Phytochromes in rice are encoded by a gene family composed of three members, PHYA, PHYB, and PHYC. Through characterizing the phytochrome mutants and wild type （WT） in terms of photomorphogenesis, roles of individua...Phytochromes in rice are encoded by a gene family composed of three members, PHYA, PHYB, and PHYC. Through characterizing the phytochrome mutants and wild type （WT） in terms of photomorphogenesis, roles of individual phytochromes have been preliminarily explored in regulating rice de-etiolation, flowering time and fertility. However, little information has been reported about whether or how phytochromes affect chlorophyll biosynthesis and chloroplast development in rice. In this study, we compared the chlorophyll contents of wild type and the phyA, phyB and phyAphyB mutants grown under either white light （WL） or red light （R）. The results suggest that phyB perceives R to positively regulate chlorophyll biosynthesis, while the role of phyA can be detected only in the phyB-deficient mutant. Analyses of the expression levels of genes involved in chlorophyll biosynthesis revealed that phytochromes affected the chlorophyll biosynthesis by regulating protochlorophyll oxidoreductase A （PORA） expression. The role of phyB in chloroplast development was also analyzed, and the results suggest that phyB perceives R to regulate chloroplast development by affecting the numbers of chloroplasts and grana, as well as the chloroplast membrane system.展开更多
基金supported by the grants from the National Natural Science Foundations of China(Grant Nos.30870192 and 30971744)the National Major Science and Technology Project to Create New Crop Varieties Using Gene Transfer Technology,China(Grant No.2009ZX08001-029B)the Shandong Natural Science Funds for Distinguished Young Scholar,China(Grant No.JQ200911)
文摘Phytochromes in rice are encoded by a gene family composed of three members, PHYA, PHYB, and PHYC. Through characterizing the phytochrome mutants and wild type （WT） in terms of photomorphogenesis, roles of individual phytochromes have been preliminarily explored in regulating rice de-etiolation, flowering time and fertility. However, little information has been reported about whether or how phytochromes affect chlorophyll biosynthesis and chloroplast development in rice. In this study, we compared the chlorophyll contents of wild type and the phyA, phyB and phyAphyB mutants grown under either white light （WL） or red light （R）. The results suggest that phyB perceives R to positively regulate chlorophyll biosynthesis, while the role of phyA can be detected only in the phyB-deficient mutant. Analyses of the expression levels of genes involved in chlorophyll biosynthesis revealed that phytochromes affected the chlorophyll biosynthesis by regulating protochlorophyll oxidoreductase A （PORA） expression. The role of phyB in chloroplast development was also analyzed, and the results suggest that phyB perceives R to regulate chloroplast development by affecting the numbers of chloroplasts and grana, as well as the chloroplast membrane system.
