The genotype of barley cultivars influences multiple aspects of their associated microbiota via differential root exudate secretion

by Alba Pacheco-Moreno, Anita Bollmann-Giolai, Govind Chandra, Paul Brett, Jack Davies, Owen Thornton, Philip Poole, Vinoy Ramachandran, James K. M. Brown, Paul Nicholson, Chris Ridout, Sarah DeVos, Jacob G. Malone Plant-associated microbes play vital roles in promoting plant growth and health, with plants secreting root exudates into the rhizosphere to attract beneficial microbes. Exudate composition defines the nature of microbial recruitment, with different plant species attracting distinct microbiota to enable optimal adaptation to the soil environment. To more closely examine the relationship between plant genotype and microbial recruitment, we analysed the rhizosphere microbiomes of landrace (Chevallier) and modern (NFC Tipple) barley (Hordeum vulgare) cultivars. Distinct differences were observed between the plant-associated microbiomes of the 2 cultivars, with the plant-growth promoting rhizobacterial genusPseudomonas substantially more abundant in the Tipple rhizosphere. Striking differences were also observed between the phenotypes of recruitedPseudomonas populations, alongside distinct genotypic clustering by cultivar. Cultivar-drivenPseudomonas selection was driven by root exudate composition, with the greater abundance of hexose sugars secreted from Tipple roots attracting microbes better adapted to growth on these metabolites and vice versa. Cultivar-driven selection also operates at the molecular level, with both gene expression and the abundance of ecological...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research