西洋梨水孔蛋白基因家族的全基因组鉴定及表达分析

Identification and Expression Analysis of the AQPs Gene Family in Pyrus communis

水孔蛋白(AQPs,aquaporins)是高效转运水分子的膜内在蛋白,具有丰富的多样性,在调控植物的水分关系中有重要作用。本研究利用西洋梨(Pyrus communis L.‘Bartlett’)基因组数据库,通过生物信息学手段鉴定西洋梨PcAQPs基因家族成员;并利用MEGA 6.0.5软件,采用邻接法构建系统发育树;利用GSDS 2.0软件进行基因结构分析,MEME程序进行Motif分析,AgBase v2.00程序进行GO分析;采用半定量RT-PCR技术研究PcAQPs基因组织表达情况。结果表明,西洋梨基因组中共有54个PcAQPs家族成员,均含有AQP特征结构域和保守的Motif基序,根据基因结构及系统进化分析可分为PIP、TIP、NIP和SIP等4个亚家族。不同基因间结构差别较大,但聚类关系较近的基因其结构类似。GO分析发现,多数PcAQPs基因具有转运蛋白活性,参与物质转运、应激反应、发育和代谢等生物学过程,但不同亚家族成员构成的细胞组分及参与的生物学过程具有明显差异。半定量结果表明,大多数PcAQPs基因在根、茎、叶和果实中均有表达,而且不同基因家族、不同基因间的组织表达模式存在差异。该研究为今后西洋梨PcAQPs基因的克隆和功能分析奠定了基础。

Aquaporins（ AQPs） are the members of the major intrinsic proteins（ MIPs） family with extraordinary ability to transport water,and play important roles in modulation of water relationships in plants. In this study,based on the genome database of Pyrus communis L.‘Bartlett＇（ http： / / www. rosaceae. org / species / pyrus / pyrus_communis / genome_v1. 0）,the AQPs gene family of Pyrus communis were identified and the sequences characteristic,phylogenetic trees,gene structure,GO function and expression profiles were analyzed. The phylogenetic tree was constructed using MEGA 6. 0. 5 software with neighbor-joining method. The structure of the genes were analyzed by GSDS 2. 0 software,the motif was analyzed by MEME program,and GO analysis was carried by Ag Base v2. 00 software. Their expression patterns in different tissues were studied with semi RT-PCR. The results showed that there were 54 PcAQPs genes which containing AQP feature domains and conserved motifs were identified systematically in Pyrus communis. According to the gene structure,conserved domains and phylogeny relationship,the PcAQPs proteins were classified into 4 subfamilies（ PIP,TIP,NIP and SIP） and the structure difference was larger between different subfamily genes,however,the genes with close relationship cluster had similar structure. GO analysis showed that the majority of PcAQPs gene had transporter activity,involved in substance transportation,stress response,growth,metabolism and other biological processes,but there were obvious differences in cellular components and biological processes between different subfamily members. Semi RT-PCR results showed that most of PcAQPs geneswere expressed in roots,stems,leaves,and fruits,and the expression patterns of different genes and different subfamilies were different. These results laid foundation for cloning and functional analysis of PcAQPs gene in Pyrus communis.