Comparison of Three Pathogenesis-related Proteins from Plants of Two Cultivars of Tobacco Infected with TMV

Abstract

SUMMARYA procedure is described for purifying the bl, b2 and b3 proteins from leaves of Nieotiana tabacum cv. Xanthi-nc, a cultivar reacting hypersensitively to tobacco mosaic virus (TMV). All three proteins consist of a single polypeptide, have similar mol. wt. of about ]4 2oo but differ in charge. In contrast, the b4 protein differs from bl to b3 in both charge and size. The same procedure purifies the proteins IV, III and II from TMV-infected leaves of N. tabacum cv. Samsun NN. The Samsun NN proteins IV to II resemble the bl to b3 proteins from Xanthi-nc in electrophoretic mobility in polyacrylamide gels and in mol. wt. ; b~, IV and III have similar amino acid compositions.It is suggested that these proteins be called pathogenesis-related proteins (PRs) and a unified system of nomenclature is proposed which groups similar proteins.

Do ethylene response factorS9 and -14 repress PR gene expression in the interaction between Piriformospora indica and Arabidopsis?

“…PR-1 has antifungal properties but the microbial targets are unkonwn. 27 The proposed antimicrobial target of PR-2 is the fungal cell wall component β-1,3 glucan. 28 PR-3 and PR-4 have chitinase activity.…”

Detection of PR 1-type Proteins in Amaranthaceae, Chenopodiaceae, Graminae and Solanaceae by Immunoelectroblotting

“…wt. of PR 1 a has been estimated at approximately 14 500 by analytical; ultracentrifugation and amino acid analysis (Antoniw et al, 1980). However, PR 1 proteins la, lb and lc behave anomalously during electrophoresis in denaturing conditions and comigrate with an apparent mol.…”

“…Pathogenesis-related (PR) proteins (Antoniw et al, 1980), also known as b-proteins, were first identified in leaves of tobacco plants infected with tobacco mosaic virus (TMV) (Gianinazzi et al, 1970;Van Loon & Van Kammen, 1970). It has since been shown that PR proteins are induced by other viruses, by bacteria and by fungi (Kassanis et al, 1974;Ahl et al, 1981;Gianinazzi et al, 1980).…”

“…wt. and amino acid compositions (Antoniw et al, 1980). An antiserum to PR 1 a protein was used to show that the PR 1 a, 1 b and 1 c proteins, but not the other eight PR proteins in cv.…”

“…PR la protein was purified as described by Antoniw et al (1980). Protein extractions at neutral pH were done by crushing leaf tissue in a mortar and pestle in 1 ml/g of SDS-PAGE sample buffer (125 mi-Tris-HC1, 10~ SDS, 10~ 2-mercaptoethanol, 10~ glycerol, pH 6.8), filtering the extract through cheesecloth, and boiling it for 2 min.…”