决明GRAS基因家族全基因组鉴定及其在盐和干旱胁迫条件下的表达分析

目的: 基于决明(Senna tora L.)全基因组数据,对GRAS家族成员、理化性质、基因结构、进化关系以及胁迫条件下的表达模式进行鉴定和分析。方法: 将决明基因组蛋白数据与拟南芥GRAS成员进行比对,分别利用TBtools、MEGA-X、CLUSTALW、MEME等生物信息学软件和工具,对决明GRAS基因家族成员进行分析。利用qRT-PCR(quantitative real-time PCR)检测干旱和盐胁迫条件下决明根中GRAS基因的表达情况。结果: 50个StGRAS分为9个亚家族,不均等地分布在13条染色体上。结构分析表明,StGRAS34和StGRAS12分别与蒺藜苜蓿(Medicago truncatula)结瘤信号蛋白NSP1和NSP2高度同源。StGRAS的启动子区域多含有与胁迫响应、激素调节等相关的响应元件。qRT-PCR结果表明,在盐胁迫条件下,StGRAS表达具有明显差异;在干旱胁迫条件下,绝大多数检测基因能够快速响应,表达显著升高;两种胁迫条件下,StGRAS28和StGRAS29表达趋势互补,具有协同调控关系。结论: GRAS基因家族能够广泛参与胁迫响应,其中StGRAS28与StGRAS29可能共同参与介导决明根的盐与干旱胁迫应答,StGRAS34和StGRAS12分别作为决明共生结瘤的NSP1和NSP2,可能与增强结瘤因子信号诱导相关,这为进一步挖掘和研究GRAS基因在决明响应胁迫和共生固氮过程所发挥的作用提供了基础。

Genome-wide Identification of GRAS Gene Family in Senna tora L. and Its Expression Analysis under Salt and Drought Stress

Objective: Based on the whole-genome data of Cassia (Senna tora L.), this study aimed to identify and analyze the physicochemical properties, gene structure, evolutionary relationship, and expression patterns of its GRAS gene family members under stress conditions. Methods: The S. tora genomic protein data were compared with Arabidopsis GRAS members using bioinformatics software and websites such as TBtools, MEGA-X, CLUSTALW, and MEME to analyze the S. tora GRAS gene family members. The expression of GRAS genes in the root under drought and salt stress conditions was examined using qRT-PCR (quantitative real-time PCR). Results: 50 StGRAS were unequally distributed on 13 chromosomes and divided into 9 subfamilies. Structural analysis showed that StGRAS34 and StGRAS12 are highly homologous to Medicago truncatula nodulation signaling proteins NSP1 and NSP2, respectively. The promoter region of StGRAS contained many elements related to stress response and hormone regulation. qRT-PCR showed that StGRAS expression was significantly different under salt stress conditions; under drought stress conditions, most of the detected genes were able to respond rapidly with significantly higher expression, and the expression trends of StGRAS28 and StGRAS29 were complementary with synergistic regulation under both salt and drought stress conditions. Conclusion: The GRAS gene family is widely involved in stress response, among which StGRAS28 and StGRAS29 may be jointly involved in mediating salt and drought stress response in S. tora root. StGRAS34 and StGRAS12, as NSP1 and NSP2 of S. tora symbiotic nodulation, respectively, may be associated with enhanced nodulation factor signal induction, which provides a basis for further exploration and study of the role of GRAS genes in S. tora response to stress and symbiotic nitrogen fixation.