The role of isoprenoids in the chemical interaction between plants and other organisms in their rhizosphere.

Agriculture has become one of the largest users of non-renewable resources in the world and contributes heavily to resource depletion, environmental pollution, and climate change. Solutions to these problems are in dire need and these can partially be found in the inter-organismal interactions surrounding the rhizosphere of our crops. The rhizosphere is a highly complex ecosystem, serving as a habitat for a diverse array of beneficial and pathogenic organisms. Here, we review how plants are performing a balancing act, in which they employ chemical communication-through the exudation of chemicals from their roots-to recruit beneficial organisms, while keeping at the same time, pathogenic ones at bay. These metabolites released by roots are incredibly chemically diverse. Among them, isoprenoids, one of the most diverse metabolite classes, containing many, highly bioactive, molecules, are the focus of this review. A better insight into the chemical communication occurring between the root, the soil, and micro-organisms, will allow harnessing of the beneficial relationships and suppression of the harmful ones. Further, this will enable us to establish knowledge-based changes in how we perform agriculture, how we use chemical inputs, how we should breed more resilient crops and can bring back resilience to our agricultural soils.