In plants, recognition of a pathogen as an invader may result in the formation of hypersensitive response (HR) lesions, i.e. localized programmed cell and tissue death associated with restriction of the pathogen to the infection site. A transient suppression of antioxidants is known to occur during relatively early stages of the HR. Here we show that the transient suppression of a catalase and an alternative oxidase gene during virusinduced local lesion formation (HR) has similar kinetics in different hosts regardless of the extent of leaf necrotization. Both
var. Columbia and a paraquat tolerant
biotype display significantly less and smaller necrotic lesions in response to inoculation by two viruses (
Tobacco mosaic virus
Tobacco necrosis virus
) in comparison to control plants (
cv. Samsun, respectively). We found that all of these plant hosts display a transient suppression of catalase and alternative oxidase transcript levels starting within six hours after virus inoculation. Our results suggest that the transient decline in antioxidant activity during early stages of an HR does not significantly influence the extent of localized cell death around infection sites.