Physiological integration of roots and shoots in plant defense strategies links above- and belowground herbivory
Physiological integration of roots and shoots in plant defense strategies links above- and belowground herbivory
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DOI：
10.1111/j.1461-0248.2008.01200.x
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发表时间：
2008-08-01
期刊：
影响因子：
8.8
通讯作者：
Denno, Robert F.
中科院分区：
文献类型：
--
作者：
Kaplan, Ian;Halitschke, Rayko;Denno, Robert F.
根在地上抗草食动物植物防御（例如抗性和耐受性）中起着关键但很大程度上未被认识的作用，因此根-叶连接可能导致地上和地下消费者之间的意外耦合。使用烟草（烟草）系统，我们强调这种现象的两个例子。第一，次生代谢物烟碱在根中产生，但转移到地上用作叶抗性性状。我们表明，线虫根草食干扰叶片烟碱动态，导致地上植食性昆虫的积极影响。值得注意的是，线虫诱导的便利化只发生在尼古丁生产的植物，而不是尼古丁缺乏的突变体。在第二种情况下，我们使用稳定的同位素和转化酶的分析表明，叶面草食性elpherous一个假定的耐受性反应，地上营养储备分配给根，从而促进植物寄生线虫。因此，植物将根整合在叶片防御的抗性和耐受机制中，并且这种根-叶连接固有地将地上和地下消费者的动态联系起来。
Roots play a critical, but largely unappreciated, role in aboveground anti-herbivore plant defense (e.g. resistance and tolerance) and root-leaf connections may therefore result in unexpected coupling between above- and belowground consumers. Using the tobacco (Nicotiana tabacum) system we highlight two examples of this phenomenon. First, the secondary metabolite nicotine is produced in roots, yet translocated aboveground for use as a foliar resistance trait. We demonstrate that nematode root herbivory interferes with foliar nicotine dynamics, resulting in positive effects on aboveground phytophagous insects. Notably, nematode-induced facilitation only occurred on nicotine-producing plants, and not on nicotine-deficient mutants. In the second case, we use stable isotope and invertase enzyme analyses to demonstrate that foliar herbivory elicits a putative tolerance response whereby aboveground nutritional reserves are allocated to roots, resulting in facilitation of phytoparasitic nematodes. Thus, plants integrate roots in resistance and tolerance mechanisms for leaf defense, and such root-leaf connections inherently link the dynamics of above- and belowground consumers.