He Ying, Chen Weiting, Tan Juhong, Luo Xixiu, Zhou Yanjin, Gong Xiaoting, Yao Juan, Zhuang Chuxiong, Jiang Dagang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China.
Theor Appl Genet. 2022 Dec;135(12):4245-4259. doi: 10.1007/s00122-022-04215-8. Epub 2022 Oct 1.
A FT/TFL1 subfamily gene, rice CENTRORADIALIS 2, also known as RCN1, regulates seed germination and increase salt tolerance via ABA-mediated pathway. The ABA synthesis and metabolism related genes were changed relative expression levels. Seed germination is a complex biological process that is affected by many factors. Although a number of germination-related genes have been reported, the molecular mechanism of germination regulation has not yet been fully elucidated. Here, we reported that the rice OsCEN2 gene can negatively regulate seed germination. The germination speed of OsCEN2-RNAi seeds was significantly faster while that of OsCEN2-overexpression (OE) seeds was slower than that of the wild type (WT). The results of qRT-PCR showed that the OsCEN2 expression was increased in the early stage of seed germination. Exogenous application of abscisic acid (ABA) on seeds and seedlings showed that OsCEN2-OE seeds and seedlings were highly sensitive to ABA during germination and post-germination growth, respectively. The determination of endogenous ABA content in seeds also showed that the ABA content of OsCEN2-RNAi seeds was lower, while that of OsCEN2-OE seeds was higher. Moreover, the transgenic plants changed salt tolerance because of the altered ABA level. In addition, differences were also observed in the expression of genes related to ABA synthesis and metabolism in the seeds of OsCEN2-transgenic lines. This study reveals that OsCEN2 regulates the germination speed by affecting the content of ABA during seed germination and provides a theoretical basis for research on rice direct seeding.
一个FT/TFL1亚家族基因，水稻CENTRORADIALIS 2，也称为RCN1，通过ABA介导的途径调节种子萌发并提高耐盐性。ABA合成和代谢相关基因的相对表达水平发生了变化。种子萌发是一个受多种因素影响的复杂生物学过程。尽管已经报道了许多与萌发相关的基因，但萌发调控的分子机制尚未完全阐明。在此，我们报道水稻OsCEN2基因可负向调节种子萌发。OsCEN2-RNAi种子的萌发速度明显更快，而OsCEN2过表达（OE）种子的萌发速度比野生型（WT）慢。qRT-PCR结果表明，OsCEN2在种子萌发早期表达增加。对种子和幼苗外源施加脱落酸（ABA）表明，OsCEN2-OE种子和幼苗在萌发和萌发后生长过程中分别对ABA高度敏感。种子内源ABA含量的测定也表明，OsCEN2-RNAi种子的ABA含量较低，而OsCEN2-OE种子的ABA含量较高。此外，转基因植物由于ABA水平的改变而改变了耐盐性。此外，在OsCEN2转基因系种子中，ABA合成和代谢相关基因的表达也存在差异。本研究揭示了OsCEN2通过影响种子萌发过程中ABA的含量来调节萌发速度，为水稻直播研究提供了理论依据。
