Make it better: Enhancing plant defence and pollinator performance by amending rhizosphere microbiome.

Plants are engaged in multiple interactions above and belowground that affect the involved organisms and have impacts on the associated community. Many studies have demonstrated plant-mediated linkages between aboveground and belowground organisms. Most of these studies have focused on the effects of belowground interactions with e.g. beneficial rhizobacteria on aboveground antagonists. Studies on the role of beneficial rhizobacteria on plant-mediated interactions between antagonists and mutualists have been neglected so far. Soil amendments such as inoculation of plant growth-promoting rhizobacteria (PGPR) or the use of waste-streams from insect production, which enhance the abundance of PGPR, may promote plant growth and induced defence. This project will investigate whether and how soil amended with wastestreams of insect production can promote plant growth and defence and the consequences for flower traits and pollinator performance. Brassica nigra rely on insect pollination for reproduction. I will investigate which flower traits are responsive to soil amendments in herbivore-induced plants and the effects on pollinator performance and plant seed set. This study will clarify the functioning of more complex networks that involve multiple members of above- and belowground communities. In addition, it will offer tools to develop sustainable strategies for pest management.