红麻海藻糖生物合成关键酶基因HcTPPJ的克隆及响应逆境的表达分析

Cloning of the key enzyme gene HcTPPJ in trehalose biosynthesis of kenaf and its expression in response to abiotic stress in kenaf

海藻糖生物合成关键酶基因TPP在植物响应各种非生物胁迫过程中具有重要作用。为了明确红麻TPP基因在应对非生物胁迫过程中的作用,本研究根据转录组CL541.Contig2Unigene序列设计特异性引物,通过PCR获得红麻TPP基因的cDNA全长序列。生物信息学分析表明,该基因最大开放读码框为1128 bp,编码一个含有375个氨基酸的蛋白质。序列一致性分析发现,该蛋白质氨基酸序列与其他物种TPPJ氨基酸序列的一致性为71.18%,故将该基因命名HcTPPJ。表达模式分析表明,该基因在根、茎、叶中均有表达,在盐、干旱胁迫下,随着胁迫时间的延长,HcTPPJ表达显著上调,表明该基因参与红麻的盐、干旱胁迫响应过程。在盐、干旱胁迫下, HcNCED3显著上调表达,而外源喷施脱落酸时,HcTPPJ表达变化不明显。由此推测,在红麻响应盐、干旱胁迫过程中,该基因的表达可能不受脱落酸信号分子的调控。这将为进一步阐明该基因在红麻响应盐、干旱胁迫过程的作用奠定基础。

Trehalose biosynthesis key enzyme gene TPP plays an important role in plant response to various abiotic stresses.In this study,in order to clarify the role of TPP gene in response to abiotic stress in kenaf,a specific primer was designed according to the sequence of CL541.contig2unigene,and the full-length cDNA sequence of TPP gene was obtained by PCR.Bioinformatics analysis showed that TPP had an open reading frame(ORF)length of 1128 bp,and encoded a protein containing 375 amino acids.The results of amino acid sequence consistency indicated that the agreement between the amino acid sequence of protein and that of TPPJ from other species was 71.18%,so the gene named as HcTPPJ.HcTPPJ was expressed in roots,stems and leaves.Under salt or drought stress,HcTPPJ was up-regulated significantly with the extension of stress treatment,indicating that the gene was involved in the response process of salt or drought stress in kenaf.Under the same conditions,HcNCED3 and HcAOC was significantly up-regulated,while the change of HcTPPJ expression was not obvious under ABA stress;HcTPPJ was significantly down-regulated,under the stress of MeJA for six hours.Therefore it was speculated that the HcTPPJ gene expression may be not regulated by the signal molecule of ABA,but negatively regulated by methyl jasmonate signal molecule.This study will lay a solid foundation for further elucidating the role of the gene in response to salt and drought stress in kenaf.