谷子磷酸烯醇式丙酮酸羧化酶基因(PEPC)对逆境胁迫的响应

Response of Phosphoenolpyruvate Carboxylase (PEPC) Gene to Abiotic Stresses in Foxtail Millet

为解析谷子磷酸烯醇式丙酮酸羧化酶(PEPC,Phosphoenolpyruvate carboxylase)在非生物逆境胁迫下的响应特征。从谷子基因组中鉴定出一个SiPEPC(Seita.1G020700)基因,利用相关软件对其氨基酸序列、蛋白特征、功能、信号途径、顺势应答元件等参数特征进行分析和预测,随后分析了该基因在幼苗期逆境胁迫下的动态表达模式及在拔节期、抽穗期、灌浆期不同光照处理和干旱胁迫下的表达。结果表明,该基因位于谷子1号染色体,基因组序列长6 652 bp,编码965个氨基酸,基因无可变剪切、不含内含子;功能域分析显示,该基因含PEPC基因的特征结构域;多序列比对发现,该PEPC蛋白与其他植物PEPC蛋白非常相似,具有非常保守的序列结构。实时荧光定量PCR分析表明,SiPEPC(Seita.1G020700)在ABA、低温、PEG、高盐胁迫下表达量均有所上调,其中,在ABA处理时,表达量呈现波动,在12 h被诱导达到峰值。在低温处理时,表达量持续上升,在24 h达到峰值;在PEG和NaCl处理时表达量整体呈上升趋势,均在12 h达到峰值,在24 h其表达量均急剧下降。进一步研究表明,SiPEPC基因在拔节期和抽穗期正常光照强度下参与了对干旱胁迫的响应,推测SiPEPC(Seita.1G020700)基因参与了谷子对非生物逆境的应答,可能在干旱和其他逆境胁迫信号途径中起关键作用。

This study aims to investigate the response of foxtail millet phosphoenolpyruvate carboxylase gene under abiotic stress.The SiPEPC(Seita.1G020700)gene was identified from the foxtail millet genome,and the amino acid sequence,protein characteristics,function,signal pathway,homeopathic response components and other parameters of SiPEPC were analyzed and predicted using corresponding software.Subsequently,the dynamic expression pattern of the gene at seedling stage under the stress and its expression at jointing,heading and filling stages under different light treatments and drought stress were analyzed.The results indicated that SiPEPC was located on chromosome 1 of foxtail millet.The sequence analysis showed that SiPEPC had a length of 6 652 bp,encoding 965 amino acid residues.SiPEPC had no alternative splicing and intron.Functional domain analysis showed that SiPEPC contained the characteristic domains of PEPC gene.Multiple sequence alignment revealed that the SiPEPC protein had a very conserved sequence,which was very similar to PEPC proteins in other plants.qRT-PCR analysis showed that the expression of SiPEPC(Seita.1G020700)was up-regulated under ABA,low temperature,PEG and high salt stress treatments.Under ABA treatment,the expression level fluctuated and reached to peak aT12 h.Under low temperature treatment,the expression level continued to rise and reach to the highest at 24 h.The overall trend of expression increased when treated with PEG and NaCl,and peaked aT12 h,but decreased sharply at 24 h.Further studies showed that SiPEPC gene participated in the response to drought stress under normal light intensity at jointing and heading stages.These results suggested that SiPEPC(Seita.1G020700)gene participated in the response to abiotic stress and might play a key role in signaling pathway of drought or other stresses.