ORCID Profile
0000-0002-6332-2627
Current Organisations
Huazhong Agriculture University
,
University of California Davis
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Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/FP15057
Abstract: Increasing leaf photosynthesis rate (A) is considered an important strategy to increase C3 crop yields. Leaf A is usually represented by point measurements, but A varies within each leaf, especially within large leaves. However, little is known about the effect of heterogeneity of A within leaves on rice performance. Here we investigated the changes in gas-exchange parameters and leaf structural and chemical features along leaf blades in two rice cultivars. Stomatal and mesophyll conductance as well as leaf nitrogen (N), Rubisco and chlorophyll contents increased from base to apex consequently, A increased along leaves in both cultivars. The variation in A, leaf N content and Rubisco content within leaves was similar to the variations among cultivars, and the extent of A heterogeneity within leaves varied between cultivars, leading to different efficiencies of biomass accumulation. Furthermore, variation of A within leaves was closely associated with leaf structural and chemical features. Our findings emphasise that functional changes along leaf blades are associated with structural and chemical trait variation and that variation of A within leaves should be considered to achieve progress in future breeding programs.
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/FP14166
Abstract: To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) in HT tolerance is related to E, a pot experiment supplied with two N levels (low N, 0.077 g urea kg–1 soil sufficient N, 0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficient N supply. The most HT-tolerant cultivar, N22, had the highest E and stem NSC concentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.
Publisher: Research Square Platform LLC
Date: 22-07-2021
DOI: 10.21203/RS.3.RS-717330/V1
Abstract: The accurate estimation of leaf hydraulic conductance ( K leaf ) is important for revealing leaf physiology characteristics and function. However, there are some uncertain influencing factors in K leaf measurement by using evaporation flux method (EFM), a widely used method. In this study, we investigated the potential impacts of plant s ling method, measurement setup, environmental factors, recording instrument, and transpiration steady status identification on K leaf estimation. Our results indicated that the s ling and rehydration time, the small gravity pressure on leaf, and degassing treatment had limited effects on K leaf values. Transpiration rate ( E ) was significantly affected by multiple environmental factors including airflow around leaf, light intensity, and leaf temperature. K leaf values decreased by 40% from 1000 to 500 µmol m -2 s -1 light intensities and by 15.1% from 27 to 37 o C. In addition, the accurate flow rate ( F ) steady state identification and the leaf water potential measurement were important for K leaf estimation. Based on the analysis of influencing factors, we provided a format for reporting the details of the EFM-based K leaf measurement methods and metadata that future studies could interpret the results in method issue.
Publisher: Oxford University Press (OUP)
Date: 26-03-2016
DOI: 10.1093/AOB/MCW022
Publisher: Wiley
Date: 18-06-2015
DOI: 10.1111/PCE.12558
Abstract: Photosynthesis in C3 plants is significantly limited by mesophyll conductance (gm ), which can vary with leaf anatomical traits and nitrogen (N) supplements. Several studies have investigated the response of gm to N supplements however, none examined the implications of N supplements on the response of gm to rapid environmental changes. Here we investigated the effect of N supplement on gm and the response of gm to change of CO2 , temperature and irradiance in rice. High N supplement (HN) increased mesophyll cell wall surface area and chloroplast surface area exposed to intercellular airspace per leaf area, and reduced cell wall thickness. These changes resulted in increased gm . The gm of leaves with HN was more sensitive to changes in CO2 concentration, temperature and irradiance. The difference in leaf structural features between low N supplement and HN indicates that a rapid change in gm is related to the regulation of diffusion through biological membranes rather than leaf structural features. These results will contribute to an understanding of the determinants of gm response to rapid changes in environmental factors.
Publisher: Oxford University Press (OUP)
Date: 16-09-2023
DOI: 10.1093/JXB/ERAD365
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.JPLPH.2022.153689
Abstract: Extreme environments, such as deserts and high-elevation ecosystems, are very important from bio ersity and ecological perspectives. However, plant physiology at those sites has been scarcely studied, likely due to logistic difficulties. In the present study, leaf physiological traits in native plants were analyzed from arid zones across an elevational transect in Western China, from Turpan Basin to the Qinghai-Tibet Plateau (QTP) at Delingha. The aim of this study was to use leaf physiological traits to help identifying potentially threatened species and true extremophiles. Physiological measurements in the field, and particularly in situ measurements of gas exchange and chlorophyll fluorescence, have been determined to be useful to determine the current state of plants at a given environment. Using this approach plus a combination of leaf traits, several species performing particularly well at the QTP were identified, e.g. Hedysarum multijugum, as well as at Manas drylands, e.g. Peganum harmala and Setaria viridis. On the other hand, several species showed marked signs of severe stress, in particular a very low photosynthetic rate over its potential maximum, as well as other negative traits, like low water and/or nitrogen-use-efficiency, which should be considered in conservation plans. Interestingly, all C
Publisher: Oxford University Press (OUP)
Date: 29-03-2021
DOI: 10.1093/JXB/ERAB144
Abstract: The key role of cell walls in setting mesophyll conductance to CO2 (gm) and, consequently, photosynthesis is reviewed. First, the theoretical properties of cell walls that can affect gm are presented. Then, we focus on cell wall thickness (Tcw) reviewing empirical evidence showing that Tcw varies strongly among species and phylogenetic groups in a way that correlates with gm and photosynthesis that is, the thicker the mesophyll cell walls, the lower the gm and photosynthesis. Potential interplays of gm, Tcw, dehydration tolerance, and hydraulic properties of leaves are also discussed. Dynamic variations of Tcw in response to the environment and their implications in the regulation of photosynthesis are discussed, and recent evidence suggesting an influence of cell wall composition on gm is presented. We then propose a hypothetical mechanism for the influence of cell walls on photosynthesis, combining the effects of thickness and composition, particularly pectins. Finally, we discuss the prospects for using biotechnology for enhancing photosynthesis by altering cell wall-related genes.
Publisher: Wiley
Date: 03-2022
DOI: 10.1111/PPL.13636
Abstract: Nitrogen (N) is one of the most important nutrients for crop growth and yield formation, as it is an important constituent in a large amount of proteins, cell walls, and membranes related to photosynthesis. Recently, increasing studies have suggested the important roles of photosynthetic induction and stomatal movement under fluctuating light in regulating plant carbon assimilation and water use efficiency. How leaf N content affects photosynthetic induction remains uncertain. Here, we observed a significantly faster photosynthetic induction with the increasing supply of N under fluctuating light conditions. Photosynthetic induction was mainly limited by biochemical processes but not stomatal opening after a stepwise increase in irradiance across different N supplies. Higher N supply enhanced photosynthetic efficiency under constant and fluctuating light conditions but reduced leaf intrinsic water use efficiency ( WUE i ). This study is mainly focused on clarifying the crucial limitation of photosynthetic induction under different N treatments, which may facilitate the improvement of photosynthetic efficiency under complicated environments in the future.
Publisher: Springer Science and Business Media LLC
Date: 25-08-2015
DOI: 10.1038/SREP13389
Abstract: Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N estimations are still unclear. In the present study, we estimated the relationships among SPAD readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple environments. There were similar relationships between SPAD readings and chlorophyll content per leaf area for the species groups, but the relationship between chlorophyll content and leaf N content per leaf area and the relationship between SPAD readings and leaf N content per leaf area varied widely among the species groups. A significant impact of light-dependent chloroplast movement on SPAD readings was observed under low leaf N supplementation in both rice and soybean but not under high N supplementation. Furthermore, the allocation of leaf N to chlorophyll was strongly influenced by short-term changes in growth light. We demonstrate that the relationship between SPAD readings and leaf N content per leaf area is profoundly affected by environmental factors and leaf features of crop species, which should be accounted for when using a chlorophyll meter to guide N management in agricultural systems.
Publisher: Cold Spring Harbor Laboratory
Date: 26-08-2022
DOI: 10.1101/2022.08.23.505027
Abstract: Leaf photosynthetic nitrogen-use efficiency (PNUE) ersified significantly among C 3 species. However, morpho-physiological mechanisms and interrelationships forming PNUE remain unclear on the evolutionary time scale. In this study, we compiled a novel extensive matrix of morpho-anatomical and physiological traits of leaf in 679 C 3 species ranging from bryophytes to angiosperms to understand the intricacy of interrelationships underlying the variations in PNUE. We found that LMA, mesophyll cell wall thickness (T cwm ), Rubisco N allocation fraction (P R ), and mesophyll conductance (g m ) together interpreted 83% of variations in PNUE, with P R and g m accounting for 65% of those variations. However, the P R effects were species-dependent on g m that is, the contribution of P R on PNUE was extensively significant in high-g m species in comparison to low-g m species. Standard major analysis (SMA) and path analysis suggested a weak correlation between PNUE and LMA, whereas the SMA correlation for PNUE–T cwm was strong. The P R was inversely proportional to T cwm , which was similar to the relationship between g m and T cwm (p-value 0.01), so that the internal CO 2 drawdown from intercellular airspace to carboxylaton sites was relatively conservative over a wide range of T cwm . Collectively, the coordination of changes in P R and g m connecting T cwm suggested the complex physiological mechanisms mediated by T cwm modulating PNUE across contrasting plant groups.
Publisher: Springer Science and Business Media LLC
Date: 30-08-2022
DOI: 10.1007/S00442-022-05250-4
Abstract: The tradeoffs between carbon assimilation and hydraulic efficiencies and drought-tolerance traits on different scales are considered a central tenet in plant ecophysiology however, no clear tradeoff between these traits has emerged in previous studies using woody angiosperms or grasses by investigating several hydraulic tolerance and gas exchange efficiency and/or water transport efficiency traits. In this study, we measured numerous efficiency, resistance, and leaf anatomical traits, including light-saturated gas exchange, leaf hydraulic vulnerability curves, pressure-volume curves, and leaf anatomical traits, in seven species with erse drought tolerance. A substantial variation in photosynthetic rate, stomatal conductance, mesophyll conductance, maximum leaf hydraulic conductance (K
Publisher: Wiley
Date: 02-08-2021
DOI: 10.1111/TPJ.15397
Abstract: The plasma membrane subfamily of aquaporins [plasma membrane intrinsic proteins (PIPs)], which facilitates the CO 2 diffusion across membranes, is proposed to play an important role in mesophyll conductance to CO 2 ( g m ), a major limiting factor of photosynthesis. However, recent studies implied no causal relationship between g m and PIPs because they failed to repeat the previous observed differences in g m between PIP knockout lines and their wild‐type. The contrasting results on the role of PIPs in g m were interpreted as the different growth conditions among studies, which has never been tested. Here, we assessed whether the differences in g m between wild‐type and PIP knockout lines, Ospip1 , Ospip1 and Ospip2 , varied with growth condition (field versus pot condition) and growth stages in rice. Under field conditions, no differences were observed in plant performance, photosynthetic rate ( A ) and g m between PIP knockout lines and the wild‐type. However, in agreement with previous studies, two out of three knockout lines showed significant declines in tiller number, plant height, A and g m under pot conditions. Moreover, we found that the differences in A and g m between PIP knockout lines and the wild‐type varied with the growth stage of the plants. Our results showed that the differences in g m between PIP knockout lines and wild‐type were depending on the growth environments and stage of the plants, and further efforts are required to reveal the underlying mechanisms.
Publisher: Oxford University Press (OUP)
Date: 26-11-2014
DOI: 10.1093/JXB/ERU434
Publisher: Oxford University Press (OUP)
Date: 22-05-2021
DOI: 10.1093/JXB/ERAB230
Abstract: The photosynthetic capacity of leaves is dramatically influenced by nitrogen (N) availability in the soil, as CO2 concentration in chloroplasts and photosynthetic biochemical capacity are related to leaf N content. The relationship between mesophyll conductance (gm) and leaf N content was expected to be shaped by leaf anatomical traits. However, the increased gm in mature leaves achieved by N top-dressing is unlikely to be caused by changes in leaf anatomy. Here, we assessed the impacts of N supply on leaf anatomical, biochemical, and photosynthetic features, specifically, the dynamic responses of leaf anatomy, biochemistry, and photosynthesis to N top-dressing in tobacco. Plant performance was substantially affected by soil N status. In comparison with the leaves of plants subjected to low N treatment, leaves of plants with high N treatment photosynthesized significantly more, due to higher CO2 diffusion conductance and photosynthetic biochemical capacity. The high gm in high N-treated leaves apparently related to modifications in the leaf anatomy however, the rapid response of gm to N top-dressing cannot be fully explained by leaf anatomical modifications.
Publisher: Springer Science and Business Media LLC
Date: 22-03-2014
DOI: 10.1007/S10529-014-1510-9
Abstract: Rice diseases (bacterial, fungal, or viral) threaten food productivity. Host resistance is the most efficient, environmentally friendly method to cope with such erse pathogens. Quantitative resistance conferred by quantitative trait loci (QTLs) is a valuable resource for rice disease resistance improvement. Although QTLs confer partial but durable resistance to many pathogen species in different crop plants, the molecular mechanisms of quantitative disease resistance remain mostly unknown. Quantitative resistance and non-host resistance are types of broad-spectrum resistance, which are mediated by resistance (R) genes. Because R genes activate different resistance pathways, investigating the genetic spectrum of resistance may lead to minimal losses from harmful diseases. Genome studies can reveal interactions between different genes and their pathways and provide insight into gene functions. Protein–protein interaction (proteomics) studies using molecular and bioinformatics tools may further enlighten our understanding of resistance phenomena.
Publisher: Wiley
Date: 12-12-2017
DOI: 10.1111/PPL.12653
Abstract: Salinity significantly limits leaf photosynthesis but the factors causing the limitation in salt-stressed leaves remain unclear. In the present work, photosynthetic and biochemical traits were investigated in four rice genotypes under two NaCl concentration (0 and 150 mM) to assess the stomatal, mesophyll and biochemical contributions to reduced photosynthetic rate (A) in salt-stressed leaves. Our results indicated that salinity led to a decrease in A, leaf osmotic potential, electron transport rate and CO
Publisher: Wiley
Date: 11-06-2023
DOI: 10.1111/PCE.14641
Abstract: Leaf photosynthetic nitrogen‐use efficiency (PNUE) ersified significantly among C 3 species. To date, the morpho‐physiological mechanisms and interrelationships shaping PNUE on an evolutionary time scale remain unclear. In this study, we assembled a comprehensive matrix of leaf morpho‐anatomical and physiological traits for 679 C 3 species, ranging from bryophytes to angiosperms, to comprehend the complexity of interrelationships underpinning PNUE variations. We discovered that leaf mass per area (LMA), mesophyll cell wall thickness (T cwm ), Rubisco N allocation fraction (P R ), and mesophyll conductance (g m ) together explained 83% of PNUE variations, with P R and g m accounting for 65% of those variations. However, the P R effects were species‐dependent on g m , meaning the contribution of P R on PNUE was substantially significant in high‐g m species compared to low‐g m species. Standard major axis (SMA) and path analyses revealed a weak correlation between PNUE and LMA ( r 2 = 0.1), while the SMA correlation for PNUE–T cwm was robust ( r 2 = 0.61). P R was inversely related to T cwm , paralleling the relationship between g m and T cwm , resulting in the internal CO 2 drawdown being only weakly proportional to T cwm . The coordination of P R and g m in relation to T cwm constrains PNUE during the course of evolution.
Publisher: Oxford University Press (OUP)
Date: 08-08-2023
DOI: 10.1093/JXB/ERAD316
Abstract: Leaf rolling is a physiological response to drought that may help to reduce water loss, but its significance as a contribution to drought tolerance is uncertain. We scored the leaf rolling of four rice genotypes along an experimental drought gradient using an improved cryo-microscopy method. Leaf water potential (Ψleaf), gas exchange, chlorophyll fluorescence, leaf hydraulic conductance, rehydration capacity, and the bulk turgor loss point were also analysed. During the drought process, stomatal conductance declined sharply to reduce water loss, and leaves rolled up before the stomata completely closed. The leaf water loss rate of rolled leaves was significantly reduced compared with artificially flattened leaves. The Ψleaf threshold of initial leaf rolling ranged from −1.95 to −1.04 MPa across genotypes. When a leaf rolled so that the leaf edges were touching, photosynthetic rate and stomatal conductance declined more than 80%. Across genotypes, leaf hydraulic conductance declined first, followed by gas exchange and chlorophyll fluorescence parameters. However, the Ψleaf threshold for a given functional trait decline differed significantly among genotypes, with the exception of leaf hydraulic conductance. Our results suggested that leaf rolling was mechanistically linked to drought avoidance and tolerance traits and might serve as a useful phenotypic trait for rice breeding in future drought scenarios.
Publisher: Wiley
Date: 12-01-2018
DOI: 10.1111/PCE.13111
Abstract: Stomatal conductance (g
Publisher: Elsevier BV
Date: 09-2017
Publisher: Wiley
Date: 08-12-2019
DOI: 10.1111/TPJ.14595
Abstract: For land plants, water is the principal governor of growth. Photosynthetic performance is highly dependent on the stable and suitable water status of leaves, which is balanced by the water transport capacity, the water loss rate as well as the water capacitance of the plant. This review discusses the links between leaf water status and photosynthesis, specifically focussing on the coordination of CO
Publisher: Cold Spring Harbor Laboratory
Date: 03-09-2021
DOI: 10.1101/2021.09.02.457988
Abstract: Functional and developmental constraints on phenotypic variation may cause traits to covary over millions of years and slow populations from reaching their adaptive optima. Alternatively, trait covariation may result from selective constraint if some trait combinations are generally maladaptive. Quantifying the relative contribution of functional, developmental, and selective constraints on phenotypic variation is a longstanding goal of macroevolution, but it is often difficult to distinguish different types of constraints. The anatomy of leaves with stomata on both surfaces ( histomatous) present a unique opportunity to test the importance of functional and developmental constraints on phenotypyic evolution. The key insight is that stomata on each leaf surface encounter the same functional and developmental constraints, but potentially different selective constraints because of leaf asymmetry in light capture, gas exchange, and other features. Independent evolution of stomatal traits on each surface imply that functional and developmental constraints alone likely do not explain trait covariance. Packing limits on how many stomata can fit into a finite epidermis and cell-size-mediated developmental integration are hypothesized to constrain variation in stomatal anatomy. The simple geometry of the planar leaf surface and knowledge of stomatal development make it possible to derive equations for phenotypic (co)variance caused by these constraints and compare them with data. We analyzed evolutionary covariance between stomatal density and length in histomatous leaves from 236 phylogenetically independent contrasts using a robust Bayesian model. Stomatal anatomy on each surface erges partially independently, meaning that packing limits and developmental integration are not sufficient to explain phenotypic (co)variation. Hence, selective constraints, which require an adaptive explanation, likely contribute to (co)variation in ecologically important traits like stomata. We show how it is possible to evaluate the contribution of different constraints by deriving expected patterns of (co)variance and testing them using similar but separate tissues, organs, or sexes.
Publisher: Wiley
Date: 22-09-2016
DOI: 10.1111/NPH.14186
Abstract: Leaf hydraulic conductance ( K leaf ) and mesophyll conductance ( g m ) both represent major constraints to photosynthetic rate ( A ), and previous studies have suggested that K leaf and g m is correlated in leaves. However, there is scarce empirical information about their correlation. In this study, K leaf , leaf hydraulic conductance inside xylem ( K x ), leaf hydraulic conductance outside xylem ( K ox ), A , stomatal conductance ( g s ), g m , and anatomical and structural leaf traits in 11 Oryza genotypes were investigated to elucidate the correlation of H 2 O and CO 2 diffusion inside leaves. All of the leaf functional and anatomical traits varied significantly among genotypes. K leaf was not correlated with the maximum theoretical stomatal conductance calculated from stomatal dimensions ( g smax ), and neither g s nor g smax were correlated with K x . Moreover, K ox was linearly correlated with g m and both were closely related to mesophyll structural traits. These results suggest that K leaf and g m are related to leaf anatomical and structural features, which may explain the mechanism for correlation between g m and K leaf .
Publisher: Springer Science and Business Media LLC
Date: 12-05-2022
DOI: 10.1186/S13007-022-00888-W
Abstract: The accurate estimation of leaf hydraulic conductance ( K leaf ) is important for revealing leaf physiological characteristics and function. However, the K leaf values are largely incomparable in previous studies for a given species indicating some uncertain influencing factors in K leaf measurement. We investigated the potential impacts of plant s ling method, measurement setup, environmental factors, and transpiration steady state identification on K leaf estimation in Oryza sativa and Cinnamomum c hora using evaporation flux method (EFM). The effects of s ling and rehydration time, the small gravity pressure gradients between water sources and leaves, and water degassing on K leaf estimation were negligible. As expected, the estimated steady flow rate ( E ) was significantly affected by multiple environmental factors including airflow around leaf, photosynthetically active radiation (PARa) on leaf surfaces and air temperature. K leaf decreased by 40% when PARa declined from 1000 to 500 µmol m −2 s −1 and decreased by 15.1% when air temperature increased from 27 to 37 °C. In addition, accurate steady-state flow rate identification and leaf water potential measurement were important for K leaf estimation. Based on the analysis of influencing factors, we provided a format for reporting the metadata of EFM-based K leaf to achieve greater comparability among studies and interpretation of differences.
Publisher: Springer Science and Business Media LLC
Date: 18-07-2017
DOI: 10.1038/S41598-017-06460-0
Abstract: The photosynthetic, biochemical, and anatomical traits of accumulation and replication of chloroplasts ( arc ) mutants of Arabidopsis thaliana were investigated to study the effects of chloroplast size and number on photosynthesis. Chloroplasts were found to be significantly larger, and the chloroplast surface area exposed to intercellular air spaces ( S c ) significantly lower in the mutants than in their wild-types. The decreased S c and increase cytoplasm thickness in the mutants resulted in a lower mesophyll conductance ( g m ) and a consequently lower chloroplast CO 2 concentration ( C c ). There were no significant differences between the mutants and their wild-types in maximal carboxylation rate ( V cmax ), maximal electron transport ( J cmax ), and leaf soluble proteins. Leaf nitrogen (N) and Rubisco content were similar in both Wassilewskija (Ws) wild-type (Ws-WT) and the Ws mutant ( arc 8), whereas they were slightly higher in Columbia (Col) wild-type (Col-WT) than the Col mutant ( arc 12). The photosynthetic rate ( A ) and photosynthetic N use efficiency (PNUE) were significantly lower in the mutants than their wild-types. The mutants showed similar A / C c responses as their wild-type counterparts, but A at given C c was higher in Col and its mutant than in Ws and its mutant. From these results, we conclude that decreases in g m and C c are crucial to the reduction in A in arc mutants.
Publisher: Wiley
Date: 20-01-2023
DOI: 10.1111/TPJ.16098
Abstract: Increasing mesophyll conductance of CO 2 ( g m ) is a strategy to improve photosynthesis in C 3 crops. However, the relative importance of different anatomical traits in determining g m in crops is unclear. Mesophyll conductance measurements were performed on 10 crops using the online carbon isotope discrimination method and the ‘variable J ’ method in parallel. The influences of crucial leaf anatomical traits on g m were evaluated using a one‐dimensional anatomical CO 2 diffusion model. The g m values measured using two independent methods were compatible, although significant differences were observed in their absolute values. Quantitative analysis showed that cell wall thickness and chloroplast stroma thickness are the most important elements along the diffusion pathway. Unexpectedly, the large variability of g m across crops was not associated with any investigated leaf anatomical traits except chloroplast thickness. The g m values estimated using the anatomical model differed remarkably from the values measured in vivo in most species. However, when the species‐specific effective porosity of the cell wall and the species‐specific facilitation effect of CO 2 diffusion across the membrane and chloroplast stoma were taken into account, the model could output g m values very similar to those measured in vivo . These results indicate that g m variation across crops is probably also driven by the effective porosity of the cell wall and effects of facilitation of CO 2 transport across the membrane and chloroplast stroma in addition to the thicknesses of the elements.
Publisher: Oxford University Press (OUP)
Date: 05-09-2018
DOI: 10.1093/JXB/ERY322
Publisher: Wiley
Date: 29-09-2021
DOI: 10.1111/PPL.13564
Abstract: Phenotypic plasticity, the capacity of an organism to generate alternative phenotypes in response to different environments, is a particularly important characteristic to enable sessile plants to adapt to rapid changes in their surroundings. Leaf anatomical and physiological traits exhibit plasticity in response to growth irradiances, but it is relatively unclear if the plasticity varies among genotypes for a species. Equally importantly, empirical results on how leaf‐level plasticity influences whole‐plant growth are largely absent. We conducted an integrated investigation into the light‐introduced plasticity by measuring 48 traits involving plant growth, leaf anatomy, leaf biochemistry, and leaf physiology of five rice genotypes grown under two irradiances. More than half of the estimated traits were significantly affected by growth light intensities, and the sizes of the cumulative effect of growth light ranged from −25.04% (stomatal conductance at high measurement light) to 135.2% (tiller number). Growth irradiance levels dramatically shifted the relationship between photosynthetic rate and stomatal conductance. However, the relationship between photosynthetic rate and mesophyll conductance was rarely influenced by growth light levels. Importantly, the present study highlights the significant variation in trait plasticity across rice genotypes and that the light‐introduced biomass changes were rarely predicted by leaf photosynthetic plasticity. Our findings imply that the genotypes with high productivity at the low growth light conditions do not necessarily have high productivity under high light conditions.
Publisher: Cold Spring Harbor Laboratory
Date: 17-10-2017
DOI: 10.1101/204578
Abstract: Salinity significantly limits leaf photosynthesis but the photosynthetic limiting factors in salt- stressed leaves remain unclear. In the present work, photosynthetic and biochemical traits were investigated in four rice genotypes under two NaCl (0 and 150 m M ) concentration to assess the stomatal, mesophyll and biochemical contributions to reduced photosynthetic rate ( A ) in salt stressed leaves. Our results indicated that salinity led to a decrease in A , leaf osmotic potential, electron transport rate and CO 2 concentrations in the chloroplasts ( C c ) of rice leaves. Decreased A in salt-stressed leaves was mainly attributable to low C c , which was determined by stomatal and mesophyll conductance. The increased stomatal limitation was mainly related to the low leaf osmotic potential caused by soil salinity. However, the increased mesophyll limitation in salt stressed leaves was related to both osmotic stress and ion stress. These findings highlight the importance of considering mesophyll conductance when developing salinity-tolerant rice cultivars. A photosynthetic rate C c , CO 2 concentration at carboxylation sites CE apparent Rubisco activity Chl total chlorophyll content C i intercellular CO 2 concentration ETR electron transport rate F 0 initial fluorescence of photosystem II in darkness F m maximum fluorescence of photosystem II F v maximum variable fluorescence of photosystem II F v / F m maximum quantum efficiency of photosystem II g m mesophyll conduction g s stomatal conduction J max maximum electron transport rate K leaf K content LMA leaf mass per area N leaf N content P leaf P content OP osmotic potential Protein leaf total soluble protein content qN non-chemical quenching efficiency R d day respiration R dark dark respiration Rubisco Rubisco content V cmax maximum carboxylation rate α leaf light absorptance efficiency β the distribution of electrons between PSI and PSII Γ * CO 2 compensation point in the absence of respiration Φ PSII quantum efficiency of photosystem II.
Publisher: Oxford University Press (OUP)
Date: 18-05-2018
DOI: 10.1093/JXB/ERY188
Publisher: Wiley
Date: 28-08-2020
DOI: 10.1111/NPH.16801
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 CO 2 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 histomatous, spanning 32 families. Photosynthesis ( A ) was tightly coupled with operational stomatal conductance ( g s ) and mesophyll conductance ( g m ) regardless of whether phylogenetic relationships were accounted for. Although the enhancement of g s from ferns and gymnosperms to angiosperms could largely be explained by the increase in leaf vein density (VLA) and stomatal density (SD), the g s 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 g s and g m . Moreover, the ratio of g s to anatomically based maximum g s 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 CO 2 diffusion via both stomata and mesophyll tissues. Modifications of stomata distribution have potential as a functional trait for photosynthesis improvement.
Publisher: Springer Science and Business Media LLC
Date: 24-01-2020
DOI: 10.1186/S13007-020-0553-2
Abstract: Over the past decades, the structural and functional genomics of rice have been deeply studied, and high density of molecular genetic markers have been developed. However, the genetic variation in leaf photosynthesis, the most important trait for rice yield improvement, was rarely studied. The lack of photosynthesis phenotyping tools is one of the bottlenecks, as traditional direct photosynthesis measurements are very low-throughput, and recently developed high-throughput methods are indirect measurements. Hence, there is an urgent need for a fast, accurate and direct measurement approach. We reported a fast photosynthesis measurement (FPM) method for phenotyping photosynthetic capacity of rice, which measures photosynthesis of excised tillers in environment-controlled lab conditions. The light response curves measured using FPM approach coped well with that the curves measured using traditional gas exchange approach. Importantly, the FPM technique achieved an average throughput of 5.4 light response curves per hour, which was 3 times faster than the 1.8 light response curves per hour using the traditional method. Tillers s led at early morning had the highest photosynthesis, stomatal conductance and the lowest variability. In addition, even 12 h after s ling, there was no significant difference of photosynthesis rate between excised tillers and in situ. We finally investigated the genetic variations of photosynthetic traits across 568 F2 lines using the FPM technique and discussed the logistics of screening several hundred s les per day per instrumental unit using FPM to generate a wealth of photosynthetic phenotypic data, which might help to improve the selection power in large populations of rice with the ultimate aim of improving yield through improved photosynthesis. Here we developed a high-throughput method that can measure the rice leaf photosynthetic capacity approximately 10 times faster than traditional gas exchange approaches. Importantly, this method can overcome measurement errors caused by environmental heterogeneity under field conditions, and it is possible to measure 12 or more hours per day under lab conditions.
Publisher: Wiley
Date: 04-08-2014
DOI: 10.1111/WRE.12104
No related grants have been discovered for Dongliang Xiong.