University of Missouri, Columbia, MO, USA.
Mol Plant Microbe Interact. 2013 Jan;26(1):87-96. doi: 10.1094/MPMI-05-12-0118-FI.
Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ENDOSPERM SURROUNDING REGION (CLE)-like effector proteins. These proteins act as ligand mimics of plant CLE peptides and are required for successful nematode infection. Previously, we showed that the CLV2/CORYNE (CRN) heterodimer receptor complex is required for nematode CLE signaling. However, there was only a partial reduction in nematode infection when this signaling was disrupted, indicating that there might be additional nematode CLE receptors. In this study, we demonstrate that CLV1 and RECEPTOR-LIKE PROTEIN KINASE 2/TOADSTOOL2 (RPK2), two additional receptors that can transmit the CLV3 signal independent of CLV2/CRN for shoot apical meristem maintenance, also play a role in nematode CLE perception. Localization studies showed that both receptors are expressed in nematode-induced syncytia. Infection assays with clv1 and rpk2 single mutants revealed a decrease in both nematode infection and syncytium size. Significantly, further reduction in nematode infection was observed when rpk2 was combined with clv1 and clv2 mutants. Taken together, our results indicate that parallel signaling pathways involving CLV1, CLV2, and RPK2 are important for nematode parasitism.
植物寄生性胞囊线虫分泌 CLAVATA3（CLV3）/胚乳周围区域（CLE）样效应蛋白。这些蛋白作为植物 CLE 肽的配体类似物发挥作用，是成功感染线虫所必需的。先前，我们表明 CLV2/CORYNE（CRN）异二聚体受体复合物是线虫 CLE 信号所必需的。然而，当这种信号被破坏时，线虫感染仅被部分减少，这表明可能存在其他线虫 CLE 受体。在这项研究中，我们证明 CLV1 和受体样蛋白激酶 2/蟾蜍素 2（RPK2），另外两个可以独立于 CLV2/CRN 传递 CLV3 信号以维持茎尖分生组织的受体，也在线虫 CLE 感知中发挥作用。定位研究表明，这两个受体都在线虫诱导的合胞体中表达。clv1 和 rpk2 单突变体的感染测定显示线虫感染和合胞体大小均减少。重要的是，当 rpk2 与 clv1 和 clv2 突变体组合时，观察到线虫感染的进一步减少。总之，我们的结果表明涉及 CLV1、CLV2 和 RPK2 的平行信号通路对于线虫寄生很重要。
