Ge Qiang, Tang Yongyan, Luo Wei, Zhang Jingyu, Chong Kang, Xu Yunyuan
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Rice (N Y). 2020 Sep 10;13(1):64. doi: 10.1186/s12284-020-00425-0.
Grain size is one of the key agronomic traits that impact grain yield. Several regulatory pathways had been reported to participate in grain size determination via cell expansion or proliferation in rice. However, little is known about cyclophilin and spliceosome participation in grain shape regulation.
Here, we identified OsCYP20-2, a cyclophilin that influences spliceosome assembly to determine grain length. oscyp20-2 t1, a knock out mutant of OsCYP20-2 caused by T-DNA insertion, produced shorter grains with deficient cell elongation. Through yeast two-hybrid screening and pull-down assays, OsSYF2, a pre-mRNA splicing factor, was identified as an interacting protein of OsCYP20-2. The phenotypes of transgenic lines indicated that OsSYF2 positively regulates grain length via its influence on cell expansion. Transcriptomic analysis showed that OsSYF2 controls the expression and pre-mRNA alternative splicing of genes involved in sugar metabolism. In addition, these two genes have similar effects on panicle architecture.
Taken together, OsSYF2, an interacting protein of OsCYP20-2, controls grain length and panicle architecture by regulating the alternative splicing of pre-mRNA involved in cell elongation and sugar metabolism.
粒型是影响谷物产量的关键农艺性状之一。据报道，水稻中有几种调控途径通过细胞扩张或增殖参与粒型的决定。然而，关于亲环蛋白和剪接体参与粒型调控的研究却很少。
在此，我们鉴定出了OsCYP20-2，一种影响剪接体组装以决定粒长的亲环蛋白。oscyp20-2 t1是由T-DNA插入导致的OsCYP20-2基因敲除突变体，产生的谷粒较短，细胞伸长不足。通过酵母双杂交筛选和下拉实验，鉴定出前体mRNA剪接因子OsSYF2是OsCYP20-2的相互作用蛋白。转基因系的表型表明，OsSYF2通过影响细胞扩张正向调控粒长。转录组分析表明，OsSYF2控制参与糖代谢的基因的表达和前体mRNA可变剪接。此外，这两个基因对穗型结构有相似的影响。
总之，OsSYF2作为OsCYP20-2的相互作用蛋白，通过调控参与细胞伸长和糖代谢的前体mRNA的可变剪接来控制粒长和穗型结构。
