Impact of Plant Growth Promoting Rhizobacteria on Crop Production

Verma, Jay Prakash; Yadav, Janardan; Tiwari, Kavindra Nath; Lavakush,; Singh, Vimal

doi:10.3923/ijar.2010.954.983

Cited by 194 publications

(121 citation statements)

References 96 publications

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“…Several dominant core genera of citrus roots (Kaistobacter and unclassified genera in Bradyrhizobiaceae and Xanthomonadaceae) were found to be associated with asymptomatic trees. Bradyrhizobiaceae are known soil bacteria and root endophytes involved in symbiotic relationships with plants as nitrogen fixers (47,48). While some members of Xanthomonadaceae are citrus pathogens (e.g., citrus canker is caused by Xanthomonas axonopodis) (49), others have been implicated in biological control (27).…”

Section: Discussionmentioning

confidence: 99%

Defining the Core Citrus Leaf- and Root-Associated Microbiota: Factors Associated with Community Structure and Implications for Managing Huanglongbing (Citrus Greening) Disease

Blaustein

Lorca

Meyer

et al. 2017

Appl Environ Microbiol

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Stable associations between plants and microbes are critical to promoting host health and productivity. The objective of this work was to test the hypothesis that restructuring of the core microbiota may be associated with the progression of huanglongbing (HLB), the devastating citrus disease caused by Liberibacter asiaticus, Liberibacter americanus, and Liberibacter africanus. The microbial communities of leaves (n ϭ 94) and roots (n ϭ 79) from citrus trees that varied by HLB symptom severity, cultivar, location, and season/time were characterized with Illumina sequencing of 16S rRNA genes. The taxonomically rich communities contained abundant core members (i.e., detected in at least 95% of the respective leaf or root samples), some overrepresented site-specific members, and a diverse community of lowabundance variable taxa. The composition and diversity of the leaf and root microbiota were strongly associated with HLB symptom severity and location; there was also an association with host cultivar. The relative abundance of Liberibacter spp. among leaf microbiota positively correlated with HLB symptom severity and negatively correlated with alpha diversity, suggesting that community diversity decreases as symptoms progress. Network analysis of the microbial community time series identified a mutually exclusive relationship between Liberibacter spp. and members of the Burkholderiaceae, Micromonosporaceae, and Xanthomonadaceae. This work confirmed several previously described plant disease-associated bacteria, as well as identified new potential implications for biological control. Our findings advance the understanding of (i) plant microbiota selection across multiple variables and (ii) changes in (core) community structure that may be a precondition to disease establishment and/or may be associated with symptom progression.IMPORTANCE This study provides a comprehensive overview of the core microbial community within the microbiomes of plant hosts that vary in extent of disease symptom progression. With 16S Illumina sequencing analyses, we not only confirmed previously described bacterial associations with plant health (e.g., potentially beneficial bacteria) but also identified new associations and potential interactions between certain bacteria and an economically important phytopathogen. The importance of core taxa within broader plant-associated microbial communities is discussed.KEYWORDS core microbiome, plant-associated microbiota, Liberibacter, pathogenmicrobe interactions

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Section: Discussionmentioning

confidence: 99%

Defining the Core Citrus Leaf- and Root-Associated Microbiota: Factors Associated with Community Structure and Implications for Managing Huanglongbing (Citrus Greening) Disease

Blaustein

Lorca

Meyer

et al. 2017

Appl Environ Microbiol

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“…Plant growth promoting rhizobacteria are a group of free living soil bacteria, which have the ability to promote growth and yield of crop plant by direct and indirect mechanism [3]. Phytohormones play an important role as signals and regulators of growth and development in plants.…”

Section: Introductionmentioning

confidence: 99%

Plant growth promotion using microbial IAA producers in conjunction with azolla: a novel approach

Raut

Shaikh

Naphade

et al. 2017

Chem. Biol. Technol. Agric.

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Studies were conducted to find efficient Indole acetic acid producing strains and assessing the effectiveness of combined dose of azolla (dried) and IAA producers on plant growth. Out of ten isolates, only two isolates, viz, F1 and G2 were found to be potent IAA producers and were used for further experiments. It was found that the isolate F1 and G2 produced maximum amount of IAA at 0.9% tryptophan and incubation for 72 h at room temperature. The optimum pH for IAA production for isolates F1 and G2 was found to be at pH 9. The isolates were also assessed for the presence of other plant growth promoting activity, such as hydrogen cyanide production, oxalate solubilization, phosphate solubilization and zinc solubilization. Effect of IAA producers on seed germination was done by pot experiments carried out into sets. Isolates F1 and G2 were found efficient for plant growth promotion in desired aspects. Effect of combined dose of azolla and IAA producers on seed germination was assessed by pot experiments. For this, dried powder of azolla was added during sowing of culture treated seeds. No further culture supply was given to the seeds. Azolla has high protein content. Slow protein releasing property of azolla can be useful to provide constant supply of the precursor (tryptophan) for IAA synthesis by isolate. In addition to the plant exudates, azolla may also give constant supply of tryptophan. From all the assessed samples, the isolates FI and G2 showed efficient growth of plants in all aspects. G2 was found to be more potent than F1. So as to assess the compatibility of isolate in natural conditions, field studies were done. Four plots designed having individual size 9 × 5 m, were used. It was found that plots 3 (only culture) and 4 (culture with azolla) showed better plant growth as compared to others. On the basis of IAA producing ability of G2, pot experiments and field studies, it was concluded that isolate G2 can be used alone or in conjunction with azolla as a biofertilizer to get better plant growth.

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“…Combined inoculation of Rhizobium with Pseudomonas striata or Bacillus megaterium led to increased dry matter, grain yield and phosphorus uptake significantly over the uninoculated control in legumes (Elkoca et al, 2008). Verma et al (2010) have reported the application of Rhizobium spp. and plant growth promoting rhizobacteria on nodulation, plant biomass and yields of chickpea plants.…”

Section: Co-inoculation Of Plant Growth-promoting Bacteriamentioning

confidence: 99%

“…Dual inoculation of legumes with Rhizobium and Azospirillum significantly increase several plant-growth variables when compared with single inoculations (Hamaoui et al, 2001;Itzigsohn et al, 2000;Remans et al, 2007;Remans et al, 2008b;Tchebotar et al, 1998). Azospirillum is considered a Rhizobium helper by stimulating nodulation, nodule function, and possibly plant metabolism (Molla et al, 2001;Verma et al, 2010). Phytohormones produced by Azospirillum promote epidermal-cell differentiation in root hairs that increased the number of potential sites for rhizobial infection leading to the formation of more nodules.…”

Section: Co-inoculation Of Plant Growth-promoting Bacteriamentioning

confidence: 99%