Relation between the endogenous jasmonic acid and decreased potato virus Y-NTN concentration in potato treated with jasmonic acid

Systemic infection of potato (Solanum tuberosum L.) cv. Igor grown in vitro with potato virus Y-NTN (PVYNTN) resulted in the accumulation of endogenou s jasmonic acid (JA) in plant roots, and in decreased plant fresh and dry w eight, especially obvious in plant roots (PETROVIC & al. 1997). The additio n of exogenous 0.1 mu M JA to the growth medium reduced virus content (PETR OVIC & RAVNIKAR 1995). In order to find the experimental explanation for lo wer PVYNTN- concentration in plants treated with 0.1 mu M JA, we compared b iochemical data on endogenous jasmonic acid with morphological characterist ics of JA-treated plants. JA-treatment did not influence the virus-induced changes in distribution endogenous JA between shoots and roots, but it redu ced the endogenous JA levels, most visible in infected roots. Simultaneousl y, JA treatment reduced virus-induced decrease in plant fresh and dry weigh t, most visible in plant shoots. Present data suggest that the virus may in fluence the sensitivity of potato plants to exogenous JA treatment.