中国农业科学 ›› 2017, Vol. 50 ›› Issue (21): 4178-4185.doi: 10.3864/j.issn.0578-1752.2017.21.012

• 园艺 • 上一篇    下一篇

红肉苹果分裂素响应基因MdMYB308的克隆与表达分析

王意程,王楠,许海峰,张宗营,姜生辉,张静,曲常志,陈学森   

  1. 山东农业大学园艺学科与工程学院/作物生物学国家重点实验室,山东泰安 271018
  • 收稿日期:2017-05-07 出版日期:2017-11-01 发布日期:2017-11-01
  • 通讯作者: 陈学森,Tel:0538-8249338;E-mail:chenxs@sdau.edu.cn
  • 作者简介:王意程,Tel:18206381380;E-mail:2270841499@qq.com。
  • 基金资助:
    国家重点研发计划(2016YFC0501505)、国家自然科学基金(31730080)

Molecular Cloning and Expression Analysis of Cytokinins Responsive Gene MdMYB308 in Red Flesh Apple

WANG YiCheng, WANG Nan, XU HaiFeng, ZHANG ZongYing, JIANG ShengHui, ZHANG Jing, QU ChangZhi, CHEN XueSen   

  1. College of Horticultural Science and Engineering, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an 271018, Shandong
  • Received:2017-05-07 Online:2017-11-01 Published:2017-11-01

摘要: 【目的】细胞分裂素是调控植物花青苷合成的重要激素,从新疆红肉苹果杂种一代优系‘紫红3号’中克隆得到分裂素响应基因MdMYB308,研究其在细胞分裂素调控苹果花青苷合成中的作用,为进一步完善红肉苹果育种的理论与技术体系提供参考。【方法】以红肉苹果‘紫红3号’(新疆红肉苹果与‘富士’杂交1代)的红色幼嫩叶片为外植体诱导的红色愈伤组织为试材,设计引物利用PCR克隆MdMYB308,对其进行生物信息学分析;并用不同浓度细胞分裂素处理,采用荧光定量PCR分析MdMYB308及花青苷合成相关基因的表达;通过酵母双杂交试验、荧光双分子互补试验验证MdMYB308与MdbHLH3的互作关系。【结果】在‘紫红3号’中克隆获得MdMYB308全长,其包含768 bp完整的开放阅读框,编码255个氨基酸,预测其编码蛋白质分子量为28.37 kD,等电点为8.94;系统进化树分析表明,MdMYB308AtMYB4FaMYB1AtMYBL2在同一个进化枝上,氨基酸序列比对发现,MdMYB308蛋白存在EAR抑制序列;提高6-BA浓度有利于苹果愈伤组织花青苷的累积,与无细胞分裂素处理相比,1 mg·L-1 6-BA处理愈伤花青苷合成结构基因MdCHSMdDFRMdUFGT与转录基因MdMYB10MdbHLH3的表达量升高,而MdMYB308表达被抑制;酵母双杂交与荧光双分子互补试验表明,MdMYB308与MdbHLH3能相互作用。【结论】细胞分裂素(6-BA)可能通过抑制MdMYB308的表达影响MdMYB308与MdbHLH3的结合从而促进花青苷的累积。

 

关键词: 苹果, 分裂素, MdMYB308, 酵母双杂, 双分子荧光互补

Abstract: 【Objective】Cytokinin is an important hormone in the regulation of anthocyanin synthesis in plants. To develop the theory and technology for red flesh apple breeding, the function in the cytokinin regulating anthocyanin metabolism of MYB transcription factor gene MdMYB308 in ‘Zihong No.3’ from Malus sieversii f. neidzwetzkyana F1 population was studied. 【Method】The callus induced from the leaves of ‘Zihong No.3’ apple was used as materials. The MdMYB308 in ‘Zihong No.3’ was cloned and its bioinformation was analyzed. The expression level of MdMYB308 and anthocyanin biosynthesis related genes in callus which grown on different concentrations of 6-BA was studied by the qRT-PCR. Meanwhile, the interaction between MdbHLH3 and MdMYB308 was verified by yeast two-hybrid system and bimolecular fluorescence complementation assay. 【Result】 The full length of MdMYB308 in ‘Zihong No.3’ was cloned, and the gene was 768 bp which encoded 255 amino acids. It was predicted that the molecular mass of this protein was 28.37 kD, and pI was 8.94. A phylogenetic tree indicated that MdMYB308, AtMYBL2, FaMYB1 and AtMYB4 are located in the same evolutionary branch. The aligned protein sequences revealed that MdMYB308 contain the EAR motif. Furthermore, the content of anthocyanin rose as 6-BA concentration increased as well. The transcript levels of anthocyanin structural genes (MdCHS, MdDFR, MdUFGT) and transcription factors (MdMYB10, MdbHLH3) were significantly higher in callus grown on 1 mg?L-1 6-BA compared with 6-BA-deprived callus. In contrast, the expression of MdMYB308 was inhibited. The results of yeast two hybrid experiments and bimolecular fluorescence complementation assays showed that the MdMYB308 could interact with MdbHLH3.【Conclusion】Cytokinin (6-BA) could promote anthocyanin accumulation by down-regulating the expression of MdMYB308 which may destroy the combination of MdMYB308 and MdbHLH3.

Key words: apple, cytokinin, MdMYB308, yeast two hybrid experiments, bimolecular fluorescence complementation assays