scholarly journals Isolation and Characterization of Salt Tolerant Endophytic and Rhizospheric Plant Growth-Promoting Bacteria (PGPB) Associated with the Halophyte Plant (Sesuvium Verrucosum) Grown in KSA

2015 ◽  
Vol 3 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Mohamed A.M. El-Awady ◽  
Mohamed M. Hassan ◽  
Yassin M. Al-Sodany

This study was designed to isolate and characterize endophytic and rhizospheric bacteria associated with the halophyte plant Sesuvium verrucosum, grown under extreme salinity soil in Jeddah, Saudi Arabia. The plant growth promotion activities of isolated bacterial were evaluated in vitro. A total of 19 salt tolerant endophytic and rhizospheric bacterial isolates were obtained and grouped into six according to genetic similarity based on RAPD data. These six isolates were identified by amplification and partial sequences of 16S rDNA as Enterobacter cancerogenus,Vibrio cholerae, Bacillus subtilis, Escherichia coli and two Enterobacter sp. Isolates were then grown until exponential growth phase to evaluate the atmospheric nitrogen fixation, phosphate solubilization, and production of phytohormones such as indole-3-acetic acid, as well as 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. While, All of the six strains were negative for ACC deaminaseactivity, two isolates showed Nitrogen fixation activity, three isolates produce the plant hormone (Indole acetic acid) and two isolates have the activity of solubiliztion of organic phosphate. Among the six isolates, the isolate (R3) from the soil around the roots is able to perform the three previous growth promoting possibilities together and it is ideal for use in promoting the growth of plants under the high salinity conditions. This isolate is candidate to prepare a friendly biofertelizer that can be used for the improvement of the crops performance under salinity conditions.Int J Appl Sci Biotechnol, Vol 3(3): 552-560

2021 ◽  
Vol 9 (1) ◽  
pp. 91
Author(s):  
Sandra Cortés-Patiño ◽  
Christian Vargas ◽  
Fagua Álvarez-Flórez ◽  
Ruth Bonilla ◽  
German Estrada-Bonilla

Plant growth-promoting bacteria (PGPB) can mitigate the effect of abiotic stresses on plant growth and development; however, the degree of plant response is host-specific. The present study aimed to assess the growth-promoting effect of Herbaspirillum (AP21, AP02), Azospirillum (D7), and Pseudomonas (N7) strains (single and co-inoculated) in perennial ryegrass plants subjected to drought. The plants were grown under controlled conditions and subjected to water deficit for 10 days. A significant increase of approximately 30% in dry biomass production was observed using three co-inoculation combinations (p < 0.01). Genomic analysis enabled the detection of representative genes associated with plant colonization and growth promotion. In vitro tests revealed that all the strains could produce indolic compounds and exopolysaccharides and suggested that they could promote plant growth via volatile organic compounds. Co-inoculations mostly decreased the in vitro-tested growth-promoting traits; however, the co-inoculation of Herbaspirillum sp. AP21 and Azospirillum brasilense D7 resulted in the highest indolic compound production (p < 0.05). Although the Azospirillum strain showed the highest potential in the in vitro and in silico tests, the plants responded better when PGPB were co-inoculated, demonstrating the importance of integrating in silico, in vitro, and in vivo assessment results when selecting PGPB to mitigate drought stress.


2018 ◽  
Author(s):  
Xiaohui Wang ◽  
Changdong Wang ◽  
Chao Ji ◽  
Qian Li ◽  
Jiamiao Zhang ◽  
...  

AbstractBacillus amyloliquefaciens subsp. plantarum XH-9 is a plant-beneficial rhizobacterium that shows good antagonistic potential against phytopathogens by releasing diffusible and volatile antibiotics, and secreting hydrolytic enzymes. Furthermore, the XH-9 strain possesses important plant growth-promoting characteristics, including nitrogen fixation (7.92 ± 1.05 mg/g), phosphate solubilization (58.67 ± 4.20 μg/L), potassium solubilization (10.07 ± 1.26 μg/mL), and the presence of siderophores (4.92 ± 0.46 μg/mL), indole-3-acetic acid (IAA) (7.76 ± 0.51 μg/mL) and 1-aminocyclopropane-1-carboxylic acid deaminase (ACC-deaminase) (4.67 ± 1.21 nmol/[mg•h]). Moreover, the XH-9 strain showed good capacities for wheat, corn, and chili root colonization, which are critical prerequisites for controlling soil-borne diseases as a bio-control agent. Real-time quantitative polymerase chain reaction experiments showed that the amount of Fusarium oxysporum DNA associated with the XH-9 strain after treatment significantly decreased compared with control group. Accordingly, wheat plants inoculated with the XH-9 strain showed significant increases in the plant shoot heights (14.20%), root lengths (32.25%), dry biomass levels (11.93%), and fresh biomass levels (16.28%) relative to the un-inoculated plants. The results obtained in this study suggest that the XH-9 strain has potential as plant-growth promoter and biocontrol agent when applied in local arable land to prevent damage caused by F. oxysporum and other phytopathogens.ImportancePlant diseases, particularly soilborne pathogens, play a significant role in the destruction of agricultural resources. Although these diseases can be controlled to some extent with crop and fungicides, while these measures increase the cost of production, promote resistance, and lead to environmental contamination, so they are being phased out. Plant growth-promoting rhizobacteria are an alternative to chemical pesticides that can play a key role in crop production by means of siderophore and indole-3-acetic acid production, antagonism to soilborne root pathogens, phosphate and potassium solubilization, and nitrogen fixation. These rhizobacteria can also promote a beneficial change in the microorganism community by significantly reducing its pathogenic fungi component. Their use is fully in accord with the principles of sustainability.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Anam Yousaf ◽  
Hassan Ahmed Khan ◽  
Tayyaba Younas

Plant are benefitted in different aspects by symbiotic bacteria. Environmental conditions, Plantconditions and type of pathogens determine these important services for plants Objective: Theresearch was conducted to assess the plant growth enhancing effects of wheat and cabbagerhizobacteria on the growth of wheat plant Methods: For this purpose, total 49 bacteria were isolatedand characterized from the rhizosphere of wheat and cabbage plants. The isolates were assessed forplant growth promoting properties such as: indole acetic acid production, phosphate solubilization,antibacterial activity and heavy metal resistance. Indole acetic acid was found to be produced by 7isolates and phosphate solubilization was shown by 20 isolates. Antibacterial activity was determinedagainst four clinical isolates like Staphylococcus aureus, Klebsiella sp., Escherichia coli and Pseudomonasaeruginosa Results: Antibacterial activity against Staphylococcus aureus was shown by 38 isolates, 12isolates showed antibacterial activity against Escherichia coli and Klebsiella sp., whereas no isolate wasfound to be positive against Pseudomonas aeruginosa. Another plant growth enhancing trait (heavymetal resistance) was shown by 28 rhizobacteria. In order to evaluate the capability of isolates toenhance the plant growth, bio-inoculation assay was performed using wheat seeds Conclusions:Rhizobacterial inoculation increased the number of roots, shoots, leaves and roots and shoot length ofwheat plantlets as compared to un-inoculated control.


2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Camila Cristina Vieira Velloso ◽  
Christiane Abreu de Oliveira ◽  
Eliane Aparecida Gomes ◽  
Ubiraci Gomes de Paula Lana ◽  
Chainheny Gomes de Carvalho ◽  
...  

ABSTRACT Plant growth promoting bacteria (PGPB) are an efficient and sustainable alternative to mitigate biotic and abiotic stresses in maize. This work aimed to sequence the genome of two Bacillus strains (B116 and B119) and to evaluate their plant growth-promoting (PGP) potential in vitro and their capacity to trigger specific responses in different maize genotypes. Analysis of the genomic sequences revealed the presence of genes related to PGP activities. Both strains were able to produce biofilm and exopolysaccharides, and solubilize phosphate. The strain B119 produced higher amounts of IAA-like molecules and phytase, whereas B116 was capable to produce more acid phosphatase. Maize seedlings inoculated with either strains were submitted to polyethylene glycol-induced osmotic stress and showed an increase of thicker roots, which resulted in a higher root dry weight. The inoculation also increased the total dry weight and modified the root morphology of 16 out of 21 maize genotypes, indicating that the bacteria triggered specific responses depending on plant genotype background. Maize root remodeling was related to growth promotion mechanisms found in genomic prediction and confirmed by in vitro analysis. Overall, the genomic and phenotypic characterization brought new insights to the mechanisms of PGP in tropical Bacillus.


2019 ◽  
Author(s):  
Adel Hadj Brahim ◽  
Mouna Jlidi ◽  
Lobna Daoud ◽  
Manel Ben-Ali ◽  
Asmahen Akremi ◽  
...  

Abstract Background There is growing interest in the use of bioinoculants based on plant growth promoting bacteria (PGPB) to promote plant growth under biotic and abiotic stresses. To our knowledge much work has not been, thus far, done on seedbiopriming of durum wheat for tolerance to biotic and abiotic stresses. In the present work, we report detailed account of the effectiveness a potent bacterial strain with proven plant growth-promoting ability and antimicrobial activity. The isolate was selected following screening of several bacterial strains isolated from halophytes that grow in a coastal saline soil in Tunisia for their role in enhancing durum wheat tolerance to both salinity stress and head blight disease. Results Accordingly, Bacillus strains MA9, MA14, MA17 and MA19 were found to have PGPB characteristics as they produced indole-3-acetic acid, siderophores and lytic enzymes, fixed free atmospheric nitrogen, and solubilized inorganic phosphate, in vitro. The in vivo study that involved in planta inoculation assays under control (25 mM NaCl) and stress (125 mM NaCl) conditions indicated that all PGPB strains significantly (P < 0.05) increased the total plant length, dry weight, root area, seed weight, nitrogen, protein and total mineral content. On the other hand, strain MA17 reduced Fusarium Head Blight (FHB) disease incidence in wheat explants by 64.5%, showing that the strain has antifungal activity as was also displayed by in vitro inhibition study. Conclusions Both in vitro and in vivo studies showed that MA9, MA14 MA9, MA14, MA17 and MA19 strains were able to play the PGPB role. Yet, biopriming with Bacillus strain MA17 offered the highest bioprotection against FHB, plant growth promotion, and salinity tolerance. Hence, the MA17 strain should further be evaluated under field condition and formulated for commercial production. Besides, the strain could further be evaluated for its potential role in bioprotection and growth promotion of other crop plants. We believe, the strain has potential to significantly contribute to wheat production in the arid and semi-arid region, especially the salt affected Middle Eastern Region, besides its potential role in improving wheat production under biotic and abiotic stresses in other parts of the world.


Author(s):  
Pooja Suneja ◽  
Rajat Maheshwari ◽  
Namita Bhutani

A total of 22 endophytic bacteria were isolated from roots and nodules of Vigna radiata (mungbean) obtained from Jind district, Haryana. These were characterized on the basis of plant growth promoting traits. Almost all the endophytic bacteria produced IAA with maximum production of 81.63µg/ml by isolate MJiR8. Among these, 100% root isolates and 84.6% nodule isolates resulted in in vitro root growth promotion of mungbean seedlings. All the isolates produced ammonia; eighteen (all root and nine nodule isolates) produced organic acid while only four root isolates were positive for siderophore production. The four isolates produced hydrogen cyanide and out of these only MJiR9 inhibited the growth of fungal pathogens Fusarium oxysporium and Aspergillus niger. All the endophytes were used to determine molecular diversity by ARDRA (Amplified Ribosomal DNA Restriction Analysis) Results revealed that the nodule isolates were more diverse, being present in separate clusters, in comparison to root isolates which were grouped together in cluster III.


Agriculture ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Betsie Martínez-Cano ◽  
Juan Fernando García-Trejo ◽  
Arantza Elena Sánchez-Gutiérrez ◽  
Manuel Toledano-Ayala ◽  
Genaro M. Soto-Zarazúa

Currently, agricultural systems are inadequate to meet the demand of the population, coupled with the constant degradation of natural resources. Therefore, it is necessary to explore alternatives to increase the productivity and quality of crops with minimal environmental impact. The use of plant growth-promoting bacteria can provide solutions to some agri-environmental problems and replace or minimize conventional agricultural practices. In this study, a Bacillus pumilus strain with plant growth-promoting properties was isolated from mature compost. In vitro, the ability of Bacillus pumilus to solubilize phosphate, inhibit the growth of phytopathogenic fungi, and its effect on the germination of tomato and lettuce seeds was evaluated. In vivo, its effect on stem thickness, height, and the number of leaves of tomato and lettuce seedlings was studied. The results show that, in vitro, Bacillus pumilus solubilizes phosphate, inhibits the growth of the fungus Fusarium oxysporum, and increases the germination percentage of tomato seeds. The results, in vivo, demonstrate that the bacteria increases the stem thickness of tomato seedlings, while, in lettuce, it increases the stem thickness and the number of leaves. The outcome implies that Bacillus pumilus has properties as a plant growth promoter and can be used as a promising inoculant to enhance the growth of tomato and lettuce seedlings.


2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  

Root−associated microbial communities play important roles in the process of adaptation of plant hosts to environment stressors, and in this perspective, the microbiome of halophytes represents a valuable model for understanding the contribution of microorganisms to plant tolerance to salt. Although considered as the most promising halophyte candidate to crop cultivation, Salicornia ramosissima is one of the least-studied species in terms of microbiome composition and the effect of sediment properties on the diversity of plant-growth promoting bacteria associated with the roots. In this work, we aimed at isolating and characterizing halotolerant bacteria associated with the rhizosphere and root tissues of S. ramosissima, envisaging their application in saline agriculture. Endophytic and rhizosphere bacteria were isolated from wild and crop cultivated plants, growing in different estuarine conditions. Isolates were identified based on 16S rRNA sequences and screened for plant-growth promotion traits. The subsets of isolates from different sampling sites were very different in terms of composition but consistent in terms of the plant-growth promoting traits represented. Bacillus was the most represented genus and expressed the wider range of extracellular enzymatic activities. Halotolerant strains of Salinicola, Pseudomonas, Oceanobacillus, Halomonas, Providencia, Bacillus, Psychrobacter and Brevibacterium also exhibited several plant-growth promotion traits (e.g., 3-indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophores, phosphate solubilization). Considering the taxonomic diversity and the plant-growth promotion potential of the isolates, the collection represents a valuable resource that can be used to optimize the crop cultivation of Salicornia under different environmental conditions and for the attenuation of salt stress in non-halophytes, considering the global threat of arable soil salinization.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


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