Abstract: Relative contents of phytochrome A(PhyA) in etiolated shoots of the photoperiod-sensitive genic male-sterile rice (PGMR) and its original line were compared by immunoblot analysis using a rabbit polyclonal antibody specific for oat PhyA. This antibody could readily immunoprobe a prominent polypeptide around 120 kD in extracts of both rice cultivars. Several lines of evidence strongly indicated that the polypeptide was rice PhyA. Immunoquantitation revealed that etiolated shoots of PGMR contained 27% more PhyA than the original line per unit protein. The difference in PhyA contents between the two cultivars was the result of de novo synthesis of PhyA polypeptide during seed germination, since no PhyA was detected prior to 36 h after seed imbibition in both rice cultivars. The significance of increased PhyA contents in etiolated PGMR shoots was discussed.

Key words: etiolated tissue, immunoblot, photoperiod-sensitive genic male sterile rice, phytochrome

摘要： 用免疫印迹检测光敏核不育水稻(农垦58S)和对照品种(农垦58)黄化苗中光敏色素A(PhyA)。结果表明，燕麦PhyA的多克隆抗体可以专一性地检测水稻黄化苗粗提液中约120 kD多肽。该肽对内源蛋白酶水解的敏感性因红光或远红光预照射而异，照射远红光后，该肽易降解；照射红光后，相对较稳定。这说明上述多肽是水稻PhyA(至少120 kD)。以单位蛋白质计，农垦58S黄化苗PhyA的相对含量比农垦58多27%。由于在干种子、吸涨36 h以前的水稻胚中均未检测到PhyA，因此，两水稻品种间PhyA含量的差异是种子萌发及幼苗生长过程中PhyA蛋白重新合成的结果。讨论了增加的PhyA含量可能影响农垦58S幼苗的光形态建成过程的可能性。

关键词: 光敏色素, 免疫印迹, 黄化苗, 光敏核不育水稻