海岛棉GbCBF6基因克隆及其在逆境胁迫下的表达分析

Molecular Cloning of GbCBF6 Gene and Its Expression in Cotton(Gossypium barbadense L.)

该研究根据棉花生物信息数据库,采用PCR方法从棉花(Gossypium barbadense L.)中克隆了1个CBF/DREB转录因子基因,命名为GbCBF6(GenBank登录号为KR233255)。GbCBF6基因开放阅读框为753bp,编码251个氨基酸,预测分子量为27.82kD,等电点为7.68。氨基酸多重序列比对结果表明,GbCBF6基因编码的蛋白与其他植物冷胁迫相关的CBF蛋白具有高度的同源性,含有1个AP2功能结构域和2个特征序列基序;与棉花已经克隆的4个GhCBF基因的氨基酸序列差异较大,是1个新的棉花CBF基因。系统进化树分析表明,GbCBF6基因属于DREB亚家族中的A-1亚组。RT-PCR分析表明,GbCBF6基因表达受干旱胁迫下调,而受4℃低温上调,在高盐(200mmol/L NaCl)处理下其表达量先下降,后增加。推测GbCBF6基因在棉花非生物胁迫的调控中起重要作用。

In this study,agene encoding the CBF/DREB transcription factor was isolated from cotton（Gossypium barbadense L.）with PCR based on bioinformation databases.Sequence analysis showed that the full-length of GbCBF6（GenBank accession No.KR233255）was a 753 bp open reading frame which encoded aprotein of 251 amino acids with predicted molecular weight of 27.82 kD and a isoelectric point of 7.68.Multiple sequence analysis showed that GbCBF6 protein share high similarity with those plant cold stressrelated CBF proteins in other plants,which contain the classic AP2 domain and two CBF signature sequences.There are dramatic amino acid sequence differences between GbCBF6 and four reported cotton GhCBFs.Phylogenetic analysis revealed that the isolated cotton GbCBF6 gene can be classified into A-1subgroup of the DREB subfamily.RT-PCR analysis indicated that the expression of GbCBF6 gene was downregulated by dehydration,but was up-regulated by cold stress.Under high salinity,the expression level of GbCBF6 gene decreased firstly,and then increased at 6hafter treatment.In summary,these results indicated GbCBF6 may play important roles in response of cotton plant to abiotic stresses.