Karban R, Baldwin I T, Baxter K J, Laue G, Felton G W
Department of Entomology, University of California, Davis, CA 95616, USA e-mail:
Max-Planck-Institute fur Chemische Okologie, Tatzendpromenade 1A, 07745 Jena, Germany, Germany.
Oecologia. 2000 Oct;125(1):66-71. doi: 10.1007/PL00008892.
The possibility of communication between plants was proposed nearly 20 years ago, although previous demonstrations have suffered from methodological problems and have not been widely accepted. Here we report the first rigorous, experimental evidence demonstrating that undamaged plants respond to cues released by neighbors to induce higher levels of resistance against herbivores in nature. Sagebrush plants that were clipped in the field released a pulse of an epimer of methyl jasmonate that has been shown to be a volatile signal capable of inducing resistance in wild tobacco. Wild tobacco plants with clipped sagebrush neighbors had increased levels of the putative defensive oxidative enzyme, polyphenol oxidase, relative to control tobacco plants with unclipped sagebrush neighbors. Tobacco plants near clipped sagebrush experienced greatly reduced levels of leaf damage by grasshoppers and cutworms during three field seasons compared to unclipped controls. This result was not caused by an altered light regime experienced by tobacco near clipped neighbors. Barriers to soil contact between tobacco and sagebrush did not reduce the difference in leaf damage although barriers that blocked air contact negated the effect.
植物之间存在交流的可能性在近20年前就已被提出，尽管之前的论证存在方法上的问题，未被广泛接受。在此，我们报告首个严谨的实验证据，证明未受损的植物会对邻居释放的信号作出反应，从而在自然环境中诱导出更高水平的抗食草动物能力。在野外被修剪的山艾树会释放出茉莉酸甲酯差向异构体脉冲，这种物质已被证明是一种挥发性信号，能够诱导野生烟草产生抗性。与有未修剪山艾树邻居的对照烟草植株相比，有被修剪山艾树邻居的野生烟草植株中假定的防御性氧化酶——多酚氧化酶的水平有所增加。在三个野外季节中，与未修剪对照相比，靠近被修剪山艾树的烟草植株遭受的蝗虫和夜蛾对叶片的损害程度大幅降低。这一结果并非由靠近被修剪邻居的烟草所经历的光照条件变化导致。烟草与山艾树之间土壤接触的障碍物并未减少叶片损害的差异，尽管阻断空气接触的障碍物消除了这种影响。
