University of Grenoble Alpes, CEA, INRA, CNRS, IRIG, PCV, Grenoble, France.
Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, Brussels, Belgium.
Plant Cell Environ. 2020 Mar;43(3):760-774. doi: 10.1111/pce.13692. Epub 2019 Dec 8.
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.
植物对微量元素过量的反应和适应的机制尚未完全描述。在这里，我们分析了蛋白质赖氨酸甲基化对植物应对镉的重要性。我们分析了镉对两种镉敏感物种拟南芥和阿氏南芥中赖氨酸甲基化蛋白和蛋白赖氨酸甲基转移酶（KMTs）的影响，以及三个具有不同镉积累和耐受特性的 A. halleri 种群。我们表明，一些蛋白质在赖氨酸残基上对 Cd 的响应存在差异甲基化，并且一些编码 KMT 的基因受到镉的调控。此外，我们表明，23 个拟南芥 KMT 基因突变体中有 9 个对镉的耐受性与野生型幼苗明显不同。我们进一步表征了其中的两个突变体，一个是钙调蛋白赖氨酸甲基转移酶基因敲除，对镉的耐受性增加，另一个是一个功能未知的 KMT 基因突变体，对镉的应对能力降低。总之，我们的结果表明，非组蛋白蛋白的赖氨酸甲基化受到镉的影响，并且几个甲基化事件对于调节拟南芥植物对镉胁迫的反应很重要。
