Herbivore-Induced Defenses in Tomato Plants Enhance the Lethality of the Entomopathogenic Bacterium, Bacillus thuringiensis var. kurstaki
Herbivore-Induced Defenses in Tomato Plants Enhance the Lethality of the Entomopathogenic Bacterium, Bacillus thuringiensis var. kurstaki
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DOI：
10.1007/s10886-018-0987-4
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发表时间：
2018-07
影响因子：
2.3
通讯作者：
Ikkei Shikano;Qinjian Pan;K. Hoover;G. Felton
中科院分区：
文献类型：
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作者：
Ikkei Shikano;Qinjian Pan;K. Hoover;G. Felton
植物可以通过多种机制影响微生物杀虫剂的有效性。这些机制之一是植物酶对植物酚的氧化，如多酚氧化酶(PPO)和过氧化物酶(POD)。这些反应产生了各种产物和中间体，在抵抗草食动物方面发挥了重要作用。邻苯二酚类化合物绿原酸被PPO氧化提高了杀虫细菌苏云金芽孢杆菌对多食性毛虫的致死率。由于食草动物的取食伤害通常会触发植物组织中更高的氧化酶活性的诱导，因此我们假设植物防御的诱导将提高这些植物上Bt的致死率。我们发现，商业制剂Bt(Dipel®PRO DF)对番茄植株的致死率如果应用于H.由植物激素茉莉酸诱导或催生的。较高比例的H。被Bt杀死的狂犬病与小叶组织中较高水平的PPO活性密切相关。更高的POD活性仅与Bt诱导的更高水平的死亡率有微弱的相关性。虽然植物介导的昆虫病原致死性变异是众所周知的，但我们的发现表明，植物可以诱导与微生物杀虫剂/昆虫病原协同工作的防御反应，以防止昆虫食草动物。
Plants can influence the effectiveness of microbial insecticides through numerous mechanisms. One of these mechanisms is the oxidation of plant phenolics by plant enzymes, such as polyphenol oxidases (PPO) and peroxidases (POD). These reactions generate a variety of products and intermediates that play important roles in resistance against herbivores. Oxidation of the catecholic phenolic compound chlorogenic acid by PPO enhances the lethality of the insect-killing bacterial pathogen,Bacillus thuringiensisvar.kurstaki(Bt) to the polyphagous caterpillar,Helicoverpa zea.Since herbivore feeding damage often triggers the induction of higher activities of oxidative enzymes in plant tissues, here we hypothesized that the induction of plant defenses would enhance the lethality ofBton those plants. We found that the lethality of a commercial formulation ofBt(Dipel® PRO DF) on tomato plants was higher if it was applied to plants that were induced byH. zeafeeding or induced by the phytohormone jasmonic acid. Higher proportions ofH. zealarvae killed byBtwere strongly correlated with higher levels of PPO activity in the leaflet tissue. Higher POD activity was only weakly associated with higher levels ofBt-induced mortality. While plant-mediated variation in entomopathogen lethality is well known, our findings demonstrate that plants can induce defensive responses that work in concert with a microbial insecticide/entomopathogen to protect against insect herbivores.