, Fatima S, Hameed M, Ahmad MSA, Ahmad F, Shah SMR, Ashraf M. Phytoremediation through microstructural and functional alterations in alkali weed ( Cressa cretica L.) in the hyperarid saline desert. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2023; 26:913-927. [PMID: 37985450 DOI: 10.1080/15226514.2023.2282044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Salt excretory halophytes are the major sources of phytoremediation of salt-affected soils. Cressa cretica is a widely distributed halophyte in hypersaline lands in the Cholistan Desert. Therefore, identification of key physio-anatomical traits related to phytoremediation in differently adapted C. cretica populations was focused on. Four naturally adapted ecotypes of non-succulent halophyte Cressa cretica L. form hyper-arid and saline desert Cholistan. The selected ecotypes were: Derawar Fort (DWF, ECe 20.8 dS m-1) from least saline site, Traway Wala Toba (TWT, ECe 33.2 dS m-1) and Bailah Wala Dahar (BWD, ECe 45.4 dS m-1) ecotypes were from moderately saline sites, and Pati Sir (PAS, ECe 52.4 dS m-1) was collected from the highly saline site. The natural population of this species was collected and carefully brought to the laboratory for different structural and functional traits. As a result of high salinity, Na+, Cl-, K+, and Ca2+ content significantly increased at root and shoot level. At root level, some distinctive modifications such as increased sclerification in vascular bundles, enlarged vascular bundles, metaxylem vessels, phloem region, and storage parenchyma (cortex) are pivotal for water storage under extreme arid and osmotic condition. At the stem level, enhanced sclerification in outer cortex and vascular bundles, stem cellular area, cortical proportion, metaxylem and phloem area, and at the leaf level, very prominent structural adaptations were thicker and smaller leaves with increased density of salt glands and trichomes at surface, few and large stomata, reduced cortical and mesophyll parenchyma, and narrow xylem vessels and phloem area represent their non-succulent nature. The ecotype collected from hypersaline environments was better adapted regarding growth traits, ion uptake and excretion, succulence, and phytoremediation traits. More importantly, structural and functional traits such as root length and biomass, accumulation of toxic ions along with K+ in root and shoot, accumulation of Ca2+ in shoot and Mg2+ in root, excretion of toxic ions were the highest in this ecotype. In conclusion, all these alterations strongly favor water conservation, which certainly contributes to ecotypes survival under salt-induced physiological drought.
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Affiliation(s)
- Nargis Naz
- Department of Botany, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Ansa Asghar
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sana Basharat
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sana Fatima
- Department of Botany, The Government Sadiq College University, Bahawalpur, Pakistan
| | - Mansoor Hameed
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | | | - Farooq Ahmad
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Syed Mohsan Raza Shah
- Department of Botany, Division of Science and Technology, University of Education, Lahore, Pakistan
| | - Muhammad Ashraf
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
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Smith DD, Adams MA, Salvi AM, Krieg CP, Ané C, McCulloh KA, Givnish TJ. Ecophysiological adaptations shape distributions of closely related trees along a climatic moisture gradient. Nat Commun 2023; 14:7173. [PMID: 37935674 PMCID: PMC10630429 DOI: 10.1038/s41467-023-42352-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 10/09/2023] [Indexed: 11/09/2023] Open
Abstract
Tradeoffs between the energetic benefits and costs of traits can shape species and trait distributions along environmental gradients. Here we test predictions based on such tradeoffs using survival, growth, and 50 photosynthetic, hydraulic, and allocational traits of ten Eucalyptus species grown in four common gardens along an 8-fold gradient in precipitation/pan evaporation (P/Ep) in Victoria, Australia. Phylogenetically structured tests show that most trait-environment relationships accord qualitatively with theory. Most traits appear adaptive across species within gardens (indicating fixed genetic differences) and within species across gardens (indicating plasticity). However, species from moister climates have lower stomatal conductance than others grown under the same conditions. Responses in stomatal conductance and five related traits appear to reflect greater mesophyll photosynthetic sensitivity of mesic species to lower leaf water potential. Our data support adaptive cross-over, with realized height growth of most species exceeding that of others in climates they dominate. Our findings show that pervasive physiological, hydraulic, and allocational adaptations shape the distributions of dominant Eucalyptus species along a subcontinental climatic moisture gradient, driven by rapid divergence in species P/Ep and associated adaptations.
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Affiliation(s)
- Duncan D Smith
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Faculty of Science, Engineering, & Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, VIC, 3363, Australia.
| | - Mark A Adams
- Faculty of Science, Engineering, & Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Amanda M Salvi
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Christopher P Krieg
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Cécile Ané
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | | | - Thomas J Givnish
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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10
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Tran KN, Pantha P, Wang G, Kumar N, Wijesinghege C, Oh DH, Wimalagunasekara S, Duppen N, Li H, Hong H, Johnson JC, Kelt R, Matherne MG, Nguyen TT, Garcia JR, Clement A, Tran D, Crain C, Adhikari P, Zhang Y, Foroozani M, Sessa G, Larkin JC, Smith AP, Longstreth D, Finnegan P, Testerink C, Barak S, Dassanayake M. Balancing growth amidst salt stress - lifestyle perspectives from the extremophyte model Schrenkiella parvula. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:921-941. [PMID: 37609706 DOI: 10.1111/tpj.16396] [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: 03/25/2022] [Accepted: 07/08/2023] [Indexed: 08/24/2023]
Abstract
Schrenkiella parvula, a leading extremophyte model in Brassicaceae, can grow and complete its lifecycle under multiple environmental stresses, including high salinity. Yet, the key physiological and structural traits underlying its stress-adapted lifestyle are unknown along with trade-offs when surviving salt stress at the expense of growth and reproduction. We aimed to identify the influential adaptive trait responses that lead to stress-resilient and uncompromised growth across developmental stages when treated with salt at levels known to inhibit growth in Arabidopsis and most crops. Its resilient growth was promoted by traits that synergistically allowed primary root growth in seedlings, the expansion of xylem vessels across the root-shoot continuum, and a high capacity to maintain tissue water levels by developing thicker succulent leaves while enabling photosynthesis during salt stress. A successful transition from vegetative to reproductive phase was initiated by salt-induced early flowering, resulting in viable seeds. Self-fertilization in salt-induced early flowering was dependent upon filament elongation in flowers otherwise aborted in the absence of salt during comparable plant ages. The maintenance of leaf water status promoting growth, and early flowering to ensure reproductive success in a changing environment, were among the most influential traits that contributed to the extremophytic lifestyle of S. parvula.
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Affiliation(s)
- Kieu-Nga Tran
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Pramod Pantha
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Guannan Wang
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Narender Kumar
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Chathura Wijesinghege
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Dong-Ha Oh
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Samadhi Wimalagunasekara
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Nick Duppen
- Albert Katz International School for Desert Studies, Ben-Gurion University of the Negev, Sde Boqer Campus, Beersheba, 8499000, Israel
| | - Hongfei Li
- Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB, Wageningen, The Netherlands
| | - Hyewon Hong
- Department of Plant Biology, University of Illinois, Urbana-Champaign, Illinois, 61801, USA
| | - John C Johnson
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Ross Kelt
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Megan G Matherne
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Thu T Nguyen
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Jason R Garcia
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Ashley Clement
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - David Tran
- Department of Biochemistry & Department of Psychology, University of Miami, Coral Gables, Florida, 33146, USA
| | - Colt Crain
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
- Louisiana School for Math, Science and the Arts, Natchitoches, Louisiana, 71457, USA
| | - Prava Adhikari
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Yanxia Zhang
- Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB, Wageningen, The Netherlands
| | - Maryam Foroozani
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Guido Sessa
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - John C Larkin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Aaron P Smith
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - David Longstreth
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Patrick Finnegan
- School of Biological Sciences, University of Western Australia, Perth, 6009, Australia
| | - Christa Testerink
- Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB, Wageningen, The Netherlands
| | - Simon Barak
- French Associates' Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boqer Campus, Beersheba, 8499000, Israel
| | - Maheshi Dassanayake
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
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11
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Iqbal U, Rehman FU, Aslam MU, Gul MF, Farooq U, Ameer A, Asghar N, Mehmood A, Ahmad KS. Survival tactics of an endangered species Withania coagulans (Stocks) Dunal to arid environments. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1363. [PMID: 37874418 DOI: 10.1007/s10661-023-11982-4] [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: 06/29/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023]
Abstract
Withania coagulans is a valuable medicinal plant with high demand, but its wild growth and local usage pose a threat to its natural habitat. This study aims to understand the plant's growth, anatomy, and physiology in different environmental conditions to aid in conservation and re-vegetation efforts. Fifteen differently adapted populations of Withania coagulans were collected from diverse ecological regions, viz., (i) along the roadside, (ii) hilly areas, (iii) barren land, and (iv) wasteland to unravel the adaptive mechanisms that are responsible for their ecological success across heterogenic environments of Punjab, Pakistan. The roadside populations had high values of photosynthetic pigments, total soluble proteins, root endodermis thickness, stem and leaf cortical thickness, and its cell area. The populations growing in hilly areas showed better growth performance such as vigorous growth and biomass production. Additionally, there was enhanced accumulation of organic osmolytes (glycine betaine and proline), chlorophyll content (chl a/b), and enlarged epidermal cells, cortical cells, vascular bundles, metaxylem vessels, and phloem region in roots. In case of stem area, epidermal thickness, cortical thickness, vascular bundle, and pith area showed improved growth. However, the barren land population showed significant increase in carotenoid contents, vascular bundle area, and metaxylem area in roots, and xylem vessels and phloem area in stems and leaves. The wasteland population surpassed the rest of the populations in having greater root dry weight, higher shoot ionic contents, increased root area, thick cortical, and vascular bundle area in roots. Likewise, cortical thickness and its cell area, and pith area in stems, whereas large vascular bundles, phloem region, and high stomatal density were recorded in leaves. Subsequently, natural populations showed the utmost behavior related to tissue organization and physiology in response to varied environmental conditions that would increase the distribution and survival of species.
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Affiliation(s)
- Ummar Iqbal
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Punjab, 64200, Pakistan
| | - Fahad Ur Rehman
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Punjab, 64200, Pakistan
| | - Muhammad Usama Aslam
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Punjab, 64200, Pakistan
| | - Muhammad Faisal Gul
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Punjab, 64200, Pakistan
| | - Umar Farooq
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Punjab, 64200, Pakistan
| | - Amina Ameer
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38040, Pakistan
| | - Naila Asghar
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38040, Pakistan
| | - Ansar Mehmood
- Department of Botany, University of Poonch Rawalakot, Rawalakot, 12350, AJK, Pakistan
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12
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Driesen E, De Proft M, Saeys W. Drought stress triggers alterations of adaxial and abaxial stomatal development in basil leaves increasing water-use efficiency. HORTICULTURE RESEARCH 2023; 10:uhad075. [PMID: 37303614 PMCID: PMC10251137 DOI: 10.1093/hr/uhad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 04/10/2023] [Indexed: 06/13/2023]
Abstract
The physiological control of stomatal opening by which plants adjust for water availability has been extensively researched. However, the impact of water availability on stomatal development has not received as much attention, especially for amphistomatic plants. Therefore, the acclimation of stomatal development in basil (Ocimum basilicum L.) leaves was investigated. Our results show that leaves developed under water-deficit conditions possess higher stomatal densities and decreased stomatal length for both the adaxial and abaxial leaf sides. Although the stomatal developmental reaction to water deficit was similar for the two leaf surfaces, it was proven that adaxial stomata are more sensitive to water stress than abaxial stomata, with more closed adaxial stomata under water-deficit conditions. Furthermore, plants with leaves containing smaller stomata at higher densities possessed a higher water use efficiency. Our findings highlight the importance of stomatal development as a tool for long-term acclimation to limit water loss, with minimal reduction in biomass production. This highlights the central role that stomata play in both the short (opening) and long-term (development) reaction of plants to water availability, making them key tools for efficient resource use and anticipation of future environmental changes.
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Affiliation(s)
| | - Maurice De Proft
- Department of Biosystems, KU Leuven, Willem De Croylaan 42, 3001 Leuven, Belgium
| | - Wouter Saeys
- Department of Biosystems, KU Leuven, Willem De Croylaan 42, 3001 Leuven, Belgium
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13
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Abstract
When microscopy meets modelling the exciting concept of a 'virtual leaf' is born. The goal of a 'virtual leaf' is to capture complex physiology in a virtual environment, resulting in the capacity to run experiments computationally. One example of a 'virtual leaf' application is capturing 3D anatomy from volume microscopy data and estimating where water evaporates in the leaf and the proportions of apoplastic, symplastic and gas phase water transport. The same 3D anatomy could then be used to improve established 3D reaction-diffusion models, providing a better understanding of the transport of CO2 across the stomata, through the airspace and across the mesophyll cell wall. This viewpoint discusses recent progress that has been made in transitioning from a bulk leaf approach to a 3D understanding of leaf physiology, in particular, the movement of CO2 and H2O within the leaf.
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14
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Martinez P, Serpe M, Barron R, Buerki S. Acclimation and hardening of a slow-growing woody species emblematic to western North America from in vitro plantlets. APPLICATIONS IN PLANT SCIENCES 2023; 11:e11515. [PMID: 37051580 PMCID: PMC10083460 DOI: 10.1002/aps3.11515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 06/19/2023]
Abstract
PREMISE Determining the tolerance of plant populations to climate change requires the development of biotechnological protocols producing genetically identical individuals used for genotype-by-environment experiments. Such protocols are missing for slow-growth, woody plants; to address this gap, this study uses Artemisia tridentata, a western North American keystone shrub, as model. METHODS AND RESULTS The production of individual lines is a two-step process: in vitro propagation under aseptic conditions followed by ex vitro acclimation and hardening. Due to aseptic growth conditions, in vitro plantlets exhibit maladapted phenotypes, and this protocol focuses on presenting an approach promoting morphogenesis for slow-growth, woody species. Survival was used as the main criterion determining successful acclimation and hardening. Phenotypic changes were confirmed by inspecting leaf anatomy, and shoot water potential was used to ensure that plantlets were not water stressed. CONCLUSIONS Although our protocol has lower survival rates (11-41%) compared to protocols developed for herbaceous, fast-growing species, it provides a benchmark for slow-growth, woody species occurring in dry ecosystems.
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Affiliation(s)
- Peggy Martinez
- Department of Biological SciencesBoise State UniversityBoiseIdahoUSA
| | - Marcelo Serpe
- Department of Biological SciencesBoise State UniversityBoiseIdahoUSA
| | | | - Sven Buerki
- Department of Biological SciencesBoise State UniversityBoiseIdahoUSA
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15
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Mano NA, Madore B, Mickelbart MV. Different Leaf Anatomical Responses to Water Deficit in Maize and Soybean. Life (Basel) 2023; 13:life13020290. [PMID: 36836647 PMCID: PMC9966819 DOI: 10.3390/life13020290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
The stomata on leaf surfaces control gas exchange and water loss, closing during dry periods to conserve water. The distribution and size of stomatal complexes is determined by epidermal cell differentiation and expansion during leaf growth. Regulation of these processes in response to water deficit may result in stomatal anatomical plasticity as part of the plant acclimation to drought. We quantified the leaf anatomical plasticity under water-deficit conditions in maize and soybean over two experiments. Both species produced smaller leaves in response to the water deficit, partly due to the reductions in the stomata and pavement cell size, although this response was greater in soybean, which also produced thicker leaves under severe stress, whereas the maize leaf thickness did not change. The stomata and pavement cells were smaller with the reduced water availability in both species, resulting in higher stomatal densities. Stomatal development (measured as stomatal index, SI) was suppressed in both species at the lowest water availability, but to a greater extent in maize than in soybean. The result of these responses is that in maize leaves, the stomatal area fraction (fgc) was consistently reduced in the plants grown under severe but not moderate water deficit, whereas the fgc did not decrease in the water-stressed soybean leaves. The water deficit resulted in the reduced expression of one of two (maize) or three (soybean) SPEECHLESS orthologs, and the expression patterns were correlated with SI. The vein density (VD) increased in both species in response to the water deficit, although the effect was greater in soybean. This study establishes a mechanism of stomatal development plasticity that can be applied to other species and genotypes to develop or investigate stomatal development plasticity.
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Affiliation(s)
- Noel Anthony Mano
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Bethany Madore
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Michael V. Mickelbart
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
- Correspondence:
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16
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Wang T, Zheng L, Xiong D, Wang F, Man J, Deng N, Cui K, Huang J, Peng S, Ling X. Stomatal Ratio Showing No Response to Light Intensity in Oryza. PLANTS (BASEL, SWITZERLAND) 2022; 12:66. [PMID: 36616195 PMCID: PMC9823486 DOI: 10.3390/plants12010066] [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: 11/16/2022] [Revised: 12/09/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Stomata control carbon and water exchange between the leaves and the ambient. However, the plasticity responses of stomatal traits to growth conditions are still unclear, especially for monocot leaves. The current study investigated the leaf anatomical traits, stomatal morphological traits on both adaxial and abaxial leaf surfaces, and photosynthetic traits of Oryza leaves developed in two different growth conditions. Substantial variation exists across the Oryza species in leaf anatomy, stomatal traits, photosynthetic rate, and stomatal conductance. The abaxial stomatal density was higher than the adaxial stomatal density in all the species, and the stomatal ratios ranged from 0.35 to 0.46 across species in two growth environments. However, no difference in the stomatal ratio was observed between plants in the growth chamber and outdoors for a given species. Photosynthetic capacity, stomatal conductance, leaf width, major vein thickness, minor vein thickness, inter-vein distance, and stomatal pore width values for leaves grown outdoors were higher than those for plants grown in the growth chamber. Our results indicate that a broad set of leaf anatomical, stomatal, and photosynthetic traits of Oryza tend to shift together during plasticity to diverse growing conditions, but the previously projected sensitive trait, stomatal ratio, does not shape growth conditions.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Xiaoxia Ling
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
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17
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Costa e Silva J, Potts BM, Wiehl G, Prober SM. Linking leaf economic and hydraulic traits with early-age growth performance and survival of Eucalyptus pauciflora. FRONTIERS IN PLANT SCIENCE 2022; 13:973087. [PMID: 36426150 PMCID: PMC9679299 DOI: 10.3389/fpls.2022.973087] [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: 06/19/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Selection on plant functional traits may occur through their direct effects on fitness (or a fitness component), or may be mediated by attributes of plant performance which have a direct impact on fitness. Understanding this link is particularly challenging for long-lived organisms, such as forest trees, where lifetime fitness assessments are rarely achievable, and performance features and fitness components are usually quantified from early-life history stages. Accordingly, we studied a cohort of trees from multiple populations of Eucalyptus pauciflora grown in a common-garden field trial established at the hot and dry end of the species distribution on the island of Tasmania, Australia. We related the within-population variation in leaf economic (leaf thickness, leaf area and leaf density) and hydraulic (stomatal density, stomatal length and vein density) traits, measured from two-year-old plants, to two-year growth performance (height and stem diameter) and to a fitness component (seven-year survival). When performance-trait relationships were modelled for all traits simultaneously, statistical support for direct effects on growth performance was only observed for leaf thickness and leaf density. Performance-based estimators of directional selection indicated that individuals with reduced leaf thickness and increased leaf density were favoured. Survival-performance relationships were consistent with size-dependent mortality, with fitness-based selection gradients estimated for performance measures providing evidence for directional selection favouring individuals with faster growth. There was no statistical support for an effect associated with the fitness-based quadratic selection gradient estimated for growth performance. Conditional on a performance measure, fitness-based directional selection gradients estimated for the leaf traits did not provide statistical support for direct effects of the focal traits on tree survival. This suggested that, under the environmental conditions of the trial site and time period covered in the current study, early-stage selection on the studied leaf traits may be mediated by their effects on growth performance, which in turn has a positive direct influence on later-age survival. We discuss the potential mechanistic basis of the direct effects of the focal leaf traits on tree growth, and the relevance of a putative causal pathway of trait effects on fitness through mediation by growth performance in the studied hot and dry environment.
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Affiliation(s)
- João Costa e Silva
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal
| | - Brad M. Potts
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
- Australian Research Council (ARC) Training Centre for Forest Value, University of Tasmania, Hobart, TAS, Australia
| | - Georg Wiehl
- CSIRO Land and Water, Private Bag 5, Wembley, WA, Australia
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18
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Wall S, Vialet‐Chabrand S, Davey P, Van Rie J, Galle A, Cockram J, Lawson T. Stomata on the abaxial and adaxial leaf surfaces contribute differently to leaf gas exchange and photosynthesis in wheat. THE NEW PHYTOLOGIST 2022; 235:1743-1756. [PMID: 35586964 PMCID: PMC9545378 DOI: 10.1111/nph.18257] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/06/2022] [Indexed: 05/12/2023]
Abstract
Although stomata are typically found in greater numbers on the abaxial surface, wheat flag leaves have greater densities on the adaxial surface. We determine the impact of this less common stomatal patterning on gaseous fluxes using a novel chamber that simultaneously measures both leaf surfaces. Using a combination of differential illuminations and CO2 concentrations at each leaf surface, we found that mesophyll cells associated with the adaxial leaf surface have a higher photosynthetic capacity than those associated with the abaxial leaf surface, which is supported by an increased stomatal conductance (driven by differences in stomatal density). When vertical gas flux at the abaxial leaf surface was blocked, no compensation by adaxial stomata was observed, suggesting each surface operates independently. Similar stomatal kinetics suggested some co-ordination between the two surfaces, but factors other than light intensity played a role in these responses. Higher photosynthetic capacity on the adaxial surface facilitates greater carbon assimilation, along with higher adaxial stomatal conductance, which would also support greater evaporative leaf cooling to maintain optimal leaf temperatures for photosynthesis. Furthermore, abaxial gas exchange contributed c. 50% to leaf photosynthesis and therefore represents an important contributor to overall leaf gas exchange.
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Affiliation(s)
- Shellie Wall
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
| | | | - Phillip Davey
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
| | - Jeroen Van Rie
- BASF BBCC – Innovation Center GentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | - Alexander Galle
- BASF BBCC – Innovation Center GentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | | | - Tracy Lawson
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
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19
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Drake PL, Callow NJ, Leopold M, Pires RN, Veneklaas EJ. Thermal imagery of woodland tree canopies provides new insights into drought-induced tree mortality. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155395. [PMID: 35452727 DOI: 10.1016/j.scitotenv.2022.155395] [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: 01/05/2022] [Revised: 04/07/2022] [Accepted: 04/15/2022] [Indexed: 06/14/2023]
Abstract
Our understanding of how water dynamics determines the probability of tree mortality during drought is incomplete. Here we help address this shortcoming by coupling approaches from the disciplines of ecophysiology, geophysics and remote sensing in a woodland ecosystem undergoing protracted drying. Water uptake and use strategies varied between the dominant canopy species of the ecosystem. At one extreme were species that tightly regulate their water status, which is broadly consistent with the definition of isohydry. The higher leaf temperatures revealed by thermal imagery of these isohydric species are likely a reflection of reduced latent cooling owing to a stringent control of transpiration rate. Where silty sediments occur in the root zone, this strategy may have the effect of limiting the water sources available to these species during prolonged drought because of an insufficient hydraulic gradient for water uptake. In contrast were species that allowed their water status to fluctuate, operating in a fashion more consistent with anisohydry. For these species, latent cooling owing to relatively high transpiration rates maintained leaf temperatures near, or below, the ambient air temperature. The resulting drawdown in leaf water potential between soil and leaves in these anisohydric species may generate a sufficient hydraulic gradient to enable water uptake from silty soil during seasonal or prolonged droughts. In this way the spatial distribution of fine textured soil could indicate areas where the isohydric hydraulic control strategy is disadvantageous during prolonged droughts or where annual soil water recharge has fallen below a critical threshold.
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Affiliation(s)
- Paul L Drake
- School of Biological Sciences, The University of Western Australia, Crawley, Australia; Earth Observation Group, Astron Environmental Services, East Perth, Australia.
| | - Nikolaus J Callow
- School of Agriculture and Environment, The University of Western Australia, Crawley, Australia
| | - Matthias Leopold
- School of Agriculture and Environment, The University of Western Australia, Crawley, Australia
| | - Rodrigo N Pires
- School of Biological Sciences, The University of Western Australia, Crawley, Australia
| | - Erik J Veneklaas
- School of Biological Sciences, The University of Western Australia, Crawley, Australia; School of Agriculture and Environment, The University of Western Australia, Crawley, Australia; Institute of Agriculture, The University of Western Australia, Crawley, Australia
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20
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Wu G, Chen D, Zhou Z, Ye Q, Wu J. Canopy nitrogen addition enhance the photosynthetic rate of canopy species by improving leaf hydraulic conductivity in a subtropical forest. FRONTIERS IN PLANT SCIENCE 2022; 13:942851. [PMID: 35991414 PMCID: PMC9389171 DOI: 10.3389/fpls.2022.942851] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Elucidating the effects of atmospheric nitrogen (N) deposition on the photosynthetic capacity of plants is critical to understand forest growth and conservation under global change. However, studies on this topic generally consider only understory N addition, which ignores the effect of canopy interception. In this study, we conducted a field experiment in a subtropical forest to compare the effects of canopy vs. understory N addition on the photosynthetic rate of canopy and understory species. We found that canopy N addition enhanced the photosynthetic rate of canopy species by increasing leaf hydraulic conductivity and shortening the distance of CO2 transportation. In contrast, understory N addition had non-significant effects on the photosynthetic rate of canopy species. Moreover, the photosynthetic rate of understory species was not affected by canopy or understory N addition. Interestingly, changes in hydraulic conductivity contributed more to accelerating the photosynthetic rate than changes in CO2 transport distance. Our results provide important insights into the dissimilar effects of canopy and understory N addition on the photosynthetic rates of species in subtropical forests. Based on our findings, we highlighted the urgent need to consider canopy processes in future studies on N deposition.
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Affiliation(s)
- Guilin Wu
- Hainan Jianfengling Forest Ecosystem National Field Science Observation and Research Station, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Dexiang Chen
- Hainan Jianfengling Forest Ecosystem National Field Science Observation and Research Station, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Zhang Zhou
- Hainan Jianfengling Forest Ecosystem National Field Science Observation and Research Station, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Jianhui Wu
- Hainan Jianfengling Forest Ecosystem National Field Science Observation and Research Station, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
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21
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Balachandar M, Koshila Ravi R, Muthukumar T. Vegetative anatomy and endorrhizal fungal morphology of an endangered medicinal plant Gloriosa superba L. Microsc Res Tech 2022; 85:3296-3308. [PMID: 35751598 DOI: 10.1002/jemt.24183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/14/2022] [Accepted: 06/06/2022] [Indexed: 11/10/2022]
Abstract
Gloriosa superba L. is of great economic importance due to its high medicinal value. Nevertheless, there is a need to reexamine species delimitation in the Gloriosa taxa as most of the species have been synonymised as G. superba. Therefore, the present study was undertaken to investigate the vegetative anatomical traits of G. superba. The leaf, scale leaf, tendril, stem, tuber, and roots of G. superba were freehand sectioned and stained with various staining solutions to record the anatomical structures. The cellular dimensions of each plant part were measured. The present study revealed the presence of intercostal and costal regions in the leaf epidermis, anomocytic stomata on abaxial surface, uniseriate epidermis covered by cuticle, undifferentiated mesophyll, and a bundle sheath surrounding vascular bundles in a leaf. Unlike the leaf, the scale leaf contains air chambers in the mesophyll region and bundle sheath is absent. The tendril had uniseriate cuticularized epidermis followed by few layers of cells developing wall thickenings, and collateral vascular bundles. The mature stem is differentiated from the young stem by the presence of bi-layered epidermis, the absence of stomata on the stem surface, and chlorenchymatous hypodermis. Air passage containing epidermis covered by thin cuticle is recorded in the stem. Starch grains are present in the tuber ground tissue. Velamen is reported for the first time in G. superba root. Scalariform perforation end plate present in root metaxylem. Roots of G. superba are colonized by arbuscular mycorrhizal and dark septate endophytic fungi. Therefore, these anatomical traits could aid in the identification of G. superba.
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Affiliation(s)
- Mayakrishnan Balachandar
- Root and Soil Biology Laboratory, Department of Botany, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Ravichandran Koshila Ravi
- Root and Soil Biology Laboratory, Department of Botany, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Thangavelu Muthukumar
- Root and Soil Biology Laboratory, Department of Botany, Bharathiar University, Coimbatore, Tamil Nadu, India
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22
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Cabrita P. Non-invasive assessment of the physiological role of leaf aerenchyma in Hippeastrum Herb. and its relation to plant water status. PLANTA 2022; 256:19. [PMID: 35750944 PMCID: PMC9232429 DOI: 10.1007/s00425-022-03930-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
The leaf patch clamp pressure probe combined with gas exchange measurements provides a non-invasive approach for measuring leaf aerenchyma pressure and study its physiological role in plants. The non-invasive leaf patch clamp pressure probe (LPCP) measures the output pressure, Pp, in response to the pressure applied by two magnets clamped to a leaf. In many plant species, it has been observed that the diel pattern of Pp follows the changes in the leaf turgor pressure reversely. The genus Hippeastrum comprises 143 species and many hybrids and cultivars of high economic value within Amaryllidaceae. Their leaves are characterized by the presence of aerenchyma composed of lacunae, running throughout the leaf and composing most of the mesophyll volume. In Hippeastrum, the diel changes of the LPCP output pressure are the reverse of that observed on the air pressure in the leaf aerenchyma, Pa, which depends on the changes in the leaf vapor pressure occurring during photosynthesis. A theoretical model is proposed and confirmed experimentally by LPCP and gas exchange measurements. The output pressure, Pp, in Hippeastrum can be related to the plant water status through the gas exchange processes that occur during photosynthesis. Considering the natural habitats of Hippeastrum species, these results agree with the physiological role of leaf aerenchyma in facilitating gas transport and light scattering in leaves, thus contributing to the photosynthetic efficiency of these plants under adverse environments. A second, but supplemental, interpretation of the LPCP output pressure, Pp, when applied on species in which the aerenchyma constitutes most of the mesophyll volume is presented.
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Affiliation(s)
- Paulo Cabrita
- IAPN-Institute of Applied Plant Nutrition, Georg-August-University Göttingen, Carl-Sprengel-Weg 1, 37075, Göttingen, Germany.
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23
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Wilson ML, VanBuren R. Leveraging millets for developing climate resilient agriculture. Curr Opin Biotechnol 2022; 75:102683. [DOI: 10.1016/j.copbio.2022.102683] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 12/16/2021] [Accepted: 01/03/2022] [Indexed: 01/31/2023]
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Grünhofer P, Herzig L, Sent S, Zeisler-Diehl VV, Schreiber L. Increased cuticular wax deposition does not change residual foliar transpiration. PLANT, CELL & ENVIRONMENT 2022; 45:1157-1171. [PMID: 35102563 DOI: 10.1111/pce.14274] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/19/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
The effect of contrasting environmental growth conditions (in vitro tissue culture, ex vitro acclimatisation, climate chamber, greenhouse and outdoor) on leaf development, cuticular wax composition, and foliar transpiration of detached leaves of the Populus × canescens clone 84 K were investigated. Our results show that total amounts of cuticular wax increased more than 10-fold when cultivated in different growth conditions, whereas qualitative wax composition did not change. With exception of plants directly taken from tissue culture showing rapid dehydration, rates of water loss (residual foliar transpiration) of intact but detached leaves were constant and independent from growth conditions and thus independent from increasing wax amounts. Since cuticular transpiration measured with isolated astomatous P. × canescens cuticles was identical to residual foliar transpiration rates of detached leaves, our results confirm that cuticular transpiration of P. × canescens leaves can be predicted with high accuracy from residual transpiration of detached leaves after stomatal closure. Our results convincingly show that more than 10-fold increased wax amounts in P. × canescens cuticles do not lead to decreased rates of residual (cuticular) transpiration.
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Affiliation(s)
- Paul Grünhofer
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
| | - Lena Herzig
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
| | - Sophie Sent
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
| | - Viktoria V Zeisler-Diehl
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
| | - Lukas Schreiber
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
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Li S, Hamani AKM, Zhang Y, Liang Y, Gao Y, Duan A. Coordination of leaf hydraulic, anatomical, and economical traits in tomato seedlings acclimation to long-term drought. BMC PLANT BIOLOGY 2021; 21:536. [PMID: 34781896 PMCID: PMC8591842 DOI: 10.1186/s12870-021-03304-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Leaf hydraulic and economics traits are critical for balancing plant water and CO2 exchange, and their relationship has been widely studied. Leaf anatomical traits determine the efficiency of CO2 diffusion within mesophyll structure. However, it remains unclear whether leaf anatomical traits are associated with leaf hydraulic and economics traits acclimation to long-term drought. RESULTS To address this knowledge gap, eight hydraulic traits, including stomatal and venation structures, four economics traits, including leaf dry mass per area (LMA) and the ratio between palisade and spongy mesophyll thickness (PT/ST), and four anatomical traits related to CO2 diffusion were measured in tomato seedlings under the long-term drought conditions. Redundancy analysis indicated that the long-term drought decreased stomatal conductance (gs) mainly due to a synchronized reduction in hydraulic structure such as leaf hydraulic conductance (Kleaf) and major vein width. Simultaneously, stomatal aperture on the adaxial surface and minor vein density (VDminor) also contributed a lot to this reduction. The decreases in mesophyll thickness (Tmes) and chlorophyll surface area exposed to leaf intercellular air spaces (Sc/S) were primarily responsible for the decline of mesophyll conductance (gm) thereby affecting photosynthesis. Drought increased leaf density (LD) thus limited CO2 diffusion. In addition, LMA may not be important in regulating gm in tomato under drought. Principal component analysis revealed that main anatomical traits such as Tmes and Sc/S were positively correlated to Kleaf, VDminor and leaf thickness (LT), while negatively associated with PT/ST. CONCLUSIONS These findings indicated that leaf anatomy plays an important role in maintaining the balance between water supply and CO2 diffusion responses to drought. There was a strong coordination between leaf hydraulic, anatomical, and economical traits in tomato seedlings acclimation to long-term drought.
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Affiliation(s)
- Shuang Li
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Abdoul Kader Mounkaila Hamani
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yingying Zhang
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China
| | - Yueping Liang
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China
| | - Yang Gao
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China.
| | - Aiwang Duan
- Farmland Irrigation Research Institute, Key Laboratory of Crop Water Use and Regulation, Chinese Academy of Agriculture Sciences, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, 453002, China.
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26
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Zhang D, Du Q, Sun P, Lou J, Li X, Li Q, Wei M. Physiological and Transcriptomic Analyses Revealed the Implications of Abscisic Acid in Mediating the Rate-Limiting Step for Photosynthetic Carbon Dioxide Utilisation in Response to Vapour Pressure Deficit in Solanum Lycopersicum (Tomato). FRONTIERS IN PLANT SCIENCE 2021; 12:745110. [PMID: 34858453 PMCID: PMC8631768 DOI: 10.3389/fpls.2021.745110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
The atmospheric vapour pressure deficit (VPD) has been demonstrated to be a significant environmental factor inducing plant water stress and affecting plant photosynthetic productivity. Despite this, the rate-limiting step for photosynthesis under varying VPD is still unclear. In the present study, tomato plants were cultivated under two contrasting VPD levels: high VPD (3-5 kPa) and low VPD (0.5-1.5 kPa). The effect of long-term acclimation on the short-term rapid VPD response was examined across VPD ranging from 0.5 to 4.5 kPa. Quantitative photosynthetic limitation analysis across the VPD range was performed by combining gas exchange and chlorophyll fluorescence. The potential role of abscisic acid (ABA) in mediating photosynthetic carbon dioxide (CO2) uptake across a series of VPD was evaluated by physiological and transcriptomic analyses. The rate-limiting step for photosynthetic CO2 utilisation varied with VPD elevation in tomato plants. Under low VPD conditions, stomatal and mesophyll conductance was sufficiently high for CO2 transport. With VPD elevation, plant water stress was gradually pronounced and triggered rapid ABA biosynthesis. The contribution of stomatal and mesophyll limitation to photosynthesis gradually increased with an increase in the VPD. Consequently, the low CO2 availability inside chloroplasts substantially constrained photosynthesis under high VPD conditions. The foliar ABA content was negatively correlated with stomatal and mesophyll conductance for CO2 diffusion. Transcriptomic and physiological analyses revealed that ABA was potentially involved in mediating water transport and photosynthetic CO2 uptake in response to VPD variation. The present study provided new insights into the underlying mechanism of photosynthetic depression under high VPD stress.
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Affiliation(s)
- Dalong Zhang
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
- State Key Laboratory of Crop Biology, Tai'an, China
- Scientific Observing and Experimental Station of Environment Controlled Agricultural Engineering in Huang-Huai-Hai Region, Ministry of Agriculture, Beijing, China
| | - Qingjie Du
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Po Sun
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
| | - Jie Lou
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
| | - Xiaotian Li
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
| | - Qingming Li
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
- State Key Laboratory of Crop Biology, Tai'an, China
- Scientific Observing and Experimental Station of Environment Controlled Agricultural Engineering in Huang-Huai-Hai Region, Ministry of Agriculture, Beijing, China
| | - Min Wei
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, China
- State Key Laboratory of Crop Biology, Tai'an, China
- Scientific Observing and Experimental Station of Environment Controlled Agricultural Engineering in Huang-Huai-Hai Region, Ministry of Agriculture, Beijing, China
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27
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Pardo J, VanBuren R. Evolutionary innovations driving abiotic stress tolerance in C4 grasses and cereals. THE PLANT CELL 2021; 33:3391-3401. [PMID: 34387354 PMCID: PMC8566246 DOI: 10.1093/plcell/koab205] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
Grasslands dominate the terrestrial landscape, and grasses have evolved complex and elegant strategies to overcome abiotic stresses. The C4 grasses are particularly stress tolerant and thrive in tropical and dry temperate ecosystems. Growing evidence suggests that the presence of C4 photosynthesis alone is insufficient to account for drought resilience in grasses, pointing to other adaptations as contributing to tolerance traits. The majority of grasses from the Chloridoideae subfamily are tolerant to drought, salt, and desiccation, making this subfamily a hub of resilience. Here, we discuss the evolutionary innovations that make C4 grasses so resilient, with a particular emphasis on grasses from the Chloridoideae (chloridoid) and Panicoideae (panicoid) subfamilies. We propose that a baseline level of resilience in chloridoid ancestors allowed them to colonize harsh habitats, and these environments drove selective pressure that enabled the repeated evolution of abiotic stress tolerance traits. Furthermore, we suggest that a lack of evolutionary access to stressful environments is partially responsible for the relatively poor stress resilience of major C4 crops compared to their wild relatives. We propose that chloridoid crops and the subfamily more broadly represent an untapped reservoir for improving resilience to drought and other abiotic stresses in cereals.
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Affiliation(s)
- Jeremy Pardo
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Horticulture, Michigan State University, East Lansing, Michigan 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, USA
| | - Robert VanBuren
- Department of Horticulture, Michigan State University, East Lansing, Michigan 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, USA
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28
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Doll Y, Koga H, Tsukaya H. Callitriche as a potential model system for evolutionary studies on the dorsiventral distribution of stomata. PLANT SIGNALING & BEHAVIOR 2021; 16:1978201. [PMID: 34538209 PMCID: PMC8525970 DOI: 10.1080/15592324.2021.1978201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/03/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Controlling the distribution of stomata is crucial for the adaptation of plants to new, or changing environments. While many plant species produce stomata predominantly on the abaxial leaf surface (hypostomy), some produce stomata on both surfaces (amphistomy), and the remaining few produce them only on the adaxial surface (hyperstomy). Various selective pressures have driven the evolution of these three modes of stomatal distribution. Despite recent advances in our understanding of stomatal development and dorsiventral leaf polarity, the genetic basis for the evolution of different stomatal distributions is still unclear. Here, we propose the genus Callitriche as a new model system to investigate patterns in the evolution of stomatal distribution. Callitriche comprises species with diverse lifestyles, including terrestrial, amphibious, and obligately aquatic plants. We found that species in this genus cover all three modes of dorsiventral stomatal distribution, making it a desirable model for comparative and evolutionary analyses on distribution modes. We further characterized the genetic basis of the different distribution modes, focusing on the stomatal key transcription factor SPEECHLESS. Future research using the promising model system Callitriche would open a new direction for evolutionary developmental biology studies on stomata.
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Affiliation(s)
- Yuki Doll
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Koga
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
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29
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Redondo-Bermúdez MDC, Gulenc IT, Cameron RW, Inkson BJ. 'Green barriers' for air pollutant capture: Leaf micromorphology as a mechanism to explain plants capacity to capture particulate matter. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117809. [PMID: 34329063 DOI: 10.1016/j.envpol.2021.117809] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 06/22/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Finding ways to mitigate atmospheric particulate matter (PM) is one of the key steps towards fighting air pollution and protecting people's health. The use of green infrastructure is one option that could help improving urban air quality and promoting more sustainable cities. Detailed knowledge of how plants capture particulate matter can support plant selection for this purpose. Previous studies have primarily focused on 2D techniques to assess the micromorphology of plant leaves. Here, 3D optical profilometry and SEM imaging (2D) are used to quantify leaf roughness and other micromorphological leaf traits of three contrasting plant species (Hedera helix 'Woerner', Thuja occidentalis 'Smaragd', and Phyllostachys nigra) located within a mixed-species green barrier. These techniques have allowed us to identify the relative distribution of adhered atmospheric PM with respect to the surface topography of leaves, with high spatial resolution. Leaf surface roughness did not show a direct relationship with PM deposition; however, the descriptors width, depth and frequency of the grooves are important to explain PM capture by the leaves. Additionally, the presence of wax on leaves was relevant for PM adherence. All species captured PM, with their overall PM capture efficiency ranked from highest to lowest as follows: Thuja occidentalis > Hedera helix > Phyllostachys nigra. All green barrier species contributed to air quality improvement, through PM capture, regardless of their location within the barrier. Having multiple species in a green barrier is beneficial due to the diverse range of leaf micromorphologies present, thus offering different mechanisms for particulate matter capture.
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Affiliation(s)
| | - Idris Tugrul Gulenc
- Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, S1 3JD, Sheffield, UK
| | - Ross W Cameron
- Department of Landscape Architecture, The University of Sheffield, The Arts Tower, S10 2TN, Sheffield, UK
| | - Beverley J Inkson
- Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, S1 3JD, Sheffield, UK
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30
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McAusland L, Smith KE, Williams A, Molero G, Murchie EH. Nocturnal stomatal conductance in wheat is growth-stage specific and shows genotypic variation. THE NEW PHYTOLOGIST 2021; 232:162-175. [PMID: 34143507 DOI: 10.1111/nph.17563] [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: 03/03/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
Nocturnal stomatal conductance (gsn ) represents a significant source of water loss, with implications for metabolism, thermal regulation and water-use efficiency. With increasing nocturnal temperatures due to climate change, it is vital to identify and understand variation in the magnitude and responses of gsn in major crops. We assessed interspecific variation in gsn and daytime stomatal conductance (gs ) in a wild relative and modern spring wheat genotype. To investigate intraspecific variation, we grew six modern wheat genotypes and two landraces under well watered, simulated field conditions. For the diurnal data, higher gsn in the wild relative was associated with significantly lower nocturnal respiration and higher daytime CO2 assimilation while both species exhibited declines in gsn post-dusk and pre-dawn. Lifetime gsn achieved rates of 5.7-18.9% of gs . Magnitude of gsn was genotype specific 'and positively correlated with gs . gsn and gs were significantly higher on the adaxial surface. No relationship was determined between harvest characteristics, stomatal morphology and gsn , while cuticular conductance was genotype specific. Finally, for the majority of genotypes, gsn declined with age. Here we present the discovery that variation in gsn occurs across developmental, morphological and temporal scales in nonstressed wheat, presenting opportunities for exploiting intrinsic variation under heat or water stressed conditions.
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Affiliation(s)
- Lorna McAusland
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Kellie E Smith
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Alexander Williams
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Gemma Molero
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera Mexico, El Batan, Texcoco, CP 56237, Mexico
| | - Erik H Murchie
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
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31
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Coupling Relationship of Leaf Economic and Hydraulic Traits of Alhagisparsifolia Shap. in a Hyper-Arid Desert Ecosystem. PLANTS 2021; 10:plants10091867. [PMID: 34579402 PMCID: PMC8465641 DOI: 10.3390/plants10091867] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/05/2021] [Accepted: 09/06/2021] [Indexed: 12/03/2022]
Abstract
In this study, Alhagisparsifolia Shap. was used to test the hypothesis that leaf economic and hydraulic traits are coupled in plants in a hyper-arid region. Five economic traits and six hydraulic traits were examined to explore the relationship. Results showed that the stomatal density (SD) on both surfaces was coupled with maximum stomatal conductance to water vapor (gwmax) and leaf tissue density (TD). SD on adaxial surface (SDaba) was significantly positively related to vein density (VD) but negatively related to leaf thickness (LT) and stomatal length on adaxial surface (SLada). Nitrogen concentration based on mass (Nmass) was significantly negatively correlated with leaf mass per area (LMA), LT, and VD, whereas nitrogen concentration based on area (Narea) was significantly positively related to LMA and TD. Mean annual precipitation (MAP) contributed the most to the changes in LT and stomatal length (SL). Soil salt contributed the most to TD, SD, and gwmax. Soli nutrients influenced the most of LMA and VD. Mean annual temperature contributed the most to Nmass and Narea. In conclusion, the economics of leaves coupled with their hydraulic traits provides an economical and efficient strategy to adapt to the harsh environment in hyper-arid regions.
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32
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Patel I, Gorim LY, Tanino K, Vandenberg A. Diversity in Surface Microstructures of Trichomes, Epidermal Cells, and Stomata in Lentil Germplasm. FRONTIERS IN PLANT SCIENCE 2021; 12:697692. [PMID: 34322146 PMCID: PMC8311464 DOI: 10.3389/fpls.2021.697692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
To develop crops capable of withstanding challenges posed by climate change, breeding strategies must focus on addressing multiple stresses occurring concurrently in plants. Leaf epidermal structures such as trichomes, stomata, and epidermal cells play an important role in mediating plant defense and could be essential traits that impart wide-ranging tolerance to biotic and abiotic stresses. Consequently, it is important to inform on the underlying diversity in these traits in lentil germplasm (Lens spp.). In this study, we characterized foliar microstructures of 12 genotypes belonging to seven wild and cultivated Lens species. We performed scanning electron microscopy on leaflet and pod surfaces for their qualitative characterization. For quantitative characterization, we observed surface imprints via light microscopy and quantified trichome density (TD), trichome length (TL), stomatal density (SD), epidermal cell density (ECD), and stomatal index (SI) on adaxial and abaxial leaflet surfaces for each genotype. We also assessed the heritability of trichome traits by evaluating interspecific recombinant inbred lines (RILs) derived from the cross Lens culinaris CDC Redberry × Lens tomentosus IG 72805. Comparing foliar microstructures, we found that TD and TL varied widely among cultivated and wild lentil genotypes. However, in most lentil genotypes, the adaxial leaflet surface had lower TD and longer trichomes compared to the abaxial surface. Pubescence on pods comprised five major phenotypes: no trichomes or glabrous pods, very short trichomes at low density, short trichomes at high density, medium-length trichomes at high density, and long trichomes at high density. Leaves of all species were amphistomatous, and SI, SD, and ECD were all higher on the adaxial compared to the abaxial surface. Adaxial surfaces had slightly sunken stomata, which might be an adaptive trait to conserve water. Quantifying TD and TL on the leaflets of interspecific RILs revealed transgressive segregation of these traits, suggesting that TD and TL are quantitative in nature. While taxonomic implications of this study are limited, a detailed description of agronomically relevant morphophysiological traits presented in this paper along with the mode of inheritance of trichomes may serve as a resource for scientists developing lentil adapted to concurrent biotic and abiotic stresses of the future.
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Affiliation(s)
- Ishita Patel
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Linda Yuya Gorim
- Department of Agricultural, Food and Nutritional Science, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, AB, Canada
| | - Karen Tanino
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Albert Vandenberg
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
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33
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Bheemanahalli R, Wang C, Bashir E, Chiluwal A, Pokharel M, Perumal R, Moghimi N, Ostmeyer T, Caragea D, Jagadish SK. Classical phenotyping and deep learning concur on genetic control of stomatal density and area in sorghum. PLANT PHYSIOLOGY 2021; 186:1562-1579. [PMID: 33856488 PMCID: PMC8260133 DOI: 10.1093/plphys/kiab174] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/28/2021] [Indexed: 05/18/2023]
Abstract
Stomatal density (SD) and stomatal complex area (SCA) are important traits that regulate gas exchange and abiotic stress response in plants. Despite sorghum (Sorghum bicolor) adaptation to arid conditions, the genetic potential of stomata-related traits remains unexplored due to challenges in available phenotyping methods. Hence, identifying loci that control stomatal traits is fundamental to designing strategies to breed sorghum with optimized stomatal regulation. We implemented both classical and deep learning methods to characterize genetic diversity in 311 grain sorghum accessions for stomatal traits at two different field environments. Nearly 12,000 images collected from abaxial (Ab) and adaxial (Ad) leaf surfaces revealed substantial variation in stomatal traits. Our study demonstrated significant accuracy between manual and deep learning methods in predicting SD and SCA. In sorghum, SD was 32%-39% greater on the Ab versus the Ad surface, while SCA on the Ab surface was 2%-5% smaller than on the Ad surface. Genome-Wide Association Study identified 71 genetic loci (38 were environment-specific) with significant genotype to phenotype associations for stomatal traits. Putative causal genes underlying the phenotypic variation were identified. Accessions with similar SCA but carrying contrasting haplotypes for SD were tested for stomatal conductance and carbon assimilation under field conditions. Our findings provide a foundation for further studies on the genetic and molecular mechanisms controlling stomata patterning and regulation in sorghum. An integrated physiological, deep learning, and genomic approach allowed us to unravel the genetic control of natural variation in stomata traits in sorghum, which can be applied to other plants.
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Affiliation(s)
- Raju Bheemanahalli
- Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, USA
| | - Chaoxin Wang
- Department of Computer Science, Kansas State University, Manhattan, Kansas 66506, USA
| | - Elfadil Bashir
- Agricultural Research Center, Kansas State University, Hays, Kansas 67601, USA
| | - Anuj Chiluwal
- Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, USA
| | - Meghnath Pokharel
- Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, USA
| | - Ramasamy Perumal
- Agricultural Research Center, Kansas State University, Hays, Kansas 67601, USA
| | - Naghmeh Moghimi
- Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, USA
| | - Troy Ostmeyer
- Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, USA
| | - Doina Caragea
- Department of Computer Science, Kansas State University, Manhattan, Kansas 66506, USA
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Zhang T, Liang X, Ye Q, BassiriRad H, Liu H, He P, Wu G, Lu X, Mo J, Cai X, Rao X, Yan J, Fu S. Leaf hydraulic acclimation to nitrogen addition of two dominant tree species in a subtropical forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 771:145415. [PMID: 33736159 DOI: 10.1016/j.scitotenv.2021.145415] [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: 11/07/2020] [Revised: 01/15/2021] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
Plant hydraulic traits have been shown to be sensitive to changes in nitrogen (N) availability in short-term studies largely using seedlings or saplings. The extent and the magnitude of N-sensitivity of the field grown mature trees in long-term experiments, however, are relatively unknown. Here, we investigated responses of leaf water relations and morphological and anatomical traits of two dominant tree species (Castanopsis chinensis and Schima superba) to a six-year canopy N addition in a subtropical forest. We found that N addition increased leaf hydraulic conductivity in both species along with higher transpiration rate and less negative water potential at 50% loss of leaf hydraulic conductivity and at leaf turgor loss point. Examination of leaf morphological and anatomical traits revealed that increased leaf hydraulic efficiency was at least in part due to increased vessel diameter which also compromised the hydraulic safety under increased water stress. Moreover, reduced vessel reinforcement and increased thickness shrinkage index further interpreted the increases in leaf hydraulic vulnerability under N addition. Our results demonstrated that N deposition may lead to increases of plant water loss to the atmosphere as well as tree vulnerability to drought.
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Affiliation(s)
- Tong Zhang
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Xingyun Liang
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Qing Ye
- 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, Xingke Road 723, Guangzhou 510650, China; College of Life Sciences, Gannan Normal University, Ganzhou 341000, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Haibin Road 1119, Nansha, Guangzhou 511458, China.
| | - Hormoz BassiriRad
- Department of Biological Sciences, University of Illinois at Chicago, 845 W. Taylor St., Chicago 60607, IL, USA
| | - Hui Liu
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Pengcheng He
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Guilin Wu
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Xiankai Lu
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Jiangming Mo
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Xi'an Cai
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Xingquan Rao
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Junhua Yan
- 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, Xingke Road 723, Guangzhou 510650, China
| | - Shenglei Fu
- College of Environment and Planning, Henan University, Jinming Avenue, Kaifeng 475004, China
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Wu C, Sun Y, Yang G, Li L, Sun W, Wang Z, Zhang H, Li Y. Natural variation in stress response induced by low CO 2 in Arabidopsis thaliana. Open Life Sci 2021; 15:923-938. [PMID: 33817279 PMCID: PMC7874586 DOI: 10.1515/biol-2020-0095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/19/2020] [Accepted: 08/29/2020] [Indexed: 11/19/2022] Open
Abstract
Variation in atmospheric carbon dioxide (CO2) concentration can dictate plant growth and development and shape plant evolution. For paired populations of 31 Arabidopsis accessions, respectively, grown under 100 or 380 ppm CO2, we compared phenotypic traits related to vegetative growth and flowering time. Four accessions showed the least variation in measured growth traits between 100 ppm CO2 and 380 ppm CO2 conditions, though all accessions exhibited a dwarf stature with reduced biomass under low CO2. Our comparison of accessions also incorporated the altitude (indicated in meters) above sea level at which they were originally collected. Notably, An-1 (50 m), Est (50 m), Ws-0 (150 m), and Ler-0 (600 m) showed the least differences (lower decrease or increase) between treatments in flowering time, rosette leaf number, specific leaf weight, stomatal density, and less negative δ13C values. When variations for all traits and seedset were considered together, Ws-0 exhibited the least change between treatments. Our results showed that physiological and phenotypic responses to low CO2 varied among these accessions and did not correlate linearly with altitude, thus suggesting that slower growth or smaller stature under ambient CO2 may potentially belie a fitness advantage for sustainable growth under low CO2 availability.
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Affiliation(s)
- Chunxia Wu
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Yulou Sun
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Guang Yang
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Li Li
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Wei Sun
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Zenglan Wang
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Hui Zhang
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
| | - Yuanyuan Li
- Key Laboratory of Systems Biology, College of Life Science, Shandong Normal University, Ji’nan, 250014, Shandong, People’s Republic of China
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Xiong D, Flexas J. From one side to two sides: the effects of stomatal distribution on photosynthesis. THE NEW PHYTOLOGIST 2020; 228:1754-1766. [PMID: 32652573 DOI: 10.1111/nph.16801] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
The functions of stomata have been studied for a long time; however, a clear understanding of the influences of stomatal distribution on photosynthesis, especially the CO2 diffusion, is still unclear. Here, we investigated the stomatal morphology, distribution on leaf surfaces, vein traits and gas exchange parameters of 61 species, of which 29 were amphistomatous, spanning 32 families. Photosynthesis (A) was tightly coupled with operational stomatal conductance (gs ) and mesophyll conductance (gm ) regardless of whether phylogenetic relationships were accounted for. Although the enhancement of gs from ferns and gymnosperms to angiosperms could largely be explained by the increase in leaf vein density (VLA) and stomatal density (SD), the gs was decoupled from VLA and SD across angiosperm species. Instead, A in angiosperms was further influenced by the allocation of stomatal pores on leaf surfaces, which dramatically increased gs and gm . Moreover, the ratio of gs to anatomically based maximum gs was, on average, 0.12 across species. Our results show that the shift of stomatal pores from one leaf side to both sides played an important role in regulating CO2 diffusion via both stomata and mesophyll tissues. Modifications of stomata distribution have potential as a functional trait for photosynthesis improvement.
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Affiliation(s)
- Dongliang Xiong
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jaume Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears/Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Carretera de Valldemossa Km 7.5, Palma de Mallorca, Illes Balears, 07121, Spain
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37
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Muir CD. A Stomatal Model of Anatomical Tradeoffs Between Gas Exchange and Pathogen Colonization. FRONTIERS IN PLANT SCIENCE 2020; 11:518991. [PMID: 33193466 PMCID: PMC7658178 DOI: 10.3389/fpls.2020.518991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Stomatal pores control leaf gas exchange and are one route for infection of internal plant tissues by many foliar pathogens, setting up the potential for tradeoffs between photosynthesis and pathogen colonization. Anatomical shifts to lower stomatal density and/or size may also limit pathogen colonization, but such developmental changes could permanently reduce the gas exchange capacity for the life of the leaf. I developed and analyzed a spatially explicit model of pathogen colonization on the leaf as a function of stomatal size and density, anatomical traits which partially determine maximum rates of gas exchange. The model predicts greater stomatal size or density increases the probability of colonization, but the effect is most pronounced when the fraction of leaf surface covered by stomata is low. I also derived scaling relationships between stomatal size and density that preserves a given probability of colonization. These scaling relationships set up a potential anatomical conflict between limiting pathogen colonization and minimizing the fraction of leaf surface covered by stomata. Although a connection between gas exchange and pathogen defense has been suggested empirically, this is the first mathematical model connecting gas exchange and pathogen defense via stomatal anatomy. A limitation of the model is that it does not include variation in innate immunity and stomatal closure in response to pathogens. Nevertheless, the model makes predictions that can be tested with experiments and may explain variation in stomatal size and density among plants. The model is generalizable to many types of pathogens, but lacks significant biological realism that may be needed for precise predictions.
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38
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Pathare VS, Sonawane BV, Koteyeva N, Cousins AB. C 4 grasses adapted to low precipitation habitats show traits related to greater mesophyll conductance and lower leaf hydraulic conductance. PLANT, CELL & ENVIRONMENT 2020; 43:1897-1910. [PMID: 32449181 DOI: 10.1111/pce.13807] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
In habitats with low water availability, a fundamental challenge for plants will be to maximize photosynthetic C-gain while minimizing transpirational water-loss. This trade-off between C-gain and water-loss can in part be achieved through the coordination of leaf-level photosynthetic and hydraulic traits. To test the relationship of photosynthetic C-gain and transpirational water-loss, we grew, under common growth conditions, 18 C4 grasses adapted to habitats with different mean annual precipitation (MAP) and measured leaf-level structural and anatomical traits associated with mesophyll conductance (gm ) and leaf hydraulic conductance (Kleaf ). The C4 grasses adapted to lower MAP showed greater mesophyll surface area exposed to intercellular air spaces (Smes ) and adaxial stomatal density (SDada ) which supported greater gm . These grasses also showed greater leaf thickness and vein-to-epidermis distance, which may lead to lower Kleaf . Additionally, grasses with greater gm and lower Kleaf also showed greater photosynthetic rates (Anet ) and leaf-level water-use efficiency (WUE). In summary, we identify a suite of leaf-level traits that appear important for adaptation of C4 grasses to habitats with low MAP and may be useful to identify C4 species showing greater Anet and WUE in drier conditions.
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Affiliation(s)
- Varsha S Pathare
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Balasaheb V Sonawane
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Nouria Koteyeva
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
- Laboratory of Anatomy and Morphology, V.L. Komarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
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39
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Richardson F, Jordan GJ, Brodribb TJ. Leaf hydraulic conductance is linked to leaf symmetry in bifacial, amphistomatic leaves of sunflower. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2808-2816. [PMID: 31970417 PMCID: PMC7210757 DOI: 10.1093/jxb/eraa035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 01/21/2020] [Indexed: 05/14/2023]
Abstract
The hydraulic implications of stomatal positioning across leaf surfaces and the impact on internal water flow through amphistomatic leaves are not currently well understood. Amphistomaty potentially provides hydraulic efficiencies if the majority of hydraulic resistance in the leaf exists outside the xylem in the mesophyll. Such a scenario would mean that the same xylem network could equally supply a hypostomatic or amphistomatic leaf. Here we examine leaves of Helianthus annuus to determine whether amphistomaty in this species is associated with higher hydraulic efficiency compared with hypostomatic leaves. We identified asymmetry in the positioning of minor veins which were significantly closer to the abaxial than the adaxial leaf surface, combined with lower Kleaf when transpiration was driven through the adaxial rather than the abaxial surface. We also identified a degree of coordination in stomatal behaviour driven by leaf hydraulics, where the hydraulic conditions experienced by an individual leaf surface affected the stomatal behaviour on the opposite surface. We found no advantage to amphistomaty based on efficiencies in construction costs of the venous system, represented by vein density:stomatal density, only limited hydraulic independence between leaf surfaces. These results suggest that amphistomaty does not substantially increase whole-leaf hydraulic efficiency.
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Affiliation(s)
- Freya Richardson
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Gregory J Jordan
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Timothy J Brodribb
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
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40
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Harrison EL, Arce Cubas L, Gray JE, Hepworth C. The influence of stomatal morphology and distribution on photosynthetic gas exchange. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:768-779. [PMID: 31583771 PMCID: PMC7065165 DOI: 10.1111/tpj.14560] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/25/2019] [Accepted: 10/03/2019] [Indexed: 05/18/2023]
Abstract
The intricate and interconnecting reactions of C3 photosynthesis are often limited by one of two fundamental processes: the conversion of solar energy into chemical energy, or the diffusion of CO2 from the atmosphere through the stomata, and ultimately into the chloroplast. In this review, we explore how the contributions of stomatal morphology and distribution can affect photosynthesis, through changes in gaseous exchange. The factors driving this relationship are considered, and recent results from studies investigating the effects of stomatal shape, size, density and patterning on photosynthesis are discussed. We suggest that the interplay between stomatal gaseous exchange and photosynthesis is complex, and that a disconnect often exists between the rates of CO2 diffusion and photosynthetic carbon fixation. The mechanisms that allow for substantial reductions in maximum stomatal conductance without affecting photosynthesis are highly dependent on environmental factors, such as light intensity, and could be exploited to improve crop performance.
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Affiliation(s)
- Emily L. Harrison
- Department of Molecular Biology and BiotechnologyUniversity of Sheffield, Western BankSheffieldUK
| | - Lucia Arce Cubas
- Department of Molecular Biology and BiotechnologyUniversity of Sheffield, Western BankSheffieldUK
| | - Julie E. Gray
- Department of Molecular Biology and BiotechnologyUniversity of Sheffield, Western BankSheffieldUK
| | - Christopher Hepworth
- Department of Molecular Biology and BiotechnologyUniversity of Sheffield, Western BankSheffieldUK
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41
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Cousins AB, Mullendore DL, Sonawane BV. Recent developments in mesophyll conductance in C3, C4, and crassulacean acid metabolism plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:816-830. [PMID: 31960507 DOI: 10.1111/tpj.14664] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 12/19/2019] [Indexed: 05/24/2023]
Abstract
The conductance of carbon dioxide (CO2 ) from the substomatal cavities to the initial sites of CO2 fixation (gm ) can significantly reduce the availability of CO2 for photosynthesis. There have been many recent reviews on: (i) the importance of gm for accurately modelling net rates of CO2 assimilation, (ii) on how leaf biochemical and anatomical factors influence gm , (iii) the technical limitation of estimating gm , which cannot be directly measured, and (iv) how gm responds to long- and short-term changes in growth and measurement environmental conditions. Therefore, this review will highlight these previous publications but will attempt not to repeat what has already been published. We will instead initially focus on the recent developments on the two-resistance model of gm that describe the potential of photorespiratory and respiratory CO2 released within the mitochondria to diffuse directly into both the chloroplast and the cytosol. Subsequently, we summarize recent developments in the three-dimensional (3-D) reaction-diffusion models and 3-D image analysis that are providing new insights into how the complex structure and organization of the leaf influences gm . Finally, because most of the reviews and literature on gm have traditionally focused on C3 plants we review in the final sections some of the recent developments, current understanding and measurement techniques of gm in C4 and crassulacean acid metabolism (CAM) plants. These plants have both specialized leaf anatomy and either a spatially or temporally separated CO2 concentrating mechanisms (C4 and CAM, respectively) that influence how we interpret and estimate gm compared with a C3 plants.
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Affiliation(s)
- Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Daniel L Mullendore
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Balasaheb V Sonawane
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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42
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Şesan TE, Oancea AO, Ştefan LM, Mănoiu VS, Ghiurea M, Răut I, Constantinescu-Aruxandei D, Toma A, Savin S, Bira AF, Pomohaci CM, Oancea F. Effects of Foliar Treatment with a Trichoderma Plant Biostimulant Consortium on Passiflora caerulea L. Yield and Quality. Microorganisms 2020; 8:E123. [PMID: 31963272 PMCID: PMC7023023 DOI: 10.3390/microorganisms8010123] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/11/2020] [Accepted: 01/13/2020] [Indexed: 11/17/2022] Open
Abstract
The influence of spore concentration on the ability of a Trichoderma consortium to colonize the Passiflora caerulea phyllosphere was evaluated by determining the effects of foliar treatments with two spore concentrations, in two repeated treatments, on the morphological, physiological, and ultrastructural characteristics, and on the yield and quality of P. caerulea. The studied crop quality features were related to its nutraceutical use: the accumulation of polyphenols and flavonoids, antioxidant activity, and effects on mouse fibroblast L929 cells. The Trichoderma consortium consisted of two strains, T. asperellum T36b and T. harzianum Td50b, and the concentrations used were 106 colony forming units (cfu)/mL and 108 cfu/mL. As a reference treatment, a commercial product that was based on herbs and algal extracts was used. As compared to the negative control, the treatment with the Trichoderma consortium at 108 cfu/mL concentration determines the accumulation of higher level of polyphenols and flavonoids and increased antioxidant activity. This enhancement of P. caerulea quality characteristics after treatment with the higher concentration of Trichoderma consortium was associated with larger leaves, increased number and size of chloroplasts, improved plant physiology characteristics, and an increased yield. The treatment with high concentration of Trichoderma consortium spores promotes phyllosphere colonization and benefits both crop yield and quality.
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Affiliation(s)
- Tatiana Eugenia Şesan
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, Aleea Portocalilor nr. 1-3, sector 6, 060101 Bucharest, Romania;
- Departments of Biotechnology and Bioresources, National Research & Development Institute for Chemistry and Petrochemistry—ICECHIM, Splaiul Independenței nr. 202, sector 6, 060021 Bucharest, Romania; (M.G.); (I.R.); (D.C.-A.)
| | - Anca Olguța Oancea
- Department of Cellular and Molecular Biology, National Research & Development Institute for Biological Sciences, Splaiul Independenței 296, sector 6, 060031 Bucharest, Romania (V.S.M.); (A.T.); (S.S.)
| | - Laura Mihaela Ştefan
- Department of Cellular and Molecular Biology, National Research & Development Institute for Biological Sciences, Splaiul Independenței 296, sector 6, 060031 Bucharest, Romania (V.S.M.); (A.T.); (S.S.)
| | - Vasile Sorin Mănoiu
- Department of Cellular and Molecular Biology, National Research & Development Institute for Biological Sciences, Splaiul Independenței 296, sector 6, 060031 Bucharest, Romania (V.S.M.); (A.T.); (S.S.)
| | - Marius Ghiurea
- Departments of Biotechnology and Bioresources, National Research & Development Institute for Chemistry and Petrochemistry—ICECHIM, Splaiul Independenței nr. 202, sector 6, 060021 Bucharest, Romania; (M.G.); (I.R.); (D.C.-A.)
| | - Iuliana Răut
- Departments of Biotechnology and Bioresources, National Research & Development Institute for Chemistry and Petrochemistry—ICECHIM, Splaiul Independenței nr. 202, sector 6, 060021 Bucharest, Romania; (M.G.); (I.R.); (D.C.-A.)
| | - Diana Constantinescu-Aruxandei
- Departments of Biotechnology and Bioresources, National Research & Development Institute for Chemistry and Petrochemistry—ICECHIM, Splaiul Independenței nr. 202, sector 6, 060021 Bucharest, Romania; (M.G.); (I.R.); (D.C.-A.)
| | - Agnes Toma
- Department of Cellular and Molecular Biology, National Research & Development Institute for Biological Sciences, Splaiul Independenței 296, sector 6, 060031 Bucharest, Romania (V.S.M.); (A.T.); (S.S.)
| | - Simona Savin
- Department of Cellular and Molecular Biology, National Research & Development Institute for Biological Sciences, Splaiul Independenței 296, sector 6, 060031 Bucharest, Romania (V.S.M.); (A.T.); (S.S.)
| | - Adriana Florina Bira
- Department of Research & Development, Hofigal SA, Intrarea Serelor, Nr. 2, Sector 4, 042124 Bucharest, Romania;
| | - Cristian Mihai Pomohaci
- Department of Mathematics, Physics and Land Measurements, Faculty of Land Reclamation and Environmental Engineering, University of Agronomical Sciences and Veterinary Medicine, Bulevardul Mărăști 59, sector 1, 011464 Bucharest, Romania;
| | - Florin Oancea
- Departments of Biotechnology and Bioresources, National Research & Development Institute for Chemistry and Petrochemistry—ICECHIM, Splaiul Independenței nr. 202, sector 6, 060021 Bucharest, Romania; (M.G.); (I.R.); (D.C.-A.)
- Biotechnologies Department, Faculty of Biotechnologies, University of Agronomical Sciences and Veterinary Medicine, Bulevardul Mărăști 59, sector 1, 011464 Bucharest, Romania
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Pathare VS, Koteyeva N, Cousins AB. Increased adaxial stomatal density is associated with greater mesophyll surface area exposed to intercellular air spaces and mesophyll conductance in diverse C 4 grasses. THE NEW PHYTOLOGIST 2020; 225:169-182. [PMID: 31400232 DOI: 10.1111/nph.16106] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/01/2019] [Indexed: 05/21/2023]
Abstract
Mesophyll conductance (gm ) is the diffusion of CO2 from intercellular air spaces (IAS) to the first site of carboxylation in the mesophyll cells. In C3 species, gm is influenced by diverse leaf structural and anatomical traits; however, little is known about traits affecting gm in C4 species. To address this knowledge gap, we used online oxygen isotope discrimination measurements to estimate gm and microscopy techniques to measure leaf structural and anatomical traits potentially related to gm in 18 C4 grasses. In this study, gm scaled positively with photosynthesis and intrinsic water-use efficiency (TEi ), but not with stomatal conductance. Also, gm was not determined by a single trait but was positively correlated with adaxial stomatal densities (SDada ), stomatal ratio (SR), mesophyll surface area exposed to IAS (Smes ) and leaf thickness. However, gm was not related to abaxial stomatal densities (SDaba ) and mesophyll cell wall thickness (TCW ). Our study suggests that greater SDada and SR increased gm by increasing Smes and creating additional parallel pathways for CO2 diffusion inside mesophyll cells. Thus, SDada , SR and Smes are important determinants of C4 -gm and could be the target traits selected or modified for achieving greater gm and TEi in C4 species.
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Affiliation(s)
- Varsha S Pathare
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
| | - Nuria Koteyeva
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
- Laboratory of Anatomy and Morphology, V.L. Komarov Botanical Institute of the Russian Academy of Sciences, 197376, St Petersburg, Russia
| | - Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
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44
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Muir CD. Is Amphistomy an Adaptation to High Light? Optimality Models of Stomatal Traits along Light Gradients. Integr Comp Biol 2019. [PMID: 31141118 DOI: 10.1101/601377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
Stomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.
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45
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Muir CD. Is Amphistomy an Adaptation to High Light? Optimality Models of Stomatal Traits along Light Gradients. Integr Comp Biol 2019; 59:571-584. [DOI: 10.1093/icb/icz085] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AbstractStomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.
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