Machado Ricardo A R, Zhou Wenwu, Ferrieri Abigail P, Arce Carla C M, Baldwin Ian T, Xu Shuqing, Erb Matthias
Root-Herbivore Interactions Group Max Planck Institute for Chemical Ecology Jena Germany.
Department of Molecular Ecology Max Planck Institute for Chemical Ecology Jena Germany.
Ecol Evol. 2017 Apr 17;7(11):3703-3712. doi: 10.1002/ece3.2953. eCollection 2017 Jun.
Induced changes in root carbohydrate pools are commonly assumed to determine plant defoliation tolerance to herbivores. However, the regulation and species specificity of these two traits are not well understood. We determined herbivory-induced changes in root carbohydrates and defoliation tolerance in seven different solanaceous plant species and correlated the induced changes in root carbohydrates and defoliation tolerance with jasmonate inducibility. Across species, we observed strong species-specific variation for all measured traits. Closer inspection revealed that the different species fell into two distinct groups: Species with a strong induced jasmonic acid (JA) burst suffered from a reduction in root carbohydrate pools and reduced defoliation tolerance, while species with a weak induced JA burst maintained root carbohydrate pools and tolerated defoliation. Induced JA levels predicted carbohydrate and regrowth responses better than jasmonoyl-L-isoleucine (JA-Ile) levels. Our study shows that induced JA signaling, root carbohydrate responses, and defoliation tolerance are closely linked, but highly species specific, even among closely related species. We propose that defoliation tolerance may evolve rapidly via changes in the plant's defense signaling network.
根系碳水化合物库的诱导变化通常被认为决定了植物对食草动物的耐落叶性。然而，这两个性状的调控和物种特异性尚未得到很好的理解。我们测定了七种不同茄科植物物种中食草动物诱导的根系碳水化合物变化和耐落叶性，并将根系碳水化合物和耐落叶性的诱导变化与茉莉酸诱导性相关联。在不同物种间，我们观察到所有测量性状都存在强烈的物种特异性变异。进一步检查发现，不同物种分为两个不同的组：茉莉酸（JA）强烈诱导爆发的物种根系碳水化合物库减少且耐落叶性降低，而茉莉酸诱导爆发较弱的物种维持根系碳水化合物库并耐受落叶。诱导的JA水平比茉莉酸异亮氨酸（JA-Ile）水平能更好地预测碳水化合物和再生反应。我们的研究表明，诱导的JA信号传导、根系碳水化合物反应和耐落叶性密切相关，但具有高度的物种特异性，即使在亲缘关系密切的物种中也是如此。我们提出，耐落叶性可能通过植物防御信号网络的变化而迅速进化。
