Arbuscular mycorrhizal fungi and belowground herbivores interact to determine plant productivity and performance of subsequently feeding conspecifics by changing plant metabolites

Abstract

Insect herbivores and arbuscular mycorrhizal fungi (AMF) often occur simultaneously on a host plant, altering plant morphological and biochemical traits and thereby not only affecting each other's performance, but also plant interactions with subsequent above-or belowground herbivores. Here, we investigate the combined effects of AMF and above-and belowground herbivory on plant productivity and performance of subsequent above-and belowground herbivores. We conducted a 3×2 full-factorial experiment with three factors of 'Herbivory (no herbivory, leaf herbivory, and tuber herbivory) and two factors of 'AMF inoculation' (no AMF inoculation and AMF inoculation) in the tuber-plant, potato (Solanum tuberosum). We showed that both AMF and tuber herbivory increased tuber biomass and tuber primary metabolites (protein, starch). Tuber herbivory reduced the performance of subsequent conspeci cs feeding on leaves potentially via increased leaf levels of phenolics, α-solanine and αchaconine. By contrast, it increased the performance of subsequent conspeci cs feeding on tubers potentially via increased protein, however, only in plants inoculated with AMF. This indicates that the belowground facilitation among conspeci c insects was contingent upon the presence of AMF. Leaf herbivory did not affect subsequent above-or belowground insect performance. These feedings improve our understanding of the ecological consequences of antagonists and mutualists interactions mediated by phytochemistry, especially for agroecosystems. Key MessageAMF and tuber herbivory increased potato tuber biomass, and concentrations of tuber primary metabolites.Tuber herbivory reduced the performance of subsequent conspeci cs feeding on leaves both in plants with and without AMF.Tuber herbivory only enhanced the performance of subsequent conspeci cs feeding on tubers in the presence of AMF, indicating that the presence of AMF was essential for this belowground facilitation.Such facilitation and inhibition potentially depend on increased levels of tuber protein and leaf phenolics, α-solanine and α-chaconine.

The Interaction between Arbuscular Mycorrhizal Fungi (AMF) and Grass Endophyte (Epichloë) on Host Plants: A Review

“…AMF increases the root absorption surface area, thereby enhancing the uptake of nutrients such as nitrogen and phosphorus, promoting photosynthesis, and regulating photosynthetic product distribution, ultimately improving plant growth [ 12 , 13 , 14 , 15 ]. Furthermore, AMF promotes the host plant’s resistance to adverse environmental stressors, including drought, heavy metals, microplastics, and biotic stresses such as pathogens and herbivory insects [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. In reciprocation, plants supply AMF with the necessary carbon sources for their growth and survival [ 26 , 27 ].…”