甜瓜CmGnT基因的克隆及非生物胁迫下的表达分析

为了探究非生物胁迫下甜瓜N–乙酰氨基葡萄糖基转移酶基因(CmGnT)的作用机制,根据甜瓜cDNA序列设计引物,利用RT-PCR技术克隆得到CmGnT。生物信息学分析表明,CmGnT的cDNA全长为2 193 bp,开放阅读框(ORF)为1 179 bp,编码392个氨基酸。CmGnT蛋白分子量约为46 kD,理论等电点(pI)为7.93。蛋白结构分析表明,CmGnT含有β–1,4–N–乙酰氨基葡萄糖转移酶结构域,属于糖基转移酶17家族。该基因编码的蛋白有1个强的跨膜螺旋结构。进化树分析表明,CmGnT氨基酸序列与黄瓜CsGnT(登录号:XP_004135275.1)亲缘关系最近,同源性为99.74%,与西瓜Cs Gn T的同源性为97.70%。实时荧光定量PCR分析结果表明,在NaCl、PEG、H_2O_2和ABA等非生物胁迫下的甜瓜叶片中CmGnT都显著上调表达,表明CmGnT受非生物胁迫诱导,推测其在甜瓜响09应非生物胁迫过程中起到重要作用。

Cloning and Expression Analyzing of CmGnT Gene in Melon Under Abiotic Stresses

The aim of this study was to explore the mechanisms of N-acetylglucosaminyltransferase gene (CmGnT) in melon under abiotic stresses.Primers were designed according to cDNA sequence of melon,and CmGnT was cloned by using RT-PCR technique.The full-length cDNA of CmGnT was 2 193 bp,and the open reading frame (ORF) was 1 179 bp,encoding 392 amino acids.The molecular weight of CmGnT protein was about 46 kD,and the theoretical isoelectric point (pI) was 7.93.Protein structure analysis showed that CmGnT contained the β-l,4-N-acetylglucosaminyltransferase domain,which belonged to the glycosyltransferases 17 family.The protein had 1 strong transmembrane helices.Phylogenetic analysis showed that CmGnT and CsGnT (accession number:XP_004135275.1) had the closest genetic relationship,and the homology was 99.74％.Homology with watermelon was 97.70％.qRT-PCR analysis showed that the expressions of CmGnT in leaf were significantly up-regulated under NaCl,PEG,H2O2 and ABA stresses,which indicated that CmGnT was induced by abiotic stresses.The results suggested that this gene in melon played an important role in response to abiotic stresses.