Role of natural products in belowground interactions between plant species

Plants are consistently releasing root exudates into the rhizosphere which have the potential to influence the growth and development of neighboring plant species. Root exudates contain low and high molecular weight compounds such as sugars, amino acids, secondary metabolites, phytohormones, proteins, enzymes, and polysaccharides. Although aboveground plant interactions through volatile compounds has been extensively studied, only few studies investigated role of the belowground chemical interactions between plant species. The aim of this study is to elucidate the belowground chemical interactions between rye and hairy vetch grown together as cover crop mixture. Rye and hairy vetch were cultivated alone and together in pots filled with micro glasssbeads. Plant were grown for three weeks in climate chamber and their root exudates were collected for the chemical analysis. Targeted analysis with LC-MS/MS was done to identify the changes occurring in secondary metabolite profile of the rye and hairy vetch’s root exudates as result of co-cultivation. Quantification results displayed that both hairy vetch and rye are altering their root exudation in response to rye-hairy vetch co cultivation. Hairy vetch significantly increased concentration of root exuded flavonoids such as kaempferol and pratensein in response to presence of rye. Concentrations of DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and BOA (1,3-benzoxazol-2-one) in rye’s root exudate were increased significantly as result of co cultivation with hairy vetch. The results from this study will increase our understanding about root exuded natural products with growth suppressive effects, which finally leads us to more sustainable plant protection system.