水稻落粒基因SH4对种子粒型的遗传调控

SH4 gene, encoding a transcription factor protein, was the first shattering gene cloned from wild rice which related to rice domestication. The spontaneous mutation sh4 in cultivars resulted in a reduction of seed shattering, but it did not eliminate the abscission layer and affect grain size. And the mutant which obtained from γ ray radiation and contained another allelic mutation of SH4 named as sh4-2, exhibited a deficiency of abscission layer and decrease of grain size. All these indicated that SH4 involved in a series processes of physiological regulation. Grain size was an important agronomic trait that affected rice yield and the molecular mechanism research of grain size regulation was important for rice breeding. In this project we plan to elucidate the genetic control and the spatial and temporal expression pattern of SH4 by genetic transformation and in situ hybridization. Meanwhile we attend to find out downstream genes of grain size controlling directly regulated by SH4 gene through transcriptomics sequencing and ChIP-Seq.

SH4是第一个从野生稻中克隆的落粒调控基因，与水稻驯化相关，编码一个转录因子蛋白。现代栽培稻中的自然突变sh4位点使栽培稻落粒性大大降低但不会阻断离层的发育，对粒型也没有影响。辐射诱变得到的SH4另一个等位突变sh4-2使突变体离层完全缺失并且粒型变小，这个结果表明SH4基因参与了一系列生理调节过程。水稻粒型是影响产量的重要农艺性状，研究水稻粒型调控的分子机理对育种研究有重要意义。本研究计划通过遗传转化、原位杂交等技术，弄清SH4基因的遗传调控和时空表达模式。重点应用转录组测序和ChIP-Seq等技术，找到SH4基因直接作用与粒型调控相关的下游基因。