美洲棉铃虫幼虫腹侧可外翻腺分泌物对番茄抗虫反应的影响

To explore the effect of secretions from the ventral eversible gland (VEG) of American cotton bollworm Helicoverpa zea caterpillars on plant anti-herbivore responses, tomato plants were used as the experimental materials and three plant damage treatments were set to compare the differences of caterpillar weight gain, defensive key enzymes of polyphenol oxidase (PPO), inhibition rate of trypsin proteinase inhibitors (TPI) and relative gene (proteinase inhibitor II, PIN2) expressions in tomato leaflets including undamaged, mechanical wounding with application of phosphate buffer saline (PBS) and mechanical wounding with application of VEG secretions in the greenhouse of Pennsylvania State University, University Park. The results showed that the application of VEG secretions significantly decreased caterpillar weight gain with 4.27 mg, which was significantly lower than caterpillars that fed on leaflets which were undamaged and mechanical wounding with application of PBS, respectively; the application of VEG secretions significantly increased the accumulation of PPO with 109.16 U/mg and inhibition rate of TPI with 27.48% and up-regulated the expression of PIN2 in tomato leaflets; which were 11.83 or 1.17 times higher than that in tomato leaflets undamaged or mechanically wounded with application of PBS. Taken together, VEG secretions of H. zea caterpillars were capable to accumulate plant defense related key enzymes, up-regulate plant defense related genes, significantly trigger plant anti-herbivore defenses and retard the subsequent caterpillars.