棉花抗逆基因GhAREB4的克隆及功能分析

Cloning and Characterization of a Transcription Factor Gene GhAREB4 in Gossypium hirsutum

AREBs转录因子家族基因主要参与干旱、高盐、低温等胁迫应答反应,在植物抵御各种逆境胁迫中起着非常重要的作用。该研究经序列电子拼接克隆了陆地棉GhAREB4基因,该基因全长1 784bp,其开放阅读框为1 227bp,编码408个氨基酸,预测分子量为44.3kD,等电点为8.88。蛋白结构预测发现,该蛋白二级结构中含有bZIP基因家族的保守结构域。系统进化树分析表明,GhAREB4与可可的AREB转录因子同源性最高。绿色荧光蛋白亚细胞定位分析表明,GhAREB4蛋白分布在细胞核内。qRT-PCR分析表明,GhAREB4基因在花中的表达量最高;且GhAREB4基因表达受到干旱、高盐、低温、脱落酸(ABA)等处理的诱导,其可能调控棉花对非生物逆境的耐性响应。研究结果为进一步研究该基因对棉花耐逆调控机制奠定了基础。

AREBs transcription factor family genes are mainly involved in plant tolerance to abiotic stresses including drought,high salt,extreme temperatures and so on.In this study,the GhAREB4 gene of upland cotton was cloned by PCR approach,which is 1 784 bp in size.Its open reading frame contains 1 227 bp,encoding a 408 amino acids peptide whose molecular weight is 44.3kD and the isoelectric point is8.88.The GhAREB4 proteinhad a conserved domain of bZIP gene family in the secondary structure.Phylogenetic tree analysis showed that GhAREB4 had the highest homology with Cocoa AREB transcription factor.Subcellular localization analysis through green fluorescent protein（GFP）fusion approach showed that GhAREB4 protein was distributed in the nucleus.Results of qRT-PCR analysis showed that GhAREB4 gene preferentially expresses in flowers.And GhAREB4 gene was induced under drought,high salt,low temperature,abscisic acid（ABA）treatment,suggesting that the gene plays an important role in cotton plant tolerance to abiotic stresses.These results could provide a foundation to further implore the function of GhAREB4 in cotton tolerance to abiotic stress.