C4 Plants

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Murugesan Chandrasekaran - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis
    Frontiers in Plant Science, 2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    : Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

  • Table_2_Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis.XLSX
    2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

  • mycorrhizal symbiotic efficiency on c3 and C4 Plants under salinity stress a meta analysis
    Frontiers in Microbiology, 2016
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, R Krishnamoorthy, Denver Walitang, Subbiah Sundaram, Manoharan Melvin Joe, G Selvakumar
    Abstract:

    A wide range of C3 and C4 plant species could acclimatize and grow under the impact of salinity stress. Symbiotic relationship between plant roots and arbuscular mycorrhizal fungi (AMF) are widespread and are well known to ameliorate the influence of salinity stress on agro-ecosystem. In the present study, we sought to understand the phenomenon of variability on AMF symbiotic relationship on saline stress amelioration in C3 and C4 Plants. Thus, the objective was to compare varied mycorrhizal symbiotic relationship between C3 and C4 Plants in saline conditions. To accomplish the above mentioned objective, we conducted a random effects models meta-analysis across 60 published studies. An effect size was calculated as the difference in mycorrhizal responses between the AMF inoculated Plants and its corresponding control under saline conditions. Responses were compared between (i) identity of AMF species and AMF inoculation, (ii) identity of host Plants (C3 vs. C4) and plant functional groups, (iii) soil texture and level of salinity and (iv) experimental condition (greenhouse vs. field). Results indicate that both C3 and C4 Plants under saline condition responded positively to AMF inoculation, thereby overcoming the predicted effects of symbiotic efficiency. Although C3 and C4 Plants showed positive effects under low (EC8 ds/m) saline conditions, C3 Plants showed significant effects for mycorrhizal inoculation over C4 Plants. Among the plant types, C4 annual and perennial Plants, C4 herbs and C4 dicot had a significant effect over other counterparts. Between single and mixed AMF inoculants, single inoculants Rhizophagus intraradices had a positive effect on C3 Plants whereas Funneliformis mosseae had a positive effect on C4 Plants than other species. In all of the observed studies, mycorrhizal inoculation showed positive effects on shoot, root and total biomass, and in nitrogen, phosphorous and potassium (K) uptake. However, it showed negative effects in sodium (Na) uptake in both C3 and C4 Plants. This influence, owing to mycorrhizal inoculation, was significantly higher in K uptake in C4 Plants. For our analysis, we concluded that AMF-inoculated C4 Plants showed more competitive K+ ions uptake than C3 Plants.

Sundaram Seshadri - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis
    Frontiers in Plant Science, 2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    : Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

  • Table_2_Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis.XLSX
    2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

Kiyoon Kim - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis
    Frontiers in Plant Science, 2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    : Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

  • Table_2_Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis.XLSX
    2019
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, M. Chanratana, Sundaram Seshadri
    Abstract:

    Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C3 and C4 Plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate (Amax), stomatal conductance (Gs), transpiration rate (E), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated Plants. Responses were compared between C3 and C4 Plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated Plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C3 Plants were higher than C4 Plants. However, C3 Plants responses regarding Gs, Amax, and E were more positive compared to C4 Plants. The increase in Gs mainly maintained E and it explains the increase in Amax and increase in E. When the two major AMF species (Rhizophagus intraradices and Funnelliformis mosseae) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated Plants performed better under salt stress. In terms of C3 and C4 plant photosynthetic pathways, the effect size of C4 was lower than C3 Plants indicating that AMF inoculation more effectively alleviated salt stress in C3 compared to C4 Plants.

  • mycorrhizal symbiotic efficiency on c3 and C4 Plants under salinity stress a meta analysis
    Frontiers in Microbiology, 2016
    Co-Authors: Murugesan Chandrasekaran, Kiyoon Kim, R Krishnamoorthy, Denver Walitang, Subbiah Sundaram, Manoharan Melvin Joe, G Selvakumar
    Abstract:

    A wide range of C3 and C4 plant species could acclimatize and grow under the impact of salinity stress. Symbiotic relationship between plant roots and arbuscular mycorrhizal fungi (AMF) are widespread and are well known to ameliorate the influence of salinity stress on agro-ecosystem. In the present study, we sought to understand the phenomenon of variability on AMF symbiotic relationship on saline stress amelioration in C3 and C4 Plants. Thus, the objective was to compare varied mycorrhizal symbiotic relationship between C3 and C4 Plants in saline conditions. To accomplish the above mentioned objective, we conducted a random effects models meta-analysis across 60 published studies. An effect size was calculated as the difference in mycorrhizal responses between the AMF inoculated Plants and its corresponding control under saline conditions. Responses were compared between (i) identity of AMF species and AMF inoculation, (ii) identity of host Plants (C3 vs. C4) and plant functional groups, (iii) soil texture and level of salinity and (iv) experimental condition (greenhouse vs. field). Results indicate that both C3 and C4 Plants under saline condition responded positively to AMF inoculation, thereby overcoming the predicted effects of symbiotic efficiency. Although C3 and C4 Plants showed positive effects under low (EC8 ds/m) saline conditions, C3 Plants showed significant effects for mycorrhizal inoculation over C4 Plants. Among the plant types, C4 annual and perennial Plants, C4 herbs and C4 dicot had a significant effect over other counterparts. Between single and mixed AMF inoculants, single inoculants Rhizophagus intraradices had a positive effect on C3 Plants whereas Funneliformis mosseae had a positive effect on C4 Plants than other species. In all of the observed studies, mycorrhizal inoculation showed positive effects on shoot, root and total biomass, and in nitrogen, phosphorous and potassium (K) uptake. However, it showed negative effects in sodium (Na) uptake in both C3 and C4 Plants. This influence, owing to mycorrhizal inoculation, was significantly higher in K uptake in C4 Plants. For our analysis, we concluded that AMF-inoculated C4 Plants showed more competitive K+ ions uptake than C3 Plants.

Andrea Bräutigam - One of the best experts on this subject based on the ideXlab platform.

  • Reactive oxygen species and redox regulation in mesophyll and bundle sheath cells of C4 Plants.
    Journal of experimental botany, 2018
    Co-Authors: Ismail Turkan, Baris Uzilday, Karl-josef Dietz, Andrea Bräutigam, Rengin Ozgur
    Abstract:

    Redox regulation, antioxidant defence, and reactive oxygen species (ROS) signalling are critical in performing and tuning metabolic activities. However, our concepts have mostly been developed for C3 Plants since Arabidopsis thaliana has been the major model for research. Efforts to convert C3 Plants to C4 to increase yield (such as IRRI’s C4 Rice Project) entail a better understanding of these processes in C4 Plants. Various photosynthetic enzymes that take part in light reactions and carbon reactions are regulated via redox components, such as thioredoxins as redox transmitters and peroxiredoxins. Hence, understanding redox regulation in the mesophyll and bundle sheath chloroplasts of C4 Plants is of paramount importance: it appears impossible to utilize efficient C4 photosynthesis without understanding its exact redox needs and the regulation mechanisms used during light reactions. In this review, we discuss current knowledge on redox regulation in C3 and C4 Plants, with special emphasis on the mesophyll and bundle sheath differences that are found in C4. In these two cell types in C4 Plants, linear and cyclic electron transport in the chloroplasts operate differentially when compared to C3 chloroplasts, changing the redox needs of the cell. Therefore, our focus is on photosynthetic light reactions, ROS production dynamics, antioxidant defence, and thiol-based redox regulation, with the aim of providing an overview of our current knowledge.

  • understanding metabolite transport and metabolism in C4 Plants through rna seq
    Current Opinion in Plant Biology, 2016
    Co-Authors: Urte Schluter, Alisandra K Denton, Andrea Bräutigam
    Abstract:

    RNA-seq, the measurement of steady-state RNA levels by next generation sequencing, has enabled quantitative transcriptome analyses of complex traits in many species without requiring the parallel sequencing of their genomes. The complex trait of C4 photosynthesis, which increases photosynthetic efficiency via a biochemical pump that concentrates CO2 around RubisCO, has evolved convergently multiple times. Due to these interesting properties, C4 photosynthesis has been analyzed in a series of comparative RNA-seq projects. These projects compared both species with and without the C4 trait and different tissues or organs within a C4 plant. The RNA-seq studies were evaluated by comparing to earlier single gene studies. The studies confirmed the marked changes expected for C4 signature genes, but also revealed numerous new players in C4 metabolism showing that the C4 cycle is more complex than previously thought, and suggesting modes of integration into the underlying C3 metabolism.

  • Comparative Proteomics of Chloroplast Envelopes from C3 and C4 Plants Reveals Specific Adaptations of the Plastid Envelope to C4 Photosynthesis and Candidate Proteins Required for Maintaining C4 Metabolite Fluxes
    Plant physiology, 2008
    Co-Authors: Andrea Bräutigam, Susanne Hoffmann-benning, Andreas P. M. Weber
    Abstract:

    C4 Plants have up to 10-fold higher apparent CO2 assimilation rates than the most productive C3 Plants. This requires higher fluxes of metabolic intermediates across the chloroplast envelope membranes of C4 Plants in comparison with those of C3 Plants. In particular, the fluxes of metabolites involved in the biochemical inorganic carbon pump of C4 Plants, such as malate, pyruvate, oxaloacetate, and phosphoenolpyruvate, must be considerably higher in C4 Plants because they exceed the apparent rate of photosynthetic CO2 assimilation, whereas they represent relatively minor fluxes in C3 Plants. While the enzymatic steps involved in the C4 biochemical inorganic carbon pump have been studied in much detail, little is known about the metabolite transporters in the envelope membranes of C4 chloroplasts. In this study, we used comparative proteomics of chloroplast envelope membranes from the C3 plant pea (Pisum sativum) and mesophyll cell chloroplast envelopes from the C4 plant maize (Zea mays) to analyze the adaptation of the mesophyll cell chloroplast envelope proteome to the requirements of C4 photosynthesis. We show that C3- and C4-type chloroplasts have qualitatively similar but quantitatively very different chloroplast envelope membrane proteomes. In particular, translocators involved in the transport of triosephosphate and phosphoenolpyruvate as well as two outer envelope porins are much more abundant in C4 Plants. Several putative transport proteins have been identified that are highly abundant in C4 Plants but relatively minor in C3 envelopes. These represent prime candidates for the transport of C4 photosynthetic intermediates, such as pyruvate, oxaloacetate, and malate.

Gerald E Edwards - One of the best experts on this subject based on the ideXlab platform.

  • differential mobility of pigment protein complexes in granal and agranal thylakoid membranes of c3 and C4 Plants
    Plant Physiology, 2012
    Co-Authors: Helmut Kirchhoff, Richard M Sharpe, Miroslava Herbstova, Robert Yarbrough, Gerald E Edwards
    Abstract:

    The photosynthetic performance of Plants is crucially dependent on the mobility of the molecular complexes that catalyze the conversion of sunlight to metabolic energy equivalents in the thylakoid membrane network inside chloroplasts. The role of the extensive folding of thylakoid membranes leading to structural differentiation into stacked grana regions and unstacked stroma lamellae for diffusion-based processes of the photosynthetic machinery is poorly understood. This study examines, to our knowledge for the first time, the mobility of photosynthetic pigment-protein complexes in unstacked thylakoid regions in the C3 plant Arabidopsis (Arabidopsis thaliana) and agranal bundle sheath chloroplasts of the C4 Plants sorghum (Sorghum bicolor) and maize (Zea mays) by the fluorescence recovery after photobleaching technique. In unstacked thylakoid membranes, more than 50% of the protein complexes are mobile, whereas this number drops to about 20% in stacked grana regions. The higher molecular mobility in unstacked thylakoid regions is explained by a lower protein-packing density compared with stacked grana regions. It is postulated that thylakoid membrane stacking to form grana leads to protein crowding that impedes lateral diffusion processes but is required for efficient light harvesting of the modularly organized photosystem II and its light-harvesting antenna system. In contrast, the arrangement of the photosystem I light-harvesting complex I in separate units in unstacked thylakoid membranes does not require dense protein packing, which is advantageous for protein diffusion.

  • compartmentation of photosynthesis in cells and tissues of C4 Plants
    Journal of Experimental Botany, 2001
    Co-Authors: Gerald E Edwards, Vladimir I Pyankov, Vincent R Franceschi, Elena V Voznesenskaya, Carlos S. Andreo
    Abstract:

    Critical to defining photosynthesis in C 4 Plants is understanding the intercellular and intracellular compartmentation of enzymes between mesophyll and bundle sheath cells in the leaf. This includes enzymes of the C 4 cycle (including three subtypes), the C 3 pathway and photorespiration. The current state of knowledge of this compartmentation is a consequence of the development and application of different techniques over the past three decades. Initial studies led to some alternative hypotheses on the mechanism of C 4 photosynthesis, and some controversy over the compartmentation of enzymes. The development of methods for separating mesophyll and bundle sheath cells provided convincing evidence on intercellular compartmentation of the key components of the C 4 pathway. Studies on the intracellular compartmentation of enzymes between organelles and the cytosol were facilitated by the isolation of mesophyll and bundle sheath protoplasts, which can be fractionated gently while maintaining organelle integrity. Now, the ability to determine localization of photosynthetic enzymes conclusively, through in situ immunolocalization by confocal light microscopy and transmission electron microscopy, is providing further insight into the mechanism of C 4 photosynthesis and its evolution. Currently, immunological, ultrastructural and cytochemical studies are revealing relationships between anatomical arrangements and photosynthetic mechanisms which are probably related to environmental factors associated with evolution of these Plants. This includes interesting variations in the C 4 syndrome in leaves and cotyledons of species in the tribe Salsoleae of the family Chenopodiaceae, in relation to evolution and ecology. Thus, analysis of structure-function relationships using modern techniques is a very powerful approach to understanding evolution and regulation of the photosynthetic carbon reduction mechanisms.

  • oxygen requirement and inhibition of C4 photosynthesis an analysis of C4 Plants deficient in the c3 and C4 cycles
    Plant Physiology, 1998
    Co-Authors: Joao Maroco, Richard C Leegood, Peter J Lea, Louisa V Dever, Robert T Furbank, Gerald E Edwards
    Abstract:

    The basis for O2 sensitivity of C4 photosynthesis was evaluated using a C4-cycle-limited mutant of Amaranthus edulis (a phosphoenolpyruvate carboxylase-deficient mutant), and a C3-cycle-limited transformant of Flaveria bidentis (an antisense ribulose-1,5-bisphosphate carboxylase/oxygenase [Rubisco] small subunit transformant). Data obtained with the C4-cycle-limited mutant showed that atmospheric levels of O2 (20 kPa) caused increased inhibition of photosynthesis as a result of higher levels of photorespiration. The optimal O2 partial pressure for photosynthesis was reduced from approximately 5 kPa O2 to 1 to 2 kPa O2, becoming similar to that of C3 Plants. Therefore, the higher O2 requirement for optimal C4 photosynthesis is specifically associated with the C4 function. With the Rubisco-limited F. bidentis, there was less inhibition of photosynthesis by supraoptimal levels of O2 than in the wild type. When CO2 fixation by Rubisco is limited, an increase in the CO2 concentration in bundle-sheath cells via the C4 cycle may further reduce the oxygenase activity of Rubisco and decrease the inhibition of photosynthesis by high partial pressures of O2 while increasing CO2 leakage and overcycling of the C4 pathway. These results indicate that in C4 Plants the investment in the C3 and C4 cycles must be balanced for maximum efficiency.