Abstract
Radopholus similis is a migratory endoparasitic nematode that is extremely harmful to host plants. Venom allergen-like proteins (VAPs) are members of the cysteine-rich secretory protein family that are widely present in plants and animals. In this study, we cloned a VAP gene from R. similis, designated as RsVAP. RsVAP contains an open reading frame of 1089 bp encoding 362 amino acids. RsVAP is specifically expressed in the esophageal gland, and the expression levels of RsVAP are significantly higher in juveniles than in other life stages of R. similis. This expression pattern of RsVAP was consistent with the biological characteristics of juveniles of R. similis, which have the ability of infection and are the main infection stages of R. similis. The pathogenicity and reproduction rate of R. similis in tomato was significantly attenuated after RsVAP was silenced. In tobacco leaves transiently expressing RsVAP, the pathogen-associated molecular pattern-triggered immunity (PTI) induced by a bacterial flagellin fragment (flg22) was inhibited, while the cell death induced by two sets of immune elicitors (BAX and Gpa2/RBP-1) was repressed. The RsVAP-interacting, ras-related protein RABA1d (LeRabA1d) was identified in tomato hosts by yeast two-hybrid and co-immunoprecipitation assays. RsVAP may interact with LeRabA1d to affect the host defense response, which in turn facilitates nematode infection. This study provides the first evidence for the inhibition of plant defense response by a VAP from migratory plant-parasitic nematodes, and, for the first time, the target protein of R. similis in its host was identified.
Highlights
Radopholus similis (Cobb, 1893) Thorne, 1949 is one of the world’s ten most important plant-parasitic nematodes [1]
This study presents the first evidence for the inhibitory effect of R. similis on plant defense responses and identifies the first host plant proteins interacting with R. similis
We found that the full-length cDNA of RsVAP carries an open reading frame (ORF) of 1089 bp, encoding a protein of 362 aa
Summary
Radopholus similis (Cobb, 1893) Thorne, 1949 is one of the world’s ten most important plant-parasitic nematodes [1]. R. similis use their stylets to enter the host and migrate through host tissues During this process, the nematode movement and secretions of stylets destroy host cells and tissues, causing extensive damage, including dark lesions, tissue necrosis, slow-growing, plant wilting and plant lodging [1]. Plant-parasitic nematodes can secrete proteins or molecules through their stylet or body wall into plant cells Most of these secretions are proteins produced by their esophageal glands, while some secretory proteins come from the head sensilla and tail [4,5]. Some studies have reported on the effectors of R. similis, whose genes play a crucial role in host infection and pathogenesis [8,9,10,11,12,13,14,15]. This study presents the first evidence for the inhibitory effect of R. similis on plant defense responses and identifies the first host plant proteins interacting with R. similis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
