Food Polyphenols and Type II Diabetes Mellitus: Pharmacology and Mechanisms.

Type II diabetes mellitus and its related complications are growing public health problems. Many natural products present in our diet, including polyphenols, can be used in treating and managing type II diabetes mellitus and different diseases, owing to their numerous biological properties. Anthocyanins, flavonols, stilbenes, curcuminoids, hesperidin, hesperetin, naringenin, and phenolic acids are common polyphenols found in blueberries, chokeberries, sea-buckthorn, mulberries, turmeric, citrus fruits, and cereals. These compounds exhibit antidiabetic effects through different pathways. Accordingly, this review presents an overview of the most recent developments in using food polyphenols for managing and treating type II diabetes mellitus, along with various mechanisms. In addition, the present work summarizes the literature about the anti-diabetic effect of food polyphenols and evaluates their potential as complementary or alternative medicines to treat type II diabetes mellitus. Results obtained from this survey show that anthocyanins, flavonols, stilbenes, curcuminoids, and phenolic acids can manage diabetes mellitus by protecting pancreatic ß-cells against glucose toxicity, promoting ß-cell proliferation, reducing ß-cell apoptosis, and inhibiting α-glucosidases or α-amylase. In addition, these phenolic compounds exhibit antioxidant anti-inflammatory activities, modulate carbohydrate and lipid metabolism, optimize oxidative stress, reduce insulin resistance, and stimulate the pancreas to secrete insulin. They also activate insulin signaling and inhibit digestive enzymes, regulate intestinal microbiota, improve adipose tissue metabolism, inhibit glucose absorption, and inhibit the formation of advanced glycation end products. However, insufficient data are available on the effective mechanisms necessary to manage diabetes.

Plant Polyphenols and Their Potential Benefits on Cardiovascular Health: A Review.

Fruits, vegetables, and other food items contain phytochemicals or secondary metabolites which may be considered non-essential nutrients but have medicinal importance. These dietary phytochemicals exhibit chemopreventive and therapeutic effects against numerous diseases. Polyphenols are secondary metabolites found in vegetables, fruits, and grains. These compounds exhibit several health benefits such as immune modulators, vasodilators, and antioxidants. This review focuses on recent studies on using dietary polyphenols to treat cardiovascular disorders, atherosclerosis, and vascular endothelium deficits. We focus on exploring the safety of highly effective polyphenols to ensure their maximum impact on cardiac abnormalities and discuss recent epidemiological evidence and intervention trials related to these properties. Kaempferol, quercetin, and resveratrol prevent oxidative stress by regulating proteins that induce oxidation in heart tissues. In addition, polyphenols modulate the tone of the endothelium of vessels by releasing nitric oxide (NO) and reducing low-density lipoprotein (LDL) oxidation to prevent atherosclerosis. In cardiomyocytes, polyphenols suppress the expression of inflammatory markers and inhibit the production of inflammation markers to exert an anti-inflammatory response. Consequently, heart diseases such as strokes, hypertension, heart failure, and ischemic heart disease could be prevented by dietary polyphenols.

Biowaste-based sorbents for arsenic removal from aqueous medium and risk assessment.

Water contamination by arsenic (As) is widespread and is posing serious health threats globally. Hence, As removal techniques/adsorbents need to be explored to minimize potentials hazards of drinking As-contaminated waters. A column scale sorption experiment was performed to assess the potential of three biosorbents (tea waste, wheat straw and peanut shells) to remove As (50, 100, 200 and 400 µg L-1) from aqueous medium at a pH range of 5-8. The efficiency of agricultural biosorbents to remove As varies greatly regarding their type, initial As concentration in water and solution pH. It was observed that all of the biosorbents efficiently removed As from water samples. The maximum As removal (up to 92%) was observed for 400 µg L-1 initial As concentration. Noticeably, at high initial As concentrations (200 and 400 µg L-1), low pH (5 and 6) facilitates As removal. Among the three biosorbents, tea waste biosorbent showed substantial ability to minimize health risks by removing As (up to 92%) compared to peanut shells (89%) and wheat straw (88%). Likewise, the values of evaluated risk parameters (carcinogenic and non-carcinogenic risk) were significantly decreased (7-92%: average 66%) after biosorption experiment. The scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray and X-ray diffraction analyses confirmed the potential of biosorbents to remediate As via successful loading of As on their surfaces. Hence, it can be concluded that synthesized biosorbents exhibit efficient and ecofriendly potential for As removal from contaminated water to minimize human health risk.

Drought-tolerant Pseudomonas sp. showed differential expression of stress-responsive genes and induced drought tolerance in Arabidopsis thaliana.

The growth and persistence of rhizobacteria in soils are highly impacted by moisture stress. In this study, we report the first transcript analysis of four Pseudomonas strains (PS1, PS2, PS3, and PS4) isolated from the root-soil interface of rice and maize associated with different moisture levels during water deprivation. Filtered Pseudomonas sp. cells incubated at low (RH10%) and high (RH85%) relative humidity showed decreased survival of all Pseudomonas sp. at RH10% when compared with RH85%. RT-PCR showed differential expression of treS (trehalose synthase), rpoS (sigma factor), mucA (alginate regulatory gene), and fliM (flagellar motor switch protein gene) in response to exposure to RH10%. However, molecular fingerprinting and nutrient assimilation profile of Pseudomonas strains demonstrated genetic and physiological variation between the four strains irrespective of water regime and host. In vitro testing of these strains showed ACC deaminase activity and gibberellic acid, abscisic acid, indole acetic acid, and exopolysaccharide production. We determined that 50 µl of 1.2 × 103 CFU ml-1 of these Pseudomonas strains was enough to protect Arabidopsis plants against drought stress in a pot experiment. Inoculated plants increased their root colonization ability and biomass; however, PS2 showed higher survival (95%), relative water content (59%), chlorophyll (30%), glycine betaine (38%), proline (23%), and reduced MDA (43%) in shoots than irrigated control under induced water deprivation. It can be concluded that all Pseudomonas strains were effective in mitigating drought stress, however, PS2 appears to impart more resistance to drought than the other strains by upregulating key defense mechanisms.

Characterization of new COBRA like (COBL) genes in wheat (Triticum aestivum) and their expression analysis under drought stress.

BACKGROUND: The COBL genes encode a plant-specific glycosylphosphatidylinositol (GPI)-anchored protein. Recently identified COBRA genes are supposed as a key regulator of the orientation of cell expansion in the root indicating that COBRA gene family members are likely to be important players at the plasma membrane-cell wall interface. METHODS AND RESULTS: Five COBL gene namely, TaCOBL 1, TaCOBL 2, TaCOBL 3, TaCOBL 4 and TaCOBL 5 were identified using database search and domain predictions. Chromosomal location of each gene was mapped on karyotype. Structure of genes, promoter analysis and phylogenetic analysis were performed using different bioinformatics tools. Set of novel SNPs were also predicted. Gene ontologies were analyzed, and the processes and pathways were identified in which COBRA genes were involved. The molecular weight all the cobra proteins was in range of 50-75 KDa with 429-461 amino acid residues. The COBL genes were mapped on homeologous groups 2, 4, 5, 6 and 7. Gene ontology analysis revealed that TaCOBL genes were involved in cellulose microfibril organization, mucilage biosynthetic process involved in seed coat development, plant-type cell wall biogenesis plant-type cell wall cellulose biosynthetic process, seed coat development and seed development. Three drought responsive cis-elements (WRKY, ABRE and DRE) were found nearby COBL genes The qRT-PCR revealed TaCOBL genes are drought responsive and can be further explored to understand their role in drought tolerance in wheat. CONCLUSION: The comprehensive annotation and expression profiling of COBL genes revealed that all five COBL genes are drought response. The promoter cis-regulatory element analysis revealed that COBL genes had stress related WRKY, ABRE and DRE cis-regulatory elements. This evidence suggest that TaCOBL genes are involved in drought stress tolerance.

Accumulation pattern and risk assessment of potentially toxic elements in selected wastewater-irrigated soils and plants in Vehari, Pakistan.

There are scarce data about the accumulation pattern and risk assessment of potentially toxic elements (PTEs) in soil and associated potential ecological risks, especially in less-developed countries. This study aims to assess the pollution levels and potential ecological risks of PTEs (As, Cr, Cd, Cu, Ni, Mn, Pb and Zn) in wastewater-irrigated arable soils and different edible-grown plants in selected areas of Vehari, Pakistan. The results revealed that the values of PTEs in soil samples were higher than their respective limit values by 20% for As, 87% for Cd, 15% for Cu, 2% for Cr, 83% for Mn, 98% for Fe, and 7% for Zn. The values of soil risk indices such as the potential ecological risk (PERI >380 for all samples), pollution load index (PLI >4 for 94% of studied samples), and degree of contamination (Dc > 24 for all samples) showed severe soil contamination in the study area. Some vegetables exhibited a high metal accumulation index (e.g., 8.1 for onion), signifying potential associated health hazards. Thus, long-term wastewater irrigation has led to severe soil contamination, which can pose potential ecological risks via PTE accumulation in crops, particularly Cd. Therefore, to ensure food safety, frequent wastewater irrigation practices need to be minimized and managed in the study area.

Drought-tolerant Bacillus megaterium isolated from semi-arid conditions induces systemic tolerance of wheat under drought conditions.

KEY MESSAGE: A detailed study of the response of wheat plants, inoculated with drought-tolerant PGPR is studied which would be beneficial to achieve genetic improvement of wheat for drought tolerance. Drought stress, a major challenge under current climatic conditions, adversely affects wheat productivity. In the current study, we observed the response of wheat plants, inoculated with drought-tolerant plant growth-promoting rhizobacteria (PGPR) Bacillus megaterium (MU2) and Bacillus licheniformis (MU8) under induced drought stress. In vitro study of 90 rhizobacteria exhibited 38 isolates showed one or more plant growth-promoting properties, such as solubilization of phosphorus, potassium, and exopolysaccharide production. Four strains revealing the best activities were tested for their drought-tolerance ability by growing them on varying water potentials (- 0.05 to - 0.73 MPa). Among them, two bacterial strains Bacillus megaterium and Bacillus licheniformis showed the best drought-tolerance potential, ACC deaminase activities, IAA production, and antagonistic activities against plant pathogens. Additionally, these strains when exposed to drought stress (- 0.73 MPa) revealed the induction of three new polypeptides (18 kDa, 35 kDa, 30 kDa) in Bacillus megaterium. We determined that 106 cells/mL of Bacillus megaterium and Bacillus licheniformis were enough to induce drought tolerance in wheat under drought stress. These drought-tolerant strains increased the germination index (11-46%), promptness index (16-50%), seedling vigor index (11-151%), fresh weight (35-192%), and dry weight (58-226%) of wheat under irrigated and drought stress. Moreover, these strains efficiently colonized the wheat roots and increased plant biomass, relative water content, photosynthetic pigments, and osmolytes. Upon exposure to drought stress, Bacillus megaterium inoculated wheat plants exhibited improved tolerance by enhancing 59% relative water content, 260, 174 and 70% chlorophyll a, b and carotenoid, 136% protein content, 117% proline content and 57% decline in MDA content. Further, activities of defense-related antioxidant enzymes were also upregulated. Our results revealed that drought tolerance was more evident in Bacillus megaterium as compared to Bacillus licheniformis. These strains could be effective bioenhancer and biofertilizer for wheat cultivation in arid and semi-arid regions. However, a detailed study at the molecular level to deduce the mechanism by which these strains alleviate drought stress in wheat plants needs to be explored.

Volatile organic compounds produced by Pseudomonas pseudoalcaligenes alleviated drought stress by modulating defense system in maize (Zea mays L.).

Research on plant growth-promoting bacteria (PGPR) revealed an effective role of bacterial volatile organic compounds (VOCs) in stress alleviation. Out of 15 PGPR strains, infection with VOCs from Pseudomonas pseudoalcaligenes' resulted in maximum germination, growth promotion, and drought tolerance in maize plants. The VOCs of P. pseudoalcaligenes caused induced systemic tolerance in maize plants during 7 days of drought stress. The VOCs exposed plants displayed resistance to drought stress by reducing electrolyte leakage and malondialdehyde content and increasing the synthesis of photosynthetic pigments, proline, and phytohormones contents. Maize plants revealed enhanced resistance by showing higher activities of antioxidant defense enzymes both in shoots and roots under drought stress. Activities of antioxidant enzymes were more pronounced in shoots than roots. Gas chromatography and mass spectrophotometric (GC-MS) analysis comparing VOCs produced by the most efficient P. pseudoalcaligenes strain and inefficient strains of Pseudomonas sp. grown in culture media revealed nine compounds that they had in common. However, dimethyl disulfide, 2,3-butanediol, and 2-pentylfuran were detected only in P. pseudoalcaligenes, indicating these compounds are potential candidates for drought stress induction. Further studies are needed to unravel the molecular mechanisms of VOCs-mediated systemic drought tolerance in plants related to each identified VOC.

Combined application of zinc oxide nanoparticles and biofertilizer to induce salt resistance in safflower by regulating ion homeostasis and antioxidant defence responses.

Salinity is a key devastating abiotic factor that hinders the development and yield of safflower. The sole and combined application of zinc oxide nanoparticles (ZnO-NPs) and a biofertilizer (BF) to improve salt tolerance in safflower has not been thoroughly explored. The response of safflower plants in a pot experiment to the foliar spray of ZnO-NPs alone and in combination with a BF was thus detected. We determined that a ZnO-NP concentration of 17 mg/L was sufficient to protect safflower against salinity (250 mM NaCl) by increasing the plant productivity, percent water content, and osmolyte levels. Coapplication of ZnO-NPs and Phytoguard protected safflower plants from salinity stress by improving the activities of antioxidant enzymes and decreasing the levels of proline (leaves (61%) and roots (63%)) and malondialdehyde (MDA) (leaves (54%) and roots (65%)). Under salt stress, the Na+ content increased, while seed coating with biofertilizer and ZnO-NP spray significantly decreased the Na+ concentration (74% in leaves and 60% in roots). For the K+ concentration, however, antagonistic outcomes were observed. Additionally, the combined treatment significantly enhanced agronomic parameters such as the number of leaves and pods per plant, capitulum weight, and the number of yellow and wilted leaves per plant under salinity stress. Thus, ZnO-NPs could be an effective bio-source for the protection of safflower plants under salinity stress. Our findings showed that in the combined treatment of ZnO-NPs and biofertilizer, the salinity tolerance was more pronounced than in the single treatment and untreated control. A thorough analysis at the molecular level, however, is still required to understand the mechanism by which ZnO-NPs and BF in safflower plants alleviate salt stress.

Multitrait Pseudomonas spp. Isolated from Monocropped Wheat (Triticum aestivum) Suppress Fusarium Root and Crown Rot.

Fusarium root and crown rot is the most common disease of wheat, especially wheat grown in arid zones where drought is a common issue. The development of environmentally safe approaches to manage diseases of food crops is important for humans. The monocropping system recruits beneficial bacteria that promote plant growth through nutrient solubilization and pathogen suppression. In this study, a field where wheat was monocropped for 5 successive years under rainfed conditions was identified. A total of 29 bacterial isolates were obtained from the rhizosphere, endosphere, and phyllosphere of wheat at its harvesting stage. The Gram-negative bacteria were less prevalent (41%) but the majority (75%) exhibited plant growth-promoting traits. The ability of strains to solubilize nutrients (solubilization index = 2.3 to 4), inhibit pathogenic fungi (25 to 56%), and produce antifungal compounds was highly variable. The rhizobacteria significantly promoted the growth and disease resistance of wheat varieties such as Pirsbak-2015 and Galaxy-2013 by inducing antioxidant enzyme activity (0.2- to 2.1-fold). The bacterial strains were identified as Ochrobactrum spp., Acinetobacter spp., and Pseudomonas mediterranea by 16S rRNA and rpoD sequence analysis. The endophytic bacterium P. mediterranea HU-9 exhibited maximum biocontrol efficacy against wheat root and crown rot diseases with a disease score/disease index from 1.8 to 3.1. The monocropping systems of rainfed agriculture are an ideal source of beneficial bacteria to use as bioinoculants for different crops.

Nutritional value of Sesamum indicum L. was improved by Azospirillum and Azotobacter under low input of NP fertilizers.

BACKGROUND: Sesame (Sesame indicum L.) is well-known as a versatile industrial crop having various usages and contains 50-55% oil, 20% protein, 14-20% carbohydrate and 2-3% fiber. Several environmental factors are known to adversely affect yield and productivity of sesame. Our overall aim was to improve the growth, yield and quality of sesame cv. TS-3 using plant growth promoting rhizobacteria (PGPR) and saving the nitrogen and phosphate fertilizers (NP) by 50%. Field experiment (randomized complete block design) was conducted during the months of July to October of two consecutive years 2012-2013. Azospirillum (AL) and Azotobacter (AV) were applied as seed inoculation alone as well as along with half of the recommended dose of nitrogen (N) and phosphate (P) fertilizers (urea and diammonium phosphate) at the rate of 25 kg/ha and 30 kg/ha respectively. RESULTS: Here we report that A. lipoferum along with half dose of NP fertilizers (ALCF) were highly effective in increasing the agronomic and yield traits of sesame as compared to the control. A. vinelandii plus NP fertilizers (AVCF) exhibited higher seed oil content. Minimum acid value, optimum specific gravity and modified fatty acid composition were observed in ALCF treatment. Increase in oleic acid by ALCF is directly linked with improved oil quality for health benefits as oleic acid is the fatty acid which creates a balance between saturation and unsaturation of oil and for the hypotensive (blood pressure reducing) effects. CONCLUSION: It is inferred that ALCF treatment improved plant growth, seed yield and oil quality of sesame pertaining to good quality edible oil production.

Antimicrobial activity, toxicity and anti-inflammatory potential of methanolic extracts of four ethnomedicinal plant species from Punjab, Pakistan.

BACKGROUND: The plant species Aristolochia indica (AI), Melilotus indicus (MI), Tribulus terrestris (TT) and Cuscuta pedicellata (CP) are widely used in folk medicine in the villages around Chowk Azam, South Punjab, Pakistan. The aim of this study was to evaluate the antioxidant activity, phytochemical composition, and the antibacterial, antifungal, cytotoxic and anti-inflammatory potential of the four medicinal plants listed above. For CP stem, this study represents (to the best of our knowledge) the first time phytochemicals have been identified and the antioxidant and anti-inflammatory potential determined. METHODS: Phytochemicals were analyzed through chemical tests, thin layer chromatography (TLC) and spectrophotometric methods. Antioxidant activities (DPPH and H2O2) were also determined through spectrophotometric methods. Extracts were evaluated for antibacterial potential via the agar well diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia and Acinetobacter baumannii. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by the microdilution method. Antifungal activities were tested using the agar tube dilution method against three species: Aspergillus fumigatus, Aspergillus flavus and Rhizopus oryzae. The cytotoxic potential of the plant extracts was checked using the brine shrimp assay. In vitro anti-inflammatory activity of the selected plant extracts was evaluated using albumin denaturation, membrane stabilization and proteinase inhibitory assays. RESULTS: Of all the methanolic extracts tested, those from CP (stem) and TTF (T. terrestris fruit) had the highest phenolic, flavonoid and flavonol contents (497±4 mg GAE/g, 385±8 mg QE/g and 139±4 mg QE/g; 426±5 mg GAE/g, 371±8 mg QE/g and 138±6 mg QE/g, respectively) and also exhibited strong antioxidant potential in scavenging DPPH and hydrogen peroxide (IC50 values; 20±1 and 18±0.7 µg/mL; 92±2 and 26±2 µg/mL, respectively). CP, TTF and TTL (T. terrestris leaf) extracts substantially inhibited the growth of the bacteria A. baumannii, S. aureus, and K. pneumonia and also exhibited the highest antifungal potential. The ranking of the plant extracts for cytotoxicity was TTF > TTL > AI > CP > MI, while the ranking for in vitro anti-inflammatory potential at a concentration of 200 µg/mL of the selected plant extracts was CP > TTL, TTF > AI > MI. The lowest IC50 (28 µg/mL) observed in the albumin denaturation assay was for CP. Positive correlations were observed between total phenolics, antioxidants, antibacterial, antifungal and anti-inflammatory potential of the selected plant extracts, indicating a significant contribution of phenolic compounds in the plant extracts to these activities. CONCLUSIONS: This study revealed the strong antimicrobial, antioxidant, cytotoxic and anti-inflammatory potential of the plant species CP and TT used in folk medicine.

Dietary supplementation of bitter gourd reduces the risk of hypercholesterolemia in cholesterol fed sprague dawley rats.

Functional and health endorsing benefits of various foods are often attributed to their phytochemistry. The bitter gourd holds potential in improving the health of the individuals owing to its incredible versatility in phytochemistry. However, the efficacy of different parts of bitter gourd needs attention of the researchers. In the current exploration, different parts of bitter gourd were evaluated for their cholesterol lowering potential in cholesterol fed Sprague dawley rats. For the purpose, four types of bitter gourd part i.e. whole fruit, seedless fruit, seeds, and seed extracts were used and compared with placebo in hypercholesterolemic rats. In placebo, momentous increase in serum cholesterol, triglycerides and LDL levels was observed. All parts attenuate the cholesterol 18.79 to 40.17% triglycerides 25.97 to 37.01% and LDL 14.49 to 26.09%. However, 1% extract powder was most effective in reducing the cholesterol and triglycerides. From the present study, it is deduced that bitter gourd extract can be supplemented in food products for the management of hypercholesterolemia. However, future studies in human subjects needs to be conducted for meticulousness of the present findings.

Protein-energy malnutrition: a risk factor for various ailments.

The wheel of industrialization that spun throughout the last century resulted in urbanization coupled with modifications in lifestyles and dietary habits. However, the communities living in developing economies are facing many problems related to their diet and health. Amongst, the prevalence of nutritional problems especially protein-energy malnutrition (PEM) and micronutrients deficiencies are the rising issues. Moreover, the immunity or susceptibility to infect-parasitic diseases is also directly linked with the nutritional status of the host. Likewise, disease-related malnutrition that includes an inflammatory component is commonly observed in clinical practice thus affecting the quality of life. The PEM is treatable but early detection is a key for its appropriate management. However, controlling the menace of PEM requires an aggressive partnership between the physician and the dietitian. This review mainly attempts to describe the pathophysiology, prevalence and consequences of PEM and aims to highlight the importance of this clinical syndrome and the recent growth in our understanding of the processes behind its development. Some management strategies/remedies to overcome PEM are also the limelight of the article. In the nutshell, early recognition, prompt management, and robust follow up are critical for best outcomes in preventing and treating PEM.

Pathogenesis-related protein expression in the apoplast of wheat leaves protected against leaf rust following application of plant extracts.

Leaf rust (Puccinia triticina) is a major disease of wheat. We tested aqueous leaf extracts of Jacaranda mimosifolia (Bignoniaceae), Thevetia peruviana (Apocynaceae), and Calotropis procera (Apocynaceae) for their ability to protect wheat from leaf rust. Extracts from all three species inhibited P. triticina urediniospore germination in vitro. Plants sprayed with extracts before inoculation developed significantly lower levels of disease incidence (number of plants infected) than unsprayed, inoculated controls. Sprays combining 0.6% leaf extracts and 2 mM salicylic acid with the fungicide Amistar Xtra at 0.05% (azoxystrobin at 10 µg/liter + cyproconazole at 4 µg/liter) reduced disease incidence significantly more effectively than sprays of fungicide at 0.1% alone. Extracts of J. mimosifolia were most active, either alone (1.2%) or in lower doses (0.6%) in combination with 0.05% Amistar Xtra. Leaf extracts combined with fungicide strongly stimulated defense-related gene expression and the subsequent accumulation of pathogenesis-related (PR) proteins in the apoplast of inoculated wheat leaves. The level of protection afforded was significantly correlated with the ability of extracts to increase PR protein expression. We conclude that pretreatment of wheat leaves with spray formulations containing previously untested plant leaf extracts enhances protection against leaf rust provided by fungicide sprays, offering an alternative disease management strategy.

Biocontrol of Rhizoctonia solani in basmati rice by the application of Lactobacillus and Weissella spp.

Rice is a staple food crop and is a major source of employment and income in the world. However, the attack of fungal disease poses a serious threat to the crop growth and productivity and leads toward yield loses. Therefore, current study was performed to evaluate the biocontrol potential of Lactobacillus and Weissella spp. on basmati rice against Rhizoctonia solani. Agar disc method was performed to evaluate the antifungal activity of both bacteria against R. solani. Petri plate and pot experiments were conducted to evaluate the growth promotion and biocontrol potential of both bacteria in Basmati rice under R. solani stress. Results indicated that maximum antifungal activity (82%) was recorded by Lactobacillus sp. Maximum phosphate solubilization and siderophore production was recorded by Weissella sp. In petri plate experiment, maximum root length, root fresh and dry weight (36%, 40% and 13%) was recorded by Weissella sp. and maximum shoot length and shoot fresh weight (99% and 107%) by Lactobacillus sp. In pot experiment, both bacteria enhanced the growth parameters of Basmati rice including root and shoot length, fresh and dry weight as well as no. of lateral roots. Application of Weissella sp. resulted in maximum increase (332% and 134%) in chlorophyll a and b content while Lactobacillus sp. + R. solani showed maximum (42%) carotenoid contents. Lactobacillus sp. + R. solani showed maximum increase in the proline (54%) and sugar contents (100%) while Lactobacillus sp. alone showed maximum (35%) soluble protein contents. Plant defense enzymes i-e SOD (400%), POD (25%), CAT (650%), PPO (14%) and PAL (124%) were notably increased by Weissella sp. + R. solani and Lactobacillus sp + R. solani. The Lactobacillus sp showed the best results in antifungal activity against R. solani and Weissella sp. showed the best results in production of defense enzymes in basmati rice against R. solani stress and can be suggested as the potent biocontrol agents for the rice crop.

Incorporation of zinc sulfide nanoparticles, Acinetobacter pittii and Bacillus velezensis to improve tomato plant growth, biochemical attributes and resistance against Rhizoctoniasolani.

Green nanobiotechnology and beneficial bacterial strains as biofertilizers are crucial in agriculture to achieve food security. Both these strategies have been individually studied in improving plant resistance against phytopathogens along with enhancing plant productivity. Therefore, objective of this study was to explore the eco-friendly and cost-effective approach of utilizing plant growth promoting and disease suppressing bacterial strains and nanoparticles, individually as well as in combination, as bio-stimulants to improve plant growth, antioxidant defense system, nutrition and yield of tomato. A pot experiment was conducted to investigate the zinc sulfide nanoparticles (ZnS NPs) synthesized by using Jacaranda mimosifolia flower extracts (JFE), Acinetobacter pittii and Bacillus velezensis either individually or in combinations to check their potential against Rhizoctonia solani in tomato to suppress root rot infection and improve growth and yield. Among all the combinations the JFE-ZnS NPs + B. velezensis compared to untreated infected plants showed minimum disease incidence and maximum significant protection (66%) against R. solani instigated root rot that was followed by JFE-ZnS NPs + A. pittii and individual application of JFE-ZnS NPs by 58%. The same treatment showed maximum significant increase in plant fresh and dry biomass. B. velezensis significantly increased the photosynthetic pigments when applied individually. However, JFE-ZnS NPs alone and in mixed treatments with B. velezensis efficiently improved total soluble protein, sugar and phenolic contents. The same interactive application of JFE-ZnS NPs + B. velezensis improved the tomato plant nutrition (silicon (Si), magnesium (Mg), calcium (Ca) and potassium (K)) and redox quenching status by improving the activity of antioxidant defense enzymes. Overall, the interactive use of JFE-ZnS NPs with A. pittii and B. velezensis very appropriately prepared the host plant to fight against the negative effects of root rot pathogen in tomato. Advancements in interactively investigating the nanoparticles with beneficial plant growth promoting bacterial strains importantly can contribute in resolving the challenges of food security. According to our information, this is a pioneer report for implying JFE-ZnS NPs in synergism with A. pittii and B. velezensis to hinder the root rot in tomatoes.

Phosphate solubilizing bacteria enhanced growth, oil yield, antioxidant properties and biodiesel quality of Kasumbha.

Biodiesel is considered as a potential alternative energy source, but problem exists with the quantity and quality of feedstock used for it. To improve the feedstock quality of biodiesel, a field experiment was conducted under natural conditions. Cultivar Thori of kasumbha was used in the experiment. Commercialized biofertilizers were applied at the rate of 20 kg per acre and chemical fertilizer (diammonium phosphate) was applied as half dose (15 kg/ha). Results indicated that number of leaf plant-1, leaf area, number of seeds capitulum-1 was significantly increased by biofertilizer treatment alone (BF) and combine treatment of biofertilizer and chemical fertilizer (BFCF). Agronomic traits such as plant height, no. of branches of a plant, no. of capitulum/plant was improved significantly by BF treatment over the control. Maximum 1000 seed weight (41%) and seed yield (23%) were recorded in half dose of chemical fertilizers treatment (CFH). Seed oil content and seed phenolics were significantly improved by BF and CF treatments while maximum biodiesel yield was recorded by BF treatment. Maximum oleic acid was recorded by BF treatment while other fatty acids being maximum in control except linoleic acid in BFCF treatment. Results for specific gravity were non-significant while acid value and free fatty acid contents were substantially reduced by BF treatment as compared to other treatments. Maximum value of iodine number was recorded in BFCF treatment while tocopherol contents were improved by BF treatment. It is inferred that biofertilizer treatment alone perform better as compared to other treatments and 50% chemical fertilizer can be replaced using biofertilizer which is a good approach for sustainable environmental-friendly agriculture.

Rhizosphere bacteria associated with Chenopodium quinoa promote resistance to Alternaria alternata in tomato.

Microorganisms can interact with plants to promote plant growth and act as biocontrol agents. Associations with plant growth-promoting rhizobacteria (PGPR) enhance agricultural productivity by improving plant nutrition and enhancing protection from pathogens. Microbial applications can be an ideal substitute for pesticides or fungicides, which can pollute the environment and reduce biological diversity. In this study, we isolated 68 bacterial strains from the root-adhering soil of quinoa (Chenopodium quinoa) seedlings. Bacterial strains exhibited several PGPR activities in vitro, including nutrient solubilization, production of lytic enzymes (cellulase, pectinase and amylase) and siderophore synthesis. These bacteria were further found to suppress the mycelial growth of the fungal pathogen Alternaria alternata. Nine bacterial strains were selected with substantial antagonistic activity and plant growth-promotion potential. These strains were identified based on their 16S rRNA gene sequences and selected for in planta experiments with tomato (Solanum lycopersicum) to estimate their growth-promotion and disease-suppression activity. Among the selected strains, B. licheniformis and B. pumilus most effectively promoted tomato plant growth, decreased disease severity caused by A. alternata infection by enhancing the activities of antioxidant defense enzymes and contributed to induced systemic resistance. This investigation provides evidence for the effectiveness and viability of PGPR application, particularly of B. licheniformis and B. pumilus in tomato, to promote plant growth and induce systemic resistance, making these bacteria promising candidates for biofertilizers and biocontrol agents.

Combined ability of salicylic acid and spermidine to mitigate the individual and interactive effects of drought and chromium stress in maize (Zea mays L.).

Application of the growth regulator salicylic acid (SA) and the polyamine spermidine (Spd) can be used to manage various plant abiotic stresses. We aimed to evaluate the sole and combined effects of SA and Spd on maize (Zea mays) under individual and combined drought and chromium (Cr) stress. Drought, Cr, and drought + Cr treatments caused oxidative stress by inducing higher production of reactive oxygen species (H2O2, O2-), enhanced malondialdehyde content and increased relative membrane permeability. Increased oxidative stress and higher Cr uptake in the host plant reduced the content of carotenoids, other photosynthetic pigments and protein, and changed carbohydrate metabolism. Combined drought + Cr stress was more damaging for the growth of maize plants than the individual stresses. Exogenous treatments of SA and Spd alleviated the adverse effects of drought and Cr toxicity, reflected by accumulations of osmolytes, antioxidants and endogenous polyamines. Single applications of Spd (0.1 mM) increased plant height, shoot fresh weight, leaf area, above-ground dry matter accumulation and polyamine content under drought, Cr, and drought + Cr stress conditions. However, the combined treatment SA + Spd (0.25 mM + 0.05 mM) was more effective in increasing protein and water contents, photosynthetic pigments, and carotenoids. The same treatment increased Cr tolerance in the maize plants by decreasing uptake of this heavy metal from root to shoot. The SA + Spd treatment also decreased oxidative stress by promoting antioxidant enzyme activities, and enhanced levels of proline, soluble sugars, and carbohydrate contents under individual and combined stress conditions. Results indicate that the combined half-dose application of SA + Spd may be utilized to boost the tolerance in maize under individual as well as combined drought and Cr stress conditions.