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Ruifu Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Bacillus velezensis Wall Teichoic Acids Are Required for Biofilm Formation and Root Colonization
    Applied and Environmental Microbiology, 2019
    Co-Authors: Zhihui Xu, Huihui Zhang, Qirong Shen, Ruifu Zhang
    Abstract:

    ABSTRACT Rhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficial Bacillus strains is essential for the use of these strains in agriculture. Here, we observed that an sfp gene mutant of the plant growth-promoting Rhizobacterium Bacillus velezensis SQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfp mutant, and impairment of the ggaA gene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaB mutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficial Bacillus strain, which will help improve its application as a biofertilizer. IMPORTANCEBacillus velezensis is a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally, Bacillus spp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficial Bacillus strains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of the gtaB gene affects the ability of B. velezensis SQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into the Bacillus root colonization process and can help improve our understanding of plant-Rhizobacterium interactions.

  • Synthesis and detoxification of nitric oxide in the plant beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 and its effect on biofilm formation.
    Biochemical and Biophysical Research Communications, 2018
    Co-Authors: Xiaoyan Dong, Qirong Shen, Jiahui Shao, Yunpeng Liu, Guishan Zhang, Dandan Wang, Xuan Zhou, Ruifu Zhang
    Abstract:

    Nitric oxide (NO) is an important gas signal that regulates many biological processes, and due to the high nitrogen recycling activity in the rhizosphere, NO is an important signaling molecule in this region. Thus, an understanding of the effect of NO on the rhizomicrobiome, especially on plant beneficial rhizobacteria, is important for the use of these bacteria in agriculture. In this study, the effect of exogenous NO on the beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 was investigated. The results showed that low concentrations of NO increased the ability of the strain SQR9 to form biofilms, while high concentrations of NO inhibited the growth of this bacterium. The SQR9 gene yflM encodes nitric oxide synthase (NOS), which is used to synthesize NO, while the gene ykvO encodes a sepiapterin reductase that is used to synthesize tetrahydrobiopterin, the coenzyme of NOS. Isothermal titration calorimetry and high-performance liquid chromatography analyses demonstrated an interaction between YkvO and NADPH. SQR9 has two hmp genes, although only one was observed to be responsible for NO detoxification through oxidization. This study revealed the effect of NO on plant beneficial Rhizobacterium and assessed the ability of this strain to adapt to exogenous NO, which will help to improve the application of this strain in agricultural production.

  • Exploring Elicitors of the Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 to Induce Plant Systemic Resistance and Their Interactions With Plant Signaling Pathways.
    Molecular Plant-Microbe Interactions®, 2018
    Co-Authors: Yunpeng Liu, Qirong Shen, Guishan Zhang, Ruifu Zhang
    Abstract:

    Beneficial rhizobacteria have been reported to produce various elicitors that induce plant systemic resistance, but there is little knowledge concerning the relative contribution of multiple elicitors from a single beneficial Rhizobacterium on the induced systemic resistance in plants and the interactions of these elicitors with plant signaling pathways. In this study, nine mutants of the plant growth-promoting Rhizobacterium Bacillus amyloliquefaciens SQR9 deficient in producing the extracellular compounds, including fengycin, bacillomycin D, surfactin, bacillaene, macrolactin, difficidin, bacilysin, 2,3-butandiol, and exopolysaccharides, were tested for the induction of systemic resistance against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea and the transcription of the salicylic acid, jasmonic acid, and ethylene signaling pathways in Arabidopsis. Deficiency in producing any of these compounds in SQR9 significantly weakened the induced plant resistance against these phytopathogens. These SQR9-produced elicitors induced different plant defense genes. For instance, the enhancement of 1,3-glucanase (PR2) by SQR9 was impaired by a deficiency of macrolactin but not surfactin. SQR9 mutants deficient in the lipopeptide and polyketide antibiotics remained only 20% functional for the induction of resistance-related gene transcription. Overall, these elicitors of SQR9 could act synergistically to induce plant systemic resistance against different phytopathogens through different signaling pathway genes, and the bacterial antibiotics are major contributors to the induction.

  • Complete Genome Sequence of Paenibacillus polymyxa SQR-21, a Plant Growth-Promoting Rhizobacterium with Antifungal Activity and Rhizosphere Colonization Ability.
    Genome Announcements, 2014
    Co-Authors: Dongqing Yang, Ruifu Zhang, Meihua Qiu, Jiahui Shao, Rong Guo, Biao Shen, Xihou Yin, Nan Zhang, Qirong Shen
    Abstract:

    ABSTRACT Here we report the complete genome sequence of a plant growth-promoting Rhizobacterium (PGPR), Paenibacillus polymyxa SQR-21, which consists of one circular chromosome of 5,828,438 bp with 5,024 coding sequences (CDS). The data presented highlight multiple sets of functional genes associated with its plant-beneficial characteristics.

Paramasamy Gunasekaran - One of the best experts on this subject based on the ideXlab platform.

Yuriy A. Knirel - One of the best experts on this subject based on the ideXlab platform.

  • identification of an o linked repetitive glycan chain of the polar flagellum flagellin of azospirillum brasilense sp7
    Carbohydrate Research, 2012
    Co-Authors: Alexei Ye Belyakov, Yuriy A. Knirel, Alexander S Shashkov, G L Burygin, Nikolai P Arbatsky, Nikolai Yu Selivanov, Larisa Yu Matora, Sergei Yu Shchyogolev
    Abstract:

    This is the first report to have identified an O-linked repetitive glycan in bacterial flagellin, a structural protein of the flagellum. Studies by sugar analysis, Smith degradation, 1 H and 13 C NMR spectroscopy, and mass spectrometry showed that the glycan chains of the polar flagellum flagellin of the plantgrowth-promoting Rhizobacterium Azospirillum brasilense Sp7 are represented by a polysaccharide with a molecular mass of 7.7 kDa, which has a branched tetrasaccharide repeating unit of the following structure:

  • Structural analysis of the O-polysaccharide of the lipopolysaccharide from Azospirillum brasilense Jm6B2 containing 3-O-methyl-D-rhamnose (D-acofriose)
    Carbohydrate Research, 2012
    Co-Authors: Alevtina S. Boyko, Yuriy A. Knirel, Yu. P. Fedonenko, Svetlana A. Konnova, Evelina L Zdorovenko, Andrey S. Dmitrenok, Vladimir V. Ignatov
    Abstract:

    Abstract Two types of neutral O-polysaccharides were obtained by mild acid degradation of the lipopolysaccharide isolated by phenol–water extraction from the asymbiotic diazotrophic Rhizobacterium Azospirillum brasilense Jm6B2. The following structure of the major O-polysaccharide was established by composition and methylation (ethylation) analyses, Smith degradation, and 1D and 2D 1H and 13C NMR spectroscopy: Download : Download full-size image where a non-stoichiometric (∼60%) 3-O-methylation of d -rhamnose is indicated by italics.

  • structural analysis of the o polysaccharide from the lipopolysaccharide of azospirillum brasilense s17
    Carbohydrate Research, 2008
    Co-Authors: Yu. P. Fedonenko, Alexander S Shashkov, Olga N. Konnova, Svetlana A. Konnova, Evelina L Zdorovenko, George V Zatonsky, V V Ignatov, Yuriy A. Knirel
    Abstract:

    Abstract A mixture of two structurally distinct neutral O-polysaccharides was obtained by mild acid degradation of the lipopolysaccharide isolated by the phenol/water extraction from the asymbiotic diazotrophic Rhizobacterium Azospirillum brasilense S17. The following structures of the O-polysaccharides were established by composition and methylation analyses, Smith degradation, and 1 H and 13 C NMR spectroscopy, including a 2D NOESY experiment: Download full-size image where l -Rha2Me stands for 2- O -methyl- l -rhamnose and S Hb for the ( S )-3-hydroxybutanoyl group. The occurrence of two distinct polysaccharides is reported for the first time in Azospirillum spp.

Paramasivan Ponraj - One of the best experts on this subject based on the ideXlab platform.

Gustavo Santoyo - One of the best experts on this subject based on the ideXlab platform.

  • SHORT GENOME REPORT Open Access Draft Genome Sequence of the Biocontrol
    2016
    Co-Authors: Plant Growth-promoting Rhizobacterium, Julie E. Hernández-salmerón, R. Hernández-león, Eduardo Valencia-cantero, Gabriel Moreno-hagelsieb, Ma. Del, Carmen Orozco-mosqueda, Gustavo Santoyo
    Abstract:

    The Pseudomonas fluorescens strain UM270 was isolated form the rhizosphere of wild Medicago spp. A previous work has shown that this pseudomonad isolate was able to produce diverse diffusible and volatile compounds involved in plant protection and growth promotion. Here, we present the draft genome sequence of the Rhizobacterium P. fluorescens strain UM270. The sequence covers 6,047,974 bp of a single chromosome, with 62.66 % G + C content and no plasmids. Genome annotations predicted 5,509 genes, 5,396 coding genes, 59 RNA genes and 110 pseudogenes. Genome sequence analysis revealed the presence of genes involved in biological control and plant-growth promoting activities. We anticipate that the P. fluorescens strain UM270 genome will contribute insights about bacterial plant protection and beneficial properties through genomic comparisons among fluorescent pseudomonads

  • Draft Genome Sequence of the Biocontrol and Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens strain UM270
    Standards in Genomic Sciences, 2016
    Co-Authors: Julie E. Hernández-salmerón, R. Hernández-león, Ma. Del Carmen Orozco-mosqueda, Eduardo Valencia-cantero, Gabriel Moreno-hagelsieb, Gustavo Santoyo
    Abstract:

    The Pseudomonas fluorescens strain UM270 was isolated form the rhizosphere of wild Medicago spp. A previous work has shown that this pseudomonad isolate was able to produce diverse diffusible and volatile compounds involved in plant protection and growth promotion. Here, we present the draft genome sequence of the Rhizobacterium P. fluorescens strain UM270. The sequence covers 6,047,974 bp of a single chromosome, with 62.66 % G + C content and no plasmids. Genome annotations predicted 5,509 genes, 5,396 coding genes, 59 RNA genes and 110 pseudogenes. Genome sequence analysis revealed the presence of genes involved in biological control and plant-growth promoting activities. We anticipate that the P. fluorescens strain UM270 genome will contribute insights about bacterial plant protection and beneficial properties through genomic comparisons among fluorescent pseudomonads.