BjMYB1, a transcription factor implicated in plant defence through activating BjCHI1 chitinase expression by binding to a W-box-like element.
BjMYB1, a transcription factor implicated in plant defence through activating BjCHI1 chitinase expression by binding to a W-box-like element.
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DOI：
10.1093/jxb/erw240
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发表时间：
2016-08
影响因子：
6.9
通讯作者：
Zhao K
中科院分区：
文献类型：
--
作者：
Gao Y;Jia S;Wang C;Wang F;Wang F;Zhao K
BjMYB 1是芥菜型油菜中的一个R2 R3-MYB蛋白，它与W-box元件而不是AC元件结合，介导植物对真菌的防御。我们以前确定的W-box-like-4（Wbl-4）元件（GTAGTGACTCAT），在BjC-P启动子的不寻常的几丁质酶基因BjCHI 1从芥菜，作为响应真菌感染的核心元件之一。在这里，我们报告的同源转录因子与WBL-4元件相互作用的分离和表征。使用Wbl-4作为靶标，我们进行了B的酵母单杂交筛选。从芥菜cDNA文库中分离到R2 R3-MYB转录因子BjMYB 1。BjMYB 1定位于植物细胞核中。EMSA分析证实BjMYB 1与Wbl-4元件结合。瞬时表达的BjMYB 1通过与烟草叶片中的Wbl-4元件结合而上调BjC-P启动子的活性。在B。BjMYB 1在感染灰葡萄孢（Botrytis cinerea）后表现出与BjCHI 1相似的诱导表达模式。此外，BjMYB 1的异源过表达显著提高了转基因拟南芥对真菌B的抗性。灰叶这些结果表明，BjMYB 1是潜在的参与宿主防御真菌的攻击，通过激活BjCHI 1的表达结合到BjC-P启动子中的Wbl-4元件。这一发现证明了植物MYB转录因子的一个新的DNA靶点。
BjMYB1, an R2R3-MYB protein from Brassica juncea, binds to W-box-like elements rather than AC elements to mediate plant defence against fungus. We previously identified the W-box-like-4 (Wbl-4) element (GTAGTGACTCAT), one of six Wbl elements in the BjC-P promoter of the unusual chitinase gene BjCHI1 from Brassica juncea, as the core element responsive to fungal infection. Here, we report the isolation and characterization of the cognate transcription factor interacting with the Wbl-4 element. Using Wbl-4 as a target, we performed yeast one-hybrid screening of a B. juncea cDNA library and isolated an R2R3-MYB transcription factor designated as BjMYB1. BjMYB1 was localized in the nucleus of plant cells. EMSA assays confirmed that BjMYB1 binds to the Wbl-4 element. Transiently expressed BjMYB1 up-regulated the activity of the BjC-P promoter through its binding to the Wbl-4 element in tobacco (Nicotiana benthamiana) leaves. In B. juncea, BjMYB1 displayed a similar induced expression pattern as that of BjCHI1 upon infection by the fungus Botrytis cinerea. Moreover, heterogeneous overexpression of BjMYB1 significantly elevated the resistance of transgenic Arabidopsis thaliana to the fungus B. cinerea. These results suggest that BjMYB1 is potentially involved in host defence against fungal attack through activating the expression of BjCHI1 by binding to the Wbl-4 element in the BjC-P promoter. This finding demonstrates a novel DNA target of plant MYB transcription factors.