INDUCTION OF PATHOGENESIS-RELATED PROTEINS IN TOBACCO-LEAVES BY PHYSIOLOGICAL (NONPATHOGENIC) DISORDERS

The PR protein-inducing effect of naturally-occurring physiological disorders of tobacco ('sharilka', due to water excess, and Mn toxicity) was established. This supports the view of PR proteins as 'stress' macromolecules rather than exclusively pathogenesis-related macromolecules. The effects of the physiological disorders were compared with those of PVYN-infection; all these treatments produced similar symptoms of necrotic spotting on leaves. It was demonstrated that non-pathogenic ('physiological') necrobiosis induced the same PR proteins as did infectious necrobiosis. © 1990 Oxford University Press.