甘蓝型油菜铵转运蛋白基因家族成员的鉴定与表达分析

Genome Wide Identification and Expression Analysis of AMT Gene Family Members in Brassica napus

了解异源四倍体甘蓝型油菜中AMT基因家族的功能,为进一步克隆和利用基因改良甘蓝型油菜的氮素利用效率和铵毒抗性提供一定的理论基础。利用生物信息学的方法鉴定出20个BnaAMTs基因,其中14个为AMT1亚家族成员,6个为AMT2亚家族成员,它们不均匀地分布在油菜的12条染色体上。进化与保守基序分析结果表明,BnaAMTs蛋白亚家族内的蛋白质序列保守性较高,但亚家族之间的差异较大。BnaAMTs基因在油菜不同组织中的表达谱显示,该基因家族表达具有组织特异性。利用转录组测序结果分析发现,根部在供应高浓度的铵态氮和硝态氮时,BnaA7.AMT1;3表达量最高;在硝态氮缺乏条件下,BnaA5.AMT1;1表达量最高;在上述几种处理下,BnaC6.AMT1;1都是地上部表达量最高的拷贝。在缺硼或缺磷条件下,油菜BnaAMTs基因整体呈现表达上升的趋势;但在盐胁迫条件下,表达量下降;镉胁迫对BnaAMTs基因的表达影响较小。这些基因可能在铵态氮与其他必需营养元素的互作、镉胁迫、盐胁迫等逆境响应中发挥一定的作用;并为进一步深入解析甘蓝型油菜AMT家族基因的分子功能奠定了基础。

Understanding the roles of BnaAMTs in allotetraploid Brassica napus could provide a theoretical basis for further cloning and using these genes to improve nitrogen use efficiency and ammonium toxicity resistance in Brassica napus.20 BnaAMTs genes were identified by bioinformatics.Among them,14 were AMT1 subfamily members and 6 were AMT2 subfamily members.They were unevenly distributed on the 12 chromosomes of Brassica napus.The results of conserved motif analysis showed that the protein sequences of BnaAMTs subfamilies were highly conserved,but the differences between subfamilies were large.The expression profile of BnaAMTs gene in different tissues of rapeseed indicated that the expression of this gene family was tissue-specific.The results of transcriptome sequencing showed that in root,BnaA7.AMT1;3 had the highest expression level when the roots were fed high concentrations of ammonium and nitrate.Under the condition of nitrogen deficiency,the expression of BnaA5.AMT1;1 was the highest in root.Under the above treatments,BnaC6.AMT1;1 had the highest expression in shoot.Under the condition of boron deficiency or phosphorus deficiency,the overall expression of BnaAMTs gene in rapeseeds showed an upward trend.However,under salt stress,the expression level decreased.Cadmium stress had little effect on the expression of BnaAMTs.These genes may involve in the interaction of ammonium with other essential nutrients and play a certain role in Cd and salt stress.This study lays a foundation for further analysis of the molecular function of AMT family genes in Brassica napus.