Abstract
1-aminocyclopropane-1-carboxylate oxidase (ACO) is one of key enzymes on the biosynthetic pathway of ethylene, gaseous phytohormone, in plant and several isozymes exist in rice. Phytochromes (phy) are red/far-red light photoreceptors. There are three members of phytochromes (phyA, phyB and phyC) in rice. In microarray experiments, we found that one of ACO genes (AK058296) showed altered expression (3-10 times higher than wild type) in phyAB and phyABC mutants. Expression levels of other ACO isozymes and ACC synthase genes were not changed. The AK058296 expression was repressed by far-red light pulse in wild type but not in phyA mutant. Contrary to our exception, ethylene production was not accelerated in phyAB nor phyABC mutants. The roles of phytochromes on the regulation of ACO gene expression are under investigation.
