The WRKY transcription factor, WRKY13, activates PDR8 expression to positively regulate cadmium tolerance in Arabidopsis
The WRKY transcription factor, WRKY13, activates PDR8 expression to positively regulate cadmium tolerance in Arabidopsis
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WRKY转录因子WRKY13激活PDR8表达以正向调节拟南芥的镉耐受性
DOI：
10.1111/pce.13457
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发表时间：
2019-03-01
影响因子：
7.3
通讯作者：
Cao, Shuqing
中科院分区：
文献类型：
--
作者：
Sheng, Yibao;Yan, Xingxing;Cao, Shuqing
镉（Cd）胁迫是植物通过减少Cd积累而获得耐镉性的重要机制。之前的研究已经确定了拟南芥ABC转运蛋白PDR 8作为赋予镉耐受性的镉挤压泵。然而，PDR 8在镉胁迫下的调控机制仍不清楚。在这项研究中，我们确定了拟南芥镉耐受显性突变体，指定xcd 3-D，从XVE标记的T-DNA插入线的功能获得性遗传筛选。相应的基因被克隆，并显示编码核WRKY转录因子WRKY 13。镉胁迫诱导WRKY 13的表达。WRKY 13的过表达导致镉积累减少和镉耐受性增强，而WRKY 13的功能丧失导致镉积累和镉敏感性增加。进一步的分析表明，WRKY 13通过直接结合其启动子来激活PDR 8的转录。遗传分析表明，WRKY 13作用于PDR 8的上游，正向调节Cd耐受性。我们的研究结果提供的证据表明，WRKY 13直接靶向PDR 8正向调节拟南芥镉耐受性。
Cadmium (Cd) extrusion is an important mechanism conferring Cd tolerance by decreasing its accumulation in plants. Previous studies have identified an Arabidopsis ABC transporter, PDR8, as a Cd extrusion pump conferring Cd tolerance. However, the regulation of PDR8 in response to Cd stress is still largely unknown. In this study, we identified an Arabidopsis cadmium-tolerant dominant mutant, designated xcd3-D, from the XVE-tagging T-DNA insertion lines by a gain-of-function genetic screen. The corresponding gene was cloned and shown to encode a nuclear WRKY transcription factor WRKY13. Expression of WRKY13 was induced by Cd stress. Overexpression of WRKY13 resulted in decreased Cd accumulation and enhanced Cd tolerance, whereas loss-of-function of WRKY13 led to increased Cd accumulation and sensitivity. Further analysis showed that WRKY13 activates the transcription of PDR8 by directly binding to its promoter. Genetic analysis indicated that WRKY13 acts upstream of PDR8 to positively regulate Cd tolerance. Our results provide evidence that WRKY13 directly targets PDR8 to positively regulate Cd tolerance in Arabidopsis.