Misión Biológica de Galicia (MBG-CSIC), Apartado de correos 28, 36080 Pontevedra, Galicia, Spain.
Misión Biológica de Galicia (MBG-CSIC), Apartado de correos 28, 36080 Pontevedra, Galicia, Spain; Department of Ecology and Evolutionary Biology, University of California-Irvine, 92697 Irvine, California, USA.
Phytochemistry. 2023 Feb;206:113561. doi: 10.1016/j.phytochem.2022.113561. Epub 2022 Dec 10.
It has been proposed that plant-plant signalling via herbivore-induced volatile organic compounds (VOCs) should be stronger between closely related than unrelated plants. However, empirical tests remain limited and few studies have provided detailed assessments of induced changes in VOCs emissions across plant genotypes to explain genetic relatedness effects. In this study, we tested whether airborne signalling in response to herbivory between Solanum tuberosum (potato) plants was contingent on plant genetic relatedness, and further investigated genotypic variation in VOCs potentially underlying signalling and its contingency on relatedness. We carried out a greenhouse experiment using 15 S. tuberosum varieties placing pairs of plants in plastic cages, i.e. an emitter and a receiver, where both plants were of the same genotype or different genotype thereby testing for self-recognition, an elemental form genetic relatedness effects. Then, for half of the cages within each level of relatedness the emitter plant was damaged by Spodoptera exigua larvae whereas for the other half the emitter was not damaged. Three days later, we placed S. exigua larvae on receivers to test for emitter VOC effects on leaf consumption and larval weight gain (i.e. induced resistance). In addition, we used a second group of plants subjected to the same induction treatment with the same S. tuberosum varieties to test for herbivore-induced changes in VOC emissions and variation in VOC emissions among these plant genotypes. We found that herbivory drove changes in VOC composition but not total emissions, and also observed quantitative and qualitative variation in constitutive and induced VOC emissions among varieties. Results from the bioassay showed that the amount of leaf area consumed and larval weight gain on receiver plants exposed to damaged emitters were significantly lower compared to mean values on receivers exposed to control emitters. However, and despite genotypic variation in induced VOCs, this signalling effect was not contingent on plant genetic relatedness. These findings provide evidence of VOCs-mediated signalling between S. tuberosum plants in response to S. exigua damage, but no evidence of self-recognition effects in signalling contingent on variation in VOC emissions among S. tuberosum varieties.
有人提出，通过草食性动物诱导的挥发性有机化合物（VOCs）进行的植物-植物信号传递应该在亲缘关系密切的植物之间比在不相关的植物之间更强。然而，实证测试仍然有限，很少有研究详细评估了不同植物基因型对 VOCs 排放的诱导变化，以解释遗传相关性效应。在这项研究中，我们测试了马铃薯（土豆）植株对草食性动物的侵害是否取决于植物的遗传亲缘关系，并且进一步研究了潜在的信号传递的基因型变异及其与亲缘关系的偶然性。我们在温室中进行了一项实验，使用了 15 种马铃薯品种，将成对的植株放在塑料笼中，即一个发射器和一个接收器，其中两个植株都是相同的基因型或不同的基因型，从而测试自我识别，这是遗传相关性效应的一种基本形式。然后，在每个亲缘关系水平的一半笼子里，发射器植株被 Spodoptera exigua 幼虫破坏，而另一半发射器植株没有被破坏。三天后，我们将 S. exigua 幼虫放在接收器上，以测试发射器 VOC 对叶片消耗和幼虫体重增加的影响（即诱导抗性）。此外，我们使用了另一组植物，用相同的诱导处理和相同的马铃薯品种进行实验，以测试草食性动物诱导的 VOC 排放变化和这些植物基因型之间的 VOC 排放变化。我们发现，草食性动物的侵害会导致 VOC 组成的变化，但不会导致总排放量的变化，而且还观察到了不同品种之间组成和诱导 VOC 排放的定量和定性变化。生物测定的结果表明，与暴露于对照发射器的接收器植物相比，暴露于受损发射器的接收器植物的叶片面积消耗和幼虫体重增加量明显较低。然而，尽管诱导的 VOC 存在基因型变异，但这种信号传递效应并不取决于植物的遗传亲缘关系。这些发现提供了证据表明，在受到 S. exigua 损害的情况下，S. tuberosum 植物之间存在 VOC 介导的信号传递，但没有证据表明信号传递取决于 S. tuberosum 品种之间 VOC 排放的变异存在自我识别效应。
