Genome-wide identification of genes involved in phytochrome (phy)-mediated anther development in rice

This study is the first research that provides valuable insight into the complex regulation networks underlying phytochrome-mediated anther development in plant. Furthermore, the results also provide new clues for cultivating new male sterile lines in hybrid rice breeding. Overall design: Phytochromes (phy) are the main plant photoreceptors that sensing and transducing red and far-red light signals to regulate multiple developmental processes. Previous studies mainly focused on their roles in photomorphogenesis, such as seed germination, de-etiolation and shade avoidance. However, the regulatory network of phytochrome-mediated anther development was largely unknown. There are three genes encoding phytochromes in rice, phyA, phyB and phyC. The single mutant of each phy gene has no effects on rice fertility, but the fertility of phyA phyB double mutant was decreased significantly. Histological and cytological analysis revealed that the reduced fertility in phyA phyB double mutant was due to defects in anther development and dehiscence. To identify genes involved in phytochrome-mediated anther development, the transcriptomes of anthers in phyA, phyB single and double mutant, and wild-type rice were compared. The results showed that carbohydrate metabolism and heat-shock responses were activated in the anther of phyA phyB double mutant. Sugar contents analysis indicated that the abnormal anther development in phyA phyB double mutant was partially caused by the increased hemicellulose content and decreased cellulose content. Quantitative reverse transcription-PCR results confirmed that the expression of most of heat-shock factors and proteins were up-regulated in phyA phyB double mutant.

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Sun W, Hui Xu X, Lu X, Xie L, Bai B, Zheng C, Sun H, He Y, Xie XZ