Are the cyst nematode hatching factor eclepins rhizosphere signalling molecules? Solanoeclepin A regulates gene expression in plants

Abstract

Background: The eclepins are a group of root-exuded compounds that induce the hatching of cyst nematodes, economically relevant pests for crops such as soybean and potato. From an evolutionary standpoint a beneficial effect of eclepins would be expected for the plant. Methods: To identify this beneficial effect, we analysed the transcriptome of two plant species in response to treatment with an eclepin. One of the eclepins, solanoeclepin A (solA), produced by members of the Solanaceae, was used in this study to treat tomato (Solanum lycopersicum) and Arabidopsis seedlings grown in vitro. Samples were used to call differentially expressed genes (DEGs) using RNAseq and followed by GO term enrichment analysis. Results: RNAseq analysis showed that solA downregulates the immune and hypoxia response, as well as ethylene biosynthesis and signalling, and promotes root growth. This response was particularly strong under N and P deficiency in Arabidopsis. Conclusions: Hence, solA affects gene expression in species it is not produced by. Furthermore, these results suggest that solA prepares the plant for colonization by microorganisms, possibly playing a role in nutrient uptake. Moreover, the change in hypoxia response and ethylene signalling and growth stimulation point toward the induction of an altered root architecture, possibly further improving the plant’s ability to recruit beneficial microbes and absorb nutrients.