scholarly journals Characterization of Phenylpyruvate Decarboxylase, Involved in Auxin Production of Azospirillum brasilense

2007 ◽  
Vol 189 (21) ◽  
pp. 7626-7633 ◽  
Author(s):  
Stijn Spaepen ◽  
Wim Versées ◽  
Dörte Gocke ◽  
Martina Pohl ◽  
Jan Steyaert ◽  
...  
Keyword(s):  
Azospirillum Brasilense ◽  
Growth Promotion ◽  
Pyruvate Decarboxylase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Size Exclusion ◽  
Knockout Mutant ◽  
Auxin Production ◽  
Specificity Constant ◽  
Plant Growth Promoting ◽  
Phenylpyruvate Decarboxylase

ABSTRACT Azospirillum brasilense belongs to the plant growth-promoting rhizobacteria with direct growth promotion through the production of the phytohormone indole-3-acetic acid (IAA). A key gene in the production of IAA, annotated as indole-3-pyruvate decarboxylase (ipdC), has been isolated from A. brasilense, and its regulation was reported previously (A. Vande Broek, P. Gysegom, O. Ona, N. Hendrickx, E. Prinsen, J. Van Impe, and J. Vanderleyden, Mol. Plant-Microbe Interact. 18:311-323, 2005). An ipdC-knockout mutant was found to produce only 10% (wt/vol) of the wild-type IAA production level. In this study, the encoded enzyme is characterized via a biochemical and phylogenetic analysis. Therefore, the recombinant enzyme was expressed and purified via heterologous overexpression in Escherichia coli and subsequent affinity chromatography. The molecular mass of the holoenzyme was determined by size-exclusion chromatography, suggesting a tetrameric structure, which is typical for 2-keto acid decarboxylases. The enzyme shows the highest k cat value for phenylpyruvate. Comparing values for the specificity constant k cat/Km , indole-3-pyruvate is converted 10-fold less efficiently, while no activity could be detected with benzoylformate. The enzyme shows pronounced substrate activation with indole-3-pyruvate and some other aromatic substrates, while for phenylpyruvate it appears to obey classical Michaelis-Menten kinetics. Based on these data, we propose a reclassification of the ipdC gene product of A. brasilense as a phenylpyruvate decarboxylase (EC 4.1.1.43).

scholarly journals The Pseudomonas Secondary Metabolite 2,4-Diacetylphloroglucinol Is a Signal Inducing Rhizoplane Expression of Azospirillum Genes Involved in Plant-Growth Promotion

2011 ◽  
Vol 24 (2) ◽  
pp. 271-284 ◽  
Author(s):  
Emeline Combes-Meynet ◽  
Joël F. Pothier ◽  
Yvan Moënne-Loccoz ◽  
Claire Prigent-Combaret
Keyword(s):  
Plant Growth ◽  
Secondary Metabolite ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Fluorescence Induction ◽  
Auxin Production ◽  
Wide Range ◽  
Enhanced Expression ◽  
Plant Growth Promoting ◽  
Negative Mutant

During evolution, plants have become associated with guilds of plant-growth-promoting rhizobacteria (PGPR), which raises the possibility that individual PGPR populations may have developed mechanisms to cointeract with one another on plant roots. We hypothesize that this has resulted in signaling phenomena between different types of PGPR colonizing the same roots. Here, the objective was to determine whether the Pseudomonas secondary metabolite 2,4-diacetylphloroglucinol (DAPG) can act as a signal on Azospirillum PGPR and enhance the phytostimulation effects of the latter. On roots, the DAPG-producing Pseudomonas fluorescens F113 strain but not its phl-negative mutant enhanced the phytostimulatory effect of Azospirillum brasilense Sp245-Rif on wheat. Accordingly, DAPG enhanced Sp245-Rif traits involved in root colonization (cell motility, biofilm formation, and poly-β-hydroxybutyrate production) and phytostimulation (auxin production). A differential fluorescence induction promoter-trapping approach based on flow cytometry was then used to identify Sp245-Rif genes upregulated by DAPG. DAPG enhanced expression of a wide range of Sp245-Rif genes, including genes involved in phytostimulation. Four of them (i.e., ppdC, flgE, nirK, and nifX-nifB) tended to be upregulated on roots in the presence of P. fluorescens F113 compared with its phl-negative mutant. Our results indicate that DAPG can act as a signal by which some beneficial pseudomonads may stimulate plant-beneficial activities of Azospirillum PGPR.

scholarly journals C4 Bacterial Volatiles Improve Plant Health

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 682
Author(s):  
Bruno Henrique Silva Dias ◽  
Sung-Hee Jung ◽  
Juliana Velasco de Castro Oliveira ◽  
Choong-Min Ryu
Keyword(s):  
Plant Growth ◽  
Volatile Compounds ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Health ◽  
Systemic Resistance ◽  
Potential Applications ◽  
Plant Growth Promoting ◽  
Bacterial Volatiles

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.

Rhizobium leguminosarum as a plant growth-promoting rhizobacterium: direct growth promotion of canola and lettuce

1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Direct Growth ◽  
Early Seedling ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.

Colonization and growth promotion of outplanted spruce seedlings pre-inoculated with plant growth-promoting rhizobacteria in the greenhouse

2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway
Keyword(s):  
Plant Growth ◽  
Seedling Growth ◽  
Picea Glauca ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Population Declines ◽  
Growth Responses ◽  
Relative Growth Rates ◽  
Plant Growth Promoting ◽  
Growth Promoting

Seeds of two hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) ecotypes were inoculated with one of six plant growth-promoting rhizobacteria (PGPR) strains previously shown to be able to stimulate spruce growth in controlled environments. The resulting seedlings were grown in the greenhouse for 17 weeks before outplanting at four reforestation sites. Inoculation with five of the six strains caused significant seedling growth promotion in the greenhouse, which necessitated analysis of relative growth rates (RGR) to evaluate seedling performance in the field. Four months after outplanting, most strains enhanced spruce shoot or root RGRs in the field, but seedling growth responses were strain specific. For example, Pseudomonas strain Ss2-RN significantly increased both shoot and root RGRs by 10-234% at all sites, but increases of 28-70% were most common. In contrast, Bacillus strain S20-R was ineffective at all outplanting sites. In addition, seedlings inoculated with four of the six strains had significantly less shoot injury than control seedlings at all sites. Evaluation of root colonization by PGPR indicated that bacterial population declines were not related to spruce growth response variability in the field. Our results indicate that once plant growth promotion is induced in the greenhouse, seedling RGR can increase by more than 100% during the first growing season in the field. However RGR increases of 21-47% were more common and may be more representative of the magnitude of biomass increases that can result from PGPR inoculation.

scholarly journals Characterization of Selected Plant Growth-Promoting Rhizobacteria and Their Non-Host Growth Promotion Effects

2021 ◽  
Author(s):  
Di Fan ◽  
Donald L. Smith
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Content Type ◽  
Host Growth ◽  
Plant Growth Promoting ◽  
Growth Promoting

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .

scholarly journals Burkholderia sp. from rhizosphere of Rhododendron arboretum: Isolation, identification and plant growth promotory (PGP) activities

2014 ◽  
Vol 6 (2) ◽  
pp. 473-479 ◽  
Author(s):  
Shweta Nailwal ◽  
Md. Shahbaz Anwar ◽  
Kamal Kant Budhani ◽  
Amit Verma ◽  
Tapan Kumar Nailwal
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Research Work ◽  
Growth Index ◽  
Wheat Plant ◽  
Plant Growth Promoting Rhizobacteria ◽  
Remarkable Change ◽  
Enhanced Production ◽  
Plant Growth Promoting

Plant growth promoting rhizobacteria (PGPR) is beneficial bacteria that colonize plant roots and enhance plant growth by wide variety of mechanism like phosphate solubilisation, etc. Use of PGPR has steadily increased in agriculture and offers an attractive way to replace chemical fertilizers, pesticides and supplements. The present research work was designed to isolate and characterize the PGP activity of Burkholderia sp. For this purpose rhizospheric soil from Rhododendron arboreum of Kumaun Himalaya was collected and efficient bacterial strain was screened on the basis of phosphate solubilization. Further, assessment of various parameters of plant growth promotion activity was done and enhanced production of IAA (16.4 μgml-1) and (20.8 μgml-1) was observed in the presence of 250μgml-1 and 500 μg ml-1 of tryptophan, respectively. Correspondingly, in respect of 7.8 μg ml-1 IAA without tryptophan, and their confirmation was executed by TLC. A remarkable change in color from green to reddish-brown zone on CAS plates, suggests the positive result for siderophore production, and finally the seed germination and pot trial experiment depicted the growth index of wheat plant. Therefore, the present study suggests that Burkholderia sp. is beneficial for plant growth promotion.

scholarly journals Impact of Plant Growth Promoting Rhizobacteria in Sustainable Agriculture: An Important Natural Resource for Crop Improvement

2019 ◽  
Vol 5 (03) ◽  
pp. 210-214
Author(s):  
Debnirmalya Gangopadhyay ◽  
Ashmita Ghosh
Keyword(s):  
Plant Growth ◽  
Sustainable Agriculture ◽  
Crop Yields ◽  
Growth Promotion ◽  
Crop Improvement ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Increasing Demand ◽  
Environmentally Sound

It is usually admitted that the chemical fertilizers and pesticides used in modern agriculture create a real environmental and public health problems. The increasing demand for production with a significant reduction of synthetic fertilizers and pesticides use is a big challenge nowadays. The use of plant growth promoting rhizobacteria or PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. They play an important role to increase in soil fertility, plant growth promotion and suppression of phytopathogens for development of ecofriendly sustainable agriculture. In view of the latest advances in PGPR biotechnology, this paper proposes to do the review on PGPR in rhizosphere and describes the different mechanisms used by PGPR to promote the plants growth and health. In prospect to a healthy and sustainable agriculture, the PGPR approach revealed as one of the best ecofriendly alternatives.

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