SRA

Soil detritivores such as Collembola indirectly impact plant performance via grazing on microorganisms, in particular fungi, and by increasing nutrient availability to plants. This enhances plant growth as well as tissue nutrient concentration. In addition, Collembola change plant root morphology and impact plant gene expression. However, studies linking Collembola-mediated changes in plant gene expression and plant resource allocation are lacking. Therefore, the pathways linking the response of plants at the level of genes with their physiological and morphological response remain unknown. We used an experimental platform comprising pedunculate oak (Quercus robur L.) microcuttings (clonally propagated seedlings) that display a typical endogenous rhythmic growth with alternating shoot flushes (SF) and root flushes (RF), the ectomycorrhizal fungus (Piloderma croceum) and fungal feeding microarthropods (Protaphorura armata; Collembola). We investigated the transcriptomic response of shoots of oak microcuttings to the presence of mycorrhiza and microarthropods and linked it to changes in resource allocation by pulse labelling the plants with 13C and 15N and tracking their incorporation into above- and belowground tree compartments. The results indicate that oaks recognize the presence of detritivores in the rhizosphere and respond in a complex way by changing the expression of genes of both plant primary and secondary metabolism, resulting in concomitant changes in plant morphology and physiology.