水曲柳TCP4转录因子克隆及胁迫和激素下的表达分析

Cloning,analysing and homologous expression of TCP4 transcription factor under abiotic stress and hormone signal in Fraxinus mandschurica

TCP转录因子家族是植物特异的一类调控生长发育和逆境胁迫的重要转录因子。本文揭示了水曲柳FmTCP4在非生物胁迫及激素信号诱导调控的表达特征,为该基因在水曲柳中调控生长发育以及逆境胁迫响应功能的研究奠定基础。通过前期研究克隆获得了水曲柳TCP4基因序列,并命名为FmTCP4,应用生物信息学软件对水曲柳FmTCP4基因的分子结构特征进行了分析,利用4℃低温、盐(Na Cl)以及干旱(PEG6000)进行非生物胁迫处理,利用脱落酸(ABA)和赤霉素(GA3)进行激素信号诱导,分析FmTCP4基因的表达特征。生物信息学分析表明该基因全长1 251 bp,具有完整的开放阅读框,编码416个氨基酸。FmTCP4具有螺旋-环-螺旋结构,为亲水性的不稳定蛋白,不存在信号肽,具有跨膜能力,亚细胞定位预测存在于细胞核中,并在细胞质到细胞核的调控中起作用。同源序列比对结果表明,FmTCP4与芝麻、烟草等物种的同源蛋白序列相比具有很高的同源性。非生物胁迫处理后,FmTCP4的表达量随处理时间而改变,但其变化趋势不同,表明FmTCP4明显响应了这3种非生物胁迫。激素信号诱导结果表明,外源植物激素调控了FmTCP4基因的表达,基因表达量相对于对照组具有显著性差异。非生物胁迫和激素信号诱导下的基因表达分析表明,FmTCP4响应了寒冷、盐、干旱等非生物胁迫以及激素信号,说明其参与了植物的生长发育和逆境胁迫的平衡。

TCP genes encode a plant-specific transcription factor family,which acts as a key role in regulating plant growing development and stress response. This paper reveals the FmT CP4 expression pattern under abiotic stress and hormonal signal induction,in an attempt to lay the foundation for the study of gene function in stress response and regulation of growing development in ashtree（ Fraxinus mandschurica）.We had cloned TCP gene named FmT CP4 from ashtree in our previous research. The molecular structure of FmT CP4 was analyzed by bioinformatics software. Abiotic stress by low temperature（ 4 ℃）,salt（ Na Cl） and water-deficit,and hormonal signal induced by abscisic acid（ ABA） and gibberellin（ GA3）were used to induce FmT CP4 in the study for analyzing the expression patterns. Bioinformatics analysis showed that FmT CP4 was 1 251 bp,and contained the complete ORF,encoding 416 amino acids（ Genebank ID： KX905155）. FmT CP4 had a helix-loop-helix structure,encoding a hydrophilic unstable protein,and no signal peptide but transmembrane ability,existed in the nucleus by analysing subcellularlocalization prediction,and played an important role in the regulation of cytoplasm to the nucleus. The results of homology sequence comparison showed that FmT CP4 had high homology with sesame,tobacco and other species. After abiotic stress treatments,FmT CP4 gene expression levels varied with abiotic stress time,but the trend was different,showing that FmT CP4 significantly responded to the three kinds of abiotic stress. The results of FmT CP4 gene expression after the induction by hormone signal were significantly different compared with the control group,suggesting that exogenous plant hormones had regulated the transcription expression of FmT CP4 gene. The analysis about FmT CP4 gene expression after the induction by abiotic stress and hormonal signal indicated that FmT CP4 gene had responded to abiotic stress（ cold,salt,drought） and hormone signal,meaning that FmT CP4 involved in the balance of growing development and stress response.