Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Int J Mol Sci. 2022 Oct 14;23(20):12280. doi: 10.3390/ijms232012280.
Fatty acid and retinol binding proteins (FAR) are unique proteins found in nematodes and are considered potential targets for controlling these parasites. However, their functions in nematode parasitism and pathogenicity and interaction with hosts are still unclear. In this study, we investigated the specific roles of rice white tip nematodes (RWTNs), , and a protein, Ab-FAR-1, to elucidate the parasitic and pathogenic processes of nematodes. The results showed that the expression level of was significantly up-regulated after infection of the plant. The immunofluorescence and subcellular localisation showed that Ab-FAR-1 was secreted into plant tissues mainly through the body wall of nematodes and might act in the nucleus and cytoplasm of plant cells. The pathogenicity of RWTNs was enhanced in overexpressing Ab-FAR-1 and inhibited in RNAi A. thaliana. Yeast two-hybrid, Co-IP, BiFC, and nematode inoculation experiments showed that Ab-FAR-1 could interact with the actin-depolymerizing factor protein AtADF3, and the mutant was more susceptible to nematodes. An in vitro actin filament depolymerisation assay demonstrated that Ab-FAR-1 could inhibit AtADF3-mediated depolymerisation of actin filaments, and the turnover process of cellular actin filaments was also affected in overexpressing Ab-FAR-1. In addition, flg22-mediated host defence responses were suppressed in overexpressing Ab-FAR-1 and adf3 mutants. Therefore, this study confirmed that RWTNs can affect the turnover of actin filament remodelling mediated by AtADF3 through Ab-FAR-1 secretion and thus inhibit plant PAMP-triggered immunity (PTI), promoting the parasitism and pathogenicity of nematodes.
脂肪酸和视黄醇结合蛋白（FAR）是存在于线虫中的独特蛋白，被认为是控制这些寄生虫的潜在靶标。然而，它们在线虫寄生和致病性以及与宿主的相互作用中的功能仍不清楚。在这项研究中，我们研究了水稻白点线虫（RWTNs）和一种蛋白 Ab-FAR-1 的特定作用，以阐明线虫的寄生和致病过程。结果表明，在感染植物后， 的表达水平显著上调。免疫荧光和亚细胞定位表明，Ab-FAR-1 主要通过线虫体壁分泌到植物组织中，可能在植物细胞的核和细胞质中发挥作用。在过表达 Ab-FAR-1 的 RWTNs 中，致病性增强，而在 RNAi 的拟南芥中，致病性受到抑制。酵母双杂交、Co-IP、BiFC 和线虫接种实验表明，Ab-FAR-1 可以与 肌动蛋白解聚因子蛋白 AtADF3 相互作用，而 突变体对线虫更敏感。体外肌动蛋白丝解聚实验表明，Ab-FAR-1 可以抑制 AtADF3 介导的肌动蛋白丝解聚，并且在过表达 Ab-FAR-1 的细胞中，细胞肌动蛋白丝的周转过程也受到影响。此外，在过表达 Ab-FAR-1 和 adf3 突变体中，flg22 介导的宿主防御反应受到抑制。因此，本研究证实，RWTNs 可以通过 Ab-FAR-1 分泌影响由 AtADF3 介导的肌动蛋白丝重排的周转，从而抑制植物 PAMP 触发的免疫（PTI），促进线虫的寄生和致病性。
