Degradation of
pectin, a major component of plant cell wall, is important for fungal necrotrophs to achieve a successful
infection. The activities of
pectin methylesterases (PMEs) from both plants and pathogens and the degree and pattern of
pectin methylesterification are critical for the outcome of plant-pathogen interaction. Partial degradation of
pectin by
pectin degrading
enzymes releases oligogalacturonides (OGs), elicitors of plant defense responses. Few analytical techniques are available to monitor
pectin methylesterification-modulating machineries and OGs produced during plant pathogen interaction. In the present study,
ruthenium red is presented as useful
dye to monitor both Botrytis cinerea mycelium growth and the induction of PME activity in plant tissue during
fungal infection. Moreover a simple, inexpensive and sensitive method, named PECTOPLATE, is proposed that allows a simultaneous phenotyping of PME and
pectinase activities expressed during pathogen
infection and of
pectinase potential in generating OGs. The results in the manuscript also indicate that PME inhibitors can be used in PECTOPLATE as a tool to discriminate the activities of plant PMEs from those of pathogen PMEs expressed during pathogenesis.