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

• Published in: Journal of general virology 1980-03, Vol.47 (1), p.79-87
• Main Authors: Antoniw, J. F, Ritter, C. E, Pierpoint, W. S, Van Loon, L. C
• Format: Article
• Language: English
• Subjects: Laboratorium voor Plantenfysiologie; Laboratory of Plant Physiology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-47-1-79

1 Biochemistry Department, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, U.K. 2 Department of Plant Physiology, Agricultural University, Wageningen, The Netherlands A procedure is described for purifying the b 1 , b 2 and b 3 proteins from leaves of Nicotiana 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 14200 but differ in charge. In contrast, the b 4 protein differs from b 1 to b 3 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 b 1 to b 3 proteins from Xanthi-nc in electrophoretic mobility in polyacrylamide gels and in mol. wt.; b 1 , 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. Received 20 July 1979; accepted 5 October 1979.