龙眼Aquaporin家族的全基因组鉴定及其在体细胞胚发生早期的表达

Genome-wide identification of Aquaporin family and expression during early somatic embryogenesis in Dimocarpus longan Lour.

水孔蛋白(AQP)是生物调控水跨膜运输的重要通道.为了解龙眼AQP基因家族的生物学功能,利用本实验室的龙眼基因组数据库,结合生物信息学的分析方法进行龙眼全基因组范围内AQP家族成员的鉴定,并对其蛋白质理化性质、系统进化关系、共线性、选择压力、基因结构、保守基序、蛋白质保守结构域、顺式作用元件、蛋白质互作和体细胞胚早期不同阶段的基因表达情况进行分析.结果显示,龙眼AQP基因家族共有35个成员,蛋白分子量在17.77×10^(3)-44.30×10^(3) kD之间,分布在14条染色体上;经系统发育树分析,可将其分为5个不同亚家族:PIPs、TIPs、NIPs、SIPs和XIPs;不同亚家族间等电点、磷酸化位点、内含子数量和motif分布差异较大;AQP家族成员间共有6对共线性基因,与拟南芥基因组间有28对共线性基因,且在进化过程中都受纯化选择作用;龙眼AQP家族蛋白质都含有MIP保守结构域;其家族成员可与SYP、PP2A和BOR发生互作,PIP亚家族内的蛋白互作关系最强;基因组的FPKM值分析发现,大部分AQP成员可在龙眼胚胎早期不同阶段进行表达,其中DlTIP4的表达量在所有阶段远高于其他成员,可能在整个过程中发挥着重要作用.本研究表明龙眼35个AQP家族成员基因可能在体细胞胚胎发育阶段发挥重要作用,并且可能响应干旱、低温等非生物胁迫和脱落酸、生长素等植物激素的调控,在功能上具有明显的多样性.

Aquaporin(AQP)is an important protein channel responsible for the regulation of water transmembrane transport.To investigate the biological function of the longan AQP gene family,the longan genome database from our laboratory and bioinformatic analysis methods were used to identify the whole AQP family,including family number identification,physical and chemical properties of the proteins,phylogenetic tree,collinearity,selection pressure,gene structure,conserved motif,conserved domain,promoter,protein interaction,and gene expression in different stages of early somatic embryos.The results show that there are 35 members of the longan AQP gene family,and the molecular weight of the proteins ranged from 17.77×10^(3) to 44.30×10^(3).The AQP family genes were distributed over 14 chromosomes.According to the phylogenetic tree analysis,the genes can be divided into five different subfamilies:PIPs,TIPs,NIPs,SIPs,and XIPs.The distribution of isoelectric points,phosphorylation sites,intron numbers,and motifs among the different subfamilies were quite different.There are six pairs of collinearity genes between longan AQP gene families,as well as 28 pairs of collinearity genes between longan AQP gene families and the Arabidopsis genome,all of which were under purified selection during the evolutionary process.The conserved domain of the longan AQP family is MIP,and the family members can be associated with SYP,PP2 A,and BRO,especially in the PIP subfamily.Analysis of the FPKM genome showed that most AQP members can be expressed in different stages during the early embryo of longan,and the expression of DlTIP4 is much higher than that of other members in all stages during the early embryo,possibly playing an important role in the whole process.Overall,this study shows that the 35 AQP family members may play an important role in the stage of somatic embryogenesis of longan,and possibly respond to abiotic stresses,such as drought and low temperature.Moreover,they can be regulated by abscisic acid,auxin,and other plant hormones as well,showing obvious functional diversity.