桑树MaPP2C8基因克隆及其干旱胁迫下的表达

Cloning of MaPP2C8 Gene from Mulberry and Its Expression under Drought Stress

该研究基于桑树转录组测序结果及基因组数据库,采用PCR技术,克隆获得桑树2C型蛋白磷酸酶基因MaPP2C8的cDNA及其启动子序列,运用生物信息学方法对序列进行分析,并采用qRT-PCR方法检测MaPP2C8在干旱胁迫处理下的表达特性,为进一步研究MaPP2C8基因在干旱胁迫响应中的功能奠定基础。结果显示:(1)MaPP2C8基因cDNA全长为1309 bp,开放阅读框(ORF)全长为1053 bp,编码350个氨基酸。(2)MaPP2C8蛋白与桑科其他植物亲缘关系较近,归属于PP2Cs家族中的A亚族。(3)MaPP2C8蛋白分布于细胞中的多个位置,包括细胞质、细胞核及细胞膜等。(4)克隆获得MaPP2C8基因编码起始位点上游长度为1612 bp启动子序列,该启动子含有3类激素相关的顺式作用元件,且与ABA相关的元件多达3个。(5)MaPP2C8基因受干旱胁迫诱导上调表达,复水处理后,其表达量显著下调。研究表明,MaPP2C8基因在桑树响应干旱胁迫过程中可能起重要作用。

In this study,based on the transcriptome results and genome database of mulberry,we cloned the cDNA and promoter sequence of MaPP2C8 using PCR method.Bioinformatics methods were used to analyze the cDNA and promoter sequence of MaPP2C8 and the expression pattern of MaPP2C8 under drought treatment was determined by using qRT-PCR method.The results show that:(1)the full-length cDNA of MaPP2C8 gene was 1309 bp,which contained an opening reading frame of 1053 bp and encoded a protein of 350 amino acids residues.(2)MaPP2C8 protein was highly homologous with the species in Moraceae and belongs to the A branch in the PP2Cs family.(3)MaPP2C8 protein may locate in multi-positions of the cell,such as the nucleus,cytoplasm,cytomembrane,etc.(4)A 1612 bp promoter fragment upstream of translation initiation site was isolated from mulberry.MaPP2C8 promoter contained three types of hormone-related cis-acting elements,and as many as 3 elements associated with ABA.(5)The expression of MaPP2C8 gene was upregulated by drought treatment,and its expression level was significantly down-regulated after rewatering treatment.Our studies suggest that MaPP2C8 gene may play an important role in response to drought stress in mulberry.