Plant growth-promoting bacteria in the rhizo- and endosphere of plants: Their role, colonization, mechanisms involved and prospects for utilization

Abstract

In both managed and natural ecosystems, beneficial plant-associated bacteria play a key role in supporting and/or increasing plant health and growth. Plant growth-promoting bacteria (PGPB) can be applied in agricultural production or for the phytoremediation of pollutants. However, because of their capacity to confer plant beneficial effects, efficient colonization of the plant environment is of utmost importance. The majority of plant-associated bacteria derives from the soil environment. They may migrate to the rhizosphere and subsequently the rhizoplane of their hosts before they are able to show beneficial effects. Some rhizoplane colonizing bacteria can also penetrate plant roots, and some strains may move to aerial plant parts, with a decreasing bacterial density in comparison to rhizosphere or root colonizing populations. A better understanding on colonization processes has been obtained mostly by microscopic visualisation as well as by analysing the characteristics of mutants carrying disfunctional genes potentially involved in colonization. In this review we describe the individual steps of plant colonization and survey the known mechanisms responsible for rhizosphere and endophytic competence. The understanding of colonization processes is important to better predict how bacteria interact with plants and whether they are likely to establish themselves in the plant environment after field application as biofertilisers or biocontrol agents.

The persistence and performance of phosphate-solubilizing Gluconacetobacter liquefaciens qzr14 in a cucumber soil

“…The colonization and persistence of introduced PGPM in soil are the bases to exert their plant growth-promoting abilities (Compant et al 2010). The colonization and persistence of introduced PGPM in rhizosphere soil had been widely investigated (Bashan et al 1995;Couillerot et al 2010;Pellegrino et al 2012;Troxler et al 2012).…”

Influence of plant growth-promoting rhizobacteria (PGPR) on blackberry (Rubus glaucus Benth. cv. thornless) growth under semi-cover and field conditions

“…In agricultural production, the implementation of beneficial bacteria, generally associated with rhizosphere, is an initiative that promotes plant health and plant growth by acting as biofertilizers (Compant, Clément, & Sessitsch, 2010). Genera such as Azospirillum, Azotobacter, Burkholderia, Enterobacter, Klebsiella, Pseudomonas and Bacillus are some of the most prominent Plant Growth-Promoting Rhizobacteria (PGPR).…”

Isolation and characterization of a new iturinic lipopeptide, mojavensin A produced by a marine-derived bacterium Bacillus mojavensis B0621A

“…5,6 Plant-associated bacteria also have the potential to improve the growth of crops as plant growth-promoting rhizobacteria. 7,8 These lipopeptides have important roles and there may be some synergistic effects in the interaction of plants, microorganisms and phytopathogens in the soil ecosystem.…”