RT Journal Article SR Electronic(1) A1 Fraser, R. S. S.YR 1982 T1 Are ‘Pathogenesis-related’ Proteins Involved in Acquired Systemic Resistance of Tobacco Plants to Tobacco Mosaic Virus? JF Journal of General Virology, VO 58 IS 2 SP 305 OP 313 DO https://doi.org/10.1099/0022-1317-58-2-305 PB Microbiology Society, SN 1465-2099, AB SUMMARY Four host-coded ‘pathogenesis-related’ proteins accumulate systemically in local-lesion-forming varieties of tobacco after infection with tobacco mosaic virus. It has been suggested that they are involved in the acquired systemic resistance of plants to a second inoculation. Pathogenesis-related protein concentration and amount of resistance (reduction in size and number of lesions formed in the second inoculation) were measured at various times after the first inoculation. The results showed no quantitative or temporal relationship between amounts of resistance and pathogenesis-related proteins. In particular, resistance could be demonstrated in leaves before detectable accumulation of pathogenesis-related protein. Abscisic acid sprayed on plants induced an apparent resistance without inducing pathogenesis-related proteins. Low doses of methyl benzimidazol-2yl-carbamate caused accumulation of pathogenesis-related protein but not resistance. Nicotiana glutinosa plants accumulated large amounts of a similar protein after infection, but became more susceptible to a second inoculation. All these results suggest that the pathogenesis-related proteins do not play a central role in the mechanism of acquired systemic resistance., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-58-2-305