小麦组蛋白甲基化酶在杂交种中干旱胁迫表达模式分析

Expression Pattern Analysis of Histone Methyltransferase Under Drought Stress in Hybrid Wheat

旨在筛选参与小麦杂交种干旱胁迫的组蛋白甲基化酶基因,为二系杂交小麦抗逆性改良提供功能标记。通过网站公开数据库和比较基因组学策略对小麦TaHMT家族175个基因进行筛选获得8个受干旱胁迫诱导表达候选基因(TaHMT21、TaHMT24、TaHMT31、TaHMT42、TaHMT49、TaHMT105、TaHMT143、TaHMT157)。采用生物信息学方法对8个TaHMTs理化性质、蛋白结构、系统发育关系、基因结构和保守基序等进行了系统分析。进一步利用干旱处理的小麦杂交组合(BS278*09YH91-5及父母本)为试材,对8个组蛋白甲基化酶候选基因进行荧光定量PCR验证,发现它们受不同程度干旱胁迫诱导表达,且随着干旱胁迫时间延长基因表达水平呈先上调后下调的模式,其中TaHMT21、TaHMT24、TaHMT42基因表达与杂交组合的抗旱表型相符合,从而推测这些基因可能参与调控杂交种的抗旱性。上述结果为深入研究小麦TaHMT家族基因在杂交种抗旱性中发挥的功能提供了重要线索,同时也为小麦分子育种提供优异抗逆基因资源。

The aim of this study is to screen the histone methyltransferases involved in the drought stress of wheat hybrids,and to provide functional markers for the improvement of stress resistance of two-line hybrid wheat.Screening of the total 175 TaHMT family genes in the wheat through the public databases on the website and the comparative genomics strategies,we obtained 8 candidate histone methyltransferases genes induced by drought stress(TaHMT21,TaHMT24,TaHMT31,TaHMT42,TaHMT49,TaHMT105,TaHMT143,TaHMT157).The physical and chemical properties,protein structures,phylogenetic relationships,gene structures and conserved motifs of 8 TaHMTs were systematically analyzed via bioinformatics.Using drought treated hybrid wheat combinations(BS278*09YH91-5 and parental)as experimental materials,the candidate genes of 8 histone methyltransferase were verified via quantitative fluorescent PCR.It was found that their expressions were induced by drought stress,and the expression pattern presented mode of up-regulation first and then down-regulation with the drought stress time prolonged.The expressions of gene TaHMT21,TaHMT24 and TaHMT42 accorded with the phenotypes of hybrid combinations,indicating that they may regulate the drought resistance of hybrids.These results provide important clues to deeply study the function of wheat TaHMT family genes in the drought resistance of hybrids as well as also provide excellent stress resistance gene resources for wheat molecular breeding.