BACKGROUND The heterotrimeric G protein complex, consisting of Gα, Gβ, and Gγ subunits, are conserved signal transduction mechanism in eukaryotes. Recent molecular researches had demonstrated that G protein signaling participates in the regulation of yield related traits. However, the effects of G protein genes on yield components and stress tolerance are not well characterized. RESULTS In this study, we generated heterotrimeric G protein mutants in rice using CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) gene-editing technology. The effects of heterotrimeric G proteins on the regulation of yield components and stress tolerance were investigated. The mutants of gs3 and dep1 generated preferable agronomic traits compared to the wild-type, whereas the mutants of rga1 showed an extreme dwarf phenotype, which led to a dramatic decrease in grain production. The mutants showed improved stress tolerance, especially under salinity treatment. We found four putative extra-large G proteins (PXLG)1-4 that also participate in the regulation of yield components and stress tolerance. A yeast two hybrid showed that the RGB1 might interact with PXLG2 but not with PXLG1, PXLG3 or PXLG4. CONCLUSION These findings will not only improve our understanding of the repertoire of heterotrimeric G proteins in rice but also contribute to the application of heterotrimeric G proteins in rice breeding.

中文翻译：

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异三聚体G蛋白参与水稻多种农艺性状的调控和胁迫耐受性。

背景技术由Gα，Gβ和Gγ亚基组成的异源三聚体G蛋白复合物是真核生物中保守的信号转导机制。最近的分子研究表明，G蛋白信号参与了产量相关性状的调控。但是，G蛋白基因对产量成分和胁迫耐受性的影响尚未很好地表征。结果在这项研究中，我们使用CRISPR / Cas9（聚簇有规律地间隔短回文重复序列）基因编辑技术在水稻中产生了异源三聚体G蛋白突变体。研究了异源三聚体G蛋白对产量成分调控和逆境耐性的影响。与野生型相比，gs3和dep1的突变体产生更好的农艺性状，而rga1的突变体表现出极矮的表型，这导致谷物产量急剧下降。突变体显示出改善的胁迫耐受性，特别是在盐度处理下。我们发现了四个推定的超大G蛋白（PXLG）1-4，它们也参与了产量成分和胁迫耐受性的调控。酵母2杂种显示RGB1可能与PXLG2相互作用，但不与PXLG1，PXLG3或PXLG4相互作用。结论这些发现不仅将增进我们对水稻中异源三聚体G蛋白组成的了解，而且还将有助于异源三聚体G蛋白在水稻育种中的应用。酵母2杂种显示RGB1可能与PXLG2相互作用，但不与PXLG1，PXLG3或PXLG4相互作用。结论这些发现不仅将增进我们对水稻中异源三聚体G蛋白组成的了解，而且还将有助于异源三聚体G蛋白在水稻育种中的应用。酵母2杂种显示RGB1可能与PXLG2相互作用，但不与PXLG1，PXLG3或PXLG4相互作用。结论这些发现不仅将增进我们对水稻中异源三聚体G蛋白组成的了解，而且还将有助于异源三聚体G蛋白在水稻育种中的应用。