Publication Date
1997
Description
Plants with C4 photosynthesis have one of three decarboxylation enzymes in their bundle sheath cells. Reports suggest that bundle sheath leakiness to CO2 is highest in the NAD-ME group, lowest in the NADP-ME group and intermediate in the PCK group. We investigated the hypothesis that growth and photosynthesis of three NADME grasses would respond more to elevated CO2 than three NADPME grasses. Contrary to our hypothesis, growth of NADP-ME grasses was greater under elevated CO2, while none of the NADME grasses had a significant response. Increased leaf non-structural carbohydrates were associated with greater growth responses of NADP-ME grasses, while none of the NAD-ME grasses had increased carbohydrates. Assimilation versus intercellular CO2 curves revealed that none of the grasses was photosynthetically saturated with CO2 at 350 μL L-1. Blue grama (Bouteloua gracilis), an NADME species, was unique in displaying photosynthetic acclimation to elevated CO2 , a trait often seen in C3 plants.
Citation
LeCain, D R. and Morgan, J A., "Growth and Physiology Respond Differently to Elevated CO2 in NAD-ME and NADP-ME C4 Grasses" (2024). IGC Proceedings (1993-2023). 6.
https://uknowledge.uky.edu/igc/1997/session9/6
Included in
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Growth and Physiology Respond Differently to Elevated CO2 in NAD-ME and NADP-ME C4 Grasses
Plants with C4 photosynthesis have one of three decarboxylation enzymes in their bundle sheath cells. Reports suggest that bundle sheath leakiness to CO2 is highest in the NAD-ME group, lowest in the NADP-ME group and intermediate in the PCK group. We investigated the hypothesis that growth and photosynthesis of three NADME grasses would respond more to elevated CO2 than three NADPME grasses. Contrary to our hypothesis, growth of NADP-ME grasses was greater under elevated CO2, while none of the NADME grasses had a significant response. Increased leaf non-structural carbohydrates were associated with greater growth responses of NADP-ME grasses, while none of the NAD-ME grasses had increased carbohydrates. Assimilation versus intercellular CO2 curves revealed that none of the grasses was photosynthetically saturated with CO2 at 350 μL L-1. Blue grama (Bouteloua gracilis), an NADME species, was unique in displaying photosynthetic acclimation to elevated CO2 , a trait often seen in C3 plants.
