野生卵穗苔草泛素结合酶基因片段的克隆与序列分析

苔草(Carex L.)是我国极具研究开发潜力的乡土草坪草种质资源。采自内蒙古大青山的卵穗苔草(Carex duriuscula)具有较强的抗旱性和耐贫瘠力,是草坪草抗性育种的重要基因源之一。本研究从野生卵穗苔草干旱抑制性消减杂交的cDNA文库中测序获得一条长度为291 bp、编码50个氨基酸的cDNA基因片段,对该基因片段进行序列分析,确定其属于泛素结合酶(ubiquitin-conjugating enzyme,E2s)蛋白家族,命名为Cd-UBC2。该基因生物信息学分析结果表明:氨基酸组成中不含吡咯赖氨酸(Ply)和硒半胱氨酸(Sec),这与其他物种UBC蛋白成分非常接近。二级结构预测表明该蛋白主要由α螺旋和无规则卷曲组成,约占92%。从野生卵穗苔草中成功获得了泛素结合酶基因片段,为克隆野生卵穗苔草泛素结合酶基因全长及最终分离、克隆苔草抗性基因,草坪草遗传改良和新品种选育奠定了基础。

Cloning and Sequence Analysis of Ubiquitin-conjugating Enzyme Gene from Wild Carex duriuscula

Carex having research and development potential is one of native turfgrass germplasm.Carex duriuscula with strong drought resistance and barren resistance collected from Daqingshan of Inner Mongolia is one of the most important genetic resources of turf grass disease resistance breeding.In this study,a 291 bp gene encoding 50 amino acid residues was cloned from wild Carex duriuscula cDNA library constructed by suppression subtractive hybridization under drought stress.This gene was identified as a belonging to the E2s family according to bioinformatics analysis,and named as Cd-UBC2.Sequence analysis showed that amino acids contained no Ply and Sec.This was quite similar to the components of UBC proteins from other species.Secondary structure prediction showed that α-helix and random coil accounting for 92% were mainly structure.Ubiquitin-conjugating enzyme gene fragments were successfully obtained from Wild Carex.This study provides the foundation for cloning of Carex ubiquitin-conjugating enzyme gene full length,finally separating,cloning resistance gene of Carex,genetic improving turfgrass.