Rhizosphere colonization by plant-beneficial Pseudomonas spp.: thriving in a heterogeneous and challenging environment.

Abstract

This chapter focuses on the establishment of the relationship with a special emphasis on the plant-driven nutrient heterogeneities of the rhizosphere and on some competitiveness enhancing traits, involved in the success of several plant-beneficial Pseudomonas spp. strains. It is established that determining plant traits supporting bacterial colonization of the rhizosphere is as crucial as studying bacterial traits, and may lead to new plant varieties optimized for PGPR colonization. Large-scale development of efficient plant-beneficial Pseudomonas spp. will be achieved by embracing an integrated vision of the rhizosphere.

Diversity of phytobeneficial traits revealed by whole‐genome analysis of worldwide‐isolated phenazine‐producing Pseudomonas spp.

“…While this genus includes, notably, the opportunistic pathogen P. aeruginosa and the plant pathogen P. syringae , most species are not pathogenic and are ubiquitously found in natural environments. In the rhizosphere, a heterogeneous and challenging environment shaped by plant rhizodeposition (Zboralski et al, ), numerous plant‐beneficial Pseudomonas spp. have been reported to display plant‐growth promotion and disease‐suppression activities (Weller, ).…”

Interplay between Arabidopsis thaliana Genotype, Plant Growth and Rhizosphere Colonization by Phytobeneficial Phenazine-Producing Pseudomonas chlororaphis

“…Different types of exudates are released into the rhizosphere, such as organic acids, sugars, amino acids, or phenolics, influencing the bacterial composition of this habitat [ 6 , 17 , 18 ]. Exudation is mainly mediated by exocytosis for high-molecular-weight compounds and by passive diffusion through the plasma membrane or active secretion by membrane transporters for lighter metabolites [ 19 ]. Different transporters involved in the latter have been identified, belonging to the Major Facilitator Superfamily (MFS), the Multidrug and Toxic Compound Extrusion (MATE) family, the Aluminium-Activated Malate Transporters (ALMT) family, and the ATP-binding cassette (ABC) families [ 13 , 20 ].…”

“…Rhizosphere colonization is crucial for numerous groups of microorganisms, including plant growth-promoting rhizobacteria (PGPR), involved in plant growth promotion and/or biocontrol of plant pathogens [ 27 , 28 , 29 ]. Their ability to competitively colonize the rhizosphere and persist in this dynamic environment is defined as rhizocompetence [ 19 , 30 ]. PGPR are able to improve plant nutrition and plant immunity, while producing an array of antimicrobial compounds, directly hampering the growth of plant pathogens and disease development [ 4 ].…”

Phenazines in plant‐beneficial Pseudomonas spp.: biosynthesis, regulation, function and genomics

“…The rhizosphere, that is, the soil zone under the influence of plant roots, is a heterogeneous and challenging environment shaped by plant rhizodeposition (Zboralski et al ., ) and inhabited by numerous microbes, including plant‐associated Pseudomonas spp. Members of the genus Pseudomonas are rod‐shaped Gram‐negative bacteria that colonize a wide diversity of ecological niches thanks to their striking metabolic diversity (Stanier et al ., ).…”