小麦类硫素基因家族鉴定及表达分析

Identification and expression analysis of Thionin-like gene family in wheat

类硫素(thionin-like,Thil)在植物应对病原微生物侵染的防御反应中具有重要生物学功能。本研究通过拟南芥(Arabidopsis thaliana)的Thil基因序列,利用同源搜寻及生物信息学方法初步鉴定到普通小麦(Triticum aestivum L.)的Thil基因家族。结果表明,Thil基因家族在普通小麦中包含26个成员。基因序列结构分析得到Thil家族存在保守的基序结构,家族各成员基因编码的蛋白质序列包含79~196个氨基酸,大部分蛋白质的氨基酸数量少于140,其中20个蛋白质包含信号肽。顺式作用元件预测分析结果显示,小麦Thil基因的启动子调控元件受到脱落酸等逆境胁迫相应激素的影响,同时基因表达谱呈现出受到病原菌胁迫诱导后的多样性表达。通过进一步qRT-PCR验证分析表明,普通小麦的TaThil-4A、TaThil-4B和TaThil-4D等3个基因在叶锈病菌早期侵染中被诱导表达。本研究结果可为小麦抗病育种及Thil基因家族的功能鉴定与应用提供参考。

Thionin-like(Thil)has important biological functions in plant defense response to pathogenic microorganisms.In this study,the Thil gene family of Triticum aestivum L.was initially identified using the homologous search and bioinformatics method based on Thil genes of the model plant Arabidopsis thaliana.A total of 26 Thil genes are included in the wheat genome.Structural analysis of gene sequences showed that the conserved motif structure exists in the Thil family,Thil genes encode proteins of 79-196 amino acids,most proteins have less than 140 amino acids,and 20 Thil proteins contain signal peptides.The cis-acting element prediction indicated that promoter elements of the Thil genes are mainly affected by corresponding hormones about adversity stress such as abscisic acid.Gene expression profiles showed that diversifying expression of the Thil family genes exists in response to pathogenic infection.qRT-PCR analysis showed that the expressions of TaThil-4A,TaThil-4B,and TaThil-4D were induced in the early response to wheat leaf rust fungus.The results of this study can provide a reference for wheat disease resistance breeding in wheat and functional study and application of the Thil gene family.