Thermosensitive genic male-sterile (TGMS) lines, which are male-sterile at restrictive (high) temperatures but male-fertile at permissive (low) temperatures, have been widely used in breeding two-line hybrid rice (Oryza sativa L.). Here we find that mutation of ?thermosensitive genic male sterile 5 (?tms5) in rice causes the TGMS trait through a loss of ?RNase ZS1 function. We show that ?RNase ZS1 processes the mRNAs of three ubiquitin fusion ribosomal protein L40 (UbL40) genes into multiple fragments in vitro and in vivo. In ?tms5 mutants, high temperature results in increased levels of UbL40 mRNAs. Overaccumulation of UbL40 mRNAs causes defective pollen production and male sterility. Our results uncover a novel mechanism of ?RNase ZS1-mediated UbL40 mRNA regulation and shows that loss of this regulation produces TGMS in rice, a finding with potential applications in hybrid crop breeding.
溫敏細胞核雄性不育系（TGMS），表現(xiàn)為僅在高溫條件下雄性不育，在適度低溫條件下可育，已在兩系雜交稻中被廣泛利用。本研究發(fā)現(xiàn)tms5變異會通過RNA酶ZS1功能缺失導(dǎo)致溫敏細胞核雄性不育性狀。RNA酶ZS1能夠在體外和體內(nèi)把三個泛素核糖體L40融合蛋白基因(UbL40) mRNA加工成多個片段。在tms5突變體中，高溫導(dǎo)致UbL40 mRNA水平上升。UbL40 mRNA的過度積累導(dǎo)致花粉形成缺陷和雄性不育。本研究揭示了RNA酶ZS1介導(dǎo)的UbL40 mRNA調(diào)控新機制，并揭示這種調(diào)控缺失會導(dǎo)致水稻細胞核雄性不育。本研究在雜交作物育種中具有潛在的應(yīng)用性。