Interaction of nuclear polyhedrosis virus with catechols: Potential incompatibility for host-plant resistance against noctuid larvae

Two major orthodihydroxy phenolics of Lycopersicon esculentum, rutin and chlorogenic acid, have previously been identified as potential sources of host-plant resistance against the tomato fruitworm Heliothis zea. We report here the possible incompatibility of these chemically based resistance factors with viral control of H, zea. We have found that both rutin and chlorogenic acid significantly inhibited the infectivity of nuclear polyhedrosis viruses. Chlorogenic acid, when added to tissue culture medium containing TN-368 ovarian cells, inhibited the infectivity of a multiply embedded virus (AcMNPV) by over 86%. Rutin or chlorogenic acid, when fed to H. zea, inhibited the infectivity of a singly embedded nuclear polyhedrosis virus (HzSNPV), with the greatest degree of inhibition occurring at low doses of viral inoculum. Additionally, the ingestion of these phytochemicals significantly prolonged the survival time of virally infected H. zea larvae. These results suggest that the effectiveness of nuclear polyhedrosis viruses in controlling H. zea populations may be adversely affected by varieties of L. esculentum with significant levels (eg. 3.5 μmol/g wet weight) of rutin or chlorogenic acid.