University of Neuchâtel, Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), Neuchâtel, Switzerland.
Ecol Lett. 2012 Jan;15(1):55-64. doi: 10.1111/j.1461-0248.2011.01708.x. Epub 2011 Nov 10.
The most valuable organs of plants are often particularly rich in essential elements, but also very well defended. This creates a dilemma for herbivores that need to maximise energy intake while minimising intoxication. We investigated how the specialist root herbivore Diabrotica virgifera solves this conundrum when feeding on wild and cultivated maize plants. We found that crown roots of maize seedlings were vital for plant development and, in accordance, were rich in nutritious primary metabolites and contained higher amounts of the insecticidal 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and the phenolic compound chlorogenic acid. The generalist herbivores Diabrotica balteata and Spodoptera littoralis were deterred from feeding on crown roots, whereas the specialist D. virgifera preferred and grew best on these tissues. Using a 1,4-benzoxazin-3-one-deficient maize mutant, we found that D. virgifera is resistant to DIMBOA and other 1,4-benzoxazin-3-ones and that it even hijacks these compounds to optimally forage for nutritious roots.
植物最重要的器官通常富含必需元素，但也有很好的防御机制。这就给需要最大限度地摄入能量同时尽量减少中毒的食草动物带来了两难的困境。我们研究了当专门以野生和栽培玉米为食的根食性昆虫 Diabrotica virgifera 进食时，它是如何解决这个难题的。我们发现玉米幼苗的冠根对植物的生长发育至关重要，因此富含营养的初级代谢物，并且含有更高浓度的杀虫 2,4-二羟基-7-甲氧基-1,4-苯并恶嗪-3-酮（DIMBOA）和酚类化合物绿原酸。一般食草动物 Diabrotica balteata 和 Spodoptera littoralis 被阻止取食冠根，而专门的 D. virgifera 则更喜欢并在这些组织上生长得最好。使用缺乏 1,4-苯并恶嗪-3-酮的玉米突变体，我们发现 D. virgifera 对 DIMBOA 和其他 1,4-苯并恶嗪-3-酮具有抗性，甚至可以劫持这些化合物来优化营养根的觅食。
