Immunological Properties of Azospirillum Cell Surface: the Structure of Carbohydrate Antigens and Evaluation of their Involvement in Bacteria-Plant Contact Interactions

Matora, L. Yu.; Solovova, G. K.; Serebrennikova, Oksana B.; Selivanov, N. Yu.; Shchyogolev, S. Yu.

doi:10.1007/978-3-642-79906-8_43

Cited by 12 publications

(4 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Wild-type and mutant strains also differed in their ability to bind to Congo red, a property that is often related to EPS composition. Earlier findings have shown the presence of identical epitopes in A. brasilense LPS and EPS, leading to the hypothesis that EPS is formed by the excreted O-specific fragments of LPS (Matora et al, 1995;Katzy et al, 1998). Whether this phenomenon, which has also been proposed for other bacterial species (Kenne & Lindberg, 1983;Whitfield et al, 1994), occurs in A. brasilense, and the biological relevance of the alterations in EPS by the wzm mutation, still need to be assessed.…”

Section: Discussionmentioning

confidence: 99%

The wzm gene located on the pRhico plasmid of Azospirillum brasilense Sp7 is involved in lipopolysaccharide synthesis

2009

View full text Add to dashboard Cite

Several genes involved in the interaction between Azospirillum brasilense Sp7 and plants are located on the pRhico plasmid. Here we report the characterization of an Sp7 mutant strain with impairment of the pRhico-located gene wzm. This gene encodes an inner-membrane component of an ATP-binding cassette (ABC) transporter with similarity to transporters involved in surface polysaccharide export. Indeed, SDS-PAGE revealed that LPS synthesis is affected in the wzm mutant. No significant differences were observed between wild-type and mutant strains in exopolysaccharide (EPS) amount; however, several differences were observed between them in EPS monosaccharide composition, and only wild-type colonies stained positively with Congo red. Microscopy revealed that wzm mutant cells are longer and thinner, and exhibit several differences in their cell surface relative to the wild-type. The wzm mutant was more resistant to oxidative stress, starvation, desiccation, heat and osmotic shock than the wild-type. In contrast, the mutant was more susceptible than the wild-type to UV radiation and saline stress. The strains also differed in their susceptibility to different antibiotics. Differences between the strains were also observed in their outer-membrane protein composition. No differences were observed between strains in their ability to attach to sweet corn roots and seeds, and to promote growth under the tested conditions. As LPS plays an important role in cell envelope structural integrity, we propose that the pleiotropic phenotypic changes observed in the wzm mutant are due to its altered LPS relative to the wild-type. INTRODUCTIONThe Azospirillum genus belongs to the alpha-proteobacteria and comprises free-living, nitrogen-fixing, vibrio-or spirillum-shaped rods that exert beneficial effects on plant growth and yield of many crops of agronomic importance (Dobbelaere et al., 2001). Plant growth promotion by Azospirillum is attributed to morphological and physiological changes in inoculated plant roots, which enhance water and mineral uptake. Plant growth substances, such as auxins, cytokinins and gibberellins (Steenhoudt & Vanderleyden, 2000;Dobbelaere et al., 2001), as well as nitric oxide (Creus et al., 2005) produced by the bacteria are at least partially responsible for the plant growth promotion.Within the Azospirillum genus, one of the most studied species is Azospirillum brasilense (Tarrand et al., 1978). A. brasilense cells are surrounded by a dense, tightly cellbound layer of capsular polysaccharides (CPSs), and by outer exopolysaccharides (EPSs), which are loosely bound to the cell and easily detached by centrifugation (Burdman et al., 2000c). EPSs and CPSs, as well as extracellular proteins, have been shown to play important roles in bacterial aggregation and in the establishment of the bacterium-plant association (Burdman et al., 1999(Burdman et al., , 2000cSteenhoudt & Vanderleyden, 2000). It has been suggested that EPSs and CPSs are involved in anchoring the bacteria to the surface of wheat roots , and in t...

show abstract

Section: Discussionmentioning

confidence: 99%

The wzm gene located on the pRhico plasmid of Azospirillum brasilense Sp7 is involved in lipopolysaccharide synthesis

2009

View full text Add to dashboard Cite

show abstract

“…Azospirillum lectins have been found to influence the activity of several plant cell enzymes (Alen'kina et al 2004) and the division of wheat root meristematic cells ). The isolated lipopolysaccharide (LPS) of azospirilla induces specific deformation of wheat seedling root hairs (Fedonenko et al 2001) and augments the synthesis of major proteins in the root cell apoplast (Matora et al 1995), with these effects being comparable to those of intact bacterial cells. Azospirillum LPS belongs to the category of major outer-membrane components of gram-negative bacteria and is a key structure ensuring the establishment and development of an association with a plant partner.…”

mentioning

confidence: 99%

Effect of Azospirillum brasilense Sp245 lipopolysaccharide on the functional activity of wheat root meristematic cells

et al. 2011

View full text Add to dashboard Cite

We studied changes in the physiological and biochemical parameters of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings treated with lipopolysaccharide isolated from the outer membrane of the associative bacterium Azospirillum brasilense Sp245. The obtained data were compared with (i) the results of plant inoculation with whole Sp245 cells and (ii) the effects exerted by the lipopolysaccharide and whole cells of the enterobacterium Escherichia coli K12 and the specific legume symbiont Rhizobium leguminosarum 249. The functional activity of meristematic cells was judged by their mitotic index and by the results of immunochemical determination of the proliferative antigen of initials, a molecular marker for wheat meristem cells. Treatment of the seedling root system with 10 μg mL −1 of Sp245 lipopolysaccharide increased the mitotic index (1.8-fold) and the antigen content (approximately 1.4-fold). These increases were comparable to the effects produced by whole cell inoculation (2-and 1.4-fold, respectively). Our findings give grounds to consider lipopolysaccharide as an active component of the Azospirillum cell surface that not only determines bacterial contact interactions with wheat roots but also participates in the induction of plant responses to these interactions. We finally discuss the linkage between the proliferative antigen of initials and the transduction of a hormonal signal to the cell, as well as the informational value of this antigen as an indicator of effectiveness of plant-bacterial interactions.

show abstract

“…Azospirillum is the most studied PGPR and is a widely used model of bacterial interactions with many plant species (Cassán et al 2020;Pereg et al 2016;Steenhoudt and Vanderleyden 2000). A. brasilense LPS are highly active in interactions with plant roots (Fedonenko et al 2001;Matora et al 1995) and in induction of plant responses (Evseeva et al 2011). Furthermore, A. brasilense Sp245 LPS can promote wheat plant growth in vitro (Vallejo-Ochoa et al 2018) and under greenhouse conditions (Chavez-Herrera et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Comparative Effects of Azospirillum brasilense Sp245 and Pseudomonas aeruginosa PAO1 Lipopolysaccharides on Wheat Seedling Growth and Peroxidase Activity

Hernández-Esquivel

Castro-Mercado

García-Pineda

2020

J Plant Growth Regul

View full text Add to dashboard Cite

The effects of lipopolysaccharides (LPS) from Azospirillum brasilense Sp245, a plant growth-promoting rhizobacteria, and Pseudomonas aeruginosa PAO1, a pathogenic bacterium, on plant growth and peroxidase (POD) activity were assessed on wheat seedlings. A. brasilense LPS (100 µg/mL) increased total length, and total fresh weight in wheat seedlings 4 days after treatment. P. aeruginosa LPS did not show effect on plant growth. A. brasilense LPS increased root hairs length similar to whole cells, while P. aeruginosa LPS increased root hairs density and slightly root hairs length. Both LPS increased POD activity and hydrogen peroxide (H 2 O 2 ) content in root; however, the LPS from the pathogenic bacterium generated higher increments. The peroxidase inhibitor salicylhydroxamic acid (SHAM) inhibited plant growth, which was not recovered by the addition of LPS neither A. brasilense nor P. aeruginosa. POD activity stimulated by LPS was calcium-dependent as confirmed by the addition of the calcium channel blocker LaCl 3 . The results suggest that plant cells sense differentially LPS from beneficial or pathogenic bacteria and that calcium is needed to respond to the presence of both LPS.

show abstract

Immunological Properties of Azospirillum Cell Surface: the Structure of Carbohydrate Antigens and Evaluation of their Involvement in Bacteria-Plant Contact Interactions

Cited by 12 publications

References 15 publications

The wzm gene located on the pRhico plasmid of Azospirillum brasilense Sp7 is involved in lipopolysaccharide synthesis

The wzm gene located on the pRhico plasmid of Azospirillum brasilense Sp7 is involved in lipopolysaccharide synthesis

Effect of Azospirillum brasilense Sp245 lipopolysaccharide on the functional activity of wheat root meristematic cells

Comparative Effects of Azospirillum brasilense Sp245 and Pseudomonas aeruginosa PAO1 Lipopolysaccharides on Wheat Seedling Growth and Peroxidase Activity

Contact Info

Product

Resources

About