Are Pathogenesis-Related Proteins Induced by Meloidogne javanica or Heterodera avenae lnvasion?

Changes in root- and leaf-soluble proteins were investigated in tomato after invasion by the root-knot nematode Meloidogyne javanica, or in barley and wheat after invasion by the cereal cyst nematode Heterodera avenae. Infection of susceptible tomato plants by M. javanica did not cause any change in the soluble-protein composition of leaves or roots compared with uninoculated plants at an early infection stage. No pathogenesis-related proteins (chitinase, glucanase, or P-14) were induced in the leaf apoplast. Changes in leaf proteins were not observed after invasion of wheat cultivars by H. avenae, whereas, in barley, a few changes in intercellular leaf proteins were recorded in resistant cultivars. These changes, however, were not the same among different H. avenae-resistant cultivars. Protein changes were found at an early stage of infection in barley and wheat roots infected with H. avenae, but no difference was found between resistant and susceptible cultivars.