State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430000, Wuhan, China.
Shandong Institute of Commerce and Technology, 250000, Jinan, China.
Plant J. 2023 Aug;115(4):895-909. doi: 10.1111/tpj.16266. Epub 2023 May 21.
Grain size is a key factor in determining rice (Oryza sativa) yield, and exploring new pathways to regulate grain size has immense potential to improve yield. In this study, we report that OsCBL5 encodes a calcineurin B subunit protein that significantly promotes grain size and weight. oscbl5 plants produced obviously smaller and lighter seeds. We further revealed that OsCBL5 promotes grain size by affecting cell expansion in the spikelet hull. Biochemical analyses demonstrated that CBL5 interacts with CIPK1 and PP23. Furthermore, double and triple mutations were induced using CRISPR/Cas9 (cr) to analyze the genetic relationship. It was found that the cr-cbl5/cipk1 phenotype was similar to that of cr-cipk1 and that the cr-cbl5/pp23, cr-cipk1/pp23, and cr-cbl5/cipk1/pp23 phenotype was similar to that of cr-pp23, indicating that OsCBL5, CIPK1, and PP23 act as a molecular module influencing seed size. In addition, the results show that both CBL5 and CIPK1 are involved in the gibberellic acid (GA) pathway and significantly affect the accumulation of endogenous active GA . PP23 participates in GA signal transduction. In brief, this study identified a new module that affects rice grain size, OsCBL5-CIPK1-PP23, which could potentially be targeted to improve rice yield.
粒型是决定水稻（Oryza sativa）产量的关键因素，探索新的途径来调节粒型具有巨大的潜力来提高产量。在这项研究中，我们报告称 OsCBL5 编码一种钙调神经磷酸酶 B 亚基蛋白，它显著促进粒型和粒重。oscbl5 植株产生的种子明显更小、更轻。我们进一步揭示了 OsCBL5 通过影响小穗颖壳中的细胞扩展来促进粒型。生化分析表明 CBL5 与 CIPK1 和 PP23 相互作用。此外，使用 CRISPR/Cas9 (cr) 诱导双和三突变来分析遗传关系。发现 cr-cbl5/cipk1 表型与 cr-cipk1 相似，而 cr-cbl5/pp23、cr-cipk1/pp23 和 cr-cbl5/cipk1/pp23 表型与 cr-pp23 相似，表明 OsCBL5、CIPK1 和 PP23 作为一个分子模块影响种子大小。此外，结果表明 CBL5 和 CIPK1 都参与赤霉素（GA）途径，并显著影响内源活性 GA 的积累。PP23 参与 GA 信号转导。总之，本研究鉴定了一个新的影响水稻粒型的模块，OsCBL5-CIPK1-PP23，它可能成为提高水稻产量的目标。
