小麦DEAD-box基因家族鉴定及其低温下的表达模式分析

Identification of DEAD-box Gene Family and Expression Analysis in Response to Cold Stress in Wheat

DEAD-box RNA解旋酶是RNA代谢途後中的关键酶,在RNA代谢过程中调控植株的生长发育和抗逆性。目前,尚未见有人对小麦DEAD-box基因家族进行系统鉴定与分析。为探究小麦DEAD-box基因的功能,本研究以水稻DEAD-box基因家族基因为参照,从小麦全基因组数据库中共鉴定到134个小麦DEAD-box家族基因,并利用生物信息学对其家族成员的理化性质、基因结构、进化树和共线性进行分析。结果表明,小麦DEAD-box蛋白多数为弱碱性蛋白,亚细胞定位分布广泛,核分布最多;小麦与水稻DEAD-box家族基因亲缘性较高,小麦DEAD-box蛋白结构域与核心基序排列有序稳定,高度保守;小麦DEAD-box家族基因在进化过程中可能发生了节段性复制事件,水稻与小麦DEAD-box基因无序共线性连线,说明DEAD-box基因在进化过程中可能存在染色体异位突变。进一步以强抗寒冬小麦品种东农冬麦1号(Dn1)和东农冬麦2号(Dn2)为材料,对其转录组库中低温差异表达的7个DEAD-box基因进行qRT-PCR分析,结果表明,这7个基因在不同品种和不同组织中表达量均有差异。Dn1中DEAD-box基因的表达量在-10℃达到峰值,而Dn2中DEAD-box基因的表达量在-25℃达到峰值。

DEAD-box RNA helicase is a key enzyme in RNA metabolism pathway,which regulates plant growth and development and stress resistance during RNA metabolism.At present,there is no systematic identification and analysis of the DEAD-box gene family in wheat.In order to explore the function of the DEAD-box gene in wheat,using the rice DEAD-box gene family as the reference,134 DEAD-box genes were identified from the wheat genome database.The physicochemical properties,gene and protein structure,phylogenetic tree and collinearity of wheat DEAD-box gene family members were analyzed by bioinformatics.The results showed that the subcellular localization of DEAD-box protein in wheat was widespread,among which most were distributed in the nuclear.The relation-ship between wheat and rice DEAD-box family is closer than that of Arabidopsis thaliana.The structure domain and core motifs of wheat DEAD-box protein are orderly and stable,and highly conserved in evolution.Segment replication events may occur in the evolution of wheat DEAD-box genes,and some disordered collinear lines between rice and wheat suggest that there may be chromosomal ectopic mutations in the evolution of the DEAD-box genes.Using strong cold-resistant winter wheat varieties Dongnongdongmai 1(Dn1)and Dongnongdongmai 2(Dn2)as materials,qRT-PCR analysis of seven DEAD-box genes which differentially expressed in the transcriptome library at low temperature was performed.The results showed that the expression levels of the seven DEAD-box genes in different tissues and wheat varieties were different.The DEAD-box genes expression in Dnl mostly peaked at-10℃,while the DEAD-box gene expression in Dn2 mostly peaked at -25℃.