Background

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.

Results

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.

Conclusions

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.

中文翻译：

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亲环蛋白OsCYP20-2与OsSYF2相互作用，通过Pre-mRNA剪接调节谷粒长度。

背景

籽粒大小是影响籽粒产量的关键农艺性状之一。据报道，有几种调控途径通过水稻中细胞的扩增或增殖参与了粒度的确定。然而，对亲环蛋白和剪接体参与晶粒形状调节的了解甚少。

结果

在这里，我们确定了OsCYP20-2，一种亲环蛋白，它会影响剪接体的组装以确定晶粒的长度。oscyp20–2 t1是由T-DNA插入引起的OsCYP20–2的敲除突变体，产生的短粒具有不足的细胞伸长率。通过酵母双杂交筛选和下拉测定，OsSYF2（一种前mRNA剪接因子）被鉴定为OsCYP20-2的相互作用蛋白。转基因系的表型表明，OsSYF2通过其对细胞扩增的影响而正调控谷粒的长度。转录组分析显示，OsSYF2控制着糖代谢相关基因的表达和mRNA的前剪接。此外，这两个基因对穗的结构有类似的影响。

结论

总之，OsCYP20-2的相互作用蛋白OsSYF2通过调节参与细胞伸长和糖代谢的前mRNA的可变剪接，控制谷物长度和穗结构。