Herbivore identity and intensity are important in mediating plant defense responses, but the effects of their interaction on the plant metabolome have not yet been fully explored. Here, gas chromatography mass spectrometry was utilized to detect the metabolic changes in leaves, stems and roots of the common reed Phragmites australis infested with different intensity combinations of leaf-chewing Laelia coenosa and stem piercing-sucking Dimorphopterus pallipes. The supervised partial least squares-discriminant analysis showed that feeding by the two insects distinctly changed the metabolic profiles of all plant tissues. Furthermore, different intensities of the two herbivores resulted in significantly different metabolites in leaves. Only a high intensity of D. pallipes activated a distinct metabolic profile in roots, whereas there was no difference in stem metabolites in response to different herbivore intensities. Significant combined feeding effects of the two herbivores on plant metabolic composition was only detected in leaves infested with high herbivore intensity. Generally, D. pallipes feeding had a stronger effect on metabolite contents in different tissues compared to L. coenosa feeding. There was mostly a linear relationship between responses of leaf metabolites and herbivore intensity, whereas root metabolites generally showed non-linear responses to herbivore intensity. Additionally, there were significant interactions during simultaneous feeding of the two herbivores in leaves, which tended to be antagonistic. In general, our study suggested that plant responses to herbivory vary among tissues and are affected differently based on herbivore identity and intensity, which may vary in their interactions on plant metabolites at the whole-plant level.

草食动物的身份和强度在介导植物防御反应中很重要，但尚未充分探讨其相互作用对植物代谢组的影响。这里，气相色谱质谱法用于检测叶片中的代谢变化，茎和芦苇的根芦苇出没叶咀嚼的不同强度的组合Laelia coenosa和茎刺吸式Dimorphopterus pallipes。有监督的偏最小二乘判别分析表明，两种昆虫的摄食明显改变了所有植物组织的代谢谱。此外，两种草食动物的强度不同，导致叶片中的代谢产物明显不同。只有高强度的苍白D. pallipes激活了根部独特的代谢谱，而响应不同草食动物强度的茎代谢产物没有差异。仅在高食草动物强度侵染的叶片中检测到两种草食动物对植物代谢成分的显着联合摄食作用。通常，D. pallipes馈送对在不同组织中代谢物含量相比更强的效果L. coenosa喂养。叶片代谢产物的响应与草食动物的强度之间大多存在线性关系，而根部代谢产物通常对食草动物的强度表现出非线性的响应。另外，在同时喂食叶片中的两种草食动物期间存在显着的相互作用，这往往具有拮抗作用。总的来说，我们的研究表明植物对草食动物的反应在不同组织之间有所不同，并且受草食动物的身份和强度的影响不同，在整个植物水平上，它们对植物代谢产物的相互作用可能会有所不同。