Priming by airborne signals boosts direct and indirect resistance in maize
Priming by airborne signals boosts direct and indirect resistance in maize
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DOI：
10.1111/j.1365-313x.2006.02935.x
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发表时间：
2007-01-01
期刊：
影响因子：
7.2
通讯作者：
Turlings, Ted C. J.
中科院分区：
文献类型：
--
作者：
Ton, Jurriaan;D'Alessandro, Marco;Turlings, Ted C. J.
植物利用多种诱导防御机制抵御食草昆虫的攻击。有毒蛋白质和代谢物的产生会立即影响食草动物的发育，这就是直接诱导防御的例子。此外，植物可能释放挥发性有机化合物（VOCs）的混合物，通过吸引食草动物的天敌来间接保护植物。最近的研究表明，这些挥发性有机化合物还可以使附近的植物在未来昆虫袭击时增强防御感应。然而，这种防御启动导致对昆虫的脆弱性降低的证据很少。在这里，我们提出了分子、化学和行为证据，证明挥发性有机化合物诱导的启动可以改善玉米的直接和间接抗性。通过对滨海夜蛾（Spodoptera littoralis）毛虫攻击诱导基因的差异杂交筛选，鉴定出10个防御相关基因，这些基因对伤害、茉莉酸（jasmonic acid， JA）或毛虫反刍物有反应。暴露于被毛虫侵染的植物的挥发性有机化合物并没有直接激活这些基因，但启动了其中的一个子集，在随后的防御激发中进行更早和/或更强的诱导。这种防御相关基因表达的启动与毛虫摄食和发育的减少有关。此外，暴露于毛毛虫诱导的挥发性有机化合物会增加芳香族和萜类化合物的排放。在挥发性有机化合物（VOC）排放的峰值，处理过的植物对寄生蜂更具吸引力。该研究表明，voc诱导的启动靶向特定的ja诱导基因子集，并在分子水平上将这些反应与增强对昆虫攻击的直接和间接抗性联系起来。
Plants counteract attack by herbivorous insects using a variety of inducible defence mechanisms. The production of toxic proteins and metabolites that instantly affect the herbivore's development are examples of direct induced defence. In addition, plants may release mixtures of volatile organic compounds (VOCs) that indirectly protect the plant by attracting natural enemies of the herbivore. Recent studies suggest that these VOCs can also prime nearby plants for enhanced induction of defence upon future insect attack. However, evidence that this defence priming causes reduced vulnerability to insects is sparse. Here we present molecular, chemical and behavioural evidence that VOC-induced priming leads to improved direct and indirect resistance in maize. A differential hybridization screen for inducible genes upon attack by Spodoptera littoralis caterpillars identified 10 defence-related genes that are responsive to wounding, jasmonic acid (JA), or caterpillar regurgitant. Exposure to VOCs from caterpillar-infested plants did not activate these genes directly, but primed a subset of them for earlier and/or stronger induction upon subsequent defence elicitation. This priming for defence-related gene expression correlated with reduced caterpillar feeding and development. Furthermore, exposure to caterpillar-induced VOCs primed for enhanced emissions of aromatic and terpenoid compounds. At the peak of this VOC emission, primed plants were significantly more attractive to parasitic Cotesia marginiventris wasps. This study shows that VOC-induced priming targets a specific subset of JA-inducible genes, and links these responses at the molecular level to enhanced levels of direct and indirect resistance against insect attack.