Submitted to: Silverleaf Whitefly Research, Action and Technology Transfer Plan
Publication Type: Proceedings
Publication Acceptance Date: 1/25/2002
Publication Date: 12/10/2002
Citation: McKenzie, C.L., Shatters, R., Doostdar, H., Inbar, M., Mayer, R.T. 2002. Differential plant response and whitefly performance in comparisons of whitefly and whitefly-tomato mottle virus (tomov) complex challenged tomato. Silverleaf Whitefly Research, Action and Technology Transfer Plan. Fourth Annual Review of the Second 5-Year Plan and Final Report for 1992-2002. USDA-ARS 2002-01:101. Interpretive Summary:
Technical Abstract: Tomato pathogenesis-related (PR) protein (chitinase, B-1,3-glucanase, peroxidase, P2 & P4) response was measured over time in tomato plants: untreated control, plants infested w/healthy whiteflies (WF), & plants infested w/ToMoV-carrying WF. Six- to seven-leaf plants were infested w/~5 adult WF per leaf. Subsequent plant samples were taken prior to WF infestation & at 14, 28, 42, & 56 days post-infestation for protein & enzyme analyses. By 56 days, there were 2.5-fold more eggs & 4.5-fold more nymphs on plants infested w/viruliferous WF than on healthy WF infested plants. Significant increase in enzymatic activity of all measured PR proteins, as compared to control plants, was only seen in viruliferous WF infested plants. No significant differences were observed in enzyme activities between uninfested & healthy WF infested plants. Foliar protein did not differ significantly among treatments for any sample dates indicating any significant changes in enzyme levels was a result of differences in specific measured enzymes.At 56 days post-infestation, virus infected plants exhibited severe virus symptoms & PR enzyme activities declined. Greatest differences for all PR proteins assayed were observed 42 days after treatment. Western blot analyses showed differences in PR protein activities among treatments were due to changes in specific enzyme levels w/in the plant & were associated w/concomitant increases in levels of P2 & P4 PR-proteins. WF-ToMoV complex is a much stronger inducer of tomato PR proteins response than WF alone. Because of the increased egg & nymph production by viruliferous WF, the cause of the increased PR protein response when virus is present may be result of either increased feeding pressure of viruliferous WF or direct interactions of virus and plant.