Plant-mediated above-belowground interactions: A phytobiome story

Abstract

Plants interact with a wide range of organisms both above- and belowground that influence each other through nutrient cycling and a wide array of signaling compounds. Plant belowground interactions with soil microbes alter plant fitness and physiology, affecting the performance of plant-associated aboveground organisms through three main pathways: through shifts in plant palatability, through the induction of plant systemic resistance, and through the modification of plant functional traits. Conversely, aboveground herbivores modify the concentration of nutrient and defense compounds in plant tissues and alter root exudation patterns, thus affecting the rhizosphere microbiome. Ecological loops can also occur through plant-soil feedbacks, whereby soil legacy effects alter the performance of aboveground organisms feeding on newly-established plants, further impacting the soil microbiome and the resistance of plants subsequently growing in that soil. A better understanding of the ecological interactions occurring within the phytobiome, combined with the advent of new technologies such as metatranscriptomics and metabolomics, could therefore provide innovative tools for maximizing plant fitness and enhancing plant resistance to herbivory through a manipulation of the phytobiome.