Modulation of plant chemistry by beneficial root microbiota

Abstract

Covering: 1981-2017Plants are colonized by an astounding number of microorganisms that can reach cell densities much greater than the number of plant cells. Various plant-associated microorganisms can have profound beneficial effects on plant growth, development, physiology and tolerance to (a)biotic stress. In return, plants release metabolites into their direct surroundings, thereby feeding the microbial community and influencing their composition, gene expression and the production of secondary metabolites. Similarly, microbes living on and in plant tissue may induce known and yet unknown biosynthetic pathways in plants leading to diverse alterations in the plant metabolome. Here, we provide an overview of the impact of beneficial microbiota on plant chemistry, with an emphasis on bacteria living on or inside root tissues. We will also provide new perspectives on deciphering the yet untapped potential of microbe-mediated alteration of plant chemistry as an alternative platform to discover new pathways, genes and enzymes involved the biosynthesis of high value natural plant products.

The soil‐borne legacy in the age of the holobiont

“…Insights will be gained into how compounds like antimicrobials, volatiles, quorum-sensing signals, and interactions based on resource preference, competition or nutritional interdependence shape relationships even in communities that modulate the biosynthesis of plant-derived natural products active against bacterial and fungal plant pathogens, nematodes and herbivores. Microbial colonization also can induce changes in the plant morphology and its metabolome, qualitatively and quantitatively altering the synthesis of phytohormones, flavours, fragrances and compounds of potential pharmaceutical value (Etalo et al, 2018). Technological advances from empirical and modelled research also will enable the extension of analyses to more natural conditions and with agronomically relevant host plants influenced by the chemical complexity of native soils, yielding a foundation of principles that can be applied to the diverse and changing environments under which agriculture is practiced.…”

Root‐associated microbes in sustainable agriculture: models, metabolites and mechanisms

“…Thus, it is now appreciated that root exudates provide plant‐associated microbes not only nutrients in the form of carbon and nitrogen sources, but also diverse signals including flavonoids, growth regulators, steroids, terpenoids, alkaloids, coumarins and vitamins, many of which can influence the composition, gene expression and production of secondary metabolites . Conversely, the associated microbes can induce alterations in the plant metabolome, affecting the quality and quantity of primary and secondary metabolites including bioactive phytochemicals and high value natural plant products . Of the model systems developed to understand the molecular dialogue between the plant and its microbiome, few have been explored as much as that involving P. simiae WCS417, a strain that induces systemic resistance in the host, A. thaliana .…”

Multilab EcoFAB study shows highly reproducible physiology and depletion of soil metabolites by a model grass

“…Phosphate limitation typically results in elongated lateral roots and root hairs in a context-dependent manner (Peret et al, 2011;Plaxton & Tran, 2011;Nestler et al, 2016) and in increased exudation of organic acids that solubilize phosphate (Neumann & Martinoia, 2002;Plaxton & Tran, 2011;Thijs et al, 2016). Root morphology and metabolism are further affected by microbes and microbial compounds (Venturi & Keel, 2016;Verbon & Liberman, 2016;Etalo et al, 2018). The presence of plant growth-promoting bacteria can stimulate lateral root and root hair growth of Arabidopsis (L opez-Bucio et al, 2007;Vacheron et al, 2013;Zamioudis et al, 2013).…”