木薯MeHSF18基因克隆及表达分析

Clone and Expression Analysis of MeHSF18 in Cassava

【目的】热激转录因子(Heat Shock Transcription Factor,HSF)在植物非生物胁迫响应过程中起重要调控作用。【方法】本研究利用PCR技术从木薯中克隆得到一个HSF家族基因,命名为MeHSF18,对其理化性质、蛋白结构域和进化关系、基因表达水平进行了分析。【结果】该基因的开放阅读框全长为867 bp,编码289个氨基酸,其蛋白质分子量为31.67 kDa,等电点为5.90。对其进行序列比对分析表明MeHSF18基因的氨基酸序列与橡胶树和麻疯树中的氨基酸序列同源性最高。木薯11个组织的表达数据表明MeHSF18基因在根相关组织中都有高表达。另外,MeHSF18基因的表达能被干旱和ABA处理显著诱导。在木薯块根的采后生理性变质过程中MeHSF18基因的表达也被显著诱导。【结论】MeHSF18基因可能在转录水平参与ABA介导的木薯干旱胁迫响应和木薯块根的采后生理性变质,可作为候选基因进一步研究其在木薯抗逆和采后储存中的功能。

【Objective】Heat Shock Transcription Factor is a key regulatory factor in defense from abiotic stresses in plants.【Method】In this research,a HSF gene designated MeHSF18 was isolated from cassava leaves through RT-PCR method.The physicochemical properties,protein domain,phylogenetic tree,and expression profiles of MeHSF18 were analyzed.【Result】The full-length cDNA of MeHSF18 was 867 bp,encoded a polypeptide of 289 amino acid residues with a predicted relative molecular mass of 31.67 kDa and an isoelectric point of 5.90.Multiple alignment showed that MeHSF18 shared a significant degree of sequence identify with other HSF proteins in Hevea brasiliensis and Jatropha curcas.The expression profile of 11 cassava tissues showed that the high expression of MeHSF18 was in root.The transcriptome data results indicated that MeHSF18 was upregulated by drought stress and ABA treatment.The expression of MeHSF18 was also induced in cassava PPD process.【Conclusion】These results suggested that MeHSF18 might be involved in ABA mediated drought stress response and participated in PPD process.