ETH Zurich, Institute of Molecular Plant Biology (D-BIOL), Zurich, Switzerland.
University of Lausanne, Department of Plant Molecular Biology, Lausanne, Switzerland.
Mol Plant. 2023 May 1;16(5):865-881. doi: 10.1016/j.molp.2023.03.015. Epub 2023 Mar 31.
Most organisms adjust their development according to the environmental conditions. For the majority, this implies the sensing of alterations to cell walls caused by different cues. Despite the relevance of this process, few molecular players involved in cell wall sensing are known and characterized. Here, we show that the wall-associated kinase-like protein RESISTANCE TO FUSARIUM OXYSPORUM 1 (RFO1) is required for plant growth and early defense against Fusarium oxysporum and functions by sensing changes in the pectin methylation levels in the cell wall. The RFO1 dwell time at the plasma membrane is affected by the pectin methylation status at the cell wall, regulating MITOGEN-ACTIVATED PROTEIN KINASE and gene expression. We show that the extracellular domain of RFO1 binds de-methylated pectin in vitro, whose distribution in the cell wall is altered during F. oxysporum infection. Further analyses also indicate that RFO1 is required for the BR-dependent plant growth alteration in response to inhibition of pectin de-methyl-esterase activity at the cell wall. Collectively, our work demonstrates that RFO1 is a sensor of the pectin methylation status that plays a unique dual role in plant growth and defense against vascular pathogens.
大多数生物会根据环境条件来调整其发育过程。对于大多数生物来说，这意味着它们能够感知细胞壁因不同信号而发生的变化。尽管这一过程非常重要，但人们对参与细胞壁感知的分子机制知之甚少。本文中，作者研究发现，细胞壁相关激酶样蛋白 RESISTANCE TO FUSARIUM OXYSPORUM 1（RFO1）在植物生长和早期抵御尖孢镰刀菌（Fusarium oxysporum）的过程中发挥重要作用，它可以通过感知细胞壁中果胶甲基化水平的变化来发挥作用。RFO1 在质膜上的停留时间受细胞壁上果胶甲基化状态的影响，从而调节丝裂原活化蛋白激酶和基因表达。作者发现，RFO1 的细胞外结构域能够在体外结合去甲基化果胶，且在尖孢镰刀菌感染过程中，细胞壁中去甲基化果胶的分布发生了改变。进一步的分析还表明，RFO1 是 BR 依赖型植物生长变化所必需的，因为它能够响应细胞壁中果胶脱甲基酯酶活性的抑制。综上所述，该研究结果表明，RFO1 是果胶甲基化状态的传感器，在植物生长和防御维管束病原体方面发挥着独特的双重作用。
