Antifungal metabolites produced by Pseudomonas hunanensis SPT26 effective in biocontrol of fusarium wilt of Lycopersicum esculentum under saline conditions.

In past few years, salinity has become one of the important abiotic stresses in the agricultural fields due to anthropogenic activities. Salinity is leading towards yield losses due to soil infertility and increasing vulnerability of crops to diseases. Fluorescent pseudomonads are a diverse group of soil microorganisms known for promoting plant growth by involving various traits including protecting crops from infection by the phytopathogens. In this investigation, salt tolerant plant growth promoting bacterium Pseudomonas hunanensis SPT26 was selected as an antagonist against Fusarium oxysporum, causal organism of fusarium wilt in tomato. P. hunanensis SPT26 was found capable to produce various antifungal metabolites. Characterization of purified metabolites using Fourier transform infrared spectroscopy (FT-IR) and liquid chromatography-electron spray ionization-mass spectrometry (LC-ESI/MS) showed the production of various antifungal compounds viz., pyrolnitrin, pyochelin and hyroxyphenazine by P. hunanensis SPT26. In the preliminary examination, biocontrol activity of purified antifungal metabolites was checked by dual culture method and results showed 68%, 52% and 65% growth inhibition by pyrolnitrin, 1- hydroxyphenazine and the bacterium (P. hunanensis SPT26) respectively. Images from scanning electron microscopy (SEM) revealed the damage to the mycelia of fungal phytopathogen due to production of antifungal compounds secreted by P. hunanensis SPT26. Application of bioinoculant of P. hunanensis SPT26 and purified metabolites significantly decreased the disease incidence in tomato and increased the plant growth parameters (root and shoot length, antioxidant activity, number of fruits per plant, etc.) under saline conditions. The study reports a novel bioinoculant formulation with the ability to promote plant growth parameters in tomato in presence of phytopathogens even under saline conditions.

Flagellin conjugated Per a 10 and its T cell peptides attenuate airway inflammation and restore cellular function.

Adjuvants were used to modulate response towards relevant immune cells. The present study aims to investigate FlaA-conjugated Per a 10 and T cell peptides in amelioration of allergic airway disease in mice. Mice given Per a 10 showed allergic features with higher cellular infiltration, IgE, Th-2 cytokines and alarmins. Fusion protein treatment reduced lung inflammation (p < 0.0001) and cellular infiltrates (p < 0.001) with higher IgG2a/IgE indicating resolution of disease. Immunotherapy with FPT1 and FPT3 reduces IL-4, IL-5 and IL-13 levels (p < 0.0001) with a fourfold increase in IFN-γ secretion in BALF. FPT1- and FPT3-treated mice have increased IL-10 and TGF-ß levels (p < 0.001) with CD4+Foxp3+ T cells (p < 0.01) indicating Treg response. There was enhanced expression of claudin-1 (1.7-fold) and occludin (fourfold) in lungs of FPT1- and FPT3-treated mice with reduced TSLP (p < 0.01) and IL-33 (p < 0.0001) secretion in BALF indicating recovery of epithelial function. Peptide-conjugated FlaA proteins showed protective immunity in mice and have potential for immunotherapy with restoration of cellular function.

NLRP3/GSDMD mediated pyroptosis induces lung inflammation susceptibility in diesel exhaust exposed mouse strains.

BACKGROUND: Genetic diversity among species influences the disease severity outcomes linked to air pollution. However, the mechanism responsible for this variability remain elusive and needs further investigation. OBJECTIVE: To investigate the genetic factors and pathways linked with differential susceptibility in mouse strains associated with diesel exhaust exposure. METHODS: C57BL/6 and Balb/c mice were exposed to diesel exhaust (DE) for 5 days/week for 30 min/day for 8 weeks. Body weight of mice was recorded every week and airway hyperresponsiveness towards DE exposure was recorded after 24 h of last exposure. Mice were euthanised to collect BALF, blood, lung tissues for immunobiochemical assays, structural integrity and genetic studies. RESULTS: C57BL/6 mice showed significantly decreased body weight in comparison to Balb/c mice (p < 0.05). Both mouse strains showed lung resistance and damage to elastance upon DE exposure compared to respective controls (p < 0.05) with more pronounced effects in C57BL/6 mice. Lung histology showed increase in bronchiolar infiltration and damage to the wall in C57BL/6 mice (p < 0.05). DE exposure upregulated pro-inflammatory and Th2 cytokine levels in C57BL/6 in comparison to Balb/c mice. C57BL/6 mice showed increase in Caspase-1 and ASC expression confirming activation of downstream pathway. This showed significant activation of inflammasome pathway in C57BL/6 mice with ∼2-fold increase in NLRP3 and elevated IL-1ß expression. Gasdermin-D levels were increased in C57BL/6 mice demonstrating induction of pyroptosis that corroborated with IL-1ß secretion (p < 0.05). Genetic variability among both species was confirmed with sanger's sequencing suggesting presence of SNPs in 3'UTRs of IL-1ß gene influencing expression between mouse strains. CONCLUSIONS: C57BL/6 mice exhibited increased susceptibility to diesel exhaust in contrast to Balb/c mice via activation of NLRP3-related pyroptosis. Differential susceptibility between strains may be attributed via SNPs in the 3'UTRs of the IL-1ß gene.

Salt-tolerant plant growth-promoting Pseudomonas atacamensis KSS-6 in combination with organic manure enhances rice yield, improves nutrient content and soil properties under salinity stress.

In the current study salt tolerant-plant growth-promoting rhizobacteria (ST-PGPR) Pseudomonas atacamensis KSS-6, selected on the basis of prominent plant growth-promoting (PGP) and stress tolerance properties was tested as bioinoculant to improve yield of rice grown in saline soil. The ST-PGPR KSS-6 was capable of maintaining the PGP traits up to 200 mM NaCl, however, higher salt stress conditions affected these activities. The study was designed to determine the effect of developed talc-based bioformulation using KSS-6 along with organic manure (OM) on growth and yield of paddy under saline conditions. Bioformulation broadcasting was also done to examine the effect on soil properties. It was found that the combinatorial treatment showed positive impact on growth and yield of rice under saline conditions. Co-application of KSS-6 with OM showed maximum increment in growth, chlorophyll content, plant fresh weight, and dry weight as compared to untreated control plants. Furthermore, the combinatorial treatment improved the nutrient content (P, K, Zn, Fe, Mg, and Mn) by more than 35% and enhanced the biochemical parameters such as proline, flavonoids, carbohydrates, protein, dietary fiber, and antioxidant content of rice grains by more than 32%. Soil parameters including pH and electrical conductivity (EC), moisture content, total organic carbon, OM, sodium, and chloride ions were also improved upon treatment. There was significant lowering of EC from 7.43 to 4.3 dS/m when combination of OM and bacteria were applied. These findings suggest that the application of KSS-6 in the form of bioinoculant could be a promising strategy to mitigate negative impacts of salt stress and enhance the yield and nutritional properties of rice grown in degraded and saline soil.

Natural variability and heritability of root-nodulation traits in chickpea (Cicer arietinum L.) minicore.

The existence of large variations for nodulation traits in chickpea minicore was revealed and genetic materials for beneficial biological nitrogen fixation (BNF) traits like early nodulation, high nodulation, and delayed nodule senescence were identified. Early-nodulating genotypes viz. ICC12968, ICC7867, ICC13816, ICC867, ICC15264, ICC15510, and ICC283 produced > 10 nodule number per plant (NNPP) at 15 as well as 30 days after sowing (DAS). Maximum of 36 NNPP at stage 3 i.e., 253% higher than check cultivar were observed in Iran originated ICC6874. Chickpea minicore showed large variations for nodule mass that ranged up to 850 mg/plant at 60 DAS and 2290 mg/plant at 90 DAS. Strong positive correlation was found between nodule fresh weight and specific weight at stage 3 (0.69) and stage 4 (0.76). Besides these, few slight positive significant correlations were also observed viz., nodule number per plant at stage 3 and 4 (0.45), nodule fresh weight at stage 3 and 4 (0.39). Principal component analysis (PCA) indicated that dimensions 1 (21%), 2 (17.6%), and 3 (13%) accounted for a substantial portion of the phenotypic variance, each contributing more than 10%. Accessions viz. ICC1431, ICC13599, ICC13764, and ICC13863 with pink active root nodules and high nodule biomass at later crop growth stages are considered as genetic resources to extend the BNF support in chickpea. High broad-sense heritability values of 76.43 and 90.23 were observed for early nodulation and delayed nodule senescence, respectively. Hence, the identified genotypes for early nodulation and delayed nodule senescence can be used for improving symbiotic efficiency in chickpea. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03908-1.

Salt tolerant Pseudomonas taiwanensis PWR-1 in combination with a reduced dose of mineral fertilizers improves the nutritional and antioxidant properties of wheatgrass grown in saline soil.

Salt-tolerant plant growth promoting rhizobacteria (ST-PGPR) are known to ameliorate salt stress in plants by various mechanisms. The current study aims to investigate the role of an ST-PGPR strain Pseudomonas taiwanensis PWR-1 applied along with a reduced dose of mineral fertilizers (N, P, and K) in the improvement of the antioxidant and nutritional properties of wheatgrass (Triticum aestivum L.) grown in saline soil. Application of P. taiwanensis PWR-1 along with 50% of the recommended dose of mineral fertilizers resulted in a significant improvement of growth parameters including shoot length (22.79%), root length (20.38%), fresh weight (13.15%), dry weight (92.34%), vigor index (13.36%), and relative water content (48.24%). The combined application of PWR-1 and mineral fertilizers increased the production of osmoprotectants (proline, total soluble sugars, glycine betaine), antioxidants (SOD, POD, APX, CAT, PPO, and reduced glutathione), and free radical scavengers (DPPH and H2O2) in wheatgrass. Furthermore, the concentration of micronutrients (Zn and Fe), macronutrients (N, and P), and vitamins (B1 and E) also increased in the above treatment. Oxidative stress markers (malondialdehyde and electrolyte leakage) and Na+ accumulation were significantly reduced whilst K+ content increased in the shoot, which helped in maintaining the K+/Na+ ratio in wheatgrass under saline conditions. The results indicated that the application of ST-PGPR could not only reduce the dosage of mineral fertilizers but might be useful for improving the nutritional and antioxidant properties of medicinal crops such as wheatgrass under salt-stress conditions. Implementing this approach could result in the reduction of chemical usage, while also facilitating enhanced uptake of micronutrients in crops, particularly in regions affected by salinity.

Resveratrol mitigates miR-212-3p mediated progression of diesel exhaust-induced pulmonary fibrosis by regulating SIRT1/FoxO3.

BACKGROUND: Diesel exhaust (DE) exposure contributes to the progression of chronic respiratory diseases and is associated with dysregulation of microRNA expression. The present study aims to investigate the involvement of miRNAs and target genes in DE-induced lung fibrosis. METHODS: C57BL/6 mice were divided into three groups. Group 1 mice were exposed to filtered air (Control). Group 2 mice were exposed to DE for 30 min per day, 5 days per week, for 8 weeks (DE). Group 3 mice received DE exposure along with resveratrol on alternate days for the last 2 weeks (DE + RES). Mice were sacrificed to isolate RNA from lung tissue for miRNA microarray profiling. Bronchoalveolar lavage fluid and lung tissues were collected for cell count and biochemical analysis. RESULTS: DE exposure resulted in differential expression of 28 miRNAs with fold change >2 (p < 0.05). The upregulated miR-212-3p was selected for further analysis. Consensus analysis revealed enrichment of SIRT1 in the FoxO pathway, along with a co-annotation of reduced body weight (p < 0.05). A549 cells transfected with a miR-212-3p inhibitor showed a dose-dependent increase in SIRT1 expression, indicating SIRT1 as a direct target. Treatment with resveratrol restored SIRT1 and miR-212-3p expression and led to a reduction in inflammatory cytokines (p < 0.05). The modulation of SIRT1 correlated negatively with macrophage infiltration, confirming its role in regulating cellular infiltration and lung inflammation. Fibronectin, alpha-SMA, and collagen levels were significantly decreased in DE + RES compared to DE group suggesting modulation of cellular functions and resolution of lung fibrosis. Furthermore, a significant decrease in FoxO3a and TGF-ß gene expressions was observed upon resveratrol administration thereby downregulating pro-fibrotic pathway. CONCLUSIONS: The present study demonstrates resveratrol treatment stabilizes SIRT1 gene expression by attenuating miR-212-3p in DE-exposed mice, leading to downregulation of TGF-ß and FoxO3a expressions. The study highlights the therapeutic role of resveratrol in the treatment of DE-induced pulmonary fibrosis.

Biofortification revisited: Addressing the role of beneficial soil microbes for enhancing trace elements concentration in staple crops.

Trace element deficiency is a pervasive issue contributing to malnutrition on a global scale. The primary cause of this hidden hunger is related to low dietary intake of essential trace elements, which is highly prevalent in numerous regions across the world. To address deficiency diseases in humans, fortification of staple crops with vital trace elements has emerged as a viable solution. Current methods for fortifying crops encompass chemical amendments, genetic breeding, and transgenic approaches, yet these approaches possess certain limitations, constraining their agricultural application. In contrast, fortifying staple crops through the utilization of soil-beneficial microbes has emerged as a promising and economically feasible approach to enhance trace element content in crops. A specific subset of these beneficial soil microbes, referred to as plant growth-promoting microbes, have demonstrated their ability to influence the interactions between plants, soil, and minerals. These microbes facilitate the transport of essential soil minerals, such as zinc, iron, and selenium, into plants, offering the potential for the development of tailored bioinoculants that can enhance the nutritional quality of cereals, pulses, and vegetable crops. Nevertheless, further research efforts are necessary to comprehensively understand the molecular mechanisms underlying the uptake, transport, and augmentation of trace element concentrations in staple crops. By delving deeper into these mechanisms, customized bioinoculants of soil-beneficial microbes can be developed to serve as highly effective strategies in combating trace element deficiency and promoting global nutritional well-being.

Diesel exhaust exposure impairs recovery of lung epithelial and cellular damage in murine model.

Studies have investigated the relationship between diesel exhaust (DE) exposure and lung health, highlighting the potential for DE to induce pulmonary inflammation and oxidative stress. However, the resolution of inflammation upon withdrawal of DE exposure needs further investigation. Therefore, resolution of diesel exhaust-induced lung damage was studied in the murine model. Mice (6 weeks) were divided into three groups. Group 1 (control) mice were exposed to filtered air, Group 2 (DE) mice were exposed to DE (5.1 ± 0.7 mg/m3) & Group 3 (DE-FA) mice were exposed to DE followed by filtered air exposure. Airway hyper-responsiveness was recorded after 24 h of the last exposure. BALF and lung samples were collected for cytokine estimation, immunobiological assays, and western blot analysis. DE exposure showed an increase in lung resistance thereby causing alteration in lung function parameters (p < 0.05) which was restored in the DE-FA group. BALF analysis showed a significant increase in total cell count and protein content in DE with no resolution in DE-FA groups (p < 0.05). Lung histology showed no reduction in the bronchiolar thickness and damage in the DE-FA group suggesting irreversible lung damage (p < 0.05). The significant increase in inflammatory cytokine levels, and collagen deposition showed persistent inflammatory phase and lung damage in the DE-FA group(p < 0.05). ZO-1 was significantly decreased in both test groups indicating disintegrated lung epithelium where in claudin-5 expression showed increased lung permeability. A significant increase in neutrophil elastase activity and decreased expression of, Elafin, resulted in lung epithelial damage in the DE-FA group. Lung injury marker alpha1-antitrypsin was increased in DE-FA groups indicating an immune defense mechanism against neutrophil elastase. The study showed that DE exposure causes persistent lung damage via neutrophil elastase-associated disruption of the epithelial barrier integrity and membrane dysfunction.

In silico tools to assess the potential allergenicity of shiitake mushrooms (Lentinula edodes).

BACKGROUND: Computational tools may have an edge over conventional methods for the preliminary evaluation of food allergenicity. In this study, the allergenic potential of Lentinula edodes was evaluated and validated using in silico tools. RESULTS: The potential cross-reactivity of mushroom proteins with fungal allergens was determined using sequence alignment - the Fast Alignment (FASTA) and Basic Local Alignment Search Tool (BLAST) algorithm. Eight L. edodes proteins were cross-reactive with allergens from fungal origin, showing 52%-89% sequence identity using FASTA algorithm-based alignment. The BLAST data were corroborated by percentage identity and query coverage. Physico-chemical property-based allergenicity was deciphered by AlgPred, Allermatch, and AllergenFP software, which predicted six out of eight proteins as potential allergens. Sequence alignment showed 66%-86% conservancy between mushroom protein and known fungal allergens. Secondary structure and amino acid composition supported structural affinity between query and fungal proteins. Three-dimensional structures of five mushroom proteins were generated, quality assessed, and superimposed with fungal allergens, suggesting possible allergenicity of mushroom proteins. An enzyme-linked immunosorbent assay (ELISA) demonstrated immunoglobulin E (IgE) binding in 13 out of 21 food-hypersensitive patients' sera. CONCLUSION: In silico tools provide preliminary indications about the potential allergenicity and cross-reactivity of mushroom proteins. This approach may be used for the prelusive allergenicity assessment of allergen sources. © 2022 Society of Chemical Industry.

TLR-5 ligand conjugated with Per a 10 and T cell peptides potentiates Treg/Th1 response through PI3K/mTOR axis.

Novel strategies are needed to enhance efficacy of immunotherapy for allergic diseases. The present study evaluates role of conjugating flagellin with allergen, Per a 10 and its T cell epitopes in DC mediated polarization. Fusion proteins (FPer a 10, FPT1, FPT2 and FPT3) were sub-cloned, expressed and purified to homogeneity. FlaA fused proteins showed TLR-5 binding in TLR5+HEK293 cells as observed by enhanced NF-κB dual luciferase assay and IL-8 secretion in culture supernatant. Fusion proteins upregulate co-stimulatory molecules CD80, CD83 and CD86 on BMDCs and enhanced IL-6, IL-ß, IL-12p70 and IL-10 secretion. Inhibition studies suggest fusion proteins mediate IL-10 secretion via activation of PI3K/mTOR/NF-κB pathway. FPT1 and FPT3 deviate Th2 cytokine milieu towards Th1/Treg by upregulating the expression of IFN-γ, IL-12p70, IL-10 and TGF-ß in BMDCs co-culture with allergen specific T cells. Flow cytometric examination of BMDC:T cell co-culture revealed CD4+ T cell differentiation towards Th1/Treg by FPT1 and FPT3. Thus, our results indicate that flagellin fused with T cell peptides are efficient immunomodulators and may possess potential for allergy therapeutics.

Immuno-informatic Prediction of B and T cell Epitopes of Cysteine Protease Allergen from Phaseolus vulgaris with Cross-reactive Potential and Population Coverage.

BACKGROUND: In-silico mapping of epitopes by immune-informatics has simplified the efforts towards understanding antigen-antibody interactions. The knowledge of allergen epitopes may help in advancing the diagnosis and therapy of allergic diseases. OBJECTIVE: This study was intended to identify B and T cell epitopes of cysteine protease allergen of Phaseolus vulgaris. METHODS: Modeller 9v20 software was used for the generation of three-dimensional model of cysteine protease and quality assessment was performed using SAVES webserver and other in silico software. Linear and conformational B and T cell epitopes were predicted via immuno-informatics based computational servers. Epitopes were synthesized and their immunoreactivity was analyzed using specific IgE ELISA with food allergy positive patient's sera. Cellular immune response of peptides was determined through basophil activation assay. Consurf and SDAP (property distance) were used to examine the evolutionary conservancy and potential cross-reactivity of predicted epitopes. MSA based positional conservancy between HDM allergen epitopes and predicted peptides was also established using IEDB epitope database. Finally, population coverage for each promiscuous T cell epitope was predicted using IEDB population coverage analysis tool. RESULTS: Cysteine protease structure was derived by homology modeling and combination of bioinformatic tools predicted three B- and three T-cell peptides by consensus method and validated computationally. ELISA with kidney bean sensitive patient's sera showed higher IgE binding of B-cell peptides as compared to T-cell or control peptides. Epitope conservancy revealed B-cell epitopes being upto 95% conserved in comparison to variable T-cell epitopes (upto 69%). B-cell peptides were crossreactive with homologous allergens based on PD values. Structural comparison of cysteine protease with Der p 1 and Der f 1 showed similar epitopic regions, validating the prediction accuracy of epitopes. Promiscuous T-cell epitopes binding to broad-spectrum class-II MHC alleles demonstrated the distribution of T-cell peptides world-wide (30-98%) and in Asian population (99%). CONCLUSION: The current approach can be applied for identification of epitopes. Analysis of crossreactive and widely-distributed specific epitopes of allergen and knowledge about their interactive surfaces will help in understanding of food allergy and related immune responses.

A Novel Bacillus safensis-Based Formulation along with Mycorrhiza Inoculation for Controlling Alternaria alternata and Simultaneously Improving Growth, Nutrient Uptake, and Steviol Glycosides in Stevia rebaudiana under Field Conditions.

The excess use of chemicals by farmers in the agroecosystems degrades soil quality, disturbs soil ecology, and increases soil salinity and health hazards in humans. Stevia rebaudiana is an important medicinal and aromatic crop whose leaves contain steviol glycosides (SGs). The Bacillus safensis NAIMCC-B-02323 strain STJP from the rhizosphere of S. rebaudiana producing salicylic acid (16.80 µg/mL), chitinase (75.58 U/mL), ß-1,3-glucanase (220.36 U/mL), and cellulase (170 U/mL) was taken as a plant growth-promoting rhizobacteria (PGPR). The cell-free supernatant (CFS) from strain STJP showed significant biocontrol activity against Alternaria alternata (80%), suggesting the protective role of extracellular metabolite(s) against phytopathogens. Paneer whey-based bioformulation (P-WBF) was developed to exploit B. safensis STJP to enhance the growth, nutrient uptake, soil properties, stevioside content, and SGs biosynthesis in S. rebaudiana under an A. alternata-infested field. The combined treatment of P-WBF and mycorrhiza (Glomus fasciculatum ABTEC) significantly enhanced plant growth parameters after 90 days, in comparison with control. The symbiotic action (P-WBF and mycorrhiza) displayed much better results in terms of chlorophyll a and b (improved by 132.85% and 39.80%, respectively), protein (by 278.75%), flavonoid (by 86.99%), carbohydrate (by 103.84%), antioxidant (by 75.11%), and stevioside (by 120.62%) contents in plants as compared to the untreated set. Further, the augmentation of potassium (by 132.39%), phosphorous (by 94.22%), and zinc (by 111.11%) uptake in plant tissues and soil was also observed by the application of P-WBF and mycorrhiza. The expression of UGT74G1 and UGT85C2 genes related to SG biosynthesis was upregulated (2.7- and 3.2-fold, respectively) in plants treated with P-WBF and mycorrhiza as further confirmed by the accumulation of SGs. The results suggest that the application of P-WBF and mycorrhiza not only provides an ecofriendly and sustainable solution to improve stevioside content in S. rebaudiana by a nutrient-linked mechanism but also paves the way to enhanced production of stevioside.

Choline chloride attenuates the allergic airway disease by inhibiting the lysophosphatidylcholine induced response in mouse model.

Aims: Allergic airway disease manifestation is induced by lysophosphatidylcholine (LPC) through CD1d-restricted Natural killer T (NKT) cells. Choline chloride (ChCl) and LPC both have the "choline" moiety in their structure and this may interplay the effect in allergic airway disease pathway. Main methods: To test the hypothesis, mice were sensitized with cockroach extract (CE); challenged with CE or exposed to LPC and were given ChCl 1hr later. Key findings: A significant increase in Airway hyperresponsiveness (AHR), total and differential cell count, Th2 cytokines, 8-isoprostanes level in bronchoalveolar lavage fluid (BALF) and inflammation score based on lung histology were observed on challenge with CE or exposure to LPC (p â€‹< â€‹0.05) indicating LPC induced airway disease manifestation in mice. These parameters were reduced significantly after administering mice with ChCl (p â€‹< â€‹0.05). The inflammatory parameters were significantly increased in LPC exposed mice, not sensitized with CE, which were significantly decreased when mice were administered with ChCl demonstrating its role in the inhibition of LPC induced allergic airway disease manifestation. Docking of CD1d with LPC and ChCl indicated the competitive inhibition of LPC induced effect by ChCl. This was validated in vivo in the form of decreased CD1d-restricted NKT cells in BALF and lung of the immunized mice on ChCl administration. There was no effect of ChCl administration on CD1d expression in BALF and lung cells. Significance: This study shows that ChCl attenuates the allergic response by inhibiting the LPC induced- NKT cell mediated AHR, inflammation and oxidative stress by competitive inhibition to LPC in binding to CD1d.

2,4-Diacetylphloroglucinol producing Pseudomonas fluorescens JM-1 for management of ear rot disease caused by Fusarium moniliforme in Zea mays L.

Maize (Zea mays L.) is a major cereal crop grown in a large number of countries. Loss in maize yield due to biotic stresses including fungal phytopathogens is a matter of immense concern. Control measures applied for eradication of fungal phytopathogens in maize are not up to the mark and more often involve harsh chemical(s)/pesticide(s) that cause deleterious effects both in humans and soil biota. Greener alternatives, such as the use of rhizosphere microbes in the form of bioinoculants, have proven to be very successful in terms of enhancing crop yield and suppressing fungal phytopathogens. In the present study, fluorescent pseudomonads were isolated from the maize rhizosphere and monitored for their plant growth-promoting (PGP) and biocontrol activities against Fusarium moniliforme. Based on various PGP traits and biocontrol potential, isolate JM-1 was found to be most effective and as per 16S rRNA gene sequencing analysis was identified as Pseudomonas fluorescens. Further experiments showed that the biocontrol potential of JM-1 against ear rot fungus involved the production of antifungal compound 2,4-diacetylphloroglucinol (DAPG). When examined for antagonistic interaction under scanning electron microscopy (SEM), structural abnormality, hyphal lysis, and deformity in fungal mycelium were observed. In the pot experiment, application of talc-based JM-1 containing bioformulation (in pot trials) showed significant enhancement in maize growth parameters (including the seed number and weight) in comparison to control even in presence of the phytopathogen. Ear fresh weight, dry weight, number of seeds per plant, and 100-grain weight were found to increase significantly by 34, 34, 52, and 18% respectively, in comparison to control. P. fluorescens JM-1 can therefore be used as a bioinoculant for ear rot disease control and sustainably enhancing maize yield. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03201-7.

Molecular and immunological characterization of cysteine protease from Phaseolus vulgaris and evolutionary cross-reactivity.

A commonly consumed legume in India, the kidney bean (Phaseolus vulgaris) is associated with allergy. We report molecular and immunological characterization of cysteine protease allergen and its cross-reactivity. In silico allergenicity assessment and phylogenetic analysis of kidney bean cysteine protease showed significant sequence homology (upto 67%) with allergens from kiwi, papaya, soybean, ragweed pollen and mites. Physicochemical properties and motif-analysis depicted cysteine protease as probable allergen. Multiple sequence alignment and phylogenetic analysis indicated structural conservation between kidney bean and homologous cysteine protease sequences. The gene was cloned, expressed and affinity purified. Cysteine protease was resolved at 42 kDa and exhibited high IgE binding (up to 89%) with hypersensitive sera. Cysteine protease showed functional property on cross-linking IgE receptors and upregulated expression of CD203c on activated basophils. In inhibition studies, 8.4 ng of cysteine protease was required for 50% self-inhibition, whereas significant inhibition was also observed with kidney bean (52 ng), black gram (155 ng), chick pea (437 ng), mesquite pollen (36 ng), house dust mite (64.85 ng), Alternaria alternata (78.8 ng) and Curvularia lunata (73.6 ng) extracts. ConSurf analysis indicated conserved active site and catalytic residues in mature domain among proteases from legumes, fruits, pollens, mites and fungus. In summary, P. vulgaris cysteine protease was molecularly characterized having functional activity. This study demonstrated, cross-reactivity between food and aeroallergens based on evolutionary conservancy that showed its clinical importance as cross-reactive allergen. PRACTICAL APPLICATIONS: Adaptation of sustainable lifestyle has led to a surge in consumption of plant-based foods especially legumes. Their high nutritional content lowers the risk of developing cardiovascular diseases, diabetes, obesity, and stroke. Kidney beans, a commonly consumed legume in Indian subcontinent, have a potential to be used as nutraceutical and functional food. Despite its alimentary nature, it elicits allergic reactions. Being a major sensitizer, trivial information regarding its allergic components has led to an urgent need for exploring its allergen repertoire. Our study reported biochemical and immunological characterization of its major cysteine protease allergen. Cysteine proteases are major cross-reactive allergens from insects, fruits and fungal sources. Identification and molecular characterization of such immunodominant allergens by RDT offers the prospect of using recombinant proteins for accurate diagnosis and therapeutic purposes. This study suggests that a potential major cross-reactive allergen may aid in developing allergy management interventions for a wide range of allergenic sources.

Whole genome sequencing of spotted stem borer, Chilo partellus, reveals multiple genes encoding enzymes for detoxification of insecticides.

Spotted stem borer, Chilo partellus, is the most important constraint for increasing the production and productivity of maize and sorghum, the two major coarse cereals in Asia and Africa. The levels of resistance to this pest in the cultivated germplasm are low to moderate, and hence, farmers have to use insecticides for effective control of this pest. However, there is no information on the detoxification mechanisms in C. partellus, which is one of the constraints for deployment of appropriate insecticides to control this pest. The ability to detoxify insecticides varies across insect populations, and hence, we sequenced different populations of C. partellus to identify and understand detoxification mechanisms to devise appropriate strategies for deployment of different insecticides for controlling this pest. Larval samples were sequenced from three different cohorts of C. partellus using the Illumina HiSeq 2500 platform. The data were subjected to identify putative genes that are involved in detoxification on insecticides in our cohort insect species. These studies resulted in identification of 64 cytochrome P450 genes (CYP450s), and 36 glutathione S-transferases genes (GSTs) encoding metabolic detoxification enzymes, primarily responsible for xenobiotic metabolism in insects. A total of 183 circadian genes with > 80% homolog and 11 olfactory receptor genes that mediate chemical cues were found in the C. partellus genome. Also, target receptors related to insecticide action, 4 acetylcholinesterase (AChE), 14 γ-aminobutyric acid (GABA), and 15 nicotinic acetylcholine (nAChR) receptors were detected. This is the first report of whole genome sequencing of C. partellus useful for understanding mode of action of different insecticides, and mechanisms of detoxification and designing target-specific insecticides to develop appropriate strategies to control C. partellus for sustainable crop production.

Per a 5-derived T-cell peptides modulate NF-kB signalling to ameliorate allergic inflammation systemically in murine model of cockroach allergic hyper-reactivity.

Peptide immunotherapy (PIT) represents a safe and efficacious therapeutic regimen with in-consequential side-effects. The present study aims to identify T-cell epitopes of Per a 5 allergen, a delta class GST from Periplaneta americana and investigate effect of peptide treatment in murine model of cockroach allergen-mediated hyper-reactivity. The epitopes (TC-P1, TC-P2, and TC-P3) were identified as promiscuous MHC-II binders by MHC-Pred, ProPred, and IEDB analysis tool. Murine model of cockroach allergic hyper-reactivity was generated in Balb/c mice. A marked reduction in cellular infiltration in lungs (3-fold compared with Non-IT) was observed in T3-IT group as evidenced by total leucocyte count in BALF and histology. Specific IgE levels were reduced 3-fold in T2-IT and T3-IT compared with Non-IT with increase in IgG2a levels. IL-4 and IL-13 were reduced upto 2.5-fold in treatment groups compared with Non-IT group. Splenocytes revealed significant increase in levels of CD4+FoxP3+ T cells in TC-P1 and TC-P2 mice demonstrating a systemic shift towards Tregs. Peptide treatment downregulated NF-kB signalling in lung and enhanced the levels of immune-regulatory molecules α1-antitrypsin and elafin. Our results indicate that TC-P1 and TC-P3 alter Th2 cytokine milieu and antibody isotype ratio to suppress allergic inflammation. PIT modulates local and systemic mechanisms to resolve inflammation and possess potential for treatment in cockroach allergy.

Diesel exhaust exposure in mice induces pulmonary fibrosis by TGF-ß/Smad3 signaling pathway.

BACKGROUND: Epidemiological studies suggest increased risk of lung cancer associated with diesel exhaust (DE) exposure. However, DE-induced lung fibrosis may lead to cancer and needs investigation. OBJECTIVES: To study the mechanism involved in the initiation of DE- induced lung fibrosis. METHODS: C57BL/6 mice were exposed to DE for 30 min/day for 5 days/weeks for 8 weeks. Pulmonary function test was performed to measure lung function. Mice were euthanized to collect BALF, blood, and lung tissue. BALF was used for cell count and cytokine analysis. Lung tissue slides were stained to examine structural integrity. RNA from lung tissue was used for RT-PCR. Immunoblots were performed to study fibrosis and EMT pathway. RESULTS: Mice exposed to DE increase lung resistance and tissue elastance with decrease in inspiratory capacity (p < 0.05) suggesting lung function impairment. BALF showed significantly increased macrophages, neutrophils and monocytes (p < 0.01). Additionally, there was an increase in inflammation and alveolar wall thickening in lungs (p < 0.01) correlates with cellular infiltration. Macrophages had black soot deposition in lung tissue of DE exposed mice. Lung section staining revealed increase in mucus producing goblet cells for clearance of soot in lung. DE exposed lung showed increased collagen deposition and hydroxyproline residue (p < 0.01). Repetitive exposure of DE in mice lead to tissue remodeling in lung, demonstrated by fibrotic foci and smooth muscles. A significant increase in α-SMA and fibronectin (p < 0.05) in lung indicate progression of pulmonary fibrosis. TGF-ß/Smad3 signaling was activated with increase in P-smad3 expression in DE exposed mice. Decreased expression of E-cadherin and increased vimentin (p < 0.05) in lungs of DE exposed mice indicate epithelial to mesenchymal transition. CONCLUSION: DE exposure to mice induced lung injury and pulmonary fibrosis thereby remodeling tissue. The study demonstrates TGF-ß/SMAD3 pathway involvement with an activation of EMT in DE exposed mice.