An immunoreactive protein to wheat-germ agglutinin antibody is induced in oat roots following invasion of the cereal cyst nematode Heterodera avenae, and by jasmonate.

A protein that cross-reacts to a wheat-germ agglutinin antibody was induced in oat roots following the invasion of second-stage juveniles (J2) of the cereal cyst nematode Heterodera avenae. This protein, designated ASP45, was acid soluble, and its molecular mass was about 45 kDa on a sodium dodecyl sulfate-polyacrylamide gel. ASP45 was induced in both compatible and incompatible interactions between the nematode and the plant, and also in roots by exposure to jasmonic acid (JA) or methyl jasmonate. However, ASP45 was not induced by elicitors of pathogenesis-related proteins, abscisic acid, or wounding. Lipoxygenase activity, which is involved in JA synthesis, was higher in nematode-infected and JA-treated roots than in their noninfected, untreated counterparts. Inhibition of lipoxygenase activity in roots abolished ASP45 induction in the nematode-infected roots. Amino acid sequences similar to that of ASP45 were found in chitinases of poplar tree and Arabidopsis, even though ASP45 showed no chitinase activity. Although the biological role of ASP45 in infected roots is not clear, JA is suggested to be involved in signal transduction after pathogen invasion of the plant.