CHANGES IN PHENOLIC COMPOUNDS IN NICOTIANA SPECIES AS A RESPONSE TO WOUNDING AND VIRAL INFECTION
S. Likić, G. Rusak
The quantitative and qualitative changes in phenolic compounds were compared in Nicotiana spp. plants that were either wounded or infected with Cucumber mosaic virus (CMV) containing satellite RNA. Significant changes in total phenolic (TP) content were analysed in N. megalosiphon, N. glutinosa and N. tabacum var. Samsun at four different time intervals. The highest decrease of TP was detected in wounded N. megalosiphon plants while the highest increase was detected in infected N. megalosiphon plants. Depending on treatment and time, a significant increase or decrease of caffeic acid, quercetin or kaempferol was detected in the investigated species. The strongest increase in quercetin concentration was observed in infected N. glutinosa. The largest number of significant changes of caffeic acid, quercetin and kaempferol concentration in the analysed time intervals was observed in infected N. megalosiphon plants. The defence response to wounding in all investigated Nicotiana species resulted in a significant decrease of detected phenolic content. The detected changes in phenolics in virus-infected plants were characteristic for each species, suggesting that each species activates a different defence response to viral infection. The observed changes of phenolics are obvious responses to wounding and viral infection, which could likely be involved in activating a distinct defence response to a specific stress.