谷子脂质转移蛋白基因SiLTP1的克隆及表达分析

Cloning and Expression Analysis of Lipid Transfer Protein Gene SiLTP1 of Foxtail Millet

植物脂质转移蛋白(LTP)是一类含量丰富并且由多基因家族编码的小分子碱性蛋白。本研究利用PCR技术从谷子中克隆得到一个LTP基因,命名为SiLTP1。该基因的开放阅读框全长为354 bp,编码117个氨基酸。对其核苷酸及蛋白序列进行生物信息学分析,并通过qRT-PCR方法分析了SiLTP1在各胁迫下的表达模式。结果表明,SiLTP1具有脂质转移蛋白家族共有特性,即N端的信号肽结构、跨膜螺旋区、8个高度保守的半胱氨酸基序;三级结构预测表明,该蛋白主要是由4个α-螺旋和无规则卷曲组成;qRT-PCR结果显示,盐、干旱、ABA及MeJA均可诱导SiLTP1表达,其中盐胁迫诱导最为明显,显示SiLTP1可能参与谷子逆境胁迫响应过程,尤其在耐盐品质形成中发挥作用。本研究为深入解析谷子中SiLTP1的生物学功能及作用机制提供了理论依据。

Lipid transfer protein(LTP)is a kind of small basic protein that is rich in content and encoded by a multi-gene family.In this study,a LTP gene named SiLTP1 was cloned from foxtail millet by PCR.The open reading frame of this gene was 354 bp in length,which encoded 117 amino acids.The nucleic acid and protein sequences and the expression of SiLTP1 under stresses were analyzed.Bioinformatics analysis showed that SiLTP1 had the common structure characteristics of lipid transfer protein family,including N-terminal signal peptide,transmembrane helix,and eight highly conserved cysteine motifs.The prediction of tertiary structure of SiLTP1 showed that the protein was mainly composed of fourα-helixes and random coil.The results of qRT-PCR showed that the expression of SiLTP1 could be induced by salt,drought,ABA and MeJA,especially by salt stress,suggesting that SiLTP1 might participate in the stress response processes,especifically in the salt tolerance trait formation of foxtail millet.This study provided a theoretical basis for further analysis of biological function and mechanisms of SiLTP1 in foxtail millet.