中国白梨PbSFBB 13-gamma基因的分子克隆与序列特征(英文)  

Molecular Cloning and Characterization of PbSFBB 13-gamma from Chinese White Pear (Pyrus bretschneideri)

作　　者：张琳[1] 谭晓风[1] 胡姣[1] 乌云塔娜[1] 袁德义[1] 何小勇 龙洪旭[1] 李秀根[3] 

机构地区：[1]中南林业科技大学资源与环境学院经济林育种与栽培国家林业局重点实验室,长沙410004 [2]浙江省丽水市科普工作指导站,丽水323000 [3]中国农业科学研究院郑州果树研究所,郑州450009

出　　处：《林业科学》2009年第11期36-43,共8页Scientia Silvae Sinicae

基　　金：Supported by the Youth Foundation of Education Bureau of Hunan Province(1014586);the Key Project of State Forestry Administration(2006-12);the Important Project of Ministry of Education

摘　　要：以5个已知S基因型的中国白梨品种为试材,设计分别对应于梨SFBB-alpha,SFBB-beta和SFBB-gamma基因的3对引物对这5个品种进行基因组PCR扩增。结果仅引物组合PSFBG-F/PSFBG-R从‘金花’（S13S18）,‘金花四号’（S13S18）和‘鹅梨’（S13S34）中扩增出一约1300bp的条带,经回收、克隆、测序后,鉴定其为SFBB-gamma基因,命名为PbSFBB13-gamma（Pyrus bretschneideri SFBB13-gamma）,GenBank登录号为EU081892。逆转录PCR结果表明PbSFBB13-gamma仅在花粉中特异表达;序列分析表明该基因不含内含子,编码区含1191个核苷酸,编码396个氨基酸,预测分子质量与等电点分别为45.4ku、4.63。PbSFBB13-gamma表现出典型的花粉SFB/SLF基因的基本结构特征,即1个F-box结构域及4个可变区;在推导氨基酸水平上,其与蔷薇科SFB/SLF基因的相似性为17.8%-97.7%。试验结果充分表明PbSFBB13-gamma应为花粉S基因的候选基因。选取蔷薇科34个SFB/SLF基因的全长氨基酸序列,构建进化树研究基因间的进化关系。结果表明,34个SFB/SLF基因形成2个亚科特异的类群,但不形成种特异的类群,其进化规律与蔷薇科S-RNase基因一致,即花粉SFB/SLF基因的形成也是在亚科形成之后、种形成之前。研究结果有助于从分子水平上揭示中国白梨的自交不亲和性机制。Five Chinese White Pear（Pyrus bretschneideri）cultivars,with known S-genotypes,were used in this study.The genomic DNAs were extracted and amplified by PCR with three pairs of primers corresponding to pear SFBB-alpha,SFBB-beta and SFBB-gamma genes,respectively.Results showed that only one primer pair PSFBG-F/PSFBG-R successfully amplified a fragment of approximately 1 300 bp from ＇Jinhua＇（S_ 13S_ 18）,＇Jinhuasihao＇（S_ 13S_ 18）and ＇Eli＇（S_ 13S_ 34）corresponding to pear SFBB-gamma gene.This gene was named PbSFBB13-gamma（Pyrus bretschneideri SFBB13-gamma）and deposited under GenBank accession No.EU081892.RT-PCR revealed that the PbSFBB13-gamma was expressed specifically in the pollen grains.The coding region of the PbSFBB13-gamma was 1 191 bp in length encoding 396 amino acids with a predicted molecular weight of 45.4 ku and isoeletric point of 4.63.The SFBB13-gamma displayed the typical structural characterization of SFB/SLF genes,i.e.an F-box motif and four variable regions.At the deduced amino acid level,it shared 17.8% to 97.7% similarities with other SFB/SLFs of rosaceous plants.These characteristics of PbSFBB13-gamma fully demonstrate that it is a candidate of pollen S-gene although its function in gametophytic self-incompatibility（GSI）response is not confirmed yet.Phylogenetic analysis revealed that 34 rosaceous SFB/SLFs were dived into two subfamily-specific groups,but did not further form species-specific subgroup.The evolutionary pattern of SFB/SLFs concurs with that of rosaceous S-RNases,suggesting that SFB/SLFs occur after divergence of subfamily but before the divergence of species as S-RNases do in Rosaceae.The present study could provide a scientific base for fully clarifying the mechanism of pear GSI at the molecular level.

关 键 词：白梨 配子体自交不亲和性 花粉S基因 S位点F-box基因 进化树 

分 类 号：S718.46[农业科学—林学] Q943.2[生物学—植物学]