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Gan SH, Sage RF. Stomatal response to VPD in C 4 plants with different biochemical sub-pathways. PLANT, CELL & ENVIRONMENT 2024; 47:3466-3477. [PMID: 38752440 DOI: 10.1111/pce.14952] [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: 12/18/2023] [Revised: 03/05/2024] [Accepted: 05/03/2024] [Indexed: 08/16/2024]
Abstract
C4 NAD-malic enzyme (NAD-ME) species occurs in drier regions and exhibit different drought responses compared to C4 NADP-malic enzyme (NADP-ME) species. However, a physiological mechanism explaining the geographical discrepancies remains uncertain. This study examined gas exchange patterns that might explain different distributions observed between two subtypes of C4 photosynthesis. We measured the response of leaf gas exchange to vapour pressure deficit (VPD) and CO2 in plants from six distinct C4 clades having closely related NAD-ME and NADP-ME species using a Li-Cor 6400 gas exchange system. We found that NAD-ME species exhibited greater relative reductions in stomatal conductance with increases in VPD than NADP-ME species but observed no consistent subtype differences in C4 cycle activity as indicated by the initial slope of the A response to intercellular CO2 concentration. Based on these results, we hypothesise the greater response of gs to increasing VPD may enable NAD-ME plants to outperform NADP-ME plants in hot, dry environments where VPD is normally high.
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Affiliation(s)
- Shu Han Gan
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology, Evolution & Environmental Biology, Columbia University, New York, New York, USA
| | - Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
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2
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Diao H, Cernusak LA, Saurer M, Gessler A, Siegwolf RTW, Lehmann MM. Dry inside: progressive unsaturation within leaves with increasing vapour pressure deficit affects estimation of key leaf gas exchange parameters. THE NEW PHYTOLOGIST 2024. [PMID: 39205457 DOI: 10.1111/nph.20078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Accepted: 08/08/2024] [Indexed: 09/04/2024]
Abstract
Climate change not only leads to higher air temperatures but also increases the vapour pressure deficit (VPD) of the air. Understanding the direct effect of VPD on leaf gas exchange is crucial for precise modelling of stomatal functioning. We conducted combined leaf gas exchange and online isotope discrimination measurements on four common European tree species across a VPD range of 0.8-3.6 kPa, while maintaining constant temperatures without soil water limitation. In addition to applying the standard assumption of saturated vapour pressure inside leaves (ei), we inferred ei from oxygen isotope discrimination of CO2 and water vapour. ei desaturated progressively with increasing VPD, consistently across species, resulting in an intercellular relative humidity as low as 0.73 ± 0.11 at the highest tested VPD. Assuming saturation of ei overestimated the extent of reductions in stomatal conductance and CO2 mole fraction inside leaves in response to increasing VPD compared with calculations that accounted for unsaturation. In addition, a significant decrease in mesophyll conductance with increasing VPD only occurred when the unsaturation of ei was considered. We suggest that the possibility of unsaturated ei should not be overlooked in measurements related to leaf gas exchange and in stomatal models, especially at high VPD.
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Affiliation(s)
- Haoyu Diao
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, 4878, Australia
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, 8092, Switzerland
| | - Rolf T W Siegwolf
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Marco M Lehmann
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
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3
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Kim GJ, Jo H, Cho MS, Noh NJ, Han SH, Khamzina A, Kim HS, Son Y. Photosynthetic responses of Larix kaempferi and Pinus densiflora seedlings are affected by summer extreme heat rather than by extreme precipitation. Sci Rep 2024; 14:5250. [PMID: 38438488 PMCID: PMC10912299 DOI: 10.1038/s41598-024-56120-3] [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: 07/03/2023] [Accepted: 02/29/2024] [Indexed: 03/06/2024] Open
Abstract
The frequency and intensity of summer extreme climate events are increasing over time, and have a substantial negative effect on plants, which may be evident in their impact on photosynthesis. Here, we examined the photosynthetic responses of Larix kaempferi and Pinus densiflora seedlings to extreme heat (+ 3 °C and + 6 °C), drought, and heavy rainfall by conducting an open-field multifactor experiment. Leaf gas exchange in L. kaempferi showed a decreasing trend under increasing temperature, showing a reduction in the stomatal conductance, transpiration rate, and net photosynthetic rate by 135.2%, 102.3%, and 24.8%, respectively, in the + 6 °C treatment compared to those in the control. In contrast, P. densiflora exhibited a peak function in the stomatal conductance and transpiration rate under + 3 °C treatment. Furthermore, both species exhibited increased total chlorophyll contents under extreme heat conditions. However, extreme precipitation had no marked effect on photosynthetic activities, given the overall favorable water availability for plants. These results indicate that while extreme heat generally reduces photosynthesis by triggering stomatal closure under high vapor pressure deficit, plants employ diverse stomatal strategies in response to increasing temperature, which vary among species. Our findings contribute to the understanding of mechanisms underlying the photosynthetic responses of conifer seedlings to summer extreme climate events.
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Affiliation(s)
- Gwang-Jung Kim
- Division of Environmental Science and Ecological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Heejae Jo
- Division of Environmental Science and Ecological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Min Seok Cho
- Forest Technology and Management Research Center, National Institute of Forest Science, Pocheon, 11186, Republic of Korea
- Research Planning and Coordination Division, National Institute of Forest Science, Seoul, 02455, Republic of Korea
| | - Nam Jin Noh
- Department of Forest Resources, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Seung Hyun Han
- Forest Technology and Management Research Center, National Institute of Forest Science, Pocheon, 11186, Republic of Korea
| | - Asia Khamzina
- Division of Environmental Science and Ecological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Hyung-Sub Kim
- Division of Environmental Science and Ecological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
- Institute of Life Science and Natural Resources Research, Korea University, Seoul, 02841, Republic of Korea
| | - Yowhan Son
- Division of Environmental Science and Ecological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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4
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Eyland D, Gambart C, Swennen R, Carpentier S. Unravelling the diversity in water usage among wild banana species in response to vapour pressure deficit. FRONTIERS IN PLANT SCIENCE 2023; 14:1068191. [PMID: 37670859 PMCID: PMC10475999 DOI: 10.3389/fpls.2023.1068191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 08/03/2023] [Indexed: 09/07/2023]
Abstract
The rise in global temperature is not only affecting plant functioning directly, but is also increasing air vapour pressure deficit (VPD). The yield of banana is heavily affected by water deficit but so far breeding programs have never addressed the issue of water deficit caused by high VPD. A reduction in transpiration at high VPD has been suggested as a key drought tolerance breeding trait to avoid excessive water loss, hydraulic failure and to increase water use efficiency. In this study, stomatal and transpiration responses under increasing VPD at the leaf and whole-plant level of 8 wild banana (sub)species were evaluated, displaying significant differences in stomatal reactivity. Three different phenotypic groups were identified under increasing VPD. While (sub)species of group III maintained high transpiration rates under increasing VPD, M. acuminata ssp. errans (group I), M. acuminata ssp. zebrina (group II) and M. balbisiana (group II) showed the highest transpiration rate limitations to increasing VPD. In contrast to group I, group II only showed strong reductions at high VPD levels, limiting the cost of reduced photosynthesis and strongly increasing their water use efficiency. M. acuminata ssp. zebrina and M. balbisiana thus show the most favourable responses. This study provides a basis for the identification of potential parent material in gene banks for breeding future-proof bananas that cope better with lack of water.
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Affiliation(s)
- David Eyland
- Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, KU Leuven, Heverlee, Belgium
| | - Clara Gambart
- Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, KU Leuven, Heverlee, Belgium
| | - Rony Swennen
- Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, KU Leuven, Heverlee, Belgium
- International Institute of Tropical Agriculture, Banana Breeding, Kampala, Uganda
| | - Sebastien Carpentier
- Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, KU Leuven, Heverlee, Belgium
- Bioversity International, Biodiversity for Food and Agriculture, Leuven, Belgium
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5
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Celiktopuz E. Determination of drought tolerance of different strawberry genotypes. PeerJ 2023; 11:e14972. [PMID: 36874961 PMCID: PMC9983431 DOI: 10.7717/peerj.14972] [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: 08/01/2022] [Accepted: 02/07/2023] [Indexed: 03/06/2023] Open
Abstract
Strawberry production future depends on productive, high quality and drought tolerant varieties. The goal of this study was to determine the most suitable variety by determining the yield and photosynthetic responses (net photosynthesis (Pn), stomatal conductance (gs), and transpiration rate (E)) of four strawberry genotypes with different characteristics (Rubygem, Festival; 33, and 59) at two different irrigation levels (IR50: water stress (WS), IR100: well-watered (WW)). It was also aimed to prepare the irrigation program by making use of the crop water stress index (CWSI). The trial was conducted at the Agronomic Research Area, University of Çukurova, Turkey during 2019-2020 experimental year. The trial was implemented as a 4 × 2 factorial scheme of genotypes and irrigation levels, in a split-plot design. Genotype Rubygem had the highest canopy temperature (Tc)-air temperature (Ta), whereas genotype 59 had the lowest, indicating that genotype 59 has better ability to thermoregulate leaf temperatures. Moreover, yield, Pn, and E were found to have a substantial negative relationship with Tc-Ta. WS reduced yield, Pn, gs, and E by 36%, 37%, 39%, and 43%, respectively, whereas it increased CWSI (22%) and irrigation water use efficiency (IWUE) (6%). Besides, the optimal time to measure leaf surface temperature of strawberries is around 1:00 pm and strawberry irrigation management might be maintained under the high tunnel in Mediterranean utilizing CWSI values between 0.49 and 0.63. Although genotypes had varying drought tolerance, the genotype 59 had the strongest yield and photosynthetic performances under both WW and WS conditions. Furthermore, 59 had highest IWUE and lowest CWSI in the WS conditions, proving to be the most drought tolerant genotype in this research.
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Affiliation(s)
- Eser Celiktopuz
- Biological and Agricultural Engineering, Texas A&M University, College Station, TX, United States.,Agricultural Structures and Irrigation, Cukurova University, Adana, Turkey
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6
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Jin C, Zha T, Bourque CPA, Jia X, Tian Y, Liu P, Li X, Liu X, Guo X, Xu M, Kang X, Guo Z, Wang N. Temporal heterogeneity in photosystem II photochemistry in Artemisia ordosica under a fluctuating desert environment. FRONTIERS IN PLANT SCIENCE 2022; 13:1057943. [PMID: 36407597 PMCID: PMC9670136 DOI: 10.3389/fpls.2022.1057943] [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: 09/30/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Acclimation strategies in xerophytic plants to stressed environmental conditions vary with temporal scales. Our understanding of environmentally-induced variation in photosystem II (PSII) processes as a function of temporal scales is limited, as most studies have thus far been based on short-term, laboratory-controlled experiments. In a study of PSII processes, we acquired near-continuous, field-based measurements of PSII-energy partitioning in a dominant desert-shrub species, namely Artemisia ordosica, over a six-year period from 2012-2017. Continuous-wavelet transformation (CWT) and wavelet coherence analyses (WTC) were employed to examine the role of environmental variables in controlling the variation in the three main PSII-energy allocation pathways, i.e., photochemical efficiency and regulated and non-regulated thermal dissipation, i.e., Φ PSII, Φ NPQ, and Φ NO, respectively, across a time-frequency domain from hours to years. Convergent cross mapping (CCM) was subsequently used to isolate cause-and-effect interactions in PSII-energy partitioning response. The CWT method revealed that the three PSII-energy allocation pathways all had distinct daily periodicities, oscillating abruptly at intermediate timescales from days to weeks. On a diurnal scale, WTC revealed that all three pathways were influenced by photosynthetically active radiation (PAR), air temperature (T a), and vapor pressure deficit (VPD). By comparing associated time lags for the three forms of energy partitioning at diurnal scales, revealed that the sensitivity of response was more acutely influenced by PAR, declining thereafter with the other environmental variables, such that the order of influence was greatest for T a, followed by VPD, and then soil water content (SWC). PSII-energy partitioning on a seasonal scale, in contrast, displayed greater variability among the different environmental variables, e.g., Φ PSII and Φ NO being more predisposed to changes in T a, and Φ NPQ to changes in VPD. CCM confirmed the causal relationship between pairings of PSII-energy allocation pathways, according to shrub phenology. A. ordosica is shown to have an innate ability to (i) repair damaged PSII-photochemical apparatus (maximum quantum yield of PSII photochemistry, with F v/F m > 0.78), and (ii) acclimatize to excessive PAR, dry-air conditions, and prolonged drought. A. ordosica is relatively sensitive to extreme temperature and exhibits photoinhibition.
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Affiliation(s)
- Chuan Jin
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Tianshan Zha
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory for Soil and Water Conservation, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Charles P.-A. Bourque
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, NB, Canada
| | - Xin Jia
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory for Soil and Water Conservation, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Yun Tian
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory for Soil and Water Conservation, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Peng Liu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xinhao Li
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xinyue Liu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xiaonan Guo
- School of Land Science and Space Planning, Hebei GEO University, Shijiazhuang, China
| | - Mingze Xu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xiaoyu Kang
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, NB, Canada
| | - Zifan Guo
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Ning Wang
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
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7
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Davidson KJ, Lamour J, Rogers A, Serbin SP. Late-day measurement of excised branches results in uncertainty in the estimation of two stomatal parameters derived from response curves in Populus deltoides Bartr. × Populus nigra L. TREE PHYSIOLOGY 2022; 42:1377-1395. [PMID: 35134232 DOI: 10.1093/treephys/tpac006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Many terrestrial biosphere models depend on an understanding of the relationship between stomatal conductance and photosynthesis. However, unlike the measurement of photosynthetic parameters, such as the maximum carboxylation capacity, where standard methods (e.g., CO2 response or ACi curves) are widely accepted, a consensus method for empirically measuring parameters representing stomatal response has not yet emerged. Most models of stomatal response to environment represent stomatal conductance as being bounded by a lower intercept parameter (g0), and linearly scaled based on a multivariate term described by the stomatal slope parameter (g1). Here we employ the widely used Unified Stomatal Optimization model, to test whether g1 and g0 parameters are impacted by the choice of measurement method, either on an intact branch or a cut branch segment stored in water. We measured paired stomatal response curves on intact and excised branches of a hybrid poplar clone (Populus deltoides Bartr. × Populus nigra L. OP367), measured twice over a diurnal period. We found that predawn branch excision did not significantly affect measured g0 and g1 when measured within 4 h of excision. Measurement in the afternoon resulted in significantly higher values of g1 and lower values of g0, with values changing by 55% and 56%, respectively. Excision combined with afternoon measurement resulted in a marked effect on parameter estimates, with g1 increasing 89% from morning to afternoon and a 25% lower g1 for cut branches than those measured in situ. We also show that in hybrid poplar the differences in parameter estimates obtained from plants measured under different conditions can directly impact models of canopy function, reducing modeled transpiration by 18% over a simulated 12.5-h period. Although these results are only for a single isohydric woody species, our findings suggest that stomatal optimality parameters may not remain constant throughout the day.
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Affiliation(s)
- Kenneth J Davidson
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973, USA
- Department of Ecology and Evolution, Stony Brook University, 650 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Julien Lamour
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Alistair Rogers
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Shawn P Serbin
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973, USA
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8
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Grossiord C, Buckley TN, Cernusak LA, Novick KA, Poulter B, Siegwolf RTW, Sperry JS, McDowell NG. Plant responses to rising vapor pressure deficit. THE NEW PHYTOLOGIST 2020; 226:1550-1566. [PMID: 32064613 DOI: 10.1111/nph.16485] [Citation(s) in RCA: 355] [Impact Index Per Article: 88.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 02/04/2020] [Indexed: 05/24/2023]
Abstract
Recent decades have been characterized by increasing temperatures worldwide, resulting in an exponential climb in vapor pressure deficit (VPD). VPD has been identified as an increasingly important driver of plant functioning in terrestrial biomes and has been established as a major contributor in recent drought-induced plant mortality independent of other drivers associated with climate change. Despite this, few studies have isolated the physiological response of plant functioning to high VPD, thus limiting our understanding and ability to predict future impacts on terrestrial ecosystems. An abundance of evidence suggests that stomatal conductance declines under high VPD and transpiration increases in most species up until a given VPD threshold, leading to a cascade of subsequent impacts including reduced photosynthesis and growth, and higher risks of carbon starvation and hydraulic failure. Incorporation of photosynthetic and hydraulic traits in 'next-generation' land-surface models has the greatest potential for improved prediction of VPD responses at the plant- and global-scale, and will yield more mechanistic simulations of plant responses to a changing climate. By providing a fully integrated framework and evaluation of the impacts of high VPD on plant function, improvements in forecasting and long-term projections of climate impacts can be made.
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Affiliation(s)
- Charlotte Grossiord
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
- École Polytechnique Fédérale de Lausanne EPFL, School of Architecture, Civil and Environmental Engineering ENAC, 1015, Lausanne, Switzerland
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, Davis, CA, 95616, USA
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, 4814, Australia
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Benjamin Poulter
- Biospheric Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - Rolf T W Siegwolf
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - John S Sperry
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Nate G McDowell
- Earth Systems Science Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
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9
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Variability and Plasticity in Cuticular Transpiration and Leaf Permeability Allow Differentiation of Eucalyptus Clones at an Early Age. FORESTS 2019. [DOI: 10.3390/f11010009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background and Objectives. Water stress is a major constraining factor of Eucalyptus plantations’ growth. Within a genetic improvement program, the selection of genotypes that improve drought resistance would help to improve productivity and to expand plantations. Leaf characteristics, among others, are important factors to consider when evaluating drought resistance evaluation, as well as the clone’s ability to modify leaf properties (e.g., stomatal density (d) and size, relative water content at the time of stomatal closure (RWCc), cuticular transpiration (Ec), specific leaf area (SLA)) according to growing conditions. Therefore, this study aimed at analyzing these properties in nursery plants of nine high-productivity Eucalyptus clones. Material and Methods: Five Eucalyptus globulus Labill. clones and four hybrids clones (Eucalyptus urophylla S.T. Blake × Eucalyptus grandis W. Hill ex Maiden, 12€; Eucalyptus urograndis × E. globulus, HE; Eucalyptus dunnii Maiden–E. grandis × E. globulus, HG; Eucalyptus saligna Sm. × Eucalyptus maidenii F. Muell., HI) were studied. Several parameters relating to the aforementioned leaf traits were evaluated for 2.5 years. Results: Significant differences in stomatal d and size, RWCc, Ec, and SLA among clones (p < 0.001) and according to the dates (p < 0.001) were obtained. Each clone varied seasonally the characteristics of its new developing leaves to acclimatize to the growth conditions. The pore opening surface potential (i.e., the stomatal d × size) did not affect transpiration rates with full open stomata, so the water transpired under these conditions might depend on other leaf factors. The clones HE, HG, and 12€ were the ones that differed the most from the drought resistant E. globulus control clone (C14). Those three clones showed lower leaf epidermis impermeability (HE, HG, 12€), higher SLA (12€, HG), and lower stomatal control under moderate water stress (HE, HG) not being, therefore, good candidates to be selected for drought resistance, at least for these measured traits. Conclusions: These parameters can be incorporated into genetic selection and breeding programs, especially Ec, SLA, RWCc, and stomatal control under moderate water stress.
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10
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Li X, Xiao J, He B, Altaf Arain M, Beringer J, Desai AR, Emmel C, Hollinger DY, Krasnova A, Mammarella I, Noe SM, Ortiz PS, Rey-Sanchez AC, Rocha AV, Varlagin A. Solar-induced chlorophyll fluorescence is strongly correlated with terrestrial photosynthesis for a wide variety of biomes: First global analysis based on OCO-2 and flux tower observations. GLOBAL CHANGE BIOLOGY 2018; 24:3990-4008. [PMID: 29733483 DOI: 10.1111/gcb.14297] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/15/2018] [Accepted: 04/18/2018] [Indexed: 05/27/2023]
Abstract
Solar-induced chlorophyll fluorescence (SIF) has been increasingly used as a proxy for terrestrial gross primary productivity (GPP). Previous work mainly evaluated the relationship between satellite-observed SIF and gridded GPP products both based on coarse spatial resolutions. Finer resolution SIF (1.3 km × 2.25 km) measured from the Orbiting Carbon Observatory-2 (OCO-2) provides the first opportunity to examine the SIF-GPP relationship at the ecosystem scale using flux tower GPP data. However, it remains unclear how strong the relationship is for each biome and whether a robust, universal relationship exists across a variety of biomes. Here we conducted the first global analysis of the relationship between OCO-2 SIF and tower GPP for a total of 64 flux sites across the globe encompassing eight major biomes. OCO-2 SIF showed strong correlations with tower GPP at both midday and daily timescales, with the strongest relationship observed for daily SIF at the 757 nm (R2 = 0.72, p < 0.0001). Strong linear relationships between SIF and GPP were consistently found for all biomes (R2 = 0.57-0.79, p < 0.0001) except evergreen broadleaf forests (R2 = 0.16, p < 0.05) at the daily timescale. A higher slope was found for C4 grasslands and croplands than for C3 ecosystems. The generally consistent slope of the relationship among biomes suggests a nearly universal rather than biome-specific SIF-GPP relationship, and this finding is an important distinction and simplification compared to previous results. SIF was mainly driven by absorbed photosynthetically active radiation and was also influenced by environmental stresses (temperature and water stresses) that determine photosynthetic light use efficiency. OCO-2 SIF generally had a better performance for predicting GPP than satellite-derived vegetation indices and a light use efficiency model. The universal SIF-GPP relationship can potentially lead to more accurate GPP estimates regionally or globally. Our findings revealed the remarkable ability of finer resolution SIF observations from OCO-2 and other new or future missions (e.g., TROPOMI, FLEX) for estimating terrestrial photosynthesis across a wide variety of biomes and identified their potential and limitations for ecosystem functioning and carbon cycle studies.
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Affiliation(s)
- Xing Li
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire
- School of Resources and Environment, University of Electronic Science and Technology of China, Chengdu, China
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire
| | - Binbin He
- School of Resources and Environment, University of Electronic Science and Technology of China, Chengdu, China
- Center for Information Geoscience, University of Electronic Science and Technology of China, Chengdu, China
| | - M Altaf Arain
- McMaster Centre for Climate Change and School of Geography and Earth Sciences, McMaster University, Hamilton, ON, Canada
| | - Jason Beringer
- The UWA school of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
| | - Ankur R Desai
- Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Carmen Emmel
- Department of Environmental Systems Science, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - David Y Hollinger
- Northern Research Station, USDA Forest Service, Durham, New Hampshire
| | - Alisa Krasnova
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Ivan Mammarella
- Faculty of Science, Institute for Atmosphere and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
| | - Steffen M Noe
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Penélope Serrano Ortiz
- Instituto Interuniversitario de Investigación del Sistema Tierra en Andalucía (IISTA-CEAMA), Universidad de Granada, Granada, Spain
| | - A Camilo Rey-Sanchez
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio
| | - Adrian V Rocha
- Department of Biological Sciences and the Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana
| | - Andrej Varlagin
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
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11
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Song L, Guanter L, Guan K, You L, Huete A, Ju W, Zhang Y. Satellite sun-induced chlorophyll fluorescence detects early response of winter wheat to heat stress in the Indian Indo-Gangetic Plains. GLOBAL CHANGE BIOLOGY 2018; 24:4023-4037. [PMID: 29749021 DOI: 10.1111/gcb.14302] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/17/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Extremely high temperatures represent one of the most severe abiotic stresses limiting crop productivity. However, understanding crop responses to heat stress is still limited considering the increases in both the frequency and severity of heat wave events under climate change. This limited understanding is partly due to the lack of studies or tools for the timely and accurate monitoring of crop responses to extreme heat over broad spatial scales. In this work, we use novel spaceborne data of sun-induced chlorophyll fluorescence (SIF), which is a new proxy for photosynthetic activity, along with traditional vegetation indices (Normalized Difference Vegetation Index NDVI and Enhanced Vegetation Index EVI) to investigate the impacts of heat stress on winter wheat in northwestern India, one of the world's major wheat production areas. In 2010, an abrupt rise in temperature that began in March adversely affected the productivity of wheat and caused yield losses of 6% compared to previous year. The yield predicted by satellite observations of SIF decreased by approximately 13.9%, compared to the 1.2% and 0.4% changes in NDVI and EVI, respectively. During early stage of this heat wave event in early March 2010, the SIF observations showed a significant reduction and earlier response, while NDVI and EVI showed no changes and could not capture the heat stress until late March. The spatial patterns of SIF anomalies closely tracked the temporal evolution of the heat stress over the study area. Furthermore, our results show that SIF can provide large-scale, physiology-related wheat stress response as indicated by the larger reduction in fluorescence yield (SIFyield ) than fraction of photosynthetically active radiation during the grain-filling phase, which may have eventually led to the reduction in wheat yield in 2010. This study implies that satellite observations of SIF have great potential to detect heat stress conditions in wheat in a timely manner and assess their impacts on wheat yields at large scales.
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Affiliation(s)
- Lian Song
- International Institute for Earth System Sciences, Nanjing University, Nanjing, China
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
| | - Luis Guanter
- Helmholtz Center Potsdam, Remote Sensing Section, GFZ German Research Center for Geosciences, Potsdam, Germany
| | - Kaiyu Guan
- Department of Natural Resources and Environmental Sciences and National Center for Supercomputing Applications, University of Illinois at Urbana Champaign, Urbana, Illinois
| | - Liangzhi You
- Macro Agriculture Research Institute, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
- International Food Policy Research Institute, Washington, District of Columbia
| | - Alfredo Huete
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Haymarket, NSW, Australia
| | - Weimin Ju
- International Institute for Earth System Sciences, Nanjing University, Nanjing, China
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
| | - Yongguang Zhang
- International Institute for Earth System Sciences, Nanjing University, Nanjing, China
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
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12
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Fukuda A, Kondo K, Ikka T, Takai T, Tanabata T, Yamamoto T. A novel QTL associated with rice canopy temperature difference affects stomatal conductance and leaf photosynthesis. BREEDING SCIENCE 2018; 68:305-315. [PMID: 30100797 PMCID: PMC6081301 DOI: 10.1270/jsbbs.17129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/31/2018] [Indexed: 05/20/2023]
Abstract
Canopy temperature can be a good indicator of stomatal conductance. To understand the genetic basis of phenotypic differences in stomatal conductance between average and high-yielding rice (Oryza sativa L.) cultivars, we conducted a quantitative trait locus (QTL) analysis of canopy temperature. We developed reciprocal series of backcross inbred lines (BC1F6) derived from a cross between the average-yielding japonica cultivar 'Koshihikari' and the high-yielding indica cultivar 'Takanari'. A stable QTL, qCTd11 (QTL for canopy temperature difference on chromosome 11) on the short arm of chromosome 11, accounted for 10.4 and 19.8% of the total phenotypic variance in the two lines; the 'Takanari' allele decreased the canopy temperature difference value. A chromosome segment substitution line carrying the Takanari qCTd11 showed a greater reduction in canopy temperature than 'Koshihikari', and had higher stomatal conductance and photosynthetic rate. These results suggest that qCTd11 is not only involved in canopy temperature, but is also involved in both stomatal conductance and photosynthetic rate.
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Affiliation(s)
- Atsunori Fukuda
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
| | - Katsuhiko Kondo
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
| | - Takashi Ikka
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
| | - Toshiyuki Takai
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
| | - Takanari Tanabata
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
| | - Toshio Yamamoto
- Institute of Crop Science, NARO,
2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602,
Japan
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13
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Wu G, Liu H, Hua L, Luo Q, Lin Y, He P, Feng S, Liu J, Ye Q. Differential Responses of Stomata and Photosynthesis to Elevated Temperature in Two Co-occurring Subtropical Forest Tree Species. FRONTIERS IN PLANT SCIENCE 2018; 9:467. [PMID: 29740458 PMCID: PMC5928911 DOI: 10.3389/fpls.2018.00467] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/23/2018] [Indexed: 05/03/2023]
Abstract
Global warming could increase leaf transpiration and soil evaporation, which can potentially cause water deficit to plants. As valves, leaf stomata can control plant water loss and carbon gain, particularly under water stress conditions. To investigate the responses of stomata to elevated temperature in Schima superba and Syzygium rehderianum, two co-occurring subtropical forest dominant tree species, functional traits related to gas exchange, stomatal anatomy, and drought resistance were measured under control and warming environment (ca. 2°C higher). We found that leaf water potential at both predawn and midday significantly decreased for the two species grown under warming conditions compared with those grown in the control environment. Warming resulted in significant decrease of stomatal size in S. rehderianum, but had no obvious effect on that of S. superba. By contrast, stomatal density of S. superba significantly decreased under warming conditions, while non-significant change was observed for S. rehderianum. In addition, warming significantly reduced photosynthetic rate, stomatal conductance, and stomatal sensitivity to leaf water potential of S. superba, but had non-significant effects on those of S. rehderianum. Overall, our results demonstrated that, confronting water deficit caused by elevated temperature, the two co-occurring subtropical tree species responded differently through the adjustment of stomatal morphology and photosynthetic function. Consequently, S. rehderianum was able to maintain similar carbon assimilation as under control environment, while S. superba showed a decrease in carbon gain that might bring adverse effect on its dominancy in subtropical forest community under future climate change.
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Affiliation(s)
- Guilin Wu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Lei Hua
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Luo
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yixue Lin
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Pengcheng He
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Shiwei Feng
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China
| | - Juxiu Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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Oksanen E, Lihavainen J, Keinänen M, Keski-Saari S, Kontunen-Soppela S, Sellin A, Sõber A. Northern Forest Trees Under Increasing Atmospheric Humidity. PROGRESS IN BOTANY 2018:317-336. [PMID: 0 DOI: 10.1007/124_2017_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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15
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Canopy Transpiration and Stomatal Responses to Prolonged Drought by a Dominant Desert Species in Central Asia. WATER 2017. [DOI: 10.3390/w9060404] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Bourne AE, Haigh AM, Ellsworth DS. Stomatal sensitivity to vapour pressure deficit relates to climate of origin in Eucalyptus species. TREE PHYSIOLOGY 2015; 35:266-278. [PMID: 25769338 DOI: 10.1093/treephys/tpv014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/24/2015] [Indexed: 06/04/2023]
Abstract
Selecting plantation species to balance water use and production requires accurate models for predicting how species will tolerate and respond to environmental conditions. Although interspecific variation in water use occurs, species-specific parameters are rarely incorporated into physiologically based models because often the appropriate species parameters are lacking. To determine the physiological control over water use in Eucalyptus, five stands of Eucalyptus species growing in a common garden were measured for sap flux rates and their stomatal response to vapour pressure deficit (D) was assessed. Maximal canopy conductance and whole-canopy stomatal sensitivity to D and reduced water availability were lower in species originating from more arid climates of origin than those from humid climates. Species from humid climates showed a larger decline in maximal sap flux density (JSmax) with reduced water availability, and a lower D at which stomatal closure occurred than species from more arid climates, implying larger sensitivity to water availability and D in these species. We observed significant (P < 0.05) correlations of species climate of origin with mean vessel diameter (R(2) = 0.90), stomatal sensitivity to D (R(2) = 0.83) and the size of the decline in JSmax to restricted water availability (R(2) = 0.94). Thus aridity of climate of origin appears to have a selective role in constraining water-use response among the five Eucalyptus plantation species. These relationships emphasize that within this congeneric group of species, climate aridity constrains water use. These relationships have implications for species choices for tree plantation success against drought-induced losses and the ability to manage Eucalyptus plantations against projected changes in water availability and evaporation in the future.
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Affiliation(s)
- Aimee E Bourne
- Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Anthony M Haigh
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
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17
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Adhikari A, White JD. Plant water use characteristics of five dominant shrub species of the Lower Rio Grande Valley, Texas, USA: implications for shrubland restoration and conservation. CONSERVATION PHYSIOLOGY 2014; 2:cou005. [PMID: 27293626 PMCID: PMC4806726 DOI: 10.1093/conphys/cou005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 01/14/2014] [Accepted: 01/20/2014] [Indexed: 05/30/2023]
Abstract
The biogeographic distribution of plant species is inherently associated with the plasticity of physiological adaptations to environmental variation. For semi-arid shrublands with a legacy of saline soils, characterization of soil water-tolerant shrub species is necessary for habitat restoration given future projection of increased drought magnitude and persistence in these ecosystems. Five dominant native shrub species commonly found in the Lower Rio Grande Valley, TX, USA, were studied, namely Acacia farnesiana, Celtis ehrenbergiana, Forestiera angustifolia, Parkinsonia aculeata and Prosopis glandulosa. To simulate drought conditions, we suspended watering of healthy, greenhouse-grown plants for 4 weeks. Effects of soil salinity were also studied by dosing plants with 10% NaCl solution with suspended watering. For soil water deficit treatment, the soil water potential of P. glandulosa was the highest (-1.20 MPa), followed by A. farnesiana (-4.69 MPa), P. aculeata (-5.39 MPa), F. angustifolia (-6.20 MPa) and C. ehrenbergiana (-10.02 MPa). For the soil salinity treatment, P. glandulosa also had the highest soil water potential value (-1.60 MPa), followed by C. ehrenbergiana (-1.70 MPa), A. farnesiana (-1.84 MPa), P. aculeata (-2.04 MPa) and F. angustifolia (-6.99 MPa). Within the species, only C. ehrenbergiana and F. angustifolia for soil water deficit treatment and A. farnesiana for the salinity treatment had significantly lower soil water potential after 4 weeks of treatment (P < 0.05). We found that soil water potential, stomatal conductance and net photosynthesis of the species significantly reduced over time for both treatments (P < 0.05). We conclude that while all species exhibited capacities to withstand current water availability, some species demonstrated limited tolerance for extreme water stress that may be important for management of future shrub diversity in Lower Rio Grande Valley.
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Affiliation(s)
- Arjun Adhikari
- The Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Joseph D. White
- The Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
- The Institute of Ecological, Earth, and Environmental Sciences, Baylor University, One Bear Place #97205, Waco, TX 76798, USA
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18
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Effects of elevated pressure on rate of photosynthesis during plant growth. J Biotechnol 2013; 168:135-41. [PMID: 23994480 DOI: 10.1016/j.jbiotec.2013.08.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 07/08/2013] [Accepted: 08/06/2013] [Indexed: 11/21/2022]
Abstract
The aim of this study is to investigate the effects of an artificially controlled environment, particularly elevated total pressure, on net photosynthesis and respiration during plant growth. Pressure directly affects not only cells and organelles in leaves but also the diffusion coefficients and degrees of solubility of CO2 and O2. In this study, the effects of elevated total pressure on the rates of net photosynthesis and respiration of a model plant, Arabidopsis thaliana, were investigated in a chamber that newly developed in this study to control the total pressure. The results clearly showed that the rate of respiration decreased linearly with increasing total pressure at a high humidity. The rate of respiration decreased linearly with increasing total pressure up to 0.2 MPa, and increased with increasing total pressure from 0.3 to 0.5 MPa at a low humidity. The rate of net photosynthesis decreased linearly with increasing total pressure under a constant partial pressure of CO2 at 40 Pa. On the other hand, the rate of net photosynthesis was clearly increased by up to 1.6-fold with increasing total pressure and partial pressure of CO2.
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Wu XY, Kuai BK, Jia JZ, Jing HC. Regulation of leaf senescence and crop genetic improvement. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012. [PMID: 23131150 DOI: 10.1016/j.envexpbot.2010.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Leaf senescence can impact crop production by either changing photosynthesis duration, or by modifying the nutrient remobilization efficiency and harvest index. The doubling of the grain yield in major cereals in the last 50 years was primarily achieved through the extension of photosynthesis duration and the increase in crop biomass partitioning, two things that are intrinsically coupled with leaf senescence. In this review, we consider the functionality of a leaf as a function of leaf age, and divide a leaf's life into three phases: the functionality increasing phase at the early growth stage, the full functionality phase, and the senescence and functionality decreasing phase. A genetic framework is proposed to describe gene actions at various checkpoints to regulate leaf development and senescence. Four categories of genes contribute to crop production: those which regulate (I) the speed and transition of early leaf growth, (II) photosynthesis rate, (III) the onset and (IV) the progression of leaf senescence. Current advances in isolating and characterizing senescence regulatory genes are discussed in the leaf aging and crop production context. We argue that the breeding of crops with leaf senescence ideotypes should be an essential part of further crop genetic improvement.
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Affiliation(s)
- Xiao-Yuan Wu
- The Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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20
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Singh SK, Raja Reddy K. Regulation of photosynthesis, fluorescence, stomatal conductance and water-use efficiency of cowpea (Vigna unguiculata [L.] Walp.) under drought. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 105:40-50. [DOI: 10.1016/j.jphotobiol.2011.07.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 06/23/2011] [Accepted: 07/01/2011] [Indexed: 10/18/2022]
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21
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Sage RF, Kocacinar F, Kubien DS. Chapter 10 C4 Photosynthesis and Temperature. C4 PHOTOSYNTHESIS AND RELATED CO2 CONCENTRATING MECHANISMS 2010. [DOI: 10.1007/978-90-481-9407-0_10] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Ozone risk for crops and pastures in present and future climates. Naturwissenschaften 2008; 96:173-94. [DOI: 10.1007/s00114-008-0468-7] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 10/29/2008] [Accepted: 11/01/2008] [Indexed: 10/21/2022]
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23
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Photosynthetic response to dynamic changes of light and air humidity in two moss species from the Tibetan Plateau. Ecol Res 2008. [DOI: 10.1007/s11284-008-0535-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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de Magalhães Erismann N, Caruso Machado E, Sant' Anna Tucci ML. Photosynthetic limitation by CO2 diffusion in drought stressed orange leaves on three rootstocks. PHOTOSYNTHESIS RESEARCH 2008; 96:163-172. [PMID: 18373209 DOI: 10.1007/s11120-008-9297-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 03/17/2008] [Indexed: 05/26/2023]
Abstract
Photosynthetic limitations under moderate water deficit were evaluated in 'Valência' orange trees grafted on three different rootstocks, in pots. Net CO(2) assimilation rate (A (N)), stomatal conductance (g (s)), and photosystem II (PS II) operating efficiency (F'(q)/F'(m)) in response to changing intercellular CO(2 ) partial pressure (C (i)) were analyzed under controlled conditions. Drought decreased A (N) and g (s), whereas F'(q)/F'(m) remained unchanged. This resulted in a higher ratio between electron transport rate (ETR) and gross CO(2) assimilation rate (A (G)). Since the comparison of A (N)-C (i) gas exchange curves can lead to incorrect conclusions, a normalization of C (i) values (C(i)(f)) of stressed leaves was applied. Then, the relationship established for irrigated trees between the ETR/A (G) ratio and C (i) was used to estimate the C(i)(f) from ETR/A (G) ratios measured under water stress. The response of A (N) to C(i)(f) suggests that the CO(2) diffusional restriction is the main factor that limits photosynthesis in orange leaves under moderate water deficit.
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Affiliation(s)
- Norma de Magalhães Erismann
- Centro de Pesquisa e Desenvolvimento de Ecofisiologia e Biofísica, Instituto Agronômico (IAC), Caixa Postal 28, 13012-970 Campinas, SP, Brasil.
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25
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Aldea M, Hamilton JG, Resti JP, Zangerl AR, Berenbaum MR, Frank TD, Delucia EH. Comparison of photosynthetic damage from arthropod herbivory and pathogen infection in understory hardwood saplings. Oecologia 2006; 149:221-32. [PMID: 16758220 DOI: 10.1007/s00442-006-0444-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Accepted: 04/20/2006] [Indexed: 10/24/2022]
Abstract
Arthropods and pathogens damage leaves in natural ecosystems and may reduce photosynthesis at some distance away from directly injured tissue. We quantified the indirect effects of naturally occurring biotic damage on leaf-level photosystem II operating efficiency (Phi(PSII)) of 11 understory hardwood tree species using chlorophyll fluorescence and thermal imaging. Maps of fluorescence parameters and leaf temperature were stacked for each leaf and analyzed using a multivariate method adapted from the field of quantitative remote sensing. Two tree species, Quercus velutina and Cercis canadensis, grew in plots exposed to ambient and elevated atmospheric CO(2) and were infected with Phyllosticta fungus, providing a limited opportunity to examine the potential interaction of this element of global change and biotic damage on photosynthesis. Areas surrounding damage had depressed Phi(PSII )and increased down-regulation of PSII, and there was no evidence of compensation in the remaining tissue. The depression of Phi(PSII) caused by fungal infections and galls extended >2.5 times further from the visible damage and was approximately 40% more depressed than chewing damage. Areas of depressed Phi(PSII) around fungal infections on oaks growing in elevated CO(2) were more than 5 times larger than those grown in ambient conditions, suggesting that this element of global change may influence the indirect effects of biotic damage on photosynthesis. For a single Q. velutina sapling, the area of reduced Phi(PSII) was equal to the total area directly damaged by insects and fungi. Thus, estimates based only on the direct effect of biotic agents may greatly underestimate their actual impact on photosynthesis.
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Affiliation(s)
- Mihai Aldea
- Program in Ecology and Evolutionary Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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26
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Eamus D, Shanahan ST. A rate equation model of stomatal responses to vapour pressure deficit and drought. BMC Ecol 2002; 2:8. [PMID: 12153703 PMCID: PMC126274 DOI: 10.1186/1472-6785-2-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2002] [Accepted: 08/01/2002] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Stomata respond to vapour pressure deficit (D) - when D increases, stomata begin to close. Closure is the result of a decline in guard cell turgor, but the link between D and turgor is poorly understood. We describe a model for stomatal responses to increasing D based upon cellular water relations. The model also incorporates impacts of increasing levels of water stress upon stomatal responses to increasing D. RESULTS The model successfully mimics the three phases of stomatal responses to D and also reproduces the impact of increasing plant water deficit upon stomatal responses to increasing D. As water stress developed, stomata regulated transpiration at ever decreasing values of D. Thus, stomatal sensitivity to D increased with increasing water stress. Predictions from the model concerning the impact of changes in cuticular transpiration upon stomatal responses to increasing D are shown to conform to experimental data. Sensitivity analyses of stomatal responses to various parameters of the model show that leaf thickness, the fraction of leaf volume that is air-space, and the fraction of mesophyll cell wall in contact with air have little impact upon behaviour of the model. In contrast, changes in cuticular conductance and membrane hydraulic conductivity have significant impacts upon model behaviour. CONCLUSION Cuticular transpiration is an important feature of stomatal responses to D and is the cause of the 3 phase response to D. Feed-forward behaviour of stomata does not explain stomatal responses to D as feedback, involving water loss from guard cells, can explain these responses.
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Affiliation(s)
- D Eamus
- Institute for Water and Environmental Resource Management, University of Technology, Sydney, Australia
| | - ST Shanahan
- School of Informatics, Northern Territory University, Darwin NT 0909
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27
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MEDRANO H, ESCALONA JM, BOTA J, GULÍAS J, FLEXAS J. Regulation of photosynthesis of C3 plants in response to progressive drought: stomatal conductance as a reference parameter. ANNALS OF BOTANY 2002; 89 Spec No:895-905. [PMID: 12102515 PMCID: PMC4233802 DOI: 10.1093/aob/mcf079] [Citation(s) in RCA: 276] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We review the photosynthetic responses to drought in field-grown grapevines and other species. As in other plant species, the relationship between photosynthesis and leaf water potential and/or relative water content in field-grown grapevines depends on conditions during plant growth and measurements. However, when light-saturated stomatal conductance was used as the reference parameter to reflect drought intensity, a common response pattern was observed that was much less dependent on the species and conditions. Many photosynthetic parameters (e.g. electron transport rate, carboxylation efficiency, intrinsic water-use efficiency, respiration rate in the light, etc.) were also more strongly correlated with stomatal conductance than with water status itself. Moreover, steady-state chlorophyll fluorescence also showed a high dependency on stomatal conductance. This is discussed in terms of an integrated down-regulation of the whole photosynthetic process by CO2 availability in the mesophyll. A study with six Mediterranean shrubs revealed that, in spite of some marked interspecific differences, all followed the same pattern of dependence of photosynthetic processes on stomatal conductance, and this pattern was quite similar to that of grapevines. Further analysis of the available literature suggests that the above-mentioned pattern is general for C3 plants. Even though the patterns described do not necessarily imply a cause and effect relationship, they can help our understanding of the apparent contradictions concerning stomatal vs. non-stomatal limitations to photosynthesis under drought. The significance of these findings for the improvement of water-use efficiency of crops is discussed.
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Affiliation(s)
- H. MEDRANO
- Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears – Instituto Mediterráneo de Estudios Avanzados (UIB‐IMEDEA), Carretera de Valldemossa Km 7·5, 07071 Palma de Mallorca, Balears, Spain
| | - J. M. ESCALONA
- Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears – Instituto Mediterráneo de Estudios Avanzados (UIB‐IMEDEA), Carretera de Valldemossa Km 7·5, 07071 Palma de Mallorca, Balears, Spain
| | - J. BOTA
- Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears – Instituto Mediterráneo de Estudios Avanzados (UIB‐IMEDEA), Carretera de Valldemossa Km 7·5, 07071 Palma de Mallorca, Balears, Spain
| | - J. GULÍAS
- Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears – Instituto Mediterráneo de Estudios Avanzados (UIB‐IMEDEA), Carretera de Valldemossa Km 7·5, 07071 Palma de Mallorca, Balears, Spain
| | - J. FLEXAS
- Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears – Instituto Mediterráneo de Estudios Avanzados (UIB‐IMEDEA), Carretera de Valldemossa Km 7·5, 07071 Palma de Mallorca, Balears, Spain
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Poulson ME, Edwards GE, Browse J. Photosynthesis is limited at high leaf to air vapor pressure deficit in a mutant of Arabidopsis thaliana that lacks trienoic fatty acids. PHOTOSYNTHESIS RESEARCH 2002; 72:55-63. [PMID: 16228534 DOI: 10.1023/a:1016054027464] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We have investigated the role of polyunsaturated fatty acids in photosynthesis using a triple mutant of Arabidopsis thaliana that lacks trienoic fatty acids (fad 3-2 fad 7-2 fad 8). Though this mutant is male sterile, vegetative growth and development under normal conditions are largely unaffected (McConn and Browse, 1996 Plant Cell 8: 403-416). At 0.2-1.0 kPa vapor pressure deficit (low VPD), maximum photosynthetic rates of wild-type and mutant plants were similar while stomatal conductance rates were up to 2 times higher in mutant plants. However, light-saturated rates of carbon assimilation and stomatal conductance in the mutant were lower than in wild-type plants when measured at ambient (35 Pa) CO(2) and 2.0-2.8 kPa vapor pressure deficit (high VPD). The limitation to photosynthesis in the mutant plants at high VPD was overcome by saturating partial pressures of CO(2) suggesting a stomatal limitation. Chlorophyll fluorescence measurements indicate that differences observed in maximum assimilation rates were not due to limitations within the photochemical reactions of photosynthesis. Stomatal response to VPD and intrinsic water use efficiency was drastically different in mutant versus wild-type plants. The results of this investigation indicate that for Arabidopsis, polyunsaturated fatty acids may be an important determinant of responses of photosynthesis and stomatal conductance to environmental stresses such as high VPD.
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Affiliation(s)
- Mary E Poulson
- Department of Biological Sciences, Idaho State University, Campus Box, 8007, Pocatello, ID, 83209-8007, USA,
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Dai Z, Hooker BS, Anderson DB, Thomas SR. Expression of Acidothermus cellulolyticus endoglucanase E1 in transgenic tobacco: biochemical characteristics and physiological effects. Transgenic Res 2000; 9:43-54. [PMID: 10853268 DOI: 10.1023/a:1008922404834] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The expression of the Acidothermus cellulolyticus endoglucanase E1 gene in transgenic tobacco (Nicotiana tabacum) was examined in this study, where E1 coding sequence was transcribed under the control of a leaf specific Rubisco small subunit promoter (tomato RbcS-3C). Targeting the E1 protein to the chloroplast was established using a chloroplast transit peptide of Rubisco small subunit protein (tomato RbcS-2A) and confirmed by immunocytochemistry. The E1 produced in transgenic tobacco plants was found to be biologically active, and to accumulate in leaves at levels of up to 1.35% of total soluble protein. Optimum temperature and pH for E1 enzyme activity in leaf extracts were 81 degrees C and 5.25, respectively. E1 activity remained constant on a gram fresh leaf weight basis, but dramatically increased on a total leaf soluble protein basis as leaves aged, or when leaf discs were dehydrated. E1 protein in old leaves, or after 5 h dehydration, was partially degraded although E1 activity remained constant. Transgenic plants exhibited normal growth and developmental characteristics with photosynthetic rates similar to those of untransformed SR1 tobacco plants. Results from these biochemical and physiological analyses suggest that the chloroplast is a suitable cellular compartment for accumulation of the hydrolytic E1 enzyme.
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Affiliation(s)
- Z Dai
- Pacific Northwest National Laboratory, Richland, WA 99352, USA.
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Requirements for the CO2-concentrating mechanism in C4 plants relative to limitations on carbon assimilation in rice**Citation: Sheehy JE, Mitchell PL, Hardy B, editors. 2000. Redesigning rice photosynthesis to increase yield. Proceedings of the Workshop on The Quest to Reduce Hunger: Redesigning Rice Photosynthesis, 30Nov.-3 Dec. 1999. Los Baños. Philippines. Makati City (Philippines): International Rice Research Institute and Amsterdam (The Netherlands): Elsevier Science B.V. 293 p. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0928-3420(00)80009-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
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Dai Z, Ku MSB, Edwards GE. Oxygen sensitivity of photosynthesis and photorespiration in different photosynthetic types in the genus Flaveria. PLANTA 1996; 198:563-571. [PMID: 28321667 DOI: 10.1007/bf00262643] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/1995] [Accepted: 09/06/1995] [Indexed: 05/08/2023]
Abstract
Two major indicators were used to access the degree of photorespiration in various photosynthetic types of Flaveria species (C3, C3-C4, C4-like, and C4): the O2 inhibition of photosynthesis measured above the O2 partial pressure which gives a maximum rate, and O2- and light-dependent whole-chain electron flow measured at the CO2 compensation point (Γ). The optimum level of O2 for maximum photosynthetic rates under atmospheric levels of CO2 (34 Pa) was lower in C3 and C3-C4 species (ca. 2 kPa) than in C4-like and C4 species (ca. 9 kPa). Increasing O2 partial pressures from the optimum for photosynthesis up to normal atmospheric levels (ca. 20 kPa) caused an inhibition of photosynthesis which was more severe under lower CO2. This inhibition was calculated as the O2 inhibition index (ΘA, the percentage inhibition of photosynthesis per kPa increase in O2). From measurements of 18 Flaveria species at atmospheric CO2, the ΘA values decreased from C3 (1.9-2.1) to C3-C4 (1.2-1.6), C4-like (0.6-0.8) and C4 species (0.3-0.4), indicating a progressive decrease in apparent photorespiration in this series. With increasing irradiance at Γ under atmospheric levels of O2, and increasing O2 partial pressure at 300 μmol quanta·m-2·s-1, there was a similar increase in the rate of O2 evolution associated with whole-chain electron flow (Jo2, calculated from chlorophyll fluorescence analysis) in the C3 and C3-C4 species compared to a much lower rate in the C4-like and C4 species. The results indicate that there is substantial O2-dependent electron flow in C3 and C3-C4 species, reflecting a high level of photorespiration compared to that in C4-like and C4 species. Consistent with these results, there was a significant decrease in Γ from C3 (6-6.2 Pa) to C3-C4 (1.0-3.0 Pa), to C4-like and C4 species (0.3-0.8 Pa), indicating a progressive decrease in apparent photorespiration. However, C3 and C3-C4 species examined had high intrinsic levels of photorespiration with the latter maintaining low apparent rates of photorespiration and lower Γ values, primarily by refixing photorespired CO2. The C4-like and C4 Flaveria species had low, but measurable, levels of photorespiration via selective localization of ribulose-1,5-bisphosphate carboxylase in bundle sheath cells and operation of a CO2 pump via the C4 pathway.
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Affiliation(s)
- Ziyu Dai
- Department of Botany, Washington State University, 99164-4238, Pullman, WA, USA
| | - Maurice S B Ku
- Department of Botany, Washington State University, 99164-4238, Pullman, WA, USA
| | - Gerald E Edwards
- Department of Botany, Washington State University, 99164-4238, Pullman, WA, USA.
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Dai Z, Ku MSB, Edwards GE. C4 Photosynthesis (The Effects of Leaf Development on the CO2-Concentrating Mechanism and Photorespiration in Maize). PLANT PHYSIOLOGY 1995; 107:815-825. [PMID: 12228406 PMCID: PMC157198 DOI: 10.1104/pp.107.3.815] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The effect of O2 on photosynthesis was determined in maize (Zea mays) leaves at different developmental stages. The optimum level of O2 for maximum photosynthetic rates was lower in young and senescing tissues (2-5 kPa) than in mature tissue (9 kPa). Inhibition of photosynthesis by suboptimal levels of O2 may be due to a requirement for functional mitochondria or to cyclic/pseudocyclic photophosphorylation in chloroplasts; inhibition by supraoptimal levels of O2 is considered to be due to photorespiration. Analysis of a range of developmental stages (along the leaf blade and at different leaf ages and positions) showed that the degree of inhibition of photosynthesis by supraoptimal levels of O2 increased rapidly once the ribulose-1,5-bisphosphate carboxylase/oxygenase and chlorophyll contents were below a critical level and was similar to that of C3 plants. Tissue having a high sensitivity of photosynthesis to O2 may be less effective in concentrating CO2 in the bundle sheath cells due either to limited function of the C4 cycle or to higher bundle sheath conductance to CO2. An analysis based on the kinetic properties of ribulose-1,5-bisphosphate carboxylase/oxygenase was used to predict the maximum CO2 level concentrated in bundle sheath cells at a given degree of inhibition of photosynthesis by supraoptimal levels of O2.
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Affiliation(s)
- Z. Dai
- Department of Botany, Washington State University, Pullman, Washington 99164-4238
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Dai Z, Ku MSB, Edwards GE. C4 Photosynthesis (The CO2-Concentrating Mechanism and Photorespiration). PLANT PHYSIOLOGY 1993; 103:83-90. [PMID: 12231916 PMCID: PMC158949 DOI: 10.1104/pp.103.1.83] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Despite previous reports of no apparent photorespiration in C4 plants based on measurements of gas exchange under 2 versus 21% O2 at varying [CO2], photosynthesis in maize (Zea mays) shows a dual response to varying [O2]. The maximum rate of photosynthesis in maize is dependent on O2 (approximately 10%). This O2 dependence is not related to stomatal conductance, because measurements were made at constant intercellular CO2 concentration (Ci); it may be linked to respiration or pseudocyclic electron flow. At a given Ci, increasing [O2] above 10% inhibits both the rate of photosynthesis, measured under high light, and the maximum quantum yield, measured under limiting light ([phi]CO2). The dual effect of O2 is masked if measurements are made under only 2 versus 21% O2. The inhibition of both photosynthesis and [phi]CO2 by O2 (measured above 10% O2) with decreasing Ci increases in a very similar manner, characteristically of O2 inhibition due to photorespiration. There is a sharp increase in O2 inhibition when the Ci decreases below 50 [mu]bar of CO2. Also, increasing temperature, which favors photorespiration, causes a decrease in [phi]CO2 under limiting CO2 and 40% O2. By comparing the degree of inhibition of photosynthesis in maize with that in the C3 species wheat (Triticum aestivum) at varying Ci, the effectiveness of C4 photosynthesis in concentrating CO2 in the leaf was evaluated. Under high light, 30[deg]C, and atmospheric levels of CO2 (340 [mu]bar), where there is little inhibition of photosynthesis in maize by O2, the estimated level of CO2 around ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the bundle sheath compartment was 900 [mu]bar, which is about 3 times higher than the value around Rubisco in mesophyll cells of wheat. A high [CO2] is maintained in the bundle sheath compartment in maize until Ci decreases below approximately 100 [mu]bar. The results from these gas exchange measurements indicate that photorespiration occurs in maize but that the rate is low unless the intercellular [CO2] is severely limited by stress.
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Affiliation(s)
- Z. Dai
- Department of Botany, Washington State University, Pullman, Washington 99164-4238
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