Potato virus Y-NTN alters the distribution and concentration of endogenous jasmonic acid in potato plants grown in vitro

To study the role of jasmonic acid (JA) in plant-virus interactions we determined the endogenous content and distribution of JA by GC-MS in healthy and infected potato (Solanum tuberosum L.) cv. Igor grown In vitro. Potatoes were infected systemically with an aggressive strain of potato virus Y-NTN (PVYNTN). In healthy plantlets JA was located primarily in the shoots, whereas in PVYNTN-infected plantlets 5.4 was located mainly in the roots. While the endogenous concentration of JA was in all cases much higher in roots compared to shoots in infected plantlets, concentrations did not show a clear trend in shoots and roots of healthy plantlets. Concentrations of JA in the roots of infected plantlets were always much higher in comparison to concentrations in the roots of healthy plantlets. The most prominent symptom resulting from the systemic PVYNTN infection was a drastic decrease in the plantlet's root system, whereas severe disease symptoms on shoots, known in systemically infected soil grown plants, did nor occur. These results indicate that plantlets accumulate JA in their roots as a consequence of the systemic viral infection, which affects the growth of this plant part. The potential interactions between JA, viral infection and other plant growth substances are discussed. We conclude that JA may play a role in plant-virus interactions. (C) 1997 Academic Press Limited.