Rhizobacteria AK1 remediates the toxic effects of salinity stress via regulation of endogenous phytohormones and gene expression in soybean

2019 ◽  
Vol 476 (16) ◽  
pp. 2393-2409 ◽  
Author(s):  
Muhammad Aaqil Khan ◽  
Sajjad Asaf ◽  
Abdul Latif Khan ◽  
Rahmatullah Jan ◽  
Sang-Mo Kang ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Salinity Stress ◽  
Inductively Coupled Plasma ◽  
Antioxidant Activities ◽  
Nacl Stress ◽  
Rhizospheric Bacteria ◽  
Plant Growth Promoting ◽  
Soybean Plants ◽  
Phosphate Solubilizing

Abstract Salinity stress adversely affects the growth and productivity of different crops. In the present study, we isolated the rhizospheric bacteria Arthrobacter woluwensis AK1 from Pohang beach, South Korea and determined its plant growth-promoting potential under NaCl salt stress (0, 100, and 200 mM). AK1 has phosphate-solubilizing activity and produce siderophores, organic acids, and phytohormones such as gibberellic acid (GA) and indole-3-acetic acid (IAA) that significantly alleviate sodium chloride (NaCl) stress and increase all plant growth attributes. Furthermore, inoculation of AK1 significantly decreased endogenous abscisic acid (ABA) content, extensively regulated the antioxidant activities and mitigated NaCl stress. Similarly, inductively coupled plasma mass spectrometry results showed that soybean plants inoculated with AK1 significantly decreased the amount of sodium (Na+) uptake during NaCl stress after 6 and 12 days. Four genes, auxin resistant 1 (GmLAX1), potassium channel AKT2 (GmAKT2), soybean salt tolerance 1 (GmST1), and salt tolerance-associated gene on chromosome 3 (GmSALT3) were up-regulated, while two genes chloride channel gene (GmNHX1) and Na+/H+ antiporter (GmCLC1) were down-regulated in soybean AK1treated plants. In conclusion, AK1 can mitigate salinity stress, increase plant growth and could be utilized as an eco-friendly bio-fertilizer under salinity stress.

scholarly journals Plant growth promoting Bipolaris sp. CSL-1 mitigate salinity stress in soybean via altering endogenous phytohormonal level, antioxidants and genes expression

2020 ◽  
Author(s):  
Lubna Lubna ◽  
Muhammad Aaqil Khan ◽  
Sajjad Asaf ◽  
Rehmatullah Jan ◽  
Muhammad Waqas ◽  
...  
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Low Cost ◽  
Dry Weight ◽  
Nacl Stress ◽  
Fungal Isolate ◽  
Pgp Traits ◽  
Biotechnological Approach ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Background Salinity stress is one of the most devastating environmental stress that inhibits plants growth and development. Many strategies including plant growth promoting fungi have been reported to mitigate salt stress. Results In this study, we adopted environmental friendly technique and screened different plant growth promoting fungi for different PGP traits and salinity stress. Among these isolate CSL1 were selected based on the basis of plant growth promoting characteristics producing IAA, GAs, organic acid and tolerance to NaCl stress. Furthermore, inoculation of fungal isolate CSL1 significantly increased shoot length (16%), root length (37%), shoot fresh and dry weight (19% and 25%), root fresh and dry weight (47 and 51%) and chlorophyll content (24%) under NaCl stress (200 mM). Endogenous ABA level (0.77 folds) were significantly decreased while SA contents (16%) were increase in CSL1 inoculated plants under NaCl stress. Similarly, higher level of antioxidants such as MDA (2 folds), SOA (29%), POD (8 folds) and PPO (3 folds) was observed in NaCl treated non-inoculated plants. ICP analysis showed an increase in Na+ (11 folds) and decrease in K+ content (15%). Furthermore, CSL-1 inoculation improved soybean adaptability against NaCl stress and a significant decrease in GmFDL19 expression (5 folds) GmNARK (4 folds) and GmSIN1 (3 folds) was observed. However, higher expression of GmAKT2 (15%) were observed in CSL-1 treated plants. Conclusion Fungal isolate CSL-1 have capability to mitigate salinity stress in soybean, increase plant growth and could be used as valuable ecofriendly microorganism resource, low cost based biotechnological approach for sustainable agriculture in salt affected areas.

scholarly journals Halotolerant Rhizobacterial Strains Mitigate the Adverse Effects of NaCl Stress in Soybean Seedlings

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Aaqil Khan ◽  
Sajjad Asaf ◽  
Abdul Latif Khan ◽  
Arjun Adhikari ◽  
Rahmatullah Jan ◽  
...  
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Nacl Stress ◽  
Ion Concentration ◽  
Oenothera Biennis ◽  
Artemisia Princeps ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Soybean Plants ◽  
Plant Growth Promoting Traits

Background. Salinity is one of the major abiotic constraints that hinder health and quality of crops. Conversely, halotolerant plant growth-promoting rhizospheric (PGPR) bacteria are considered biologically safe for alleviating salinity stress. Results. We isolated halotolerant PGPR strains from the rhizospheric soil of Artemisia princeps, Chenopodium ficifolium, Echinochloa crus-galli, and Oenothera biennis plants; overall, 126 strains were isolated. The plant growth-promoting traits of these isolates were studied by inoculating them with the soil used to grow soybean plants under normal and salt stress (NaCl; 200 mM) conditions. The isolates identified as positive for growth-promoting activities were subjected to molecular identification. Out of 126 isolates, five strains—Arthrobacter woluwensis (AK1), Microbacterium oxydans (AK2), Arthrobacter aurescens (AK3), Bacillus megaterium (AK4), and Bacillus aryabhattai (AK5)—were identified to be highly tolerant to salt stress and demonstrated several plant growth-promoting traits like increased production of indole-3-acetic acid (IAA), gibberellin (GA), and siderophores and increased phosphate solubilization. These strains were inoculated in the soil of soybean plants grown under salt stress (NaCl; 200 mM) and various physiological and morphological parameters of plants were studied. The results showed that the microbial inoculation elevated the antioxidant (SOD and GSH) level and K+ uptake and reduced the Na+ ion concentration. Moreover, inoculation of these microbes significantly lowered the ABA level and increased plant growth attributes and chlorophyll content in soybean plants under 200 mM NaCl stress. The salt-tolerant gene GmST1 was highly expressed with the highest expression of 42.85% in AK1-treated plants, whereas the lowest expression observed was 13.46% in AK5-treated plants. Similarly, expression of the IAA regulating gene GmLAX3 was highly depleted in salt-stressed plants by 38.92%, which was upregulated from 11.26% to 43.13% upon inoculation with the microorganism. Conclusion. Our results showed that the salt stress-resistant microorganism used in these experiments could be a potential biofertilizer to mitigate the detrimental effects of salt stress in plants via regulation of phytohormones and gene expression.

scholarly journals Silicon and Plant Growth-Promoting Rhizobacteria Pseudomonas psychrotolerans CS51 Mitigates Salt Stress in Zea mays L.

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 272
Author(s):  
Happy Anita Appiah Kubi ◽  
Muhammad Aaqil Khan ◽  
Arjun Adhikari ◽  
Muhammad Imran ◽  
Sang-Mo Kang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Salinity Stress ◽  
Nacl Stress ◽  
Luria Bertani ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Maize Plants ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Salinity is a significant abiotic stress for crop plants and a threat to global food security. Optimizing yield without adversely affecting the ecosystem is necessary for a sustainable agriculture. Silicon and plant growth-promoting bacteria were reported for mitigating several abiotic and biotic stress in plants. In our study, we identified the salt-tolerant rhizobacterium Pseudomonas psychrotolerans CS51. This species produces several plant-growth-promoting biochemicals like indole-3-acetic acid (33 ± 1.8 ng/mL) and gibberellic acid (GA3; 38 ± 1.3 and GA4; 23 ± 1.2 ng/mL) in Luria-Bertani(LB) media, and LB media spiked with 200 mM NaCl (indole-3-acetic acid(IAA); 17.6 ± 0.4 ng/mL, GA3; 21 ± 0.9 and GA4; 19 ± 1.0 ng/mL). In the current study, we aimed to investigate the effect of isolate CS51 and exogenous silicon (3 mM) on maize under salinity stress (200 mM). Our results showed that the sole application of isolate CS51, Si, and combined CS51 + Si significantly enhanced maize biomass and chlorophyll content under normal and salinity stress. Phytohormonal results showed that salinity stress increased abscisic acid (ABA; three folds) and jasmonic acid (JA; 49.20%). However, the sole and combined isolate CS51 + Si application markedly reduced ABA (1.5 folds) and JA content (14.89%). Besides, the sole and isolate CS51 + Si co-application strengthened the antioxidant system, such as flavonoid (97%) and polyphenol (19.64%), and lowered the proline content (57.69%) under NaCl stress. Similarly, the CS51 and Si inoculation (solely or combined) significantly enhanced the Si uptake (4 folds) and reduced the Na+ uptake (42.30%) in maize plants under NaCl stress. In conclusion, the current finding suggests that combining CS51 with Si can be used against salinity stress in maize plants and may be commercialized as a biofertilizer.

scholarly journals PGPR Characteristics of Rhizospheric Bacteria to Understand the Mechanisms of Faba Bean Growth

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 27
Author(s):  
Rim Tinhinen Maougal ◽  
Maya Kechid ◽  
Chaima Ladjabi ◽  
Abdelhamid Djekoun
Keyword(s):  
Plant Growth ◽  
Faba Bean ◽  
Biochemical Characterization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Rhizospheric Bacteria ◽  
Plant Growth Promoting ◽  
Pgpr Traits ◽  
Taxonomic Groups ◽  
High Degree

Rhizobacteria play an important role in maintaining soil balance. Among these bacteria, there are those taht have shown their ability to promote the growth of plants, known as Plant Growth Promoting Rhizobacteria (PGPR). In our work, we are interested in characterizing 110 bacterial strains isolated in the field in the region of Ben Badis (Constantine Algeria) from 5 varieties of faba bean. Phenotypic and biochemical characterization showed that most of the isolates are cream-colored, slightly raised, flat and opaque, Gram−, catalase+ and oxidase−, and Bacillus form. PCA analysis allowed us to select 40 isolates with a high degree of variability to continue our work. The results obtained have directed us towards different taxonomic groups (rhizobium, Pseudomonas, Bacillus etc.). The evaluation of the PGPR potential of bacteria (phytostimulation, biofertilization and biocontrol), showed that 100% of bacteria are able to produce auxin at different concentrations, with the highest concentration (177.77 µg/mL) for the isolate 6, and that more than 50% of isolates are capable of producing nitrogen, ammonia and phytate mineralization. These PGPR traits have a direct effect on plant growth of five varieties of the faba bean and can be used to select the best performing bacteria for inoculation tests.

scholarly journals Genome Insights into the Novel Species Jejubacter calystegiae, a Plant Growth-Promoting Bacterium in Saline Conditions

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 24
Author(s):  
Ling Min Jiang ◽  
Yong Jae Lee ◽  
Ho Le Han ◽  
Myoung Hui Lee ◽  
Jae Cheol Jeong ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Novel Species ◽  
Endophytic Bacterium ◽  
Morning Glory ◽  
Plant Growth Promoting Bacteria ◽  
Illumina Hiseq ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Sequencing Platforms

Jejubacter calystegiae KSNA2T, a moderately halophilic, endophytic bacterium isolated from beach morning glory (Calystegia soldanella), was determined to be a novel species in a new genus in the family Enterobacteriaceae. To gain insights into the genetic basis of the salinity stress response of strain KSNA2T, we sequenced its genome using two complementary sequencing platforms (Illumina HiSeq and PacBio RSII). The genome contains a repertoire of metabolic pathways, such as those for nitrogen, phosphorus, and some amino acid metabolism pathways. Functional annotation of the KSNA2T genome revealed several genes involved in salt tolerance pathways, such as those encoding sodium transporters, potassium transporters, and osmoprotectant enzymes. Plant growth-promoting bacteria-based experiments indicated that strain KSNA2T promotes the germination of vegetable seeds in saline conditions. Overall, the genetic and biological analyses of strain KSNA2T provide valuable insights into bacteria-mediated salt tolerance in agriculture.

scholarly journals Multi-Trait Wheat Rhizobacteria from Calcareous Soil with Biocontrol Activity Promote Plant Growth and Mitigate Salinity Stress

2021 ◽  
Vol 9 (8) ◽  
pp. 1588
Author(s):  
Anastasia Venieraki ◽  
Styliani N. Chorianopoulou ◽  
Panagiotis Katinakis ◽  
Dimitris L. Bouranis
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Calcareous Soil ◽  
In Vitro Studies ◽  
Pgp Traits ◽  
Biocontrol Activity ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Microbial Fertilizers

Plant growth promoting rhizobacteria (PGPR) can be functional microbial fertilizers and/or biological control agents, contributing to an eco-spirit and safe solution for chemical replacement. Therefore, we have isolated rhizospheric arylsulfatase (ARS)-producing bacteria, belonging to Pseudomonas and Bacillus genus, from durum wheat crop grown on calcareous soil. These isolates harbouring plant growth promoting (PGP) traits were further evaluated in vitro for additional PGP traits, including indole compounds production and biocontrol activity against phytopathogens, limiting the group of multi-trait strains to eight. The selected bacterial strains were further evaluated for PGP attributes associated with biofilm formation, compatibility, salt tolerance ability and effect on plant growth. In vitro studies demonstrated that the multi-trait isolates, Bacillus (1.SG.7, 5.SG.3) and Pseudomonas (2.SG.20, 2.C.19) strains, enhanced the lateral roots abundance and shoots biomass, mitigated salinity stress, suggesting the utility of beneficial ARS-producing bacteria as potential microbial fertilizers. Furthermore, in vitro studies demonstrated that compatible combinations of multi-trait isolates, Bacillus sp. 1.SG.7 in a mixture coupled with 5.SG.3, and 2.C.19 with 5.SG.3 belonging to Bacillus and Pseudomonas, respectively, may enhance plant growth as compared to single inoculants.

First insights into salt tolerance improvement of Stevia by plant growth-promoting Streptomyces species

2019 ◽  
Vol 201 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Sahar T. M. Tolba ◽  
Mohamed Ibrahim ◽  
Essam A. M. Amer ◽  
Doaa A. M. Ahmed
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Streptomyces Species ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Tolerance Improvement

Interactive effect of biochar and plant growth-promoting bacterial endophytes on ameliorating salinity stress in maize

2015 ◽  
Vol 42 (8) ◽  
pp. 770 ◽  
Author(s):  
Saqib Saleem Akhtar ◽  
Mathias Neumann Andersen ◽  
Muhammad Naveed ◽  
Zahir Ahmad Zahir ◽  
Fulai Liu
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Crop Production ◽  
Interactive Effect ◽  
Nutrient Balance ◽  
Bacterial Strains ◽  
Negative Effects ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Salt Affected Soils

The objective of this work was to study the interactive effect of biochar and plant growth-promoting endophytic bacteria containing 1-aminocyclopropane-1-carboxylate deaminase and exopolysaccharide activity on mitigating salinity stress in maize (Zea mays L.). The plants were grown in a greenhouse under controlled conditions, and were subjected to separate or combined treatments of biochar (0% and 5%, w/w) and two endophytic bacterial strains (Burkholderia phytofirmans (PsJN) and Enterobacter sp. (FD17)) and salinity stress. The results indicated that salinity significantly decreased the growth of maize, whereas both biochar and inoculation mitigated the negative effects of salinity on maize performance either by decreasing the xylem Na+ concentration ([Na+]xylem) uptake or by maintaining nutrient balance within the plant, especially when the two treatments were applied in combination. Moreover, in biochar-amended saline soil, strain FD17 performed significantly better than did PsJN in reducing [Na+]xylem. Our results suggested that inoculation of plants with endophytic baterial strains along with biochar amendment could be an effective approach for sustaining crop production in salt-affected soils.

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