Immunoassay of Phytochrome A Content in Photoperiod-sensitive Genie Male-sterile Rice

摘要

A rice mutant (Oryza sativa L. Nongkcn 58S) 'photoperiod-scnsitivc male-sterile rice' (PGMR) is sterile under long day-length (LD), but fertile in short days-length (SD). Phytochrome (Phy) has proved to be the photoreceptor involved in photoperiod-induced male sterile process in PGMR. To speculate how phytochromc functions, PhyA levels in leaf extracts of PGMR and wild-type rice (Oryza sativa L. Nongkcn 58) under different photoperiods were measured by means of a sandwich enzyme-linked immunosorbcntassay (ELISA). The top two leaves of treated rice plants were sampled at the end of the last dark phase for 10 cycles at photoperiod-sensitive stage for fertility alteration in the mutant. Compared with LD treatment, the SD treatment resulted in 39% increase of relative PhyA content (per unit fresh weight) in PGMR, but only in 18% increase in its wild-type. In addition, after 10 cycles of end of far-red irradiations of day, the heading and flowering dates of PGMR were delayed for 2 days, while its malefertility almost remained unchanged. It is well known that the end of day far-red responses arc mediated by PhyB. These results suggested that in PGMR PhyA took part in regulation of male sterility, but PhyB was involved in mediating flowering time.