Azospirillum plant growth-promoting strains are nonpathogenic on tomato, pepper, cotton, and wheat

1998 ◽  
Vol 44 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Yoav Bashan
Keyword(s):  
Plant Growth ◽  
Plant Species ◽  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Dry Weight ◽  
Plant Growth Promoting Bacteria ◽  
Disease Symptoms ◽  
Plant Growth Promoting ◽  
Growth Promoting

Six strains of Azospirillum belonging to five species of plant growth-promoting bacteria (A. brasilense, A. lipoferum, A. amazonense, A. irakense, and A. halopraeference) did not cause visible disease symptoms on the roots or leaves of tomato, pepper, cotton, and wheat, failed to inhibit seed germination, and did not reduce plant dry weight when seven standard techniques for the inoculation of plant pathogens were used. Similar inoculation conditions with plant pathogens (Pseudomonas syringae pv. tomato, Xanthomonas campestris pv. vesicatoria, Xanthomonas campestris pv. translucens, and Xanthomonas campestris pv. malvacearum) induced typical disease symptoms. None of Azospirillum strains caused the hypersensitive reaction on eggplant, whereas all pathogens did. All Azospirillum strains increased phytoalexin production in all disease-resistant plant species to moderate levels, but the levels were significantly lower than those induced by the compatible pathogens. The various phytoalexins produced in plants had the capacity to inhibit growth of all Azospirillum strains. Azospirillum amazonense, A. irakense, and A. halopraeference had no apparent effect on plant growth, while A. brasilense and A. lipoferum increased the dry weight of all plant species. Under partial mist conditions, all Azospirillum strains were capable of colonizing leaf surfaces (103-107 cfu/g dry weight) regardless of the plant species. These results provide experimental evidence that Azospirillum sp. might be considered safe for the inoculation of several plant species.Key words: Azospirillum, beneficial bacteria, environmental protection, plant inoculation, plant growth-promoting bacteria.

scholarly journals Protection of Tomato Seedlings against Infection by Pseudomonas syringae pv. Tomato by Using the Plant Growth-Promoting Bacterium Azospirillum brasilense

2002 ◽  
Vol 68 (6) ◽  
pp. 2637-2643 ◽  
Author(s):  
Yoav Bashan ◽  
Luz E. de-Bashan
Keyword(s):  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
Tomato Plants ◽  
Bacterial Speck ◽  
Plant Growth Promoting ◽  
Bacterial Speck Disease ◽  
Growth Promoting ◽  
Mist Chamber

ABSTRACT Pseudomonas syringae pv. tomato, the causal agent of bacterial speck of tomato, and the plant growth-promoting bacterium Azospirillum brasilense were inoculated onto tomato plants, either alone, as a mixed culture, or consecutively. The population dynamics in the rhizosphere and foliage, the development of bacterial speck disease, and their effects on plant growth were monitored. When inoculated onto separate plants, the A. brasilense population in the rhizosphere of tomato plants was 2 orders of magnitude greater than the population of P. syringae pv. tomato (107 versus 105 CFU/g [dry weight] of root). Under mist chamber conditions, the leaf population of P. syringae pv. tomato was 1 order of magnitude greater than that of A. brasilense (107 versus 106 CFU/g [dry weight] of leaf). Inoculation of seeds with a mixed culture of the two bacterial strains resulted in a reduction of the pathogen population in the rhizosphere, an increase in the A. brasilense population, the prevention of bacterial speck disease development, and improved plant growth. Inoculation of leaves with the mixed bacterial culture under mist conditions significantly reduced the P. syringae pv. tomato population and significantly decreased disease severity. Challenge with P. syringae pv. tomato after A. brasilense was established in the leaves further reduced both the population of P. syringae pv. tomato and disease severity and significantly enhanced plant development. Both bacteria maintained a large population in the rhizosphere for 45 days when each was inoculated separately onto tomato seeds (105 to 106 CFU/g [dry weight] of root). However, P. syringae pv. tomato did not survive in the rhizosphere in the presence of A. brasilense. Foliar inoculation of A. brasilense after P. syringae pv. tomato was established on the leaves did not alleviate bacterial speck disease, and A. brasilense did not survive well in the phyllosphere under these conditions, even in a mist chamber. Several applications of a low concentration of buffered malic acid significantly enhanced the leaf population of A. brasilense (>108 CFU/g [dry weight] of leaf), decreased the population of P. syringae pv. tomato to almost undetectable levels, almost eliminated disease development, and improved plant growth to the level of uninoculated healthy control plants. Based on our results, we propose that A. brasilense be used in prevention programs to combat the foliar bacterial speck disease caused by P. syringae pv. tomato.

scholarly journals Growth response of wheat cultivars to bacterial inoculation in calcareous soil

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 570-573 ◽  
Author(s):  
D. Egamberdieva
Keyword(s):  
Plant Growth ◽  
Calcareous Soil ◽  
Dry Weight ◽  
Plant Growth Promoting Bacteria ◽  
Wheat Cultivars ◽  
Bacterial Strains ◽  
Bacterial Inoculation ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Selection Of

In this study the plant growth-promoting bacteria were analysed for their growth-stimulating effects on two wheat cultivars. The investigations were carried out in pot experiments using calcareous soil. The results showed that bacterial strains Pseudomonas spp. NUU1 and P. fluorescens NUU2 were able to colonize the rhizosphere of both wheat cultivars. Their plant growth-stimulating abilities were affected by wheat cultivars. The bacterial strains Pseudomonas sp. NUU1 and P. fluorescens NUU2 significantly stimulated the shoot and root length and dry weight of wheat cv. Turon, whereas cv. Residence was less affected by bacterial inoculation. The results of our study suggest that inoculation of wheat with Pseudomonas strains can improve plant growth in calcareous soil and it depends upon wheat cultivars. Prior to a selection of good bacterial inoculants, it is recommended to select cultivars that benefit from association with these bacteria.

scholarly journals Synergistic and offset effects of fungal species combinations on plant performance

2021 ◽  
Author(s):  
Yoshie Hori ◽  
Hiroaki Fujita ◽  
Kei Hiruma ◽  
Kazuhiko Narisawa ◽  
Hirokazu Toju
Keyword(s):  
Plant Growth ◽  
Synergistic Effects ◽  
Dry Weight ◽  
Fungal Species ◽  
Plant Performance ◽  
Plant Growth Promoting Bacteria ◽  
Microbial Species ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Dual Inoculation

In natural and agricultural ecosystems, survival and growth of plants depend substantially on microbes in the endosphere and rhizosphere. Although numerous studies have reported the presence of plant-growth promoting bacteria and fungi in below-ground biomes, it remains a major challenge to understand how sets of microbial species positively or negatively affect plants' performance. By conducting a series of single- and dual-inoculation experiments of 13 endophytic and soil fungi targeting a Brassicaceae plant species, we here evaluated how microbial effects on plants depend on presence/absence of co-occurring microbes. The comparison of single- and dual-inoculation experiments showed that combinations of the fungal isolates with the highest plant-growth promoting effects in single inoculations did not yield highly positive impacts on plant performance traits (e.g., shoot dry weight). In contrast, pairs of fungi including small/moderate contributions to plants in single-inoculation contexts showed the greatest effects on plants among the 78 fungal pairs examined. These results on the offset and synergistic effects of pairs of microbes suggest that inoculation experiments of single microbial species/isolates can result in the overestimation or underestimation of microbial functions in multi-species contexts. Because keeping single-microbe systems in outdoor conditions is impractical, designing sets of microbes that can maximize performance of crop plants is an important step for the use of microbial functions in sustainable agriculture.

scholarly journals Biofilm Producing Rhizobacteria With Multiple Plant Growth-Promoting Traits Promote Growth of Tomato Under Water-Deficit Stress

2020 ◽  
Vol 11 ◽  
Author(s):  
Md. Manjurul Haque ◽  
Md Khaled Mosharaf ◽  
Moriom Khatun ◽  
Md. Amdadul Haque ◽  
Md. Sanaullah Biswas ◽  
...  
Keyword(s):  
Plant Growth ◽  
Water Deficit ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Water Deficit Stress ◽  
Rrna Gene ◽  
Growth Promoters ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Plant Growth Promoting Traits

Plant growth-promoting rhizobacteria (PGPR) not only enhance plant growth but also control phytopathogens and mitigate abiotic stresses, including water-deficit stress. In this study, 21 (26.9%) rhizobacterial strains isolated from drought-prone ecosystems of Bangladesh were able to form air–liquid (AL) biofilms in the glass test tubes containing salt-optimized broth plus glycerol (SOBG) medium. Based on 16S rRNA gene sequencing, Pseudomonas chlororaphis (ESR3 and ESR15), P. azotoformans ESR4, P. poae ESR6, P. fluorescens (ESR7 and ESR25), P. gessardii ESR9, P. cedrina (ESR12, ESR16, and ESR23), P. veronii (ESR13 and ESR21), P. parafulva ESB18, Stenotrophomonas maltophilia ESR20, Bacillus cereus (ESD3, ESD21, and ESB22), B. horikoshii ESD16, B. aryabhattai ESB6, B. megaterium ESB9, and Staphylococcus saprophyticus ESD8 were identified. Fourier transform infrared spectroscopy studies showed that the biofilm matrices contain proteins, polysaccharides, nucleic acids, and lipids. Congo red binding results indicated that these bacteria produced curli fimbriae and nanocellulose-rich polysaccharides. Expression of nanocellulose was also confirmed by Calcofluor binding assays and scanning electron microscopy. In vitro studies revealed that all these rhizobacterial strains expressed multiple plant growth-promoting traits including N2 fixation, production of indole-3-acetic acid, solubilization of nutrients (P, K, and Zn), and production of ammonia, siderophores, ACC deaminase, catalases, lipases, cellulases, and proteases. Several bacteria were also tolerant to multifarious stresses such as drought, high temperature, extreme pH, and salinity. Among these rhizobacteria, P. cedrina ESR12, P. chlororaphis ESR15, and B. cereus ESD3 impeded the growth of Xanthomonas campestris pv. campestris ATCC 33913, while P. chlororaphis ESR15 and B. cereus ESD21 prevented the progression of Ralstonia solanacearum ATCC® 11696TM. In a pot experiment, tomato plants inoculated with P. azotoformans ESR4, P. poae ESR6, P. gessardii ESR9, P. cedrina ESR12, P. chlororaphis ESR15, S. maltophilia ESR20, P. veronii ESR21, and B. aryabhattai ESB6 exhibited an increased plant growth compared to the non-inoculated plants under water deficit-stressed conditions. Accordingly, the bacterial-treated plants showed a higher antioxidant defense system and a fewer tissue damages than non-inoculated plants under water-limiting conditions. Therefore, biofilm-producing PGPR can be utilized as plant growth promoters, suppressors of plant pathogens, and alleviators of water-deficit stress.

scholarly journals Microarray Analysis of the Gene Expression Profile Induced by the Endophytic Plant Growth-Promoting Rhizobacteria, Pseudomonas fluorescens FPT9601-T5 in Arabidopsis

2005 ◽  
Vol 18 (5) ◽  
pp. 385-396 ◽  
Author(s):  
Yanqing Wang ◽  
Yumiko Ohara ◽  
Hitoshi Nakayashiki ◽  
Yukio Tosa ◽  
Shigeyuki Mayama
Keyword(s):  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Microarray Analysis ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Responses ◽  
Disease Symptoms ◽  
Global View ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Physiological And Biochemical

Pseudomonasz fluorescens FPT9601-T5 was originally identified as an endophytic plant growth-promoting rhizobacteria (PGPR) on tomato. To perform a molecular dissecttion of physiological and biochemical changes occurring in the host triggered by P. fluorescens FPT9601-T5 colonization, the model plant Arabidopsis was used in this study. Root colonization of Arabidopsis with P. fluorescens FPT9601-T5 promoted plant growth later than three weeks after inoculation and partially suppressed disease symptoms caused by Pseudomonas syringae pv. tomato DC3000, indicating that P. fluorescens FPT9601-T5 acted as a PGPR on Arabidopsis. To obtain a global view on transcript modification during the Arabidopsis-FPT9601-T5 interaction, we performed microarray analysis using Affymetrix Genechip probe arrays representing approximately 22,800 genes. The results showed that 95 and 105 genes were up- or down-regulated, respectively, more than twofold in FPT9601-T5-treated Arabidopsis plants as compared with control plants. Those up-regulated included genes involved in metabolism, signal transduction, and stress response. Noteworthy, upon FPT9601-T5 colonization, putative auxin-regulated genes and nodulin-like genes were up-regulated, and some ethylene-responsive genes were down-regulated. Our results suggest that P.fluorescens FPT9601-T5 triggered plant responses in a manner similar to known PGPR and, at least in some aspects, to rhizobia.

scholarly journals Identification of Plant Growth Promoting Bacteria Within Space Crop Production Systems

2021 ◽  
Vol 8 ◽  
Author(s):  
David Handy ◽  
Mary E. Hummerick ◽  
Anirudha R. Dixit ◽  
Anna Maria Ruby ◽  
Gioia Massa ◽  
...  
Keyword(s):  
Plant Growth ◽  
Crop Production ◽  
Plant Pathogens ◽  
Life Support ◽  
Production Systems ◽  
Space Station ◽  
Fungal Species ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting

As we establish colonies beyond Earth, resupply missions will become increasingly difficult, logistically speaking, and less frequent. As a result, the on-site production of plants will be mission critical for both food production as well as complementing life support systems. Previous research on space crop production aboard the International Space Station (ISS) has determined that the spaceflight environment, though capable of supporting plant growth, is inherently stressful to plants. The combined stressors of this environment limits yield by inhibiting growth, as well as increasing susceptibility to infection by plant pathogens such as Fusarium spp. We propose that a consortium of space-viable, plant growth-promoting bacteria (PGPB) could assist in mitigating challenges to plant growth in a sustainable fashion. Here, we utilize biochemical and phenotypic assessments to identify potential PGPB derived from previously acquired isolates from the VEGGIE crop production system aboard the ISS. These assays confirmed the presence of bacteria capable of producing and/or interfering with plant hormones, facilitating plant uptake of high-value target nutrients for plants such as iron and phosphorus, and able to inhibit the growth of problematic fungal species. We discuss our findings with regards to their potential to support plant growth aboard spaceflight platforms as well as the Moon and Mars.

scholarly journals Biomass Yield, Nitrogen Content and Uptake, And Nutritive Value of Alfalfa Co-Inoculated with Plant-Growth Promoting Bacteria

2020 ◽  
Vol 8 (5) ◽  
pp. 400-420
Author(s):  
Cecilio Viega Soares Filho ◽  
Leonardo Aurélio Silva ◽  
Jaqueline Silva Boregio ◽  
Mariangela Hungria ◽  
Adônis Moreira ◽  
...  
Keyword(s):  
Plant Growth ◽  
Sinorhizobium Meliloti ◽  
Nutritive Value ◽  
Dry Weight ◽  
N Fertilizer ◽  
Neutral Detergent Fiber ◽  
Plant Growth Promoting Bacteria ◽  
Total N ◽  
Plant Growth Promoting ◽  
Growth Promoting

Alfalfa (Medicago sativa L.) has high forage yield potential, protein quality, palatability, and digestibility, and low seasonality. The aim of this study was to evaluate the effects of strains of Sinorhizobium meliloti and Azospirillum brasilense on the nutritive content, bromatological composition (crude protein [CP], neutral detergent fiber [NDF], acid detergent fiber [ADF], and in vitro digestibility of dry weight [IVDDW]), and shoot dry weight (SDW), relative chlorophyll index (RCI), number of tillers (NT), plant height (PH), and root dry weight (RDW) and volume (RV), of alfalfa grown in a Typic Ultisol. The experiment consisted of eight combinations of plant-growth promoting bacteria (PGPB). The treatments were as follows: T1:non-inoculated control without N-fertilizer (NI); T2: NI + N-fertilizer, and inoculated with T3: Sinorhizobium (=Ensifer) meliloti SEMIA 116 + N-fertilizer; T4: S. meliloti SEMIA 116 + A. brasilense Ab-V5 + Ab-V6 + N-fertilizer; T5: S. meliloti SEMIA 134 + N-fertilizer; T6: S. meliloti SEMIA 134 + co-inoculation + N-fertilizer; T7: S. meliloti SEMIA 135 + N-fertilizer; and T8: S. meliloti SEMIA 135 + co-inoculation + N-fertilizer. S. meliloti strains are used in commercial inoculants for the alfalfa, and A. brasilense for several non-legumes and legumes in Brazil. The experiment was performed for three successive cuts under greenhouse conditions. Application of N-fertilization increases the production cost, making alfalfa cultivation unviable. Inoculation with three strains of Sinorhizobium meliloti highly promoted alfalfa growth, considering several parameters, including PH, RCI, NT, SDW and RDW, nutritive value, and with an emphasis on RV, and total N content and total N accumulated in shoots and roots. No further increases were observed with the co-inoculation with the PGPB A. brasilense. Studies in field and greenhouse conditions are necessary to verify the benefits of the use of PGPB in the cultivation of alfalfa.

scholarly journals Plant growth-promoting bacteria belonging to the genera Pseudomonas and Bacillus improve the growth of sorghum seedings in a low-nutrient soil

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Enriqueta Amora-Lazcano ◽  
Héctor J. Quiroz-González ◽  
Cristofer I. Osornio-Ortega ◽  
Juan A. Cruz-Maya ◽  
Janet Jan-Roblero
Keyword(s):  
Plant Growth ◽  
Growth Parameters ◽  
Dry Weight ◽  
Plant Growth Promoting Bacteria ◽  
Phosphate Solubilizing Bacteria ◽  
Bacterial Strains ◽  
Shoot Dry Weight ◽  
Soil Bioassay ◽  
Plant Growth Promoting ◽  
Growth Promoting

Background: Deficiency in sorghum growth in ecosystems of low-nutrient soils has been scarcely studied. This soil deficiency can be overcome by the addition of plant growth-promoting bacteria which increase sorghum growth. Questions and/or Hypotheses: indole acetic acid (IAA) producing and phosphate solubilizing bacteria can promote sorghum growth under nutritional stress. Studied species: Sorghum bicolor (L.) Moench. Study site and dates: Mexico City, 2018. Methods: Of the twelve bacterial strains utilized, three produce IAA (group BI), two strains produce IAA and siderophores (BIS group), four strains produce IAA and solubilize phosphate (BIP group), and three strains produce IAA, solubilize phosphate, and produce siderophores (BIPS group). Hydroponic bioassays and low-nutrient soil bioassay were used. Results: In hydroponic bioassays, for BI and BIS groups, five strains significantly increased the growth parameters with respect to the control, and for the BIP and BIPS groups, two strains promoted stem development and shoot dry weight. In a low-nutrient soil bioassay, Pseudomonas sp. BI-1 (from BI group) was the one that presented the highest percentages 32, 48, 140 and 79 % in stem diameter, height and dry weight of the shoot and dry weight of the root, respectively, followed by the P. mohnii BIPS-10 strain (from BIPS group) that exhibited similar results. Conclusions: IAA producing Pseudomonas strains improve the sorghum growth in a low-nutrient soil and suggest thatPseudomonas sp. BI-1 and P. mohnii BIPS-10 could be used as potential bioinoculants for sorghum.

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