Me. Candela et al., ISOPEROXIDASE INVOLVEMENT IN THE RESISTANCE OF CAPSICUM-ANNUUM TO INFECTION BY CUCUMBER MOSAIC-VIRUS, Journal of plant physiology, 143(2), 1994, pp. 213-217
Cucumber mosaic virus (CMV) infection of Capsicum annuum leaves provok
es a strong increase in soluble peroxidase activity. Isoelectrofocusin
g of the peroxidase activity in polyacrylamide gel patterns, after sta
ining the soluble protein fractions from both healthy and infected lea
ves with benzidine/H2O2, revealed the presence of two acidic and one b
asic isoperoxidases, the increase in peroxidase activity being mainly
due to the former. Staining of peroxidase activity in the gels with co
niferyl alcohol/H2O2 showed that acidic isoenzymes were more capable o
f catalyzing coniferyl alcohol oxidation than basic isoenzymes. Native
polyacrylamide gel electrophoresis of the soluble fraction showed tha
t the increase in peroxidase isoenzymes. CMV elicitation of the acidic
isoperoxidase through its involvement in the lignification process mi
ght be considered as a part of the defense mechanism of Capsicum annuu
m against viral infection, and lignin deposition on plasmodesmata coul
d act as a physical barrier against the cell-to-cell advance of viral
particles.