Cross-protection mechanisms between biotic and abiotic stresses in plants

In order to investigate cross-protection mechanisms between stresses of different origins, greenhouse experiments were conducted to determine whether resistance levels to the fungal pathogen P. capsici were affected on wounded plants. To this purpose, tomato roots were wounded at 24h-intervals and allowed to age for up to 7 days before inoculation. Data from preliminary experiments indicate first (0–48 h old wounds) an increase in disease severity in wounded as compared to unwounded tomato plants infected with P. capsici. Then, as the wounds age, disease severity decreases to the point that plants wounded 3 days before inoculation are less susceptible than nonwounded plants. Here, with the use of tomato mutant lines, we suggest the involvement of ethylene (C2H4) and jasmonates (Ja) in the development of these responses towards P. capsici upon wounding of tomato plants.