C. Egea et al., CAPSIDIOL ACCUMULATION IN CAPSICUM-ANNUUM STEMS DURING THE HYPERSENSITIVE REACTION TO PHYTOPHTHORA-CAPSICI, Journal of plant physiology, 149(6), 1996, pp. 762-764
Inoculation of the seems of the three varieties of C. annuum (L.), wit
h different sensitivities to the pepper pathogen, P. capsici, resulted
in a hypersensitive reaction of different length along the stems and
the accumulation of capsidiol. This suggests that all the pepper culti
vars analyzed contain a mechanism for recognizing this pathogen and th
e genetic information for initiating the defense response. The differe
nces lie in the inhibitory capacity towards the fungal hyphae, which i
s only really effective in Smith-5, the sole variety in which pathogen
ic attack is stopped totally. Capsidiol accumulates in the stems of al
l the pepper cultivars when inoculated with P. capsici, although there
are significant differences depending on the cultivar and on the hist
ological zone of the stem studied. The greatest accumulation of capsid
iol corresponds to the 6th day of infection in the necrotic zone of th
e resistant variety (Smith-5), suggesting that this variety alone has
the ability to accumulate sufficiently high phytoalexin levels to inhi
bit fungal development.