Changes in motility of the rhizobacterium Azospirillum brasilense in the presence of plant lectins

Abstract

The plant-beneficial bacterium Azospirillum brasilense can swim in liquids and swarm or migrate with the formation of microcolonies in soft media. To get closer to understanding the influence of natural environments on A. brasilense motility, we studied the individual and social movement of the bacterium in the presence of various plant lectins. The lectins with specificity for N-acetyl-beta-d-glucosamine oligomers (wheat germ, Solanum tuberosum and Ulex europeus agglutinins) decreased A. brasilense swimming speed and induced the formation of branched-granular colonies instead of the swarming rings. These effects seemed to be a consequence of specific interactions between the agglutinins and the lectin-binding polymers present in the A. brasilense cell envelope. Concanavalin A (with an affinity for terminal alpha-d-mannosyl and alpha-d-glucosyl residues) and Phaseolus vulgaris phytohemagglutinin P (with unknown specificity) almost did not affect the motility of A. brasilense.

Intercropping with legume for agroecological cropping systems: Complementarity and facilitation processes and the importance of soil microorganisms. A review

“…Similar results have been obtained in intercropping experiments in which bacterial biomass and activity differed from those in mono-cropping systems (Latati et al, 2014;Li et al, 2009;Qiang et al, 2004;Song et al, 2006;Tang et al, 2014;Wang et al, 2007). Although more experiments are needed to identify the processes involved and the soil communities specifically targeted, the production and exudation of lectins by legumes has been shown to be capable of impacting Plant Growth-Promoting Rhizobacteria (PGPR) mobility, improving root colonization and the phytobeneficial activity of these PGPR (Schelud'ko et al, 2009). In the same way, the secretion of certain flavonoids, naringenin, for example, involved in the well-known symbiotic association between legumes and Rhizobium bacteria, could be responsible for Azospirillum brasilense Sp245 (PGPR) lateral root colonization (Jain and Gupta, 2003).…”

Tea-Soybean Intercropping Improves Tea Quality and Nutrition Uptake by Inducing Changes of Rhizosphere Bacterial Communities

“…Several theories have been proposed to explain the effect of legume intercropping on the structure of rhizobacterial communities. It has been demonstrated that legume secretion such as flavonoids, have the ability to influence plant growth-promoting rhizobacteria (PGPR) mobility, improving root colonization and phytobeneficial activity of these PGPR, leading to plant facilitation [14,15]. Another example is that N-acyl homoserine lactone (N-AHL) in several legume root exudates affects gene expression in quorum sensing, a bacterial regulation process [16,17].…”

The Collection of Rhizosphere Microorganisms: its importance for the study of associative plant-bacterium interactions

“…and spontaneous and induced changes in the genome, in particular, in the structure of megaplasmids, have a great influence on the social behavior of the bacteria. The genome changes are accompanied by phenotypic variations in the social motility of azospirilla (swarming → accelerated swarming; swarming → spreading with the formation of microcolonies; spreading with the formation of microcolonies → accelerated swarming), and they can lead to changes in the formation of biofilms and in the early stages of plant-root colonization (Katsy, Prilipov, 2009;Schelud'ko et al, 2009). Insertion elements responsible for the plasticity of A. brasilense megaplasmids were described for the first time.…”