Abstract
Plant mitochondria have multiple energy-dissipating pathways. In the present study, we examined a regulation mechanism for the respiratory gene expression under high-light stress and the differences among the respiratory pathways in Arabidopsis. Gene expression of AOX1a, NDA1, NDB2, NDC1, COX6b, and CI76 were induced after the high-light treatment. NDB2 co-expressed with AOX1a strongly, but some light-induced genes showed distinct expression patterns. Manipulation of the photosynthesis or respiration using several chemicals revealed that there are distinct regulation manners for each respiratory gene expression. When high-light was treated in conjunction with high CO2, the several respiratory genes were further induced, suggesting that the changes in metabolic pathways by elevated photosynthesis are involved in the respiratory gene expression. From these results, we propose the regulation model of respiratory gene expression under the high-light stress.
