柑橘MYB15基因的克隆与表达分析

Cloning and Expression Analysis of MYB15 Genes from Citrus

采用电子克隆和RT-PCR方法从柚(Citrus maxima(Burm.)Merr.)、枳(Poncirus trifoliata(L.)Raf.)和柠檬(Citrus limon(L.)Burm.f.)实生苗中克隆了3个MYB蛋白基因,分别命名为CmMYB15、PtMYB15和ClMYB15;并用实时定量qRT-PCR技术检测了该基因在脱落酸(ABA)、干旱、低温和高盐胁迫处理下的时空表达。结果显示,CmMYB15、PtMYB15和ClMYB15的cDNA序列全长分别为994、992、988 bp,分别编码267、266、265个氨基酸,且编码的氨基酸序列N端均含有2个串联的不完全重复的MYB DNA-binding结构域,由此推测该3个基因均属于R2R3亚类;MYB15基因均能被ABA、干旱、低温和高盐胁迫诱导表达,且在柚、枳和柠檬中存在表达差异。本研究表明柚CmMYB15、枳PtMYB15和柠檬ClMYB15是MYB基因家族成员,可能在柑橘响应非生物胁迫过程中起到一定的作用。

Three MYB genes,including CmMYB15,PtMYB15 and ClMYB15,were cloned from seedlings of pomelo（Citrus maxima（Burm.）Merr.）,trifoliate orange（Poncirus trifoliata（L.）Raf.）and lemon（Citrus limon（L.）Burm.f.）,respectively,by in silico and reverse transcription PCR approaches.Results showed that the full length cDNA sequences of the three genes were 994,992 and 988 bp,and encoded 267,266 and 265 amino acids,respectively.The N-terminal of the three novel proteins contained two series of incomplete repeat MYB DNA-binding domains,suggesting that the three genes belonged to the R2R3 subclass of the MYB family.Moreover,the expression patterns of these genes were analyzed by real-time quantitative PCR（qRT-PCR）under the stress of ABA,drought,cold and salt.Results indicated that the expressions of the three MYB15 genes were induced by all stress treatments.However,their expression levels after stress differed among the citrus species.The results of this paper suggested that CmMYB15,PtMYB15 and ClMYB15 were members of the MYB gene family,and might play important roles in citrus in response to abiotic stress.