Effect of α-aminooxyacetate, a competitive inhibitor of phenylalanine ammonia-lyase, on the hypersensitive resistance of tobacco to tobacco mosaic virus

摘要: Abstract Tobacco leaves reacting hypersensitively to infection by tobacco mosaic virus elicit a strong metabolic stimulus that activates particularly the phenylpropanoid pathway. We tested effect, on hypersensitive resistance, of aminooxyacetate, potent competitive inhibitor in vitro first enzyme pathway, phenylalanine ammonia-lyase. Aminooxyacetate supplied infected did not change number TMV-induced local lesions, but it increased 2- 4-fold size lesions for three tobacco-TMV combinations examined. It was effective even when at low concentrations (10 50 μ m ) and up just 6 h before appearance lesions. weakened mechanism localization as evidenced presence lesion edges. Virus content these large however, parallel their increase area. shown aminooxyacetate had inhibited ammonia-lyase activity vivo reduced flux derivatives without suppressing elicitor(s) synthesis activity. suggest enhanced production phenylalanine-derived metabolites (such lignins or lignin-like compounds) is directly involved resistance viral infection, this may be due an inability spread elicitor-stimulated cells.