Control of Grain Size and Weight by the GSK2-LARGE1/OML4 Pathway in Rice
Control of Grain Size and Weight by the GSK2-LARGE1/OML4 Pathway in Rice
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GSK2-LARGE1/OML4 途径对水稻籽粒大小和重量的控制
DOI：
10.1105/tpc.19.00468
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发表时间：
2020-06-01
期刊：
影响因子：
11.6
通讯作者：
Li, Yunhai
中科院分区：
文献类型：
--
作者：
Lyu, Jia;Wang, Dekai;Li, Yunhai
被GSK2磷酸化的LARGE1/LARGE1/ me2样蛋白4 （OML4）负向调控水稻的粒级和重量。籽粒大小的调控是提高作物产量的关键，也是发育生物学的一个基本方面。然而，遗传和分子机制的粮食大小控制的作物仍然很大程度上未知，尽管他们的核心重要性。在这里，我们报道了由LARGE1基因编码的MEI2-LIKE蛋白4 （OML4）被糖原合成酶激酶2 （GSK2）磷酸化，并负向控制水稻（Oryza sativa）的粒大小和重量。OML4功能缺失导致籽粒大而重，而OML4过表达导致籽粒小而轻。OML4通过限制小穗壳内细胞的膨胀来调节籽粒大小。OML4在发育中的穗和籽粒中表达，GFP-OML4融合蛋白定位于细胞核中。生化分析表明，GSK2与OML4物理相互作用并使其磷酸化，从而可能影响OML4的稳定性。遗传分析支持GSK2和OML4至少在一定程度上在控制水稻晶粒大小的共同途径中起作用。这些结果揭示了GSK2-OML4调控模块在籽粒大小调控中的遗传和分子机制，提示该途径是改善作物种子大小和重量的合适靶点。
The LARGE1/LARGE1/Mei2-Like protein4 (OML4), which is phosphorylated by GSK2, negatively regulates grain size and weight in rice. Regulation of grain size is crucial for improving crop yield and is also a basic aspect in developmental biology. However, the genetic and molecular mechanisms underlying grain size control in crops remain largely unknown despite their central importance. Here, we report that the MEI2-LIKE PROTEIN4 (OML4) encoded by the LARGE1 gene is phosphorylated by GLYCOGEN SYNTHASE KINASE2 (GSK2) and negatively controls grain size and weight in rice (Oryza sativa). Loss of function of OML4 leads to large and heavy grains, while overexpression of OML4 causes small and light grains. OML4 regulates grain size by restricting cell expansion in the spikelet hull. OML4 is expressed in developing panicles and grains, and the GFP-OML4 fusion protein is localized in the nuclei. Biochemical analyses show that the GSK2 physically interacts with OML4 and phosphorylates it, thereby possibly influencing the stability of OML4. Genetic analyses support that GSK2 and OML4 act, at least in part, in a common pathway to control grain size in rice. These results reveal the genetic and molecular mechanism of a GSK2-OML4 regulatory module in grain size control, suggesting that this pathway is a suitable target for improving seed size and weight in crops.