Ultraviolet B-induced MdWRKY72 expression promotes anthocyanin synthesis in apple
Ultraviolet B-induced MdWRKY72 expression promotes anthocyanin synthesis in apple
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紫外线B诱导MdWRKY72表达促进苹果花青素合成
DOI：
10.1016/j.plantsci.2019.110377
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发表时间：
2020-03-01
期刊：
影响因子：
5.2
通讯作者：
Chen, Xuesen
中科院分区：
文献类型：
--
作者：
Hu, Jiafei;Fang, Hongcheng;Chen, Xuesen
紫外线-B(UV-B)辐射促进了许多植物花青素的合成。虽然有几种转录因子促进花青素的合成以响应UV-B辐射，但其潜在的机制仍不清楚。本研究从‘台山早夏’苹果基因组中分离到MdWRKY72转录因子基因。实时荧光定量聚合酶链式反应分析表明，与花青素合成途径有关的编码酶和转录因子的基因(MdANS、MdDFR、MdUFGT和MdMYB1)在MdWRKY72过表达的愈伤组织中比野生型‘Orin’苹果愈伤组织中表达更高。结果表明，MdWRKY72促进了UV-B辐射诱导的转基因愈伤组织花青素的合成。凝胶漂移实验和染色质免疫沉淀的结果表明，MdWRKY72通过与MdHY5启动子中的W-box元件结合和直接与MdMYB1启动子中的W-box元件结合而间接促进MdMYB1的表达。因此，MdWRKY72通过直接和间接机制促进花青素的合成。这些发现可能有助于阐明MdWRKY72介导的UV-B诱导花色苷合成的分子机制。
Ultraviolet-B (UV-B) radiation promotes anthocyanin synthesis in many plants. Although several transcription factors promote anthocyanin synthesis in response to UV-B radiation, the underlying mechanism remains unclear. In this study, the MdWRKY72 transcription factor gene was isolated from the 'Taishanzaoxia' apple genome. Quantitative real-time PCR analyses revealed that the genes encoding enzymes and transcription factors involved in the anthocyanin synthesis pathway (MdANS, MdDFR, MdUFGT, and MdMYB1) were more highly expressed in MdWRKY72-overexpressing transgenic calli than in the wild-type 'Orin' apple calli. The results indicated that MdWRKY72 increases anthocyanin synthesis in transgenic calli exposed to UV-B radiation. The results of a gel shift assay and chromatin immunoprecipitation proved that MdWRKY72 promotes MdMYB1 expression indirectly by binding to a W-box element in the MdHY5 promoter and directly by binding to a W-box element in the MdMYB1 promoter. Thus, MdWRKY72 increases anthocyanin synthesis via direct and indirect mechanisms. These findings may be useful for elucidating the molecular mechanism underlying UV-B-induced anthocyanin synthesis mediated by MdWRKY72.