Metabolite pools and carbon flow during C4 photosynthesis in maize: 13CO2 labeling kinetics and cell type fractionation.

ABSTRACT: Worldwide efforts to engineer C₄ photosynthesis into C₃ crops require a deep understanding of how this complex pathway operates. CO₂ is incorporated into four-carbon metabolites in the mesophyll, which move to the bundle sheath where they are decarboxylated to concentrate CO₂ around RuBisCO. We performed dynamic ¹³CO₂ labeling in maize to analyze C flow in C₄ photosynthesis. The overall labeling kinetics reflected the topology of C₄ photosynthesis. Analyses of cell-specific labeling patterns after fractionation to enrich bundle sheath and mesophyll cells revealed concentration gradients to drive intercellular diffusion of malate, but not pyruvate, in the major CO₂-concentrating shuttle. They

SUBMITTER: Arrivault S 

PROVIDER: S-EPMC5853532 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature