过表达苹果多肽激素基因MdCEP1促进花青苷积累

Overexpression of Apple Peptide Hormone Gene MdCEP1 Promotes the Accumulation of Anthocyanins

以‘王林’苹果(Malus×domestica‘Orin’)愈伤组织为试材,初步探讨苹果多肽激素Md CEP1(C-TERMINALLY ENCODED PEPTIDE1)在调控花青苷合成方面的作用。分析显示Md CEP1位于苹果第15号染色体,只有1个外显子。蛋白序列比对显示不同物种中CEP结构域非常保守。启动子分析表明,Md CEP1启动子序列包含多个顺式作用元件,包括与分生组织有关的CAT-box元件、赤霉素响应元件(P-box)、光响应元件(MNF1)和与类黄酮合成相关的MYB类蛋白结合位点(MBSI)。通过农杆菌介导的遗传转化获得Md CEP1转基因苹果愈伤组织,进一步分析发现过表达Md CEP1能够明显促进愈伤组织花青苷积累,并且促进花青苷合成相关基因的表达。Md CEP1在拟南芥中异位表达,同样能够促进拟南芥中花青苷的积累,并且促进拟南芥花青苷合成相关基因的表达。研究结果表明,Md CEP1能够正调控苹果花青苷的合成。

The effects of apple peptide hormone MdCEP1（C-TERMINALLY ENCODED PEPTIDE1）on the regulation of anthocyanin synthesis were investigated by using Malus × domestica‘Orin＇as the test material,to provide reference for further study on the mechanism of anthocyanin synthesis and characterization of MdCEP1 function. Chromosomal localization analysis revealed that MdCEP1 was located on the chromosome 15 of the apple genome and had only one exon. Protein sequence alignment showed that CEP domains were conserved in different species. Promoter analysis showed that the MdCEP1 promoter sequence contained a number of cis-acting elements,including CAT-box elements associated with meristem,gibberellin response elements（P-boxes）,light-responsive elements（MNF1）and the MYB binding site（MBSI）involved in flavonoid biosynthesis. MdCEP1 transgenic apple calli were obtained by Agrobacterium tumefaciens-mediated genetic transformation. Further analysis found that overexpression of MdCEP1 could significantly promote the anthocyanin accumulation,and promote the expression of apple anthocyanin biosynthetic genes. Ectopic expression of MdCEP1 in Arabidopsis thaliana,could also promote the accumulation of anthocyanin,and promote the expression of anthocyanin biosynthetic genes in Arabidopsis thaliana. The results showed that MdCEP1 could positively control the synthesis of anthocyanin.