Cyst nematode parasitism of Arabidopsis thaliana is inhibited by salicylic acid (SA) and elicits uncoupled SA-independent pathogenesis-related gene expression in roots.

Compatible plant-nematode interactions involve the formation of an elaborate feeding site within the host root that requires the evasion of plant defense mechanisms by the parasite. Little is known regarding plant defense signaling pathways that limit nematode parasitism during a compatible interaction. Therefore, we utilized Arabidopsis thaliana mutants perturbed in salicylic acid (SA) biosynthesis or signal transduction to investigate the role of SA in inhibiting parasitism by the beet cyst nematode Heterodera schachtii.

Mutation of a UDP-glucose-4-epimerase alters nematode susceptibility and ethylene responses in Arabidopsis roots.

In Arabidopsis, mutation of RHD1, a UDP-glucose-4-epimerase, causes root-specific phenotypes, including hypersusceptibility to the cyst nematode Heterodera schachtii, increased root hair elongation, decreased root length, and root epidermal bulging. Previous experiments suggested that increased ethylene sensitivity or production mediated the rhd1-4 phenotypes. In the present study, double mutant analyses revealed that only rhd1-4 hypersusceptibility to H.