Inhibition of DNA demethylation enhances plant tolerance to cadmium toxicity by improving iron nutrition
Inhibition of DNA demethylation enhances plant tolerance to cadmium toxicity by improving iron nutrition
复制标题
抑制 DNA 去甲基化可通过改善铁营养来增强植物对镉毒性的耐受性
DOI：
10.1111/pce.13670
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发表时间：
2019-11-12
影响因子：
7.3
通讯作者：
Jin, Chong Wei
中科院分区：
文献类型：
--
作者：
Fan, Shi Kai;Ye, Jia Yuan;Jin, Chong Wei
虽然在植物中经常观察到由于非生物胁迫（如暴露于有毒金属镉（Cd））而导致的DNA甲基化的改变，但很少有人知道这种表观遗传变化是否与植物适应胁迫的能力有关。在此，我们报告了DNA甲基化和镉胁迫下拟南芥植物的适应性反应之间的密切联系。Cd胁迫显著抑制了Col-0根中3个DNA去甲基化酶基因ROS 1/DML 2/DML 3（RDD）的表达，并在全基因组水平上提高了DNA甲基化水平。此外，在镉暴露的Col-0根的DNA甲基化的轮廓是相似的，在rdd三突变体的根，其中缺乏RDD，表明镉诱导的DNA甲基化与RDD的抑制。有趣的是，rdd中DNA甲基化的升高赋予了对Cd胁迫的更高耐受性，并改善了根组织中的细胞铁营养。此外，降低铁的供应取消提高镉的耐受性，由于缺乏RDD在rdd。总之，这些数据表明，RDD介导的DNA去甲基化的抑制，在根镉反过来又提高植物对镉胁迫的耐受性，通过改善铁营养的反馈机制。
Although the alteration of DNA methylation due to abiotic stresses, such as exposure to the toxic metal cadmium (Cd), has been often observed in plants, little is known about whether such epigenetic changes are linked to the ability of plants to adapt to stress. Herein, we report a close linkage between DNA methylation and the adaptational responses in Arabidopsis plants under Cd stress. Exposure to Cd significantly inhibited the expression of three DNA demethylase genes ROS1/DML2/DML3 (RDD) and elevated DNA methylation at the genome-wide level in Col-0 roots. Furthermore, the profile of DNA methylation in Cd-exposed Col-0 roots was similar to that in the roots of rdd triple mutants, which lack RDD, indicating that Cd-induced DNA methylation is associated with the inhibition of RDD. Interestingly, the elevation in DNA methylation in rdd conferred a higher tolerance against Cd stress and improved cellular Fe nutrition in the root tissues. In addition, lowering the Fe supply abolished improved Cd tolerance due to the lack of RDD in rdd. Together, these data suggest that the inhibition of RDD-mediated DNA demethylation in the roots by Cd would in turn enhance plant tolerance to Cd stress by improving Fe nutrition through a feedback mechanism.