scholarly journals Coordinate Regulation of Phosphoenolpyruvate Carboxylase and Phosphoenolpyruvate Carboxykinase by Light and CO2 during C4 Photosynthesis

2007 ◽  
Vol 144 (1) ◽  
pp. 479-486 ◽  
Author(s):  
Karen J. Bailey ◽  
Julie E. Gray ◽  
Robert P. Walker ◽  
Richard C. Leegood
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
C4 Photosynthesis ◽  
Coordinate Regulation

Carbon metabolism in transgenic rice plants that express phosphoenolpyruvate carboxylase and/or phosphoenolpyruvate carboxykinase

Plant Science ◽  
2006 ◽  
Vol 170 (5) ◽  
pp. 1010-1019 ◽  
Author(s):  
Shoichi Suzuki ◽  
Nobuhiko Murai ◽  
Keisuke Kasaoka ◽  
Toru Hiyoshi ◽  
Hidemasa Imaseki ◽  
...  
Keyword(s):  
Transgenic Rice ◽  
Carbon Metabolism ◽  
Phosphoenolpyruvate Carboxylase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Rice Plants ◽  
Transgenic Rice Plants

scholarly journals Developmental Effects on Relative Use of PEPCK and NADP-ME Pathways of C4 Photosynthesis in Maize

2021 ◽  
Author(s):  
Jennifer J Arp ◽  
Shrikaar Kambhampati ◽  
Kevin Chu ◽  
Somnath Koley ◽  
Lauren M Jenkins ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Leaf Development ◽  
Phosphoenolpyruvate Carboxykinase ◽  
C4 Photosynthesis ◽  
Leaf Age ◽  
Bundle Sheath ◽  
Decarboxylase Activity ◽  
Mesophyll Cells ◽  
Source To Sink ◽  
Canopy Position

C4 photosynthesis is an adaptive photosynthetic pathway which concentrates CO2 around Rubisco in specialized bundle sheath cells to reduce photorespiration. Historically, the pathway has been characterized into three different subtypes based on the decarboxylase involved, although recent work has provided evidence that some plants can use multiple decarboxylases, with maize in particular using both the NADP-malic enzyme (NADP-ME) pathway and phosphoenolpyruvate carboxykinase (PEPCK) pathway. Parallel C4 pathways could be advantageous in balancing energy and reducing equivalents between bundle sheath and mesophyll cells, in decreasing the size of the metabolite gradients between cells and may better accommodate changing environmental conditions or source to sink demands on growth. The enzyme activity of C4 decarboxylases can fluctuate with different stages of leaf development, but it remains unclear if the pathway flexibility is an innate aspect of leaf development or an adaptation to the leaf microenvironment that is regulated by the plant. In this study, variation in the two C4 pathways in maize were characterized at nine plant ages throughout the life cycle. Two positions in the canopy were examined for variation in physiology, gene expression, metabolite concentration, and enzyme activity, with particular interest in asparagine as a potential regulator of C4 decarboxylase activity. Variation in C4 and C3 metabolism was observed for both leaf age and canopy position, reflecting the ability of C4 pathways to adapt to changing microenvironments.

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