Pseudomonas Fluorescens Research Articles

Feasibility of Fruit Waste-Derived Media for Microbial Culture: A Sustainable and Low-cost Approach

The present study, conducted at the College of Agriculture, Latur during 2023-2024, explores the viability of using fruit waste-derived media as a cost-effective alternative to conventional media for the growth of plant pathogens. The research focuses on the growth performance of Pseudomonas fluorescens, Fusarium oxysporum f. sp. udum, and Sclerotium rolfsii on media prepared from fruit peel of eight fruits (Banana, Pineapple, Papaya, Orange, Guava, Pomegranate, Dragon fruit, and Sapota). These fruit-based media were compared to traditional Nutrient Agar (NA) and Potato Dextrose Agar (PDA). Results revealed that Sclerotium rolfsii showed maximum growth on Papaya Dextrose Agar, while Pseudomonas fluorescens exhibited the most robust growth on Banana, Papaya and Dragon Fruit Dextrose Agar. Fusarium oxysporum f. sp. udum demonstrated the highest radial growth on Banana Dextrose Agar. The study also observed that fruit-based media significantly reduced costs compared to Potato Dextrose Agar and Nutrient Agar making them a sustainable and accessible option for microbiological research, particularly in resource-limited environments.

Impact of bioinoculants on growth enhancement, physicochemical characteristics, biochemical profiles, and enzymatic defense mechanisms in tomato (Lycopersicum esculentum)

The excessive use of fungicides in agriculture causes challenges like pathogen resistance, soil and water contamination, and potential health risks. Sustainable options like Pseudomonas spp. and yeast are being explored as bioinoculants to promote plant growth and inhibit fungal proliferation. 87 isolates, comprising 36 fluorescent Pseudomonas spp. and 51 yeast isolates were obtained from healthy fruits and vegetables. Yeast (YFSL) and Pseudomonas (PFSL) isolates significantly (p < 0.05) inhibited the in-vitro growth of Fusarium solani and Drechslera sp. Experiments in a screen house for 90 days used a randomized block design to study the effects of bioinoculants on plant and fruit health. Moreover, plants and fruits treated with these bioinoculants showed increased levels of salicylic acid (66.14%), total phenolic content (59.67%), chlorophyll (24.31%), carbohydrates (40.38%), phosphorus (0.24%), and antioxidant activity (90%). The treatments displayed higher levels of plant defensive enzymes, chitinase (0.09 mg/h/protein) and β-1-3-glucanase (0.093 mg/h/protein). The increased concentrations of antioxidant enzymes like SOD (0.07 U/L), POD (0.23 U/L), and APX (0.24 U/L) were also observed in the fruits of bio-inoculated plants. However., the difference in results was non-significant (P ≤ 0.05). This study demonstrates the Efficacy of bioinoculants in improving plant growth, compositional characteristics, and antioxidant activities while reducing losses in tomato plants and fruits.

Biofertilizer-mediated salt tolerance in sunflower: synergistic effects of Glomus mosseae and Pseudomonas fluorescens

Biofertilizer-mediated salt tolerance in sunflower: synergistic effects of Glomus mosseae and Pseudomonas fluorescens

Efficacy of Bio-Agents in Managing Root Rot of Okra Caused by Rhizoctonia solani

Okra or lady’s finger [Abelmoschus esculentus (L.) Moench] is one of the most important summer vegetables of Rajasthan as well as India. Okra is attacked by several diseases caused by fungi and important one is root rot caused by Rhizoctonia solani Kuhn, which is an important constraint to the crop and causes significant economic losses. During present study, two bio-agents were evaluated alone and in combination Trichoderma harzianum through seed (4 g/kg) and soil (4 kg/ha) applications for two consecutive years under artificial inoculation conditions in the field. Among these, seed + soil application of Trichoderma harzianum was found most effective in reducing disease incidence (48.76%) and in increasing pod yield (13.46%) followed by seed treatment with T. harzianum + soil application of Pseudomonas fluorescens (46.41% and 12.84%, respectively). Looking to the increasing demand of organically produces in the market, root rot disease can be managed effectively with these eco-friendly approaches for supplying organically produced vegetables to fulfil the ever-increasing demand among health-conscious people.

Determining conditions for inactivation of multispecies biofilm cells by peracetic acid applying response surface methodology

Biofilms can form on various surfaces and are typically associated with multiple microbial species. Particularly in the food industry, biofilms are often a source of contamination, necessitating mitigation strategies. In this study, Response Surface Methodology (RSM) was utilized to optimize conditions for the inactivation of multispecies biofilm cells, with peracetic acid (PAA) (0.05% to 0.5%), treatment time (5 to 30 minutes), and temperature (25 to 60 ºC) as independent variables. The multispecies biofilm consisted of Gram-positive and Gram-negative bacteria previously isolated from biofilms formed in the presence of raw milk. Stainless steel (SS) coupons were immersed in reconstituted whole milk inoculated with Pseudomonas fluorescens, Rahnella inusitata, Staphylococcus aureus, and Micrococcus aloeverae. Sessile cell counts of approximately 108 CFU/cm2 were obtained after 10 days of incubation at 4 ºC. The response surface model exhibited a good fit, with R2 of 0.949 and adjR2 of 0.883. All independent variables had a positive effect on the inactivation of biofilm cells. The maximum inactivation achieved was approximately 7 log (CFU/cm2), with the highest values observed at 0.5% PAA, for 30 min at 60°C. Epifluorescence microscopy revealed that many cells in the biofilm were dead or injured after treatment at the central point (PAA = 0.275%; Time = 17.5 min; Temperature = 42.5 ºC). RSM helps to predict better conditions for maximum biofilm eradication and proves to be a promising approach for monitoring the inactivation of multispecies biofilm cells, which warrants further exploration.

The insights into the activity of the extracts from Polygonum aviculare L. and Pseudomonas fluorescens for enhancing and modeling seed germination and seedling growth of Melilotus officinalis L. Lam

The empirical evidence indicated that chemicals in plants and selected microorganisms can promote the germination process and determine the growth, viability, survival and yield potential of industrial crop plants. The main objective of this study was exploring the phytochemical and microbiological synergistic activity between plant extracts from Polygonum aviculare L. and beneficial bacteria Pseudomonas fluorescens to enhance germination of Melilotus officinalis seeds and improve morphological characteristics of seedlings. The derived plant preparations were analyzed qualitatively, which showed that the aqueous extracts of P. aviculare were characterized by a higher content of phenolic compounds, micro- and macroelements and carbohydrates compared to the macerates, and that no phytohormones were detected in both the infusions and macerates. Pure macerates (MAC), infusions (IF), bacterial cultures (PF) and their mixtures (MAC+PF; INF+PF) were used for seed treatment of test plants. In the control group, lower values of M. officinalis seed germination and seedling growth rates were observed in relation to the applied treatments. The most effective germination rates were obtained after the application of pure infusions (IF) and their mixture with P. fluorescens (IF+PF), while the highest growth rates (including an almost twofold increase in the length of the nostril shoots compared to the control) were obtained after the application of P. fluorescens inoculum (PF) and the mixture of the infusion and these bacteria (IF+PF).The use of modeling, as a tool for predicting germination efficiency, has been shown to provide screening opportunities for identifying the effectiveness of biostimulant treatments. Thereby, this indicates the need to develop such an approach under field conditions.

Autofluorescence-guided Removal of Bacterial Biofilms from Tissues Using Cold Atmospheric Pressure Plasma (CAP).

Cold atmospheric pressure plasma (CAP) has the potential to completely remove biofilms from surfaces. The goal of this study is to employ the autofluorescence nature of bacterial biofilms to guide the removal of these biofilms using a CAP scalpel. Pseudomonas fluorescens biofilms, which produce a green fluorescence under 405 nm UV light, were grown on 12 chicken samples. The tissue model (chicken tissue) is placed on a motorized X-Y stage with the plasma discharge device directly above the sample. Fluorescent-guided CAP treatment of biofilm regions was carried out using a 1.37 lpm Ar/H2O plasma device with 39.5 × 54 mm2 dimension and a 1 * 0.6 mm2 plasma discharge outlet with discharge speed was 1 mm/s and sample distance of 4 mm. The discharge voltage and current were 3.24 kV and 1.2 mA respectively. Results based on analysis of the fluorescent images show that 97% biofilm removal; CFU analysis confirms that up to 99.98% of the bacteria are now absent from the tissue's surface. This is the first instance of two new applications: using cold atmospheric plasma (CAP) to remove bacterial biofilms from soft tissues and employing CAP in an image-guided procedure.

PRP5 Induction by Infection of Pythium Sp. in Tomato

The Pseudomonas fluorescens isolate FP 7 was found to protect the tomato plants against soil borne fungus, Pythium aphanidermatum. The ability to induce defense proteins viz. -1,3 glucanase, peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) by this P. fluorescens isolate FP 7 against P. aphanidermatum fungus was further studied. Increased activity of PO, PPO and -1,3 glucanase were observed in plants pretreated with FP 7 isolate. Native PAGE (polyacrylamide gel electrophoresis) of PO showed the single isoform in all the treatment including the control and difference is by the increased intensity of the band in the inoculated control and FP 7 treatment in the tomato plant. Isoform analysis of the PPO showed the induction of the PPO in the P. fluorescens treated plants challenged with P. aphanidermatum. -1,3 glucanase in tomato cultivar, Co 3 with and without challenge inoculation of P. aphanidermatum, revealed changes in the isoform pattern after staining the gel with 2,3,5-triphenyl tetrazolium chloride. Moreover, higher accumulation of phenolics was noticed in plants pretreated with P. fluorescens isolate FP 7 challenged with P. aphanidermatum. The relevant function of Thaumatin like defense proteins and secondary metabolites involved in the phenylpropanoid pathway collectively contributing to enhanced resistance is discussed.

The Microbiota of the Outer Gut Mucus Layer of the Migrating Northeast Arctic Cod (Gadus morhua) as Determined by Shotgun DNA Sequencing

Animals form functional units with their microbial communities, termed metaorganisms. Despite extensive research on some model animals, microbial diversity in many species remains unexplored. Here, we describe the taxonomic profile of the microbes from the outer gut mucus layer from the Northeast Arctic cod using a shotgun DNA sequencing approach. We focused on the mucus to determine if its microbial composition differs from that of the fecal microbiota, which could reveal unique microbial interactions and functions. Metagenomes from six individuals were analyzed, revealing three different taxonomic profiles: Type I is dominated in numbers by Pseudomonadaceae (44%) and Xanthomonadaceae (13%), Type II by Vibrionaceae (65%), and Type III by Enterobacteriaceae (76%). This stands in sharp contrast to the bacterial diversity of the transient gut content (i.e., feces). Additionally, binning of assembled reads followed by phylogenomic analyses place a high-completeness bin of Type I within the Pseudomonas fluorescens group, Type II within the Photobacterium phosphoreum clade, and Type III within the Escherichia/Shigella group. In conclusion, we describe the adherent bacterial diversity in the Northeast Arctic cod’s intestine using shotgun sequencing, revealing different taxonomic profiles compared to the more homogenous transient microbiota. This suggests that the intestine contains two separate and distinct microbial populations.

Biological decolorisation of the anionic Dye Acid Blue 9 by bacterial consortium: A sustainable and ecofriendly approach for the treatment of textile wastewater

Industrialization has led to the proliferation of dye waste, posing significant environmental challenges due to the structural complexity of dyes. Various industries discharge untreated toxic waste into water bodies, posing severe environmental hazards to humans as well as aquatic ecosystem. Synthetic dyes from textiles exacerbate this issue due to their toxicity, making the management of industrial wastewater a significant environmental challenge. This study offers a potential solution by investigating the degradation of hazardous Acid Blue-9 (AB9) dye using bacterial consortium containing Pseudomonas fluorescens and Bacillus subtilis. The experiments were conducted in minimal salt media with varying concentrations of different parameters (pH, temperature, initial dye concentration, size of inoculum, carbon and nitrogen sources) used for optimization process. Using the One-Factor-At-A-Time method, the consortium in the study was able to decolorize at a noteworthy rate of decolorisation about 85–87.2 %. This rate was notably increased to around 90.02 % with the implementation of Response Surface Methodology. Additionally, the decolorisation process was further confirmed by using UV-Visible Spectroscopy and Fourier Transform InfraRed Spectroscopy. Additionally, a phytotoxicity assessment test on crops of agricultural significance supports the potential of this bacterial consortium for the bioremediation of AB9 contaminated water. The dye samples treated with bacterial consortium showed significantly higher seed germination rates (∼82.9 %), along with increased shoot (∼9.13 cm) and root lengths(∼3.01 cm), compared to the untreated samples. This promising finding suggests the potential for reusing treated water in agriculture and industry, offering a sustainable solution to water pollution.

Water-soluble chlorogenic acid-chitosan and polydatin-chitosan conjugates: antibacterial activity and inhibition of lipid and protein oxidation.

Chitosan (CS), an abundant alkaline polysaccharide, is valued for its biocompatibility, non-toxicity, and antibacterial properties. However, its limited solubility and modest antioxidant activity constrain its utility. Grafting polyphenols onto chitosan through the use of grafting reactions can enhance both the solubility and bioactivity of chitosan. Among the techniques employed, the free radical grafting method is favored for its simplicity, environmental sustainability, and its effectiveness in preserving biological activity. In this study, chlorogenic acid (CGA) and polydatin (PLD) were conjugated successfully to chitosan by a Vc/H2O2 redox system. Analytical techniques such as ultraviolet-visible (UV-visible) spectroscopy, fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and proton nuclear magnetic resonance (1H NMR) were employed to confirm the formation of covalent bonding between the polyphenol molecules and the chitosan backbone. The novel conjugates displayed superior antioxidant properties in comparison with pristine chitosan, as evidenced by their enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, and hydroxyl radical scavenging capacities, and Fe2+ reducing power. Both CGA-CS and PLA-CS exhibited excellent lipid and protein oxidation inhibition capabilities. Furthermore, the conjugates were shown to have significant antibacterial effects against four common pathogenic bacteria: Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas putida, and Staphylococcus aureus (P < 0.05). The newly synthesized water-soluble polyphenol-chitosan conjugates demonstrated remarkable biological activity, particularly CGA-CS. This study offers new insights and a strong theoretical foundation for developing natural food preservation materials with potential applications in the food industry. © 2024 Society of Chemical Industry.

SYNERGISTIC EFFECT OF BACILLUS MUCILAGINOSUS AND PSEUDOMONAS FLUORESCENS ON THE AVAILABILITY OF SOIL POTASSIUM, GROWTH AND YIELD OF CUCURBITA PEPO L.

A field experiment was carried out at the field of Agricultural Research and Experiments Station during the season 2021-2022 in order to study the synergestic effect and compatible between Bacillus mucilaginosus and Pseudomonas fluorescens when they added as combination on potassium availability in the soil and on some plant growth characteristics and yield of Cucurbita pepo L. The experiment included four treatments B0, control , B1 addition of Bacillus mucilaginosus inoculum, B2 addition Pseudomonas fluorescens inoculum and B1 B2 addition of acombination of B1 and B2 inoculum . The experiment was conducted by using randomised complete blocks design in three replicates . The results showed that the co- inoculation with Bacillus mucilaginous and Pseudomonas fluorescens significant effect on quantity of soluble,exchangeable potassium as well as the plant height, dry weight of shoots, percentage of potassium in the shoot and in the fruits and total yield as compared with individual inoculation for any bacteria B1 or B2 which refers to positive synergestic effect. B1B2 treatment achieved the highest mean of soluble, exchangeable potassium which amounted to(0.163,0.856) cmol kg-1 soil respectively with an increase of (21.642 %, 15.676%) and (33.606%, 22.636%) of what was achieved by treatment (B1, B2) for the mean of soluble, exchangeable potassium respectively . B1B2 treatment achieved the lowest mean of( non-exchangeable and mineral) potassium which amounted to (35.280) cmol kg-1 soil.

Visible light-activated dye-sensitized TiO2 antibacterial film: A novel strategy for enhancing food safety and quality

Antibacterial packaging holds promise in addressing food spoilage by inactivating bacteria, but current antimicrobial packaging solutions face challenges like depletion of antibacterials and concerns of antibiotic abuse. In response to these limitations of existing packaging materials, we developed a novel antibacterial packaging film by incorporating titanium dioxide (TiO2)- tetra(4-carboxyphenyl) porphyrin (TcPP) conjugates into cellulose nanofibrils (CNF) films. Unlike conventional antimicrobial packaging, this film harnesses visible light energy to excite electrons from TcPP to TiO2, generating reactive oxygen species (ROS) that inactivate bacteria without relying on antibiotics. Results demonstrated that the film reduced 4.5, 4.6, 4.1, and 4.7-log Escherichia coli, Pseudomonas fluorescens, Leuconostoc lactis, and Listeria innocua, respectively, in phosphate-buffered saline within 72h under 6000 lux light (3.13mW/cm2). The antimicrobial efficacy decreased as the light intensity decreased. Notably, it retains significant antimicrobial properties even under an extremely low light intensity of 600 lux (0.60mW/cm2). The analysis also revealed that singlet oxygen and hydrogen peroxide are the major generated ROS from the film under light exposure. When applied to cucumbers, the film reduced E. coli by 3.5 logs after 48-hour light exposure. The designed photocatalytic antibacterial film represents a major advancement in sustainable food preservation, reducing food waste by extending the shelf life of fresh produce.

A Review on Green Synthesized Metal Nanoparticles Applications

Nanotechnology pertains to the manipulation of materials at exceedingly small scales, specifically between 1 and 100 nanometers. Materials at this scale exhibit significantly different properties compared to the same materials at larger scales. An emerging trend is the utilization of nanoparticles (NPs) to address environmental issues. Metallic nanoparticles are among the several nanoparticles that are extensively utilized in environmentally sustainable endeavors. A sustainable, economical, and enduring approach is to synthesize nanoparticles through a more ecologically friendly procedure instead of a physical or chemical method. Plant components primarily function as reducing and capping agents in eco-friendly synthesis. Diverse metallic nanoparticles of various sizes and shapes have been created utilizing extracts from plant materials, including leaves, bark, fruits, and flowers. The synthesis of Nobel laureate metal nanoparticles is essential to the medical sector. A diverse array of glycosides and phenolic compounds constitutes numerous organic constituents in plants, facilitating the synthesis of metal nanoparticles. The absence of detrimental by-products in metal nanoparticle synthesis is the primary significance of green synthesis. The nanoparticles generated by an eco-friendly approach demonstrate several significant biological activity. A substantial body of literature demonstrates that the synthesized nanoparticles are efficacious against both gram-positive and gram-negative bacteria, including E. coli, Bacillus subtilis, Klebsiella pneumoniae, and Pseudomonas fluorescens. The synthesized nanoparticles not only display antifungal efficacy against several cancer cell lines, including those of breast cancer, but also demonstrate antifungal activity against Trichophyton simii, Trichophyton mentagrophytes, and Trichophyton rubrum. Moreover, they exhibit potent antioxidant properties. The dimensions and morphology of these metal nanoparticles substantially influence their functionalities. Particles characterized by a large surface area and diminutive size provide significant potential for medical applications. This paper aims to provide a comprehensive summary of current advancements in the synthesis of nanoparticles utilizing biological entities and their numerous potential applications.

Pre-sowing recurrent inoculation with Pseudomonas fluorescens promotes maize growth

Pre-sowing recurrent inoculation with Pseudomonas fluorescens promotes maize growth

Prevalence of Resistance Genes Among Multidrug-Resistant Gram-Negative Bacteria Isolated from Waters of Rivers Swat and Kabul, Pakistan.

The waters of rivers Swat and Kabul are the main water source for domestic and irrigation purposes in the northwestern part of Pakistan. However, this water has been contaminated due to human activities. This study aimed to analyze the water of these rivers for occurrence of antibiotic resistance genes among Gram-negative bacteria. Samples were collected from 10 different locations of these rivers. The samples were processed for the isolation of Gram-negative bacteria. Isolated bacteria were checked against 12 different antibiotics for susceptibility. The isolates were also analyzed for the presence of seven antibiotic resistance genes. A total of 50 bacterial isolates were recovered that belonged to five different bacterial genera, that is, Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Raoultella terrigena (Klebsiella terrigena), and Pseudomonas fluorescens. Antibiotic resistance pattern was cefixime 72%, cephalothin 72%, ampicillin 68%, nalidixic acid 68%, kanamycin 54%, streptomycin 42%, sulfamethoxazole-trimethoprim 28%, chloramphenicol 28%, meropenem 8%, gentamicin 8%, amikacin 2%, and tobramycin 2%. The prevalence of bla-TEM gene was 72% (n = 36), aadA gene 34% (n = 17), sul gene 32% (n = 16), bla-CTXM gene 12% (n = 6), int gene 66% (n = 33), and int1 gene 6% (n = 3). This information highlights the need for controlling and monitoring the release of domestic wastes to rivers.

Biochemical Changes and Germination Response of Indian Sandalwood (Santalum album L.) Seeds Subjected to Biopriming Techniques and Variable Post-priming Storage

Understanding of the storage behaviour of endangered plant species such as Indian Sandalwood, Santalum album L. is important for successful conservation. We tested biopriming method with five biopriming agents (e.g. Effective microorganisms; Plant growth promoting rhizobacteria (PGPR-I and PGPR-II); Pseudomonas fluorescens and Piriformospora indica) with four uniform durations of treatments viz. 2, 4, 6 and 8 days. Hydropriming was also performed with similar condition for comparison of seed performance. The study examined the biochemical changes that occur in Sandalwood seeds during different post-priming storage periods (0, 30, 60, 90 days) to assess the efficacy of biopriming techniques on seed germination and health. Biopriming with Pseudomonas fluorescens for eight days recorded the highest germination percentage (70.67%) and the highest germination rate index (0.84). Longer durations of PGPR-I and Piriformospora indica treatment (6-8 days) lowered the imbibition period and mean germination time while increasing the germination rate. After a post-priming storage period of 30 days, only EM and Pseudomonas fluorescens treated seeds germinated while all other treatments failed to germinate. Absence of germination in any biopriming group at 60 and 90 days storage period indicated that the sandal seeds deteriorated over extended storage period. The reduction in seed viability of sandal seeds was consequent to the changes in the biochemical characteristics and action of enzymes (α and β amylases) involved in seed food reserve depletion and loss in membrane integrity.

Optimizing pectin lyase production using the one-factor-at-a-time method and response surface methodology.

Pectinases are commonly industrially synthesized by molds. This study aimed to optimize pectin lyase synthesis by a bacterium, Pseudomonas fluorescens, using both the one-factor-at-a-time (OFAT) method and response surface methodology. First, on optimization of pectin lyase fermentation by the OFAT method, the effects of pectin, peptone, yeast extract, (NH4)2SO4, pH, and salts were investigated. The highest pectin lyase activity was determined to be 28.63U/mL at pH 8, 30°C, with 1% (w/v) pectin and 0.14% (w/v) (NH4)2SO4 concentration at the 90th hour. The effect of substrate inhibition on the microbial growth was also investigated, and the results showed that the process can be described by noncompetitive inhibition model. The values of kinetic constants were determined as µm=0.175h-1, KS=6.931g/L, and, KI=6.932g/L by nonlinear regression analysis. It was reported that pectin lyase enzymes exhibited peak activity at 50°C and pH 8. Finally, response surface methodology (RSM) was utilized to optimize pH, concentrations of ammonium sulfate, and pectin, which were chosen as independent variables. The interactions between these variables were also examined. According to RSM, the optimum values of the parameters to achieve a maximum pectin lyase activity of 35.62U/mL were determined to be pH 7.97, 1.25% (w/v) pectin concentration, and 0.25% (w/v) (NH4)2SO4 concentration.

Synergy between bio-control agents to trigger the defensive responses against Rhizoctonia root rot and enhance the growth, yield, and physiological and anatomical traits of pea plants

AbstractRhizoctonia solani (Rs) is the fungus that causes the primary and deadly disease that attacks pea plants throughout the cool growing season. It causes seed rot, damping off, and pea root rot diseases. The current study used arbuscular mycorrhizal fungi; Rhizoglomus clarum, Gigaspora margarita, Rhizophagus irregularis and Funneliformis mosseae (AMF), Pseudomonas fluorescens HE21 (Pf), and Trichoderma harzianum HL9 (TH) singly or in combination to suppress Rhizoctonia root rot of pea in a greenhouse. Using the in vitro dual culture assay, TH and Pf inhibited the radial growth of the Rs by 73.3 and 60.0%, respectively. The results of greenhouse experiments showed that all treatments significantly decreased the percentages of pre- and post-emergence damping while significantly increasing the number of surviving plants, particularly in the dual and triple combination treatments. Furthermore, all treatments improved yield and seed quality in addition to plant growth, total phenol content and antioxidant enzyme activity. There were also noted modifications to the treated plants’ anatomical, physiological, and distinctive features. The synergistic triple treatment consisting of M, TH, and Pf achieved the maximum reduction of disease severity (78.5%) compared to the untreated control treatment. As a result of the synergistic triple treatment due to their effectiveness and eco-safety, we recommend using the synergistic triple by M + Pf + TH to manage the root rot disease in peas caused by Rs and to enhance the crop’s growth, yield, and seed quality.

Impact of Plant Growth-Promoting Microorganism (PGPM) Consortium on Biochemical Properties and Yields of Tomato Under Drought Stress.

Drought is the most important abiotic stress that restricts the genetically predetermined yield potential of the crops. In the present study, four tomato varieties: Kashi Vishesh, Kashi Aman, Kashi Abhiman, and Kashi Amrit, were used to study the effect of PGPMs (plant growth-promoting microorganisms). PGPM strains, Bacillus megaterium BHUPSB14, Pseudomonas fluorescens BHUPSB06, Pseudomonas aeruginosa BHUPSB01, Pseudomonas putida BHUPSB0, Paenibacillus polymixa BHUPSB17, and Trichoderma horzianum, were used as the consortium. The control group was irrigated up to 80% of field capacity, while 7-, 14-, and 21-day water-deficit-exposed (DWD) plants' pot soil moisture was maintained to 40, 25, and 15% of the field capacity, both with and without the PGPM inoculation condition. The physiological parameters, such as electrolyte leakage, relative water content, photosynthetic efficiency, and chlorophyll color index, were significantly improved by PGPM application under progressive drought stress, compared to the control. PGPM application enhanced the proline accumulation and reduced the formation of hydrogen peroxide and lipid peroxidation under drought stress. The plant growth attributes were significantly increased by PGPM application. The Kashi Amrit variety showed the highest fruit yield among the four varieties under all the treatments. The PGPM consortium application also improved the soil physico-biological properties and nutrient availability in the soil. The PGPM consortium used in this study can potentially mitigate drought stress on tomato in drought-prone regions and act as a biofertilizer. The present study will open a new avenue of drought stress management in tomato.