甘薯水通道蛋白基因家族的全基因组鉴定和表达分析

Genome-wide Identification and Expression Pattern Profiling of Aquaporin Gene Family in Ipomoea batatas

水通道蛋白(aquaporin,AQP)基因家族是植物必需的一类膜蛋白,在植物生长、发育和胁迫条件下具有多种功能。本研究通过搜索甘薯(Ipomoea batatas)基因组,并从中挖掘水通道蛋白家族基因,进一步对该家族蛋白质的理化性质、系统发育、基因结构、互作网络和组织及干旱胁迫下的表达进行分析。结果表明:甘薯基因组中共有46个水通道蛋白编码基因,这些基因通过系统发育分析分为四个亚家族(PIP;TIP;NIP;SIP)。甘薯AQP基因存在于除6号染色体外的所有甘薯染色体上,11号染色体上最多有7个基因,3、4、10号染色体上最少有1个基因。基因重复分析表明,甘薯AQP基因家族的扩增可能是由于大片段重复和串联重复。基于转录组的组织及干旱条件下表达特性分析表明,甘薯AQP基因呈现出较强的组织差异性表达,且大部分的AQP基因在干旱胁迫后表达量下调。甘薯AQP在不同植物部位和胁迫条件下的表达谱为了解甘薯不同渗透胁迫条件下AQP的参与提供了有价值的数据。本研究不仅为进一步研究甘薯AQP作为甘薯耐旱性遗传改良研究的候选基因提供了参考和资源,也提高了我们对植物水通道蛋白进化的了解。

The aquaporin(AQP)gene family constitute essential membrane proteins which possess multiple functions all through plant growth,development and under stress conditions.This study aimed to identify the AQP gene family in the Ipomoea batata genome and analyze its protein physical and chemical properties,phylogenetic tree,gene structure,protein interaction and gene expression.The results showed that there were 46 members of AQP gene family in I.batatas genome,that were separated by phylogenetic analysis into four sub-families(PIP,TIP,NIP,SIP).The AQP genes were found on all of the I.batatas chromosomes,except chromosome 6,with a maximum of 7 genes on chromosome 11,and a minimum of 1 gene on chromosome 3,4,10.Gene duplication analysis indicated that the expansion of I.batatas AQP gene family might have been due to segmental and tandem duplications.Transcriptome-based expression characteristics analysis of tissue and drought stress showed that I.batatas AQP genes showed strong tissue differential expression,and most of the AQP genes were down-regulated after drought stress.The expression profiles of AQP in different tissue and stress conditions provided valuable data to understand the involvement of AQP under different osmotic stress conditions in I.batatas.The present work not only contributes a reference and resource for further investigation of AQP as candidate genes for genetic improvement studies of drought stress tolerance in I.batatas,but also improve our knowledge of plant aquaporin evolution more generally.