scholarly journals Plant growth-promoting properties of cultivable endophytic root nodule bacterial isolates from Acacia mangium Willd

2016 ◽  
Vol 6 ◽  
Author(s):  
Fatin Syafikah Ismail ◽  
Masnindah Malahubban ◽  
Mohammad Hailmi Sajili ◽  
Zakry Fitri Ab. Aziz
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Root Nodules ◽  
Acacia Mangium ◽  
Dry Weight ◽  
Winged Bean ◽  
Bacterial Isolates ◽  
Root And Shoot Length ◽  
Plant Growth Promoting ◽  
Growth Promoting

<strong>The present study was conducted to isolate and characterize endophytic bacteria isolated from root nodules of <em>Acacia mangium</em> Willd and subsequently tested for plant growth promotion. A total of five bacterial isolates were successfully isolated and subjected to morphological and biochemical examination. The present study found that all isolates had almost similar morphologically but differed in growth rate. All isolates were negative on N-free and IAA tests, though positive on P solubilisation test. The present study demonstrated that the inoculation with isolate FSI3 had significantly improved (p&lt;0.05) root and shoot dry weight of winged bean seedlings as compared to uninoculated control. However, the inoculation did not significantly alter (p&gt;0.05) root and shoot length of winged bean seedlings. The present study suggests that the stimulatory effect by isolate FSI3 may be associated with P-solubilizing ability. A further test on isolate FSI3 is considered essential in future to uncover the several other possible plant growth-promoting mechanisms. </strong>

scholarly journals Isolation and Characterization of Nodule-AssociatedExiguobacterium sp. from the Root Nodules ofFenugreek(Trigonella foenum-graecum) and Their Possible Role in Plant Growth Promotion

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Geetha Rajendran ◽  
Maheshwari H. Patel ◽  
Sanket J. Joshi
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Root Nodules ◽  
Dry Weight ◽  
Gram Positive ◽  
Associated Bacteria ◽  
Trigonella Foenum Graecum ◽  
Isolation And Characterization ◽  
Root And Shoot Length

One of the ways to increase the competitive survivability of rhizobial biofertilizers and thus achieve better plant growth under such conditions is by modifying the rhizospheric environment or community by addition of nonrhizobial nodule-associated bacteria (NAB) that cause better nodulation and plant growth when coinoculated with rhizobia. A study was performed to investigate the most commonly associated nodule-associated bacteria and the rhizospheric microorganisms associated with theFenugreek(Trigonella foenum-graecum) plant. Isolation of nonrhizobial isolates from root nodules ofFenugreekwas carried out along with the rhizospheric isolates. About 64.7% isolates obtained fromFenugreeknodules were gram-negative coccobacilli, 29.41% were gram-positive bacilli, and all rhizospheric isolates except one were gram-positive bacilli. All the isolates were characterized for their plant growth promoting (PGP) activities. Two of the NAB isolates M2N2c and B1N2b (Exiguobacterium sp.) showed maximum positive PGP features. Those NAB isolates when coinoculated with rhizobial strain—S. meliloti, showed plant growth promotion with respect to increase in plant’s root and shoot length, chlorophyll content, nodulation efficiency, and nodule dry weight.

scholarly journals Halotolerant-Koccuria rhizophila (14asp)-Induced Amendment of Salt Stress in Pea Plants by Limiting Na+ Uptake and Elevating Production of Antioxidants

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1907
Author(s):  
Amir Abdullah Khan ◽  
Tongtong Wang ◽  
Tayyaba Hussain ◽  
Amna ◽  
Fayaz Ali ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Plant Growth ◽  
Growth Promotion ◽  
Antioxidant Systems ◽  
Plant Growth Promoting Bacteria ◽  
Mineral Contents ◽  
Root And Shoot Length ◽  
Plant Growth Promoting ◽  
Growth Promoting

Endophytic bacteria are useful for their safe services in plant growth improvement and for ameliorating abiotic and biotic stresses. Salt-tolerant plant-growth-promoting Kocuria rhizophila 14asp (accession number KF 875448) was investigated for its role in pea plants under a saline environment. Salt stress (75 mM and 150 mM NaCl) was subjected to two pea varieties, peas2009 and 9800-10, in a greenhouse under a complete randomized design. Different parameters such as plant growth promotion, relative water content, chlorophyll, antioxidants, and mineral contents were analyzed to elucidate the extent of tolerance persuaded by PGPB (plant-growth-promoting bacteria). Exhibition of adverse effects was noticed in uninoculated varieties. However, inoculation of K. rhizophila improved the morphological parameters, antioxidant enzymes, and minimized the uptake of Na+ in plants under various saline regimes. Pea variety 9800-10 exhibited more tolerance than peas2009 in all traits, such as root and shoot length, fresh and dry biomass, chlorophyll contents, and antioxidant enzymes. Our results showed that halotolerant K. rhizophila inoculation plays a vital role in enhancing plant growth by interacting ingeniously with plants through antioxidant systems, enduring saline conditions.

scholarly journals In vitro antagonistic potential, plant growth-promoting activity and indole-3-acetic acid producing trait of bacterial isolates from spent mushroom substrate of Agaricus bisporus

2020 ◽  
Vol 25 (2) ◽  
pp. 22
Author(s):  
Rethinasamy Velazhahan ◽  
Shima Nasser Hamed Al-Mamari ◽  
Abdullah Mohammed Al-Sadi ◽  
Issa Hashil Al-Mahmooli ◽  
S. P. Sathish Babu
Keyword(s):  
Plant Growth ◽  
Agaricus Bisporus ◽  
Growth Promotion ◽  
Inhibition Zone ◽  
Bacterial Isolates ◽  
Plant Growth Promoting ◽  
Antagonistic Potential ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Spent mushroom substrate (SMS) is widely used as fertilizer and to control plant diseases. The microorganisms surviving in SMS play a crucial role in plant growth promotion and biocontrol properties of SMS. In this study, an effort was made to isolate and characterize the bacterial species present in the SMS of Agaricus bisporus and to study their antagonistic potential, plant growth-promoting ability and indole-3-acetic acid (IAA) producing trait. Six different bacterial isolates exhibiting morphological variabilities were obtained from the SMS by serial dilution technique. On the basis of 16S rRNA gene sequences, these isolates were identified as Staphylococcus epidermidis (Sh1 and Sh3), S. aureus (Sh2), Bacillus albus (Sh4), Delftia lacustris (Sh6) and Comamonas aquatica (Sh7). These bacterial strains were assayed for their antagonism against Pythium aphanidermatum, a phytopathogenic oomycete. The results of in vitro dual culture assay revealed that all the 6 bacterial isolates showed low levels of suppression of P. aphanidermatum and recorded less than 5 mm inhibition zone. Among the bacterial isolates, S. epidermidis Sh3 recorded the maximum inhibition zone of 4.2 mm. Plant growth promotion test using roll paper towel method revealed that C. aquatica Sh7, B. albus Sh4, D. lacustris Sh6 and S. epidermidis Sh3 caused a significant increase in seedling vigour of cucumber compared to control. The seeds treated with the bacterial isolate C. aquatica Sh7 showed the maximum seedling vigor. Assessment of in vitro production of IAA by the bacterial isolates revealed that the bacterial isolates highly varied (ranging from 0.28 to 9.25 mg L-1) in their potential for production of IAA. The maximum amount of IAA was produced by C. aquatica Sh7 (9.25 mg L-1), while the minimum was produced by S. epidermidis Sh1 (0.28 mg L-1).

scholarly journals In-Vitro Plant Growth Promotion of Rhizobium Strains Isolated from Lentil Root Nodules under Abiotic Stresses

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1006
Author(s):  
Badreddine Sijilmassi ◽  
Abdelkarim Filali-Maltouf ◽  
Sara Fahde ◽  
Youness Ennahli ◽  
Said Boughribil ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Salt Tolerance ◽  
Plant Growth ◽  
Growth Promotion ◽  
Root Nodules ◽  
Rhizobium Strains ◽  
Drought And Salt Tolerance ◽  
Significant Difference ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plant growth-promoting rhizobia are known to improve crop performance by multiple mechanisms. However, the interaction between host plants and Rhizobium strains is highly influenced by growing conditions, e.g., heat, cold, drought, soil salinity, nutrient scarcity, etc. The present study was undertaken to assess the use of Rhizobium as plant growth promoters under abiotic stress conditions. Fifteen Rhizobium strains isolated from lentil root nodules were tested for phosphate solubilization activity (PSA) and phytohormones production under salt and drought conditions. The results showed that 15 Rhizobium strains were significant phosphate solubilizers, and indole acedic acid (IAA) and gibberellic acid (GA3) producers based on least significant difference (LSD) analysis (p ≤ 0.05). The highest rate of PSA was attributed to three strains namely, 1145N5, 1159N11, and 1159N32 with a range of 144.6 to 205.6 P2O5 (µg/mL). The highest IAA production was recorded in the strain 686N5 with 57.68 ± 4.25 µg/mL as compared to 50.8667 ± 1.41 µg/mL and 37.32 ± 12.59 µg/mL for Rhizobium tropici CIAT 899 and Azospirillum brasilense DSM-1690, respectively. Strain 318N2111 produced 329.24 ± 7.84 µg/mL of GA3 as against 259.84 ± 25.55 µg/mL for A. brasilense DSM-1690. R. tropici CIAT 899 showed tolerance to salt (5% NaCl) and drought (ψ = −2.6 MPa) stress, whereas strain 686N5 showed an extremely high level of salt-tolerance (5% NaCl) and moderate level of drought tolerance (ψ = −0.75 MPa). These results indicate different pathways for drought and salt tolerance mechanisms. The assessment of plant growth promoting (PGP) activities of Rhizobium showed differences between bacterial viability and bacterial PGP activity in terms of abiotic stress tolerance where bacterial PGP activity is interrupted before reaching the bacterial tolerance threshold. These results integrate a new concept of PGPR screening based on PGP activity under abiotic stress.

scholarly journals Genome-guided insights of tropical Bacillus strains efficient in maize growth promotion

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 ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Dry Weight ◽  
Phenotypic Characterization ◽  
Plant Growth Promoting Bacteria ◽  
Maize Genotypes ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Bacillus Strains

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.

A gnotobiotic bioassay for studying interactions between potatoes and plant growth-promoting rhizobacteria

1997 ◽  
Vol 43 (9) ◽  
pp. 801-808 ◽  
Author(s):  
Kenneth L. Conn ◽  
George Lazarovits ◽  
Jerzy Nowak
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Potato Cultivar ◽  
Fold Increase ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Single Node ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Potato Plantlets

A gnotobiotic bioassay, using potato plantlets derived from single-node explants and grown in test tubes containing potato nodal cutting medium (PNCM), was found to be highly useful for investigations of direct growth promotion by a nonfluorescent Pseudomonas sp. strain PsJN. Strain PsJN was used to optimize and evaluate this bioassay for purposes of screening other rhizosphere bacteria and identification of Tn5 mutants of strain PsJN deficient in growth-promoting properties. The selection of potato cultivar used in this bioassay was critical, as growth promotion of potatoes by strain PsJN was cultivar specific. Inoculated plantlets of cultivars Norchip, Kennebec, Shepody, and Chaleur showed, in root dry weight, a five- to eight-fold increase, two- to three-fold increase, no response, and a decrease of 50%, respectively. Haulm dry weight followed similar trends but was not as consistent an indicator of growth promotion. Bioassay results were not altered to any extent by minor changes in PNCM composition or by slight changes in temperature and light conditions. A rapid method for preparation of bacterial suspensions and inoculation of explants was developed. Inoculation of three explants taken from 6-week-old stock plantlets of cv. Kennebec for each Tn5 transconjugate of strain PsJN (total of 1500 transconjugates) enabled the elimination of 93% of those isolates that retained growth-promoting activity. The remaining 7% of isolates were retested and seven were confirmed to have lost growth-promoting ability. Bacteria from different genera were also screened with this bioassay. None of these bacteria increased the growth of potato plantlets, but several inhibited root and haulm growth.Key words: plant growth-promoting rhizobacteria, gnotobiotic, tissue culture, nonfluorescent pseudomonad, bacterium, potato.

scholarly journals Identification of Plant Growth Promoting Rhizobacteria That Improve the Performance of Greenhouse-Grown Petunias under Low Fertility Conditions

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1410
Author(s):  
Kaylee A. South ◽  
Nathan P. Nordstedt ◽  
Michelle L. Jones
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Genomic Analysis ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Low Fertility ◽  
Plant Performance ◽  
Flower Bud ◽  
Plant Growth Promoting ◽  
Growth Promoting

The production of greenhouse ornamentals relies on high fertilizer inputs to meet scheduling deadlines and quality standards, but overfertilization has negative environmental impacts. The goals of this study were to identify plant-growth-promoting rhizobacteria (PGPR) that can improve greenhouse ornamental crop performance with reduced fertilizer inputs, and to identify the best measurements of plant performance for assessing the beneficial impact of PGPR on ornamentals. A high-throughput greenhouse trial was used to identify 14 PGPR isolates that improved the flower/bud number and shoot dry weight of Petunia × hybrida ‘Picobella Blue’ grown under low fertility conditions in peat-based media. These 14 PGPR were then applied to petunias grown under low fertility conditions (25 mg L−1 N). PGPR-treated plants were compared to negative (untreated at 25 mg L−1 N) and positive (untreated at 50, 75, 100, and 150 mg L−1 N) controls. Multiple parameters were measured in the categories of flowering, vegetative growth, and vegetative quality to determine the best measurements to assess improvements in ornamental plant performance. Caballeronia zhejiangensis C7B12-treated plants performed better in almost all parameters and were comparable to untreated plants fertilized with 50 mg L−1 N. Genomic analysis identified genes that were potentially involved in plant growth promotion. Our study identified potential PGPR that can be used as biostimulants to produce high-quality greenhouse ornamentals with lower fertilizer inputs.

scholarly journals Rhizobacterial Inoculants Increase Root and Shoot Growth in ‘Tifway’ Hybrid Bermudagrass

2014 ◽  
Vol 32 (3) ◽  
pp. 149-154 ◽  
Author(s):  
R. Murphey Coy ◽  
David W. Held ◽  
Joseph W. Kloepper
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Growth Promotion ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Agronomic Crops ◽  
Plant Growth Promoting ◽  
Bacterial Treatment ◽  
Growth Promoting

Plant growth-promoting rhizobacteria (PGPR) are non-pathogenic, beneficial bacteria that colonize seeds and roots of plants and enhance plant growth. Although there has been extensive PGPR research with agronomic crops, there has been little emphasis on development of PGPR for grasses in pastures or as turf. Accordingly, experiments were conducted to evaluate novel bacterial inoculants for growth promotion in ‘Tifway’ hybrid bermudagrass. Replicated laboratory and greenhouse experiments evaluated effects of various PGPR mixtures, each with 3 to 5 PGPR strains and applied as weekly root inoculations, in comparison to nontreated plants. Growth promotion was assessed by measuring foliar growth from 3 to 8 wk and root growth at 8 wk after the first treatment. In all experiments, at least one bacterial treatment of bermudagrass resulted in significantly increased top growth and greater root growth (length, surface area, volume, or dry weight). PGPR blends 20 and MC3 caused the greatest growth promotion of roots and shoots. These results suggest that the bacterial strains could be used in strategies to reduce nitrogen or water inputs to turf.

scholarly journals Evaluation of Phytase Producing Bacteria for Their Plant Growth Promoting Activities

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Singh ◽  
Vinod Kumar ◽  
Sanjeev Agrawal
Keyword(s):  
Plant Growth ◽  
Phosphate Solubilization ◽  
Growth Promotion ◽  
Growth Parameters ◽  
Growth Effect ◽  
Bacterial Isolates ◽  
Iaa Production ◽  
Plant Growth Promoting Activities ◽  
Plant Growth Promoting ◽  
Growth Promoting

Bacterial inoculants are known to possess plant growth promoting abilities and have potential as liquid biofertilizer application. Four phytase producing bacterial isolates (phytase activity in the range of 0.076–0.174 U/mL), identified asAdvenellaspecies (PB-05, PB-06, and PB-10) andCellulosimicrobiumsp. PB-09, were analyzed for their plant growth promoting activities like siderophore production, IAA production, HCN production, ammonia production, phosphate solubilization, and antifungal activity. All isolates were positive for the above characteristics except for HCN production. The solubilization index for phosphorus on Pikovskaya agar plates was in the range of 2–4. Significant amount of IAA (7.19 to 35.03 μg/mL) production and solubilized phosphate (189.53 to 746.84 μg/mL) was noticed by these isolates at different time intervals. Besides that, a greenhouse study was also conducted with Indian mustard to evaluate the potential of these isolates to promote plant growth. Effect of seed bacterization on various plant growth parameters and P uptake by plant were used as indicators. The plant growth promoting ability of bacterial isolates in pot experiments was correlated to IAA production, phosphate solubilization, and otherin vitrotests. On the basis of present findings, isolate PB-06 was most promising in plant growth promotion with multiple growth promoting characteristics.

scholarly journals Plant Growth Promotion and Biocontrol of Pythium ultimum by Saline Tolerant Trichoderma Isolates under Salinity Stress

2019 ◽  
Vol 16 (11) ◽  
pp. 2053 ◽  
Author(s):  
Brenda Sánchez-Montesinos ◽  
Fernando Diánez ◽  
Alejandro Moreno-Gavira ◽  
Francisco J. Gea ◽  
Mila Santos
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Growth Promotion ◽  
Biological Control Agent ◽  
Dry Weight ◽  
Pythium Ultimum ◽  
Saline Stress ◽  
Growth Promoter ◽  
Plant Growth Promoting ◽  
Growth Promoting

This present study evaluates three isolates of Trichoderma as plant growth promoting or biological control agents: Trichoderma aggressivum f. sp. europaeum, Trichoderma saturnisporum, and the marine isolate obtained from Posidonia oceanica, Trichoderma longibrachiatum. The purpose is to contribute to an overall reduction in pesticide residues in the fruit and the environment and to a decrease in chemical fertilizers, the excess of which aggravates one of the most serious abiotic stresses, salinity. The tolerance of the different isolates to increasing concentrations of sodium chloride was evaluated in vitro, as well as their antagonistic capacity against Pythium ultimum. The plant growth promoting capacity and effects of Trichoderma strains on the severity of P. ultimum on melon seedlings under saline conditions were also analysed. The results reveal that the three isolates of Trichoderma, regardless of their origin, alleviate the stress produced by salinity, resulting in larger plants with an air-dry weight percentage above 80% in saline stress conditions for T. longibrachiatum, or an increase in root-dry weight close to 50% when T. aggressivum f. sp. europaeum was applied. Likewise, the three isolates showed antagonistic activity against P. ultimum, reducing the incidence of the disease, with the highest response found for T. longibrachiatum. Biological control of P. ultimum by T. aggressivum f. sp. europaeum and T. saturnisporum is reported for the first time, reducing disease severity by 62.96% and 51.85%, respectively. This is the first description of T. aggressivum f. sp. europaeum as a biological control agent and growth promoter. The application of these isolates can be of enormous benefit to horticultural crops, in both seedbeds and greenhouses.

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