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

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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Salix purpurea and Eleocharis obtusa Rhizospheres Harbor a Diverse Rhizospheric Bacterial Community Characterized by Hydrocarbons Degradation Potentials and Plant Growth-Promoting Properties

Plants ◽

10.3390/plants10101987 ◽

2021 ◽

Vol 10 (10) ◽

pp. 1987

Author(s):

Fahad Alotaibi ◽

Soon-Jae Lee ◽

Marc St-Arnaud ◽

Mohamed Hijri

Keyword(s):

Carbon Source ◽

Plant Growth ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Petrochemical Plant ◽

Bacterial Isolates ◽

Pgp Traits ◽

Degrading Bacteria ◽

Plant Growth Promoting ◽

Growth Promoting

Phytoremediation, a method of phytomanagement using the plant holobiont to clean up polluted soils, is particularly effective for degrading organic pollutants. However, the respective contributions of host plants and their associated microbiota within the holobiont to the efficiency of phytoremediation is poorly understood. The identification of plant-associated bacteria capable of efficiently utilizing these compounds as a carbon source while stimulating plant-growth is a keystone for phytomanagement engineering. In this study, we sampled the rhizosphere and the surrounding bulk soil of Salixpurpurea and Eleocharis obusta from the site of a former petrochemical plant in Varennes, QC, Canada. Our objectives were to: (i) isolate and identify indigenous bacteria inhabiting these biotopes; (ii) assess the ability of isolated bacteria to utilize alkanes and polycyclic aromatic hydrocarbons (PAHS) as the sole carbon source, and (iii) determine the plant growth-promoting (PGP) potential of the isolates using five key traits. A total of 438 morphologically different bacterial isolates were obtained, purified, preserved and identified through PCR and 16S rRNA gene sequencing. Identified isolates represent 62 genera. Approximately, 32% of bacterial isolates were able to utilize all five different hydrocarbons compounds. Additionally, 5% of tested isolates belonging to genera Pseudomonas, Acinetobacter, Serratia, Klebsiella, Microbacterium, Bacillus and Stenotrophomonas possessed all five of the tested PGP functional traits. This culture collection of diverse, petroleum-hydrocarbon degrading bacteria, with multiple PGP traits, represents a valuable resource for future use in environmental bio- and phyto-technology applications.

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The Production of ACC Deaminase and Trehalose by the Plant Growth Promoting Bacterium Pseudomonas sp. UW4 Synergistically Protect Tomato Plants Against Salt Stress

Frontiers in Microbiology ◽

10.3389/fmicb.2019.01392 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 22

Author(s):

Ma. del Carmen Orozco-Mosqueda ◽

Jin Duan ◽

Mercedes DiBernardo ◽

Elizabeth Zetter ◽

Jesús Campos-García ◽

...

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Acc Deaminase ◽

Pseudomonas Sp ◽

Tomato Plants ◽

Plant Growth Promoting ◽

Growth Promoting

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Screening of plant growth-promoting bacterial endophytes and rhizobacteria isolated from Curcuma xanthorrhiza

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/913/1/012022 ◽

2021 ◽

Vol 913 (1) ◽

pp. 012022

Author(s):

N A Saryanah ◽

Y P Roswanjaya ◽

S Himawati ◽

Sulastri ◽

I S Bidara ◽

...

Keyword(s):

Plant Growth ◽

Seed Treatment ◽

Rice Seedling ◽

Rice Seed ◽

Bacterial Endophytes ◽

Bacterial Isolates ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Curcuma Xanthorrhiza

Abstract Bacterial endophyte and rhizobacteria were reported to associate with medicinal plants including Zingiberaceae plants and involved in growth promotion. These beneficial bacteria are promising candidates as biostimulants because of their ability in promoting plant growth. This study aims to evaluate the activity of endophytic and rhizosphere bacteria isolated from Curcuma xanthorrhiza (Javanese turmeric) in promoting rice seedling and Javanese turmeric growth. Fifty-seven of 150 total bacterial isolates with negative hemolysis and hypersensitivity reactions were characterized to investigate their plant growth-promoting (PGP) traits. Ten selected bacteria (two bacterial endophytes and eight rhizobacteria) with multiple PGP traits were inoculated to rice seed with seed treatment and inoculated to Javanese turmeric rhizome with seed treatment and seed treatment+soil soil drenching. Our results showed that bacterial isolates tested on rice seed promoted rice seedling growth significantly. A total of five, three, six, and three bacterial isolates could increase leaf number, root length, fresh shoot weight, and fresh root weight of rice seedling (p<0.05), respectively. In contrast, all of the bacterial isolates tested on Javanese turmeric rhizomes showed a non-significant effect on the plant growth. Further studies should be considered to investigate the effect of formulated potential bacterial isolates with different application frequencies and environmental conditions on the harvest yield of rice and Javanese turmeric as well as active compounds of Javanese turmeric.

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Microbial Diversity of Psychrotolerant Bacteria Isolated from Wild Flora of Andes Mountains and Patagonia of Chile towards the Selection of Plant Growth-Promoting Bacterial Consortia to Alleviate Cold Stress in Plants

Microorganisms ◽

10.3390/microorganisms9030538 ◽

2021 ◽

Vol 9 (3) ◽

pp. 538 ◽

Cited By ~ 1

Author(s):

Paulina Vega-Celedón ◽

Guillermo Bravo ◽

Alexis Velásquez ◽

Fernanda P. Cid ◽

Miryam Valenzuela ◽

...

Keyword(s):

Plant Growth ◽

Cold Stress ◽

Acc Deaminase ◽

Andes Mountains ◽

Wild Plants ◽

Rrna Gene ◽

Plant Growth Promoting Bacteria ◽

Bacterial Consortia ◽

Plant Growth Promoting ◽

Growth Promoting

Cold stress decreases the growth and productivity of agricultural crops. Psychrotolerant plant growth-promoting bacteria (PGPB) may protect and promote plant growth at low temperatures. The aims of this study were to isolate and characterize psychrotolerant PGPB from wild flora of Andes Mountains and Patagonia of Chile and to formulate PGPB consortia. Psychrotolerant strains were isolated from 11 wild plants (rhizosphere and phyllosphere) during winter of 2015. For the first time, bacteria associated with Calycera, Orites, and Chusquea plant genera were reported. More than 50% of the 130 isolates showed ≥33% bacterial cell survival at temperatures below zero. Seventy strains of Pseudomonas, Curtobacterium, Janthinobacterium, Stenotrophomonas, Serratia, Brevundimonas, Xanthomonas, Frondihabitans, Arthrobacter, Pseudarthrobacter, Paenarthrobacter, Brachybacterium, Clavibacter, Sporosarcina, Bacillus, Solibacillus, Flavobacterium, and Pedobacter genera were identified by 16S rRNA gene sequence analyses. Ten strains were selected based on psychrotolerance, auxin production, phosphate solubilization, presence of nifH (nitrogenase reductase) and acdS (1-aminocyclopropane-1-carboxylate (ACC) deaminase) genes, and anti-phytopathogenic activities. Two of the three bacterial consortia formulated promoted tomato plant growth under normal and cold stress conditions. The bacterial consortium composed of Pseudomonas sp. TmR5a & Curtobacterium sp. BmP22c that possesses ACC deaminase and ice recrystallization inhibition activities is a promising candidate for future cold stress studies.

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Isolation of plant growth-promoting Pseudomonas sp. PPR8 from the rhizosphere of Phaseolus vulgaris L.

Archives of Biological Sciences ◽

10.2298/abs150701028k ◽

2016 ◽

Vol 68 (2) ◽

pp. 363-374 ◽

Cited By ~ 4

Author(s):

Pankaj Kumar ◽

Ramesh Dubey ◽

Dinesh Maheshwari ◽

Yong-Ha Park ◽

Vivek Bajpai

Keyword(s):

Phaseolus Vulgaris ◽

Plant Growth ◽

Growth Promotion ◽

Rrna Gene ◽

Sequencing Analysis ◽

Pseudomonas Sp ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting

In vitro screening of plant growth-promoting (PGP) traits was carried out using eight Pseudomonas spp., PPR1 to PPR8, isolated from the rhizosphere of Phaseolus vulgaris growing on the Uttarakhand Himalayan range in India. All the isolates were fast growers, positive for catalase, oxidase and urease activities, and utilized lactose and some amino acids. All the isolates were indole acetic acid (IAA) positive, however PPR8 solubilized potassium and zinc along with various other types of inorganic (tricalcium, dicalcium and zinc phosphate) and organic (calcium phytate) phosphates, as well as producing siderophore and ACC deaminase. PPR8 also produced cyanogens, extracellular chitinase, ?-1,3-glucanase, ?-1,4-glucanase and oxalate oxidase. Based on the PGP traits of all isolates, PPR8 was found to be the most potent plant growth-promoting rhizobacteria (PGPR). Further, PPR8 was identified as Pseudomonas sp. PPR8, based on 16S rRNA gene sequencing analysis. Moreover, the PGP activities of PPR8 confirmed it to be a potent biocontrol agent, inhibiting the growth of various plant pathogenic fungi. This study reveals the potential of Pseudomonas sp. PPR8 to be used as a good bioinoculant for growth promotion of common bean and for the protection of important legume crops from various deleterious phytopathogens.

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Cultivable Endophytic Bacteria in Seeds of Dongxiang Wild Rice and Their Role in Plant-Growth Promotion

Diversity ◽

10.3390/d13120665 ◽

2021 ◽

Vol 13 (12) ◽

pp. 665

Author(s):

Zhibin Zhang ◽

Tingting Liu ◽

Xiao Zhang ◽

Jing Xie ◽

Ya Wang ◽

...

Keyword(s):

Plant Growth ◽

Wild Rice ◽

Endophytic Bacteria ◽

Agronomic Traits ◽

Oryza Rufipogon ◽

Rrna Gene ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Dongxiang Wild Rice

Dongxiang wild rice (Oryza rufipogon Griff.) germplasm is a precious resource for the improvement of agronomic traits in rice. Rice seeds also harbor a diverse endophytic bacterial community, and their interactions with their hosts and each other can influence plant growth and adaptability. Here, we investigated the community composition of cultivable endophytic bacteria obtained from the surface-sterilized seeds of Dongxiang wild rice and screened them for plant growth-promoting traits. Phylogenetic analysis of 16S rRNA gene sequences indicated that the 47 isolates were affiliated with five classes and 13 discrete genera, and Bacillus and Microbacterium predominated. Evaluations of plant growth promoting (PGP) traits showed that 45 endophytic bacteria isolates produced between 3.37 and 90.11 μg mL−1 of Indole-3-acetic acid (IAA), with the highest yield of 90.11 μg mL−1 (Fse28). Further, 37 of the isolates were able to solubilize mineral phosphate, while 28 other isolates had the ability of N2-fixation, 17 isolates possessed 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity with the highest yield of 20.72 μmol mg−1 protein h−1 (Fse35), and 17 isolates were also able to produce siderophores. The two strains Fse28 and Fse35 had multiple PGP traits that significantly improved the agronomic traits (root length, shoot length, dry matter, and chlorophyll content) of cultivated rice seedlings. Our results illustrate the rich diversity of seed endophytic bacteria in Dongxiang wild rice and their potential for developing novel efficient bioinoculants to enhance soil fertility and favor seedling growth.

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New insights into the role of constitutive bacterial rhizobiome and phenolic compounds in two Pinus spp. with contrasting susceptibility to pine pitch canker

Tree Physiology ◽

10.1093/treephys/tpab119 ◽

2021 ◽

Author(s):

Frederico Leitão ◽

Glória Pinto ◽

Joana Amaral ◽

Pedro Monteiro ◽

Isabel Henriques

Keyword(s):

Phenolic Compounds ◽

Plant Growth ◽

Rrna Gene ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Pinus Spp ◽

Pine Species

Abstract The rhizobiome is being increasingly acknowledged as a key player in plant health and breeding strategies. The pine pitch canker (PPC), caused by the fungus Fusarium circinatum, affects pine species with varying susceptibility degrees. Our aims were to explore the bacterial rhizobiome of a susceptible (Pinus radiata) and a resistant (Pinus pinea) species together with other physiological traits, and to analyze shifts upon F. circinatum inoculation. Pinus seedlings were stem inoculated with F. circinatum spores and needle gas exchange and antioxidant-related parameters were analyzed in non-inoculated and inoculated plants. Rhizobiome structure was evaluated through 16S rRNA gene massive parallel sequencing. Species (non-inoculated plants) harbored distinct rhizobiomes (<40% similarity), where P. pinea displayed a rhizobiome with increased abundance of taxa described in suppressive soils, displaying plant-growth-promoting (PGP) traits and/or antifungal activity. Plants of this species also displayed higher levels of phenolic compounds. Fusarium circinatum induced slight changes in the rhizobiome of both species and a negative impact in photosynthetic-related parameters in P. radiata. We concluded that the rhizobiome of each pine species is distinct and higher abundance of bacterial taxa associated to disease protection was registered for the PPC-resistant species. Furthermore, differences in the rhizobiome are paralleled by a distinct content in phenolic compounds, which are also linked to plants’ resistance against PPC. This study unveils a species-specific rhizobiome and provides insights to exploit the rhizobiome for plant selection in nurseries and for rhizobiome-based plant-growth-promoting strategies, boosting environmentally friendly disease control strategies.

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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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