大豆再生相关基因GmLEC的克隆及生物信息学分析

利用同源克隆技术,对拟南芥再生相关基因LEC进行同源序列比对,从大豆中克隆LEC基因两个成员的全长CDS序列,得到大豆再生相关基因Gm LEC1-a,Gm LEC1-b及Gm LEC2-a,Gm LEC2-b,用生物信息学方法对大豆Gm LEC1及Gm LEC2基因核苷酸序列以及蛋白质结构、亲水性和疏水性及进化树等进行分析。结果表明,大豆再生相关基因Gm LEC1-a编码区长度为672 bp,编码223个氨基酸,Gm LEC1-b编码区长度为681 bp,编码226个氨基酸,Gm LEC2-a编码区长度为2 205 bp,编码734个氨基酸,Gm LEC2-b编码区长度为2 196 bp,编码731个氨基酸,Gm LEC蛋白为亲水性不稳定蛋白;通过对LEC蛋白功能结构域进行分析发现,Gm LEC1为H4超家族成员,Gm LEC2为B3超家族成员,并均与拟南芥属植物亲缘较近。

Effect of GmLEC1-A Expression on ABA Content at Germination Stage in Soybean(Glycine max)

LEAFY COTYLEDON1(LEC1) is a key regulator of seed maturation, which gives embryos the ability to withstand desiccation. In this study, a novel transcription factor that is homologous to LEC1 in soybean(Glycine max) was isolated from Dongnong 50 by homologous cloning and was named as GmLEC1-A(GenBank accession number: MF681785). Sequence analysis showed that GmLEC1-A contained conserved B regions, which were functional domains of H4 factor. The relative expression level of GmLEC1-A was the highest in seeds of the soybean cultivar Dongnong 50. To verify the function of GmLEC1-A, ectopic expression of Arabidopsis thaliana and over-expression of soybean plants were generated. In Arabidopsis, the expression of GmLEC1-A restored the tolerance of lec1 mutant to seed drying, indicating that GmLEC1-A was a functional homolog of LEC1,and it might regulate the maturation phase of seed development. In soybean, over-expression of GmLEC1-A caused slower growth and lower germination rates as compared to that of wild-type soybeans. Furthermore, over-expression of GmLEC1-A seemed to increase the level of endogenous abscisic acid(ABA) at the germination stage. These results suggested that GmLEC1-A had a function in regulating ABA content at the germination stage.

大豆GmLEC2基因的生物信息学及表达分析

AtLEC2基因最早发现于拟南芥中,是参与体细胞胚胎发生与种子发育过程的重要基因,在植物生长和发育过程中起着非常关键的作用。本研究选择功能已知的AtLEC2基因作为参考,对大豆GmLEC2基因的启动子元件、蛋白的功能、等电点、脂肪指数、亲水性、不稳定系数、信号肽、跨膜结构、亚细胞定位、二级结构、三级结构和结构域进行预测分析。并采用荧光定量RT-PCR方法对GmLEC2基因的组织特异性表达进行分析。本研究的结果为今后进一步研究该基因的生物学功能提供了理论基础。