Dual Microbial Inoculation, a Game Changer? – Bacterial Biostimulants With Multifunctional Growth Promoting Traits to Mitigate Salinity Stress in Spring Mungbean

Soil microbes play a vital role in improving plant growth, soil health, ameliorate biotic/abiotic stress and enhance crop productivity. The present study was aimed to investigate a coordinated effect of compatible consortium [salt tolerating Rhizobium and rhizobacterium with 1-aminocyclopropane-1-carboxylate (ACC) deaminase] in enhancing plant growth promoting (PGP) traits, symbiotic efficiency, nutrient acquisition, anti-oxidative enzymes, grain yield and associated profitability in spring mungbean. We identified a non-pathogenic compatible Rhizobium sp. LSMR-32 (MH644039.1) and Enterococcus mundtii LSMRS-3 (MH644178.1) from salt affected areas of Punjab, India and the same were assessed to develop consortium biofertilizer based on salt tolerance, multifarious PGP traits, antagonistic defense activities and presence of nifH, acds, pqq, and ipdc genes. Indole Acetic acid (IAA), P-solubilization, biofilm formation, exo-polysaccharides, siderophore, salt tolerance, ACC deaminase activities were all found highly significant in dual inoculant (LSMR-32 + LSMRS-3) treatment compared to LSMR-32 alone. Under saline soil conditions, dual inoculant showed a higher seed germination, plant height, biomass, chlorophyll content and macro and micro-nutrient uptake, than un-inoculated control. However, symbiotic (nodulation, nodule biomass and leghaemoglobin content) and soil quality parameters (phosphatase and soil dehydrogenase enzymes) increased numerically with LSMR-32 + LSMRS-3 over Rhizobium sp. LSMR-32 alone. Dual bacterial inoculation (LSMR-32 + LSMRS-3) increased the proline content (2.05 fold), anti-oxidative enzymes viz., superoxide dismutase (1.50 fold), catalase (1.43 fold) and peroxidase (3.88 folds) in contrast to control treatment. Decreased Na+ accumulation and increased K+ uptake resulted in favorable K+/Na+ ratio through ion homeostasis. Co-inoculation of Rhizobium sp. LSMR-32 and Enterococcus mundtii LSMRS-3 significantly improved the grain yield by 8.92% and led to superior B: C ratio over Rhizobium sp. alone under salt stress. To best of our knowledge this is perhaps the first field report from Indian soils that largely describes dual inoculation of Rhizobium sp. LSMR-32 and Enterococcus mundtii LSMRS-3 and the same can be considered as a game-changer approach to simultaneously induce salt tolerance and improve productivity in spring mungbean under saline stress conditions.

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Evaluation of Pseudomonas sp. for its multifarious plant growth promoting potential and its ability to alleviate biotic and abiotic stress in tomato (Solanum lycopersicum) plants

Scientific Reports ◽

10.1038/s41598-020-77850-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Sangeeta Pandey ◽

Shikha Gupta

Keyword(s):

Plant Growth ◽

Seed Treatment ◽

Acc Deaminase ◽

Hydrocyanic Acid ◽

Rrna Gene ◽

Pgp Traits ◽

Tomato Plants ◽

Biochemical Characterisation ◽

Plant Growth Promoting ◽

Growth Promoting

Abstract1-Aminocyclopropane-1-carboxylate (ACC) deaminase activity is one of the most beneficial traits of plant growth promoting (PGP) rhizobacteria responsible for protecting the plants from detrimental effects of abiotic and biotic stress. The strain S3 with ACC deaminase activity (724.56 nmol α-ketobutyrate mg−1 protein hr−1) was isolated from rhizospheric soil of turmeric (Curcuma longa), a medicinal plant, growing in Motihari district of Indian state, Bihar. The halotolerant strain S3, exhibited optimum growth at 8% (w/v) NaCl. It also exhibited multiple PGP traits such as indole acetic acid production (37.71 μg mL−1), phosphate solubilization (69.68 mg L−1), siderophore, hydrocyanic acid (HCN) and ammonia production as well as revealed antagonism against Rhizoctonia solani. The potential of isolated strain to alleviate salinity stress in tomato plants was investigated through pots trials by inoculating strain S3 through-seed bacterization, soil drenching, root dipping as well as seed treatment + soil drenching. The strain S3 inoculated through seed treatment and soil drenching method led to improved morphological attributes (root/shoot length, root/shoot fresh weight and root/shoot dry weight), photosynthetic pigment content, increased accumulation of osmolytes (proline and total soluble sugar), enhanced activities of antioxidants (Catalase and Peroxidase) and phenolic content in salt stressed tomato plants. The biochemical characterisation, FAMEs analysis and 16S rRNA gene sequencing revealed that strain S3 belongs to the genus Pseudomonas. The overall findings of the study revealed that Pseudomonas sp. strain S3 can be explored as an effective plant growth promoter which stimulate growth and improve resilience in tomato plants under saline condition.

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Rhizobacteria containing ACC-deaminase confer salt tolerance in maize grown on salt-affected fields

Canadian Journal of Microbiology ◽

10.1139/w09-092 ◽

2009 ◽

Vol 55 (11) ◽

pp. 1302-1309 ◽

Cited By ~ 104

Author(s):

Sajid Mahmood Nadeem ◽

Zahir Ahmad Zahir ◽

Muhammad Naveed ◽

Muhammad Arshad

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Plant Growth ◽

Ethylene Production ◽

Acc Deaminase ◽

Plant Growth Promoting Rhizobacteria ◽

Growth And Yield ◽

Negative Effect ◽

Plant Growth Promoting ◽

Growth Promoting

Salt stress is one of the major constraints hampering agricultural production owing to its impact on ethylene production and nutritional imbalance. A check on the accelerated ethylene production in plants could be helpful in minimizing the negative effect of salt stress on plant growth and development. Four Pseudomonas , 1 Flavobacterium , and 1 Enterobacter strain of plant growth promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate (ACC)-deaminase were selected and their effects on growth and yield of maize were investigated to improve the salt tolerance of maize grown on salt-affected fields. The selected rhizobacterial isolates reduced or eliminated the classical “triple” response, indicating their ability to reduce stress-induced ethylene levels. Results showed that rhizobacterial strains, particularly Pseudomonas and Enterobacter spp., significantly promoted the growth and yield of maize compared with the non-inoculated control. Pseudomonas fluorescens increased plant height, biomass, cob yield, grain yield, 1000 grain mass, and straw yield of maize up to 29%, 127%, 67%, 60%, 17%, and 166%, respectively, over the control. Under stress conditions, more N, P, and K uptake and high K+–Na+ ratios were recorded in inoculated plants compared with the control. The results imply that inoculation with plant growth promoting rhizobacteria containing ACC-deaminase could be a useful approach for improving growth and yield of maize under salt-stressed conditions.

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Preliminary investigations on inducing salt tolerance in maize through inoculation with rhizobacteria containing ACC deaminase activity

Canadian Journal of Microbiology ◽

10.1139/w07-081 ◽

2007 ◽

Vol 53 (10) ◽

pp. 1141-1149 ◽

Cited By ~ 197

Author(s):

Sajid Mahmood Nadeem ◽

Zahir Ahmad Zahir ◽

Muhammad Naveed ◽

Muhammad Arshad

Keyword(s):

Salt Tolerance ◽

Plant Growth ◽

Pseudomonas Syringae ◽

Acc Deaminase ◽

Salinity Level ◽

Growth And Yield ◽

Total Biomass ◽

Plant Growth Promoting ◽

Salinity Levels ◽

Growth Promoting

Twenty rhizobacterial strains containing 1-aminocyclopropane-1-carboxylate deaminase were isolated from the rhizosphere of salt-affected maize fields. They were screened for their growth-promoting activities under axenic conditions at 1, 4, 8, and 12 dS·m–1salinity levels. Based upon the data of the axenic study, the 6 most effective strains were selected to conduct pot trials in the wire house. Besides one original salinity level (1.6 dS·m–1), 3 other salinity levels (4, 8, and 12 dS·m–1) were maintained in pots and maize seeds inoculated with selected strains of plant growth-promoting rhizobacteria, as well as uninoculated controls were sown. Results showed that the increase in salinity level decreased the growth of maize seedlings. However, inoculation with rhizobacterial strains reduced this depression effect and improved the growth and yield at all the salinity levels tested. Selected strains significantly increased plant height, root length, total biomass, cob mass, and grain yield up to 82%, 93%, 51%, 40%, and 50%, respectively, over respective uninoculated controls at the electrical conductivity of 12 dS·m–1. Among various plant growth-promoting rhizobacterial strains, S5 ( Pseudomonas syringae ), S14 ( Enterobacter aerogenes ), and S20 ( Pseudomonas fluorescens ) were the most effective strains for promoting the growth and yield of maize, even at high salt stress. The relatively better salt tolerance of inoculated plants was associated with a high K+/Na+ratio as well as high relative water and chlorophyll and low proline contents.

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Inoculation of native symbiotic effective Sinorhizobium spp. enhanced soybean [Glycine max (L.) Merr.] grain yield in Ethiopia

ENVIRONMENTAL SYSTEMS RESEARCH ◽

10.1186/s40068-020-00205-1 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Diriba Temesgen ◽

Fassil Assefa

Keyword(s):

Glycine Max ◽

Plant Growth ◽

Grain Yield ◽

Phenotypic Variability ◽

Computer Software ◽

Field Trials ◽

Soybean Plant ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting

Abstract Background Soybean [Glycine max (L) Merr.] is an annual leguminous crop serving as a source of food and feed, green manure, biodiesel and fiber. It is nodulated by diverse slow growing and fast growing rhizobia belonging to the genus Bradyrhizobium and Sinorhizobium, respectively. In Ethiopia, it has been cultivated since 1950s with lower grain yield history. Yield improvement efforts have been more concentrated on agronomic studies, inoculation of exotic Bradyrhizobium japonicum including TAL379 and/or fertilizer application. The results have usually been unsatisfactory and inconsistent. This study was initiated to identify promising indigenous soybean rhizobial inoculant that can enhance yield of the crop in the country. Methods Native soybean rhizobia, designated GMR for Glycine max rhizobia, were trapped using soybean (cv. Ethio-Yugoslavia) from soils collected across agro-ecologies of Ethiopia. They were screened for in vitro tolerance against physico-chemical stresses, plant growth promoting (PGP) traits and symbiotic performances at greenhouse and field levels. A reference B. japonicum (TAL379) was included in all experiments. A soybean plant growth promoting Achromobacter sp. was also included in field trials for co-inoculation. Quantitative data were assessed by analysis of variance (ANOVA) employing SAS computer software package version 9.3. Mean separations were undertaken using Duncan’s Multiple Range Test at p ≤ 0.05. Phenotypic variability of the test bacteria was undertaken using PAST4.03 Computer Software. Result GMR that produced acid and grew faster with larger colonies were identified as Sinorhizobium spp. and those which produced alkali and grew slowly with smaller colonies were identified as Bradyrhizobium spp. though further genetic analysis should be performed for verification and identification of their genus and species, respectively. Two Sinorhizobium spp. (GMR120C and GMR125B) profoundly nodulated different soybean cultivars under greenhouse conditions and significantly improved grain yield (p ≤ 0.05; maximum 3.98 tons ha−1) compared to 2.41, 2.82 and 2.69 recorded as maximum grain yield (tons ha−1) for TAL379 inoculation, positive control and negative control, respectively in field trials. Higher yield was recorded when GMR125B was co-inoculated with Achromobacter sp., but when GMR120C was inoculated singly. These GMR also showed efficient utilization of numerous substrates, some PGP traits and potential adaptation to various ecological stresses. Conclusion The two Sinorhizobium spp. (GMR120C and GMR125B) are promising soybean inoculants that can be used to enhance the productivity of the crop in the country.

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Inducing salt tolerance in mung bean through coinoculation with rhizobia and plant-growth-promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate deaminase

Canadian Journal of Microbiology ◽

10.1139/w11-044 ◽

2011 ◽

Vol 57 (7) ◽

pp. 578-589 ◽

Cited By ~ 119

Author(s):

Maqshoof Ahmad ◽

Zahir A. Zahir ◽

H. Naeem Asghar ◽

M. Asghar

Keyword(s):

Salt Tolerance ◽

Plant Growth ◽

Pseudomonas Fluorescens ◽

Mung Bean ◽

Acc Deaminase ◽

Plant Growth Promoting Rhizobacteria ◽

Saline Stress ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Axenic Conditions

Twenty-five strains of plant-growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and 10 strains of rhizobia were isolated from rhizosphere soil samples and nodules of mung bean. They were screened in separate trials under salt-stressed axenic conditions. The three most effective strains of PGPR (Mk1, Pseudomonas syringae ; Mk20, Pseudomonas fluorescens ; and Mk25, Pseudomonas fluorescens biotype G) and Rhizobium phaseoli strains M1, M6, and M9 were evaluated in coinoculation for their growth-promoting activity at three salinity levels (original, 4 dS·m–1, and 6 dS·m–1) under axenic conditions. The results showed that salinity stress significantly reduced plant growth but inoculation with PGPR containing ACC deaminase and rhizobia enhanced plant growth, thus reducing the inhibitory effect of salinity. However, their combined application was more effective under saline conditions, and the combination Mk20 × M6 was the most efficient for improving seedling growth and nodulation. The effect of high ethylene concentrations on plant growth and the performance of these strains for reducing the negative impact of saline stress was also evaluated by conducting a classical triple-response bioassay. The intensity of the classical triple response decreased owing to inoculation with these strains, with the root and shoot lengths of inoculated mung bean seedlings increasing and stem diameter decreasing, which is a typical response to the dilution in a classical triple response bioassay. Thus, coinoculation with PGPR containing ACC deaminase and Rhizobium spp. could be a useful approach for inducing salt tolerance and thus improving growth and nodulation in mung bean under salt-affected conditions.

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Salinity Stress: Toward Sustainable Plant Strategies and Using Plant Growth-Promoting Rhizobacteria Encapsulation for Reducing It

Sustainability ◽

10.3390/su132212758 ◽

2021 ◽

Vol 13 (22) ◽

pp. 12758

Author(s):

Roohallah Saberi Riseh ◽

Marzieh Ebrahimi-Zarandi ◽

Elahe Tamanadar ◽

Mojde Moradi Pour ◽

Vijay Kumar Thakur

Keyword(s):

Salt Tolerance ◽

Plant Growth ◽

Ion Homeostasis ◽

Acc Deaminase ◽

Plant Growth Promoting Rhizobacteria ◽

Crop Productivity ◽

Nutrient Mobilization ◽

Hormonal Stimulation ◽

Plant Growth Promoting ◽

Growth Promoting

Salinity is one of the most important abiotic stresses that influences plant growth and productivity worldwide. Salinity affects plant growth by ionic toxicity, osmotic stress, hormonal imbalance, nutrient mobilization reduction, and reactive oxygen species (ROS). To survive in saline soils, plants have developed various physiological and biochemical strategies such as ion exchange, activation of antioxidant enzymes, and hormonal stimulation. In addition to plant adaption mechanisms, plant growth-promoting rhizobacteria (PGPR) can enhance salt tolerance in plants via ion homeostasis, production of antioxidants, ACC deaminase, phytohormones, extracellular polymeric substance (EPS), volatile organic compounds, accumulation of osmolytes, activation of plant antioxidative enzymes, and improvement of nutrients uptake. One of the important issues in microbial biotechnology is establishing a link between the beneficial strains screened in the laboratory with industry and the consumer. Therefore, in the development of biocontrol agents, it is necessary to study the optimization of conditions for mass reproduction and the selection of a suitable carrier for their final formulation. Toward sustainable agriculture, the use of appropriate formulations of bacterial agents as high-performance biofertilizers, including microbial biocapsules, is necessary to improve salt tolerance and crop productivity.

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Inoculation of Native Symbiotic Effective Sinorhizobium Spp. Enhanced Soybean [Glycine Max (L) Merr.] Grain Yield in Ethiopia

10.21203/rs.3.rs-71397/v1 ◽

2020 ◽

Author(s):

Diriba Temesgen Dagaga ◽

Fassil Assefa Tuji

Keyword(s):

Glycine Max ◽

Plant Growth ◽

Grain Yield ◽

Field Trials ◽

Soybean Plant ◽

Pgp Traits ◽

Soybean Rhizobia ◽

Plant Growth Promoting ◽

Growth Promoting

Abstract BackgroundSoybean [Glycine max (L) Merr.] is an annual leguminous crop serving as a source of food and feed, green manure, biodiesel and fiber It is nodulated by diverse slow growing and fast growing rhizobia belonging to the genus Bradyrhizobium and Sinorhizobium, respectively. In Ethiopia, it has been cultivated since 1950s with lower grain yield history. Yield improvement efforts have been more concentrated on agronomic studies, inoculation of exotic Bradyrhizobium japonicum including TAL379 and/or fertilizer application. The results have usually been unsatisfactory and inconsistent. This study was initiated to identify promising indigenous soybean rhizobial inoculant that can enhance yield of the crop in the country.Methods Native soybean rhizobia, designated GMR for Glycine max rhizobia, were trapped using soybean (cv. Ethio-Yugoslavia) from soils collected across agro-ecologies of Ethiopia. Indigenous soybean rhizobia were screened for in vitro tolerance against physico-chemical stresses, plant growth promoting (PGP) traits and symbiotic performances at greenhouse and field levels A reference B. japonicum (TAL379) was included in all experiments. A soybean plant growth promoting Achromobacter sp. was also included in field trials for co-inoculation. Quantitative data were assessed by analysis of variance (ANOVA) employing SAS computer software package version 9.3. Mean separations were undertaken using the Duncan’s Multiple Range Test at p≤0.05.Result GMR that produced acid and grew faster with larger colonies were identified as Sinorhizobium spp. and those which produced alkali and grew slowly with smaller colonies were identified as Bradyrhizobium spp though further genetic analysis should be performed for verification and identification of their genus and species, respectively. Two Sinorhizobium spp (GMR120C and GMR125B) profoundly nodulated different soybean cultivars under greenhouse conditions and significantly improved grain yield (p≤0.05; maximum 3.98 tons ha-1) compared to 2.41, 2.82 and 2.69 recorded as maximum grain yield (tons ha-1) for TAL379 inoculation, positive control and negative control, respectively in field trials. Higher yield was recorded when GMR125B was coinoculated with Achromobacter sp., but when GMR120C was inoculated singly. These GMR also showed efficient utilization of numerous substrates, some PGP traits and potential adaptation to various ecological stresses. Conclusion The two Sinorhizobium spp. (GMR120C and GMR125B) are promising soybean inoculants that can be used to enhance the productivity of the crop in the country.

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Evaluation of ACC-deaminase-producing rhizobacteria to alleviate water-stress impacts in wheat (Triticum aestivum L.) plants

Canadian Journal of Microbiology ◽

10.1139/cjm-2018-0636 ◽

2019 ◽

Vol 65 (5) ◽

pp. 387-403 ◽

Cited By ~ 17

Author(s):

Dinesh Chandra ◽

Rashmi Srivastava ◽

Vadakattu V.S.R. Gupta ◽

Christopher M.M. Franco ◽

Anil Kumar Sharma

Keyword(s):

Triticum Aestivum ◽

Water Stress ◽

Plant Growth ◽

Acc Deaminase ◽

Triticum Aestivum L ◽

Stress Conditions ◽

Nutrient Concentrations ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting

Application of plant-growth-promoting rhizobacteria (PGPR) is an environmentally sustainable option to reduce the effects of abiotic and biotic stresses on plant growth and productivity. Bacteria isolated from rain-fed agriculture field soils in the Central Himalaya Kumaun region, India, were evaluated for the production of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. Those producing ACC deaminase in high amounts were evaluated for their potential to improve wheat (Triticum aestivum L.) plant growth under irrigated and water-stress conditions in two glasshouse experiments. Some of the isolates also showed other plant-growth-promoting (PGP) traits, e.g., N2 fixation, siderophore production, and phosphate solubilization; however, strains with higher ACC deaminase activity showed the greatest effects. These were Variovorax paradoxus RAA3; Pseudomonas spp. DPC12, DPB13, DPB15, DPB16; Achromobacter spp. PSA7, PSB8; and Ochrobactrum anthropi DPC9. In both simulated irrigated and water-stress conditions, a single inoculation of RAA3 and a consortium of DPC9 + DPB13 + DPB15 + DPB16 significantly improved wheat plant growth and foliar nutrient concentrations and caused significant positive changes in antioxidant properties compared with noninoculated plants especially under water stress. These findings imply that PGPB having ACC deaminase activity together with other PGP traits could potentially be effective inoculants to improve the growth of wheat plants in water-stressed rain-fed environments.

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Isolasi dan Karakterisasi Bakteri Tanah Sawah di Kecamatan Medan Satria dan Bekasi Utara, Kota Bekasi, Jawa Barat

JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI ◽

10.36722/sst.v3i4.233 ◽

2017 ◽

Vol 3 (4) ◽

pp. 187 ◽

Cited By ~ 1

Author(s):

Arief Pambudi ◽

Nita Noriko ◽

Endah Permata Sari

Keyword(s):

Plant Growth ◽

Soil Bacteria ◽

Rice Field ◽

Plant Growth Promoting Rhizobacteria ◽

Fertilizer Application ◽

Rice Production ◽

Production Costs ◽

Soil Conditions ◽

Nitrogen Fixation Activity ◽

Growth Promoting

Abstrak - Produksi padi di Indonesia setiap tahun mengalami peningkatan, namun peningkatan ini belum mampu memenuhi kebutuhan nasional sehingga impor masih harus dilakukan. Salah satu masalah dalam produksi beras adalah penggunaan pupuk berlebih yang tidak hanya meningkatkan biaya produksi, namun juga merusak kondisi tanah. Aplikasi bakteri tanah sebagai Plant Growth Promoting Rhizobacteria (PGPR) dapat menjadi salah satu solusi terhadap masalah ini. Penelitian ini bertujuan untuk mengisolasi bakteri tanah dari 3 lokasi sawah daerah Bekasi, membandingkan keberadaan total bakteri pada ketiga lokasi tersebut, dan melakukan karakterisasi isolat berdasarkan karakter yang dapat memicu pertumbuhan tanaman. Dari ketiga lokasi, diperoleh total 59 isolat dan 5 diantaranya berpotensi sebagai PGPR karena kemampuan fiksasi Nitrogen, melarutkan Fosfat, katalase positif, dan motil. Dari ketiga lokasi pengambilan sampel, BK1 memiliki jumlah total bakteri terendah karena aplikasi pemupukan dan pestisida berlebih yang ditandai tingginya kadar P total, serta tingginya residu klorpirifos, karbofuran, dan paration. Kondisi fisik tanah BK1 juga didominasi partikel liat yang menyebabkan tanah menjadi lebih padat. Peningkatan jumlah penggunaan pupuk tidak selalu diikuti peningkatan produktivitas tanaman. Kata Kunci - Bakteri tanah, Rhizosfer sawah, PGPR, Pupuk Hayati Abstract - Rice production in Indonesia has increased annually, but this increase has not reached national demand,so imports still done. One of the problems in rice production is the use of excessive fertilizers that not only increase production costs, but also decreased the soil conditions. The application of soil bacteria as Plant Growth Promoting Rhizobacteria (PGPR) can be the one solution to face this problem. The objective of this study was isolate soil bacteria from 3 locations of rice field in Bekasi, compare the total bacteria in the three locations, and characterize isolates based on the character that can promote plant growth. From three locations, a total of 59 isolates were obtained and 5 of them were potential as a PGPRs due to its Nitrogen fixation activity, Phosphate solubilization, positive catalase, and motility. From three sampling sites, BK1 has the lowest TPC value because of excessive fertilizers and pesticides application which indicated by high total P levels, and also high chlorpyrifos, carbofuran and paration residues. The physical condition of BK1 soil is also dominated by clay particles which causes the soil more solid. Increasing of fertilizer application is not always followed by increased plant productivity. Keywords - Biofertilizer, PGPR, Rice field rhizosphere, Soil Bacteria

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