State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Guangdong Laboratory for Lingnan Modern Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 5100642, China.
Nat Commun. 2024 Nov 4;15(1):9537. doi: 10.1038/s41467-024-53898-8.
Cadmium (Cd) is a detrimental heavy metal propagated from soil to the food chain via plants, posing a great risk to human health upon consumption. Despite the understanding of Cd tolerance mechanisms in plants, whether and how plants actively respond to Cd and in turn restrict its uptake and accumulation remain elusive. Here, we identify a cell wall-associated receptor-like kinase 4 (WAKL4) involved in specific tolerance to Cd stress. We show that Cd rapidly and exclusively induces WAKL4 accumulation by promoting WAKL4 transcription and blocking its vacuole-dependent proteolysis in roots. The accumulated WAKL4 next interacts with and phosphorylates the Cd transporter NRAMP1 at Tyr488, leading to the enhanced ubiquitination and vacuole-dependent degradation of NRAMP1, and consequently reducing Cd uptake. Our findings therefore uncover a mechanism conferred by the WAKL4-NRAMP1 module that enables plants to actively respond to Cd and limit its uptake, informing the future molecular breeding of low Cd accumulated crops or vegetables.
镉（Cd）是一种有害的重金属，通过植物从土壤传播到食物链，对人类健康构成极大威胁。尽管人们已经了解了植物对镉的耐受机制，但植物是否以及如何主动应对镉，从而限制其吸收和积累，仍然难以捉摸。在这里，我们鉴定了一个与细胞壁相关的类受体激酶 4（WAKL4），它参与了对 Cd 胁迫的特定耐受。我们表明，Cd 通过促进 WAKL4 转录和阻止其液泡依赖性蛋白水解，在根中快速且特异性地诱导 WAKL4 积累。积累的 WAKL4 随后与 Cd 转运蛋白 NRAMP1 相互作用并在 Tyr488 处磷酸化，导致 NRAMP1 的泛素化和液泡依赖性降解增强，从而减少 Cd 的吸收。因此，我们的发现揭示了一个由 WAKL4-NRAMP1 模块赋予的机制，使植物能够主动应对 Cd 并限制其吸收，为未来低 Cd 积累作物或蔬菜的分子育种提供了信息。
