The mechanisms underlying the response and adaptation of plants to excess of trace elements are not fully described. Here, we analysed the importance of protein lysine methylation for plants to cope with cadmium. We analysed the effect of cadmium on lysine-methylated proteins and protein lysine methyltransferases (KMTs) in two cadmium-sensitive species, Arabidopsis thaliana and A. lyrata, and in three populations of A. halleri with contrasting cadmium accumulation and tolerance traits. We showed that some proteins are differentially methylated at lysine residues in response to Cd and that a few genes coding KMTs are regulated by cadmium. Also, we showed that 9 out of 23 A. thaliana mutants disrupted in KMT genes have a tolerance to cadmium that is significantly different from that of wild-type seedlings. We further characterized two of these mutants, one was knocked out in the calmodulin lysine methyltransferase gene and displayed increased tolerance to cadmium, and the other was interrupted in a KMT gene of unknown function and showed a decreased capacity to cope with cadmium. Together, our results showed that lysine methylation of non-histone proteins is impacted by cadmium and that several methylation events are important for modulating the response of Arabidopsis plants to cadmium stress.

中文翻译：

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蛋白质赖氨酸甲基化有助于调节敏感和耐受的拟南芥对镉胁迫的响应。

尚未充分描述植物对过量痕量元素的响应和适应的潜在机制。在这里，我们分析了蛋白质赖氨酸甲基化对于植物应对镉的重要性。我们分析了镉对两个对镉敏感的物种拟南芥和拟南芥以及三个不同种群的哈里埃拉中赖氨酸甲基化蛋白和赖氨酸甲基转移酶（KMTs）的影响，这些镉具有相反的镉积累和耐受性状。我们表明，某些蛋白质对Cd的响应在赖氨酸残基处被甲基化，而一些编码KMT的基因受镉的调节。此外，我们显示在KMT基因中被破坏的23个拟南芥突变体中有9个对镉的耐受性与野生型幼苗的镉耐受性显着不同。我们进一步表征了这些突变体中的两个，一个在钙调蛋白赖氨酸甲基转移酶基因中被敲除并显示出对镉的耐受性增加，另一个在功能未知的KMT基因中被打断，并且显示出应对镉的能力下降。在一起，我们的结果表明，非组蛋白的赖氨酸甲基化受镉的影响，并且几个甲基化事件对于调节拟南芥植物对镉胁迫的响应很重要。