福州野生蕉FeSOD家族基因的克隆及在低温胁迫下的表达分析  

Clone and Expression Analysis under Cold Stress of FeSOD Family Genes from the Wild Banana in Fuzhou

作　　者：冯新[1] 徐蕾[1] 赖恭梯[1] 谢晓清[1] 林玉玲[1] 赖钟雄[1] 

机构地区：[1]福建农林大学园艺植物生物工程研究所,福州350002

出　　处：《西北植物学报》2015年第5期853-864,共12页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家香蕉产业技术体系专项资金(CARS-32-11);福建省农业科技平台(2008N2001)

摘　　要：以抗寒性较强的福州野生蕉为材料,采用RACE和RT-PCR扩增得到铁超氧化物歧化酶(FeSOD)家族基因(FeSOD)的2个成员共4条转录本,分别命名为MuFSD1A(登录号JX844026)、MuFSD1B(登录号KJ786318)、MuFSD1B-variant1(登录号KJ786319)和MuFSD1B-variant2(登录号KJ786320)。MuFSD1A基因cDNA全长为1 277bp,编码300个氨基酸;MuFSD1B基因cDNA全长为1 378bp,编码260个氨基酸。基因结构分析表明MuFSD1B-variant1和MuFSD1B-variant2为MuFSD1B的可变剪接转录本。生物信息学和亚细胞定位分析显示,MuFSD1A和MuFSD1B主要定位于叶绿体,但他们的理化性质、磷酸化位点、蛋白结构等存在差异。序列比对分析发现MuFSD1A和MuFSD1B相似性仅为33.33%,但都具有保守的金属结合位点和FeSOD的特征氨基酸。进化树分析显示,MuFSD1A和MuFSD1B聚在不同的分支中。qRT-PCR分析表明,低温诱导MuFSD1A基因的表达而抑制MuFSD1B基因的表达,且MuFSD1A基因的相对表达量随着温度的降低而显著增加,说明该成员可能在香蕉抗寒中起主要作用。In this study,the wild banana in Fuzhou with stronger anti-cold ability was used as materials to clone the iron superoxide dismutase family （FeSOD） genes. Two FeSOD genes with four transcripts,designed as MuFSD1A （Accession No. JX844026 ）, MuFSD1B （ Accession No. KJ786318 ）, MuFSDIB-variantl （Accession No. KJ786319） and MuFSD1B-variant2 （Accession No. KJ786320）, respectively, were ob- tained by RACE and RT-PCR. The full-length eDNA sequences of MuFSDIA were 1 277 bp, encoding a 300 aa polypeptide,while that of the MuFSD1B were 1 378 bp,encoding 260 amino acids. Genomic structure analysis revealed that MuFSD1B-variantl and MuFSD1B-variant2 were alternatively spliced variants of MuFSDIB..Bioinformatics and subcelluar localization analyses indicated that both MuFSD1A and MuFSDIB were mainly located in chloroplast, but their physicochemical properties, phosphorylation sites and protein structures were different from each other. Sequence alignments showed that MuFSD1A and MuFSDIB shared a low sequence identity （33.33%）, although they all carried the conserved metal ligand binding sites and residues essential for distinguishing FeSOD from MnSOD. Phylogenetic analysis suggested MuFSDIA and MuFSDIB are grouped into different clusters, qRT-PCR results revealed that cold stress induced the expression of MuFSD1A but suppressed MuFSD1B expression. In addition,the expression level of MuFSD1A was significantly enhanced with the temperature decreasing, indicating this gene member might play a major role in banana cold resistance.

关 键 词：福州野生蕉 FeSOD家族基因 可变剪接 低温胁迫 基因表达 

分 类 号：Q785[生物学—分子生物学] Q786