Defect in Cyclic Electron Flow around Photosystem I (CEF-PSI) alters [CO₂]-responsive Gene Expression in Arabidopsis thaliana

Abstract

In response to environmental cues, plants fine-tune activity of photosynthesis. Physiological functions of CEF-PSI were proposed to be the production of additional ATP for CO₂ fixation and induction of NPQ via the formation of trans-thylakoid ΔpH. Thus the defect in CEF-PSI drastically affects the cellular metabolisms. In this study, we analyzed the effect of the defect in CEF-PSI on gene expression in response to CO₂ concentration by microarray analyses in Arabidopsis wild type and pgr5 lacking the main pathway of CEF-PSI.
The transcriptome in both wild-type and pgr5 plants grown at elevated CO₂, i.e., 2,000 ppm CO₂, or ambient CO₂ for 10 days were analyzed. The gene expression did not respond to the increase in CO₂ concentration in pgr5. This result suggests that CEF-PSI is involved in the gene regulation in the acclimation process to elevated CO₂.