Induced defense in Nicotiana attenuata (Solanaceae) fruit and flowers
Induced defense in Nicotiana attenuata (Solanaceae) fruit and flowers
复制标题
烟草（茄科）果实和花朵的诱导防御
DOI：
10.1007/s00442-005-0284-0
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发表时间：
2005
期刊：
影响因子：
2.7
通讯作者：
R. Karban
中科院分区：
文献类型：
--
作者：
A. McCall;R. Karban
植物使用一系列策略来保护自己免受食草动物的侵害，从组成型防御到间歇性诱导反应。诱导防御可能无法提供立即和最大程度的保护，但当持续防御的能量或生态成本很高时，它可能是有利的。因此，花朵中的诱导防御可以帮助保护相对有价值的组织，同时保持生殖结构对传粉者的可及性和吸引力。迄今为止，还没有人在田间证明诱导防御对花卉食草动物（florivores）的功效。在这里，我们表明，野生烟草（茄科）的机械叶片损伤减少了田间花和果实的食草性，外源施用茉莉酸甲酯（诱导反应的有效诱导剂）可以减少自然群体中叶片和花的损伤。这一结果与田间损害调查结果一致，表明叶片损害与花果损害呈负相关。尽管最佳防御理论预测，由于其高适应性价值，诱导防御在生殖组织中应该很少见，但我们的结果表明并非如此。叶子和生殖组织中的诱导防御可能使植物能够有效地应对防御食草动物和吸引传粉者的随之而来的压力。
Plants protect themselves against herbivory using a continuum of strategies, ranging from constitutive defenses to intermittent induced responses. Induced defenses may not provide immediate and maximum protection, but could be advantageous when continuous defense is either energetically or ecologically costly. As such, induced defenses in flowers could help defend relatively valuable tissue while keeping reproductive structures accessible and attractive to pollinators. Thus far, no one has demonstrated the efficacy of induced defenses against floral herbivores (florivores) in the field. Here we show that mechanical leaf damage in wild tobacco, Nicotiana attenuata (Solanaceae), reduced both flower and fruit herbivory in the field and that exogenous application of methyl jasmonate, a potent elicitor of induced responses, reduced both leaf and floral damage in natural populations. This result is consistent with a survey of damage in the field, which showed a negative relationship between leaf damage and flower and fruit damage. Although optimal defense theory predicts that induced defenses should be rare in reproductive tissues, owing to their high fitness value, our results suggest otherwise. Induced defenses in leaves and reproductive tissues may allow plants to respond effectively to the concomitant pressures of defending against herbivory and attracting pollinators.