长链非编码RNA对水稻光敏感雄性不育的调控

Two-line hybrid rice has made great contribution to rice production, and the discovery and utilization of the photoperiod sensitive male sterility has made it possible for the development of two-line hybrid rice. The original photoperiod sensitive male sterile rice Nongken 58S was found as a spontaneous mutant in Hubei in 1973. This mutant showed male sterility under long-day/high temperature conditions while fertile under short day/low-temperature conditions, providing an ideal germplasm for hybrid rice breeding. Progeny from crosses between Nongken 58S and many rice varieties showed two locus segregation which were named pms1 and pms3. We have been working on this system for 28 years and recently cloned these two loci. We found that both of the loci encode long noncoding RNAs (lncRNAs), providing a unique opportunity for studying the function of lncRNAs in plants. In this project, we proposed to investigate the genetic and molecular mechanisms by which pms1 and pms3 regulate male fertility, individually and in combination. We anticipate that the results would demonstrate the roles and modes of lncRNAs in male fertility regulation of rice, which would enrich our understanding of male sterility in plants as well as the function of lncRNA in plant development. The results would also be useful for hybrid rice breeding.

两系法杂交稻的应用为水稻生产作出了重大贡献，光敏感雄性不育水稻的发现和利用使两系杂交稻的培育成为可能。光敏不育水稻农垦58S于1973年在湖北发现，具有长日高温不育、短日低温可育的特点，为两系杂交稻育种提供了雄性不育资源。光敏不育水稻农垦58S与多数品种杂交花粉育性表现为两位点遗传，命名为pms1、pms3。本课题组历经28年，克隆了这两个位点，发现它们均为长链非编码RNA。光敏不育水稻为植物长链非编码RNA的研究提供了一个重要切入点。本课题拟在此基础上，从pms1和pms3调控雄性不育的方式与网络、两基因遗传及分子互作等方面进行研究，阐明长链非编码RNA对水稻光敏不育的调控机理，丰富植物雄性不育的理论和非编码RNA的功能，为杂交稻育种雄性不育系的培育提供理论基础和基因标记。

两系法杂交稻的应用为水稻生产做出了重大贡献，光敏感雄性不育水稻的发现和利用使两系杂交稻的培育成为可能。课题计划从两个重要的光敏感雄性不育位点pms1和pms3，其调控雄性不育的机理，及两基因遗传及分子互作等方面开展研究，阐明lncRNAs在光敏感雄性不育基因中的作用方式、作用机理以及发挥功能的关键区段，揭示其调控的雄性不育的生物学过程以及分子生物学机制。.课题分离克隆了光敏感雄性不育基因PMS1T（pms1）。PMS1是一个长链非编码RNA，能被miR2118剪切形成18对21-nt phasiRNA，PMS1T-phasiRNA参与了光敏雄性不育的调控。PMS1T是到目前为止鉴定到的第一个具有生物学功能的PHAS基因，研究结果加深了对于光敏感雄性核不育机理的理解。为更好地了解phasiRNAs的时空表达特点和phasiRNAs的作用模式与机理，对农垦58从二次枝梗时期的幼穗到含有成熟花粉的花药7个时期的 sRNA进行测序和分析，发现21-nt phasiRNA具有顺式作用活性可以靶定并剪切它们的前体，21-nt pahsiRNAs在光敏不育的发生过程中发挥重要作用。应Plant Reproduction杂志邀请，撰写发表了题为“Genetic and molecular characterization of photoperiod and thermo-sensitive male sterility in rice”的综述文章。对光敏雄性不育和温敏雄性不育在水稻中的发现、光温敏特性、遗传分析及相关基因位点的定位和分子生物学机理研究、育种应用等方面的进展进行了全面总结。课题的研究结果丰富植物雄性不育的理论和非编码RNA的功能，为杂交稻育种雄性不育系的培育提供理论基础和基因标记。