Suppression of red light-induced resistance in broad beans to Botrytis cinerea by salicylic acid

• Published in: Physiological and molecular plant pathology Vol. 66; no. 1; pp. 20 - 29
• Main Authors: Khanam, Nurun Nahar, Ueno, Makoto, Kihara, Junichi, Honda, Yuichi, Arase, Sakae
• Format: Journal Article
• Language: English
• Published: London Elsevier India Pvt Ltd 01.01.2005; Elsevier
• Subjects: ascorbic acid; Biological and medical sciences; Botrytis cinerea; Broad bean; catalase; disease resistance; enzyme inhibition; faba beans; Fundamental and applied biological sciences. Psychology; fungal diseases of plants; Fungal plant pathogens; host-pathogen relationships; Hydrogen peroxide; NADH or NADPH oxidoreductases; NADPH oxidase; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; plant biochemistry; plant pathogenic fungi; Red light; salicylic acid; Salicylic acid (SA); signal transduction; Susceptibility; Vicia faba; Red light; Hydrogen peroxide; Broad bean; Botrytis cinerea; Salicylic acid (SA); Susceptibility; Oxidative stress; Plant pathology; Plant pathogen; Mycosis; Metabolite; Suppression; Environmental factor; Biochemistry; Oxidant; Induced resistance; Spectral data; Fungi; Signal transduction; Botiytis cinerea; Catalase; Dicotyledones; Angiospermae; Mould; Fungi Imperfecti; Thallophyta; Light effect; Salicylic acid; Pathophysiology; Enzyme; Host agent relation; Vicia faba; Photobiology; Antioxidant; Fungus resistance; Infection; Grain legume; Sensitivity resistance; Leguminosae; Peroxidases; Vegetable crop; Spermatophyta; Oxidoreductases
• ISSN: 0885-5765; 1096-1178
• DOI: 10.1016/j.pmpp.2005.03.006

We investigated the effect of salicylic acid (SA) on red light-induced resistance in broad beans to Botrytis cinerea. Both lesion formation and fungal development were suppressed on broad bean leaves kept under red light, producing anti-fungal compound(s). However, SA pre-treatment inhibited expression of red light-induced resistance dose-dependently, generating hydrogen peroxide (H 2O 2). Red light-induced resistance was recovered in the presence of a H 2O 2 scavenger, ascorbic acid or a NADPH oxidase inhibitor, diphenylene iodonium even in SA-pre-treated broad bean leaves. These results suggest that breakdown of red light-induced resistance in broad beans to B. cinerea is induced by membrane-mediated H 2O 2 generation. On the other hand, catalase activity in broad bean leaves was significantly enhanced under red light, but not in those pre-treated with SA and aminotriazole. We hypothesize that enhanced antioxidant enzyme catalase activity contributes to the inhibition of cell death in broad beans scavenging endogenous H 2O 2 generated by B. cinerea infection and to elicitor-dependent production of anti-fungal component(s) by living host cells; as a consequence, red light-induced resistance may be established. It is possible that an SA-dependent signaling pathway in broad beans is playing different roles in the plant-pathogen pathosystem.