Immunodetection of PR-1-like proteins in grapevine leaves infected with Oidium tuckeri and in elicited suspension cell cultures

Abstract

Three pathogenesis-related (PR-1-like) proteins extractable at pH 8.0 were found to accumulate in grapevine leaves after fungal pathogen (Oidium tuckeri) infection. These proteins were called gPR-1 (grapevine pathogenesis-related) proteins. Estimated molecular masses in SDS-containing gels were: gPR-1a 15.5 kDa; gPR-1b 16.8 kDa; gPR-1c 17.7 kDa. Antiserum raised against tobacco PR-la reacted specifically with grapevine counterparts. Likewise, stimulation of gPR-1 protein accumulation was observed when a set of prototype elicitors was added to grapevine cell suspension cultures. Results with inducing elicitors also showed that the extracellular PR-1-like proteins represent the only isoforms of this prominent group of pathogenesis-related proteins found in grapevine