Role of PGPR and silver nanoparticles on the physiology of Momordica charantia L. irrigated with polluted water comprising high Fe and Mn.

The current investigation designed to estimate the bioremediation potential of plant growth-promoting rhizobacteria (PGPR) and Ag-nanoparticles. Tube well and HIT water comprising Mn and Fe above recommended values were used as treatments while tap water irrigation was treated as control. The HIT water showed 24, 200, and 64.11% higher content of Na, K Ca over control. Seeds were sterilized in 95% ethanol and soaked for 3 h before sowing in 73 h old culture of Pseudomonas stutzeri (Kx574858) @ 108 cells/ml. Phytotoxic effect of Fe and Mn reduce plant biomass and suppress photosynthetic activity indicates. The carotenoids, proline, and proline activity were 366, 450, and 678% higher in tube well water with combined PGPR and Ag-nanoparticles treatments. Pseudomonas stutzeri was more effective than Ag-nanoparticles to reduce oxidative stress with higher production of carotenoids, flavonoids, proline content, and enzyme SOD and CAT activities in HIT water. It is contingent that the high Mn and Fe bearing waste water enhance PGPR bioremediation potential to reduce metal stress in plants with synergistic action of PGPR and organic matter to alleviate oxidative stresses under metal stress. The residual effect of P. stutzeri on organic matter content of the rhizosphere soil and germination rate was higher for Momordica charantia L.

This is the first statement indicating that Ag-nanoparticles oxidize Mn and Fe efficiently to reduce COD and organic matter works synergistically with PGPR and Ag-nanoparticles to enhance ROS production that increase proline, carotenoids, flavonoids, phenolics, and enzymes SOD, POD, PAL, and CAT activities to reduce oxidative stress in cucurbits.

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.

Role of PGPR on the physiology of sunflower irrigated with produced water containing high total dissolved solids (TDS) and its residual effects on soil fertility.

The present study was conducted to evaluate the bioremediation potential of plant growth-promoting rhizobacteria (PGPR) PGPR isolates from high total dissolved solids (TDS) bearing produced water on the water quality, soil physicochemical properties and growth and physiology of sunflower irrigated with high TDS bearing produced water having salinity level 130 times higher above seawater and also containing traces of oil and grease. Seeds of sunflower hybrid Parsun 3 were soaked for 3-4 h prior to sowing in 72 h old culture of PGPR strains W1 and W2 isolated from high TDS bearing polluted water. The control plants were irrigated with 90% diluted TDS water supplemented with 5 ml LB media. Whereas, the inoculated plants were irrigated with 90% diluted TDS water supplemented with 5 ml PGPR inocula.in LB media. The plants were grown under natural conditions. The 16S rRNA sequence analyses identified the isolate W1 bearing 100% similarity with the plant growth-promoting rhizobacteria (PGPR) Ralstonia pickettii and W2 bearing 99.7% similarity with Brevibacillus invocatus. Both the isolate were catalase and oxidase positive. The Ralstonia pickettii and Brevibacillus invocatus treatments decreased the EC and TDS values significantly such that the EC and TDS values of 90% diluted TDS water were 29 times and 19 times higher than tap water. Sodium adsorption ratio (SAR), organic matter, nitrogen, potassium, magnesium and carbon content were 1.96, 1.10, 2.28 1.20, 6.63 and 1.00 times greater than control in the rhizosphere soil of Ralstonia pickettii inoculated plants irrigated with high TDS bearing water There were significant increases in plant growth, sugar, flavonoids and phenolics, chlorophyll b, total chlorophyll, carotenoids content and activities of superoxide dismutase, catalase and peroxidase in plants inoculated with Ralstonia pickettii and Brevibacillus invocatus. The flavonoids, phenolics and proline contents were 0.54, 0.72 and 0.30 times higher in Ralstonia pickettii inoculated plants. Shoot/root dry weight ratio was about (50%) lower than control in Ralstonia pickettii and Brevibacillus invocatus treatments. Ralstonia pickettii was more effective than Brevibacillus invocatus to combat oxidative and osmotic stresses. It is inferred that the high TDS bearing produced water from oil factory harbor Plant growth-promoting rhizobacteria (PGPR) having the potential to combat high salinity stress in plants when used as bioinoculant. The broth culture containing the bacteria may be supplemented with the saline water used for irrigation as it provides nutrients for the growth and proliferation of bacteria present in the saline water and hence the synergistic action of bacterial inocula with the indigenous bacteria present in saline water may better alleviate osmotic and oxidative stresses of plants encountered under salinity stress. The residual effect of Ralstonia pickettii on organic matter and Ca, Mg, K and P content of the rhizosphere soil was notably higher for succeeding crops. Novelty statement This is the first report demonstrating that rhizobacteria can proliferate in water containing salinity higher above seawater in addition to oil grease and TSS. Their efficiency to reduce TDS can be augmented by an exogenous supply of LB broth culture of PGPR isolated from the polluted water. These indigenous rhizobacteria when used as bioinoculant on the plant can act as plant growth promoters as well as bioremediation of salinity effects.

Comparative Analysis of Microbial Consortiums and Nanoparticles for Rehabilitating Petroleum Waste Contaminated Soils.

Nano-bioremediation application is an ecologically and environmentally friendly technique to overcome the catastrophic situation in soil because of petroleum waste contamination. We evaluated the efficiency of oil-degrading bacterial consortium and silver nanoparticles (AgNPs) with or without fertilizer to remediate soils collected from petroleum waste contaminated oil fields. Physicochemical characteristics of control soil and petroleum contaminated soils were assessed. Four oil-degrading strains, namely Bacillus pumilus (KY010576), Exiguobacteriaum aurantiacum (KY010578), Lysinibacillus fusiformis (KY010586), and Pseudomonas putida (KX580766), were selected based on their in vitrohydrocarbon-degrading efficiency. In a lab experiment, contaminated soils were treated alone and with combined amendments of the bacterial consortium, AgNPs, and fertilizers (ammonium nitrate and diammonium phosphate). We detected the degradation rate of total petroleum hydrocarbons (TPHs) of the soil samples with GC-FID at different intervals of the incubation period (0, 5, 20, 60, 240 days). The bacterial population (CFU/g) was also monitored during the entire period of incubation. The results showed that 70% more TPH was degraded with a consortium with their sole application in 20 days of incubation. There was a positive correlation between TPH degradation and the 100-fold increase in bacterial population in contaminated soils. This study revealed that bacterial consortiums alone showed the maximum increase in the degradation of TPHs at 20 days. The application of nanoparticles and fertilizer has non-significant effects on the consortium degradation potential. Moreover, fertilizer alone or in combination with AgNPs and consortium slows the rate of degradation of TPHs over a short period. Still, it subsequently accelerates the rate of degradation of TPHs, and a negligible amount remains at the end of the incubation period.

Modulation of Secondary Metabolites: A Halotolerance Strategy of Plant Growth Promoting Rhizobacteria Against Sodium Chloride Stress.

An experiment was conducted to evaluate the role of bacterial secondary metabolites against induced salt stress. Five bacterial strains were isolated from three different habitats: Khewra salt range, oily sludge field in Chakwal, and garden soil of Quaid-i-Azam University Islamabad, Pakistan. The 16S rRNA gene and BLAST analysis of bacterial strains showed 99% sequence similarity with Pseudomonas putida AMUPP-2 (KM435273), Lysinibacillus sphaericus OUG29GKBB (KM972671), Bacillus pumilus MB431 (KP723538) isolated from salt range, Pseudomonas fluorescens B8 (KF010368) from garden soil and Exiguobacterium aurantiacum SPD2 (KX121703) from oily sludge, respectively. Pseudomonas fluorescens produced 294.98 µg/g of proline in the M9 medium supplemented with 125 mM NaCl, but its growth rate was decreased from 1.81 to 0.37. The P. putida showed faster growth rate even than control at 125 mM NaCl. B. pumilus and L. sphaericus did not show any decline in growth rate up to 100 mM NaCl. The synthesis of new amino acids were recorded at 125 mM NaCl stress, e.g., Pro, Leu, Arg in P. fluorescens and L. sphaericus, Pro, Lys, Phe, Ala in P. putida, Lys, Ala in B. pumilus, Met, Val, and Ala in E. aurantiacum. Liquid chromatography-mass spectrometry analysis of ethyl acetate extract of P. putida and L. sphaericus demonstrated that NaCl (125mM) induced the production of 3-oxo-C12 homoserine lactone, oxosteroids, and steroid esters in addition to steroidal alkaloid lysophosphatidylcholines, antibiotics phenazine-1 carboxamide, 2,4-diacetyl phloroglucinol, carbazole, phosphatidylcholine, phosphatidyl ethanol amine, and salicylic acid as signaling compound. It was concluded that P. putida and L. sphaericus could be exploited for the production of secondary metabolites that have a wide range of implications in biotic and abiotic stresses and for the production of important pharmaceutical products.

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.

UPLC-HRMS-based untargeted metabolic profiling reveals changes in chickpea (Cicer arietinum) metabolome following long-term drought stress.

Genetic improvement for drought tolerance in chickpea requires a solid understanding of biochemical processes involved with different physiological mechanisms. The objective of this study is to demonstrate genetic variations in altered metabolic levels in chickpea varieties (tolerant and sensitive) grown under contrasting water regimes through ultrahigh-performance liquid chromatography/high-resolution mass spectrometry-based untargeted metabolomic profiling. Chickpea plants were exposed to drought stress at the 3-leaf stage for 25 days, and the leaves were harvested at 14 and 25 days after the imposition of drought stress. Stress produced significant reduction in chlorophyll content, Fv /Fm , relative water content, and shoot and root dry weight. Twenty known metabolites were identified as most important by 2 different methods including significant analysis of metabolites and partial least squares discriminant analysis. The most pronounced increase in accumulation due to drought stress was demonstrated for allantoin, l-proline, l-arginine, l-histidine, l-isoleucine, and tryptophan. Metabolites that showed a decreased level of accumulation under drought conditions were choline, phenylalanine, gamma-aminobutyric acid, alanine, phenylalanine, tyrosine, glucosamine, guanine, and aspartic acid. Aminoacyl-tRNA and plant secondary metabolite biosynthesis and amino acid metabolism or synthesis pathways were involved in producing genetic variation under drought conditions. Metabolic changes in light of drought conditions highlighted pools of metabolites that affect the metabolic and physiological adjustment in chickpea that reduced drought impacts.

The stimulatory effects of plant growth promoting rhizobacteria and plant growth regulators on wheat physiology grown in sandy soil.

The present study was aimed to investigate the effects of plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGRs) on the physiology and yield of wheat grown in less fertile sandy soil. The isolated PGPR strains were identified by 16S-rRNA gene sequencing as Planomicrobium chinense (P1), Bacillus cereus (P2) and Pseudomonas fluorescens (P3). Wheat varieties (Galaxy-13 and Pak-2013) differing in sensitivity to drought were soaked in fresh cultures of bacterial isolates and the PGRs (salicylic acid and putrescine) were sprayed at 150 mg/L on seedlings at three leaf stage. PGPR and PGRs treated plants showed significant increase in the contents of chlorophyll, sugar and protein even under harsh environmental conditions. Drought stress enhanced the production of proline, antioxidant enzymes and lipid peroxidation but a decrease was noted in the biochemical content (i.e. chlorophyll, protein and sugar) of inoculated plants. PGPR inoculation also significantly enhanced the yield parameters (i.e. plant height, spike length, grain yield and weight) and improved the fertility status of sandy soil. The accumulation of macronutrient, total NO3-N and P concentration and soil moisture content of rhizosphere soil was also enhanced by PGPRs inoculation. It is concluded that the combined effects of PGPR and PGRs have profound effects on the biochemical responses and drought tolerance of wheat grown in sandy soils.

Effects of exogenously applied salicylic acid and putrescine alone and in combination with rhizobacteria on the phytoremediation of heavy metals and chickpea growth in sandy soil.

The present attempt was made to study the role of exogenously applied salicylic acid (SA) and putrescine (Put) on the phytoremediation of heavy metals and on the growth parameters of chickpea grown in sandy soil. The SA and Put were applied alone as well as in combination with plant growth promoting rhizobacteria (PGPR). The PGPRs, isolated from the rhizosphere of chickpea, were characterized on the basis of colony morphology and biochemical traits through gram staining, catalase and oxidase tests, and identified by 16S-rRNA gene sequencing as Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium. The chickpea seeds were soaked in 24 h old fresh cultures of isolates for 2-3 h prior to sowing. The growth regulators (PGRs), SA and Put (150 mg/L), were applied to the seedlings as foliar spray at three-leaf stage. The result revealed that plants treated with SA and Put alone or in combination with PGPRs, significantly enhanced the accumulation of heavy metals in plant shoot. PGPR induces Ni accumulation in sensitive variety and Pb in both the varieties, the PGR in combination augment the bioremediation effects of PGPR and both sensitive and tolerant variety showed significant accumulation of Ni, Cd, and Pb. SA was more effective in accumulating Ni and Cd whereas, significant accumulation of Pb was recorded in Put. PGPRs further augmented the PGRs induced accumulation of heavy metals and macronutrients in chickpea shoot and in rhizosphere. SA increased the proline content of tolerant variety while decreasing the lipid peroxidation and proline content of the sensitive variety but decreased the stimulating effect of PGPR in proline production. Interactive effects of PGPR and PGRs are recommended for inducing phytoremediation in chickpea plants under drought stress.

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.

Alleviation of heavy metals toxicity by the application of plant growth promoting rhizobacteria and effects on wheat grown in saline sodic field.

The aim of the study was to determine tolerance of plant growth promoting rhizobacteria (PGPR) in different concentrations of Cu, Cr, Co, Cd, Ni, Mn, and Pb and to evaluate the PGPR-modulated bioavailability of different heavy metals in the rhizosphere soil and wheat tissues, grown in saline sodic soil. Bacillus cereus and Pseudomonas moraviensis were isolated from Cenchrus ciliaris L. growing in the Khewra salt range. Seven-day-old cultures of PGPR were applied on wheat as single inoculum, co-inoculation and carrier-based biofertilizer (using maize straw and sugarcane husk as carrier). At 100 ppm of Cr and Cu, the survival rates of rhizobacteria were decreased by 40%. Single inoculation of PGPR decreased 50% of Co, Ni, Cr and Mn concentrations in the rhizosphere soil. Co-inoculation of PGPR and biofertilizer treatment further augmented the decreases by 15% in Co, Ni, Cr and Mn over single inoculation except Pb and Co where decreases were 40% and 77%, respectively. The maximum decrease in biological concentration factor (BCF) was observed for Cd, Co, Cr, and Mn. P. moraviensis inoculation decreases the biological accumulation coefficient (BAC) as well as translocation factor (TF) for Cd, Cr, Cu Mn, and Ni. The PGPR inoculation minimized the deleterious effects of heavy metals, and the addition of carriers further assisted the PGPR.

Role of plant growth promoting rhizobacteria and Ag-nano particle in the bioremediation of heavy metals and maize growth under municipal wastewater irrigation.

The investigation evaluated the role of plant growth promoting rhizobacteria (PGPR) and Ag-nano particle on the growth and metabolism of maize irrigated with municipal wastewater (MW). Three PGPR isolated from MW were identified on the basis of 16S-rRNA gene sequence analyses as Pseudomonas sp., Pseudomonas fluorescence, and Bacillus cereus. The municipal waste water was used to irrigate the maize seeds inoculated with 3 isolated PGPR. The isolated PGPR had catalase and oxidase enzymes, solubilize insoluble bound phosphate and exhibit antifungal and antibacterial activities. The colony forming unit (cfu) of the PGPR was inhibited by Ag-nano particle, but was stimulated by the municipal wastewater. The Ag-nano particles augmented the PGPR induced increase in root area and root length. The root-shoot ratio was also changed with the Ag-nano particles. The plants irrigated with municipal wastewater had higher activities of peroxidase and catalase which were further augmented by Ag-nano particle. The Ag- nano particle application modulated level of ABA (34%), IAA (55%), and GA (82%), increased proline production (70%) and encountered oxidative stress and augmented the bioremediation potential of PGPR for Pb, Cd, and Ni. Municipal wastewater needs to be treated with PGPR and Ag nano particle prior to be used for irrigation. This aims for the better growth of the plant and enhanced bioremediation of toxic heavy metals.

Modulation of phytoremediation and plant growth by the treatment with PGPR, Ag nanoparticle and untreated municipal wastewater.

The present attempt was made to determine the effects of untreated municipal wastewater (MW) on growth and physiology of maize and to evaluate the role of Ag nanoparticle and plant-growth-promoting rhizobacteria (PGPR) when interacting with MW used for irrigation. It was used for the isolation of PGPR. The isolates were identified and characterized based on the colony morphology, C/N source utilization pattern using miniaturized identification system (QTS 24), catalase (CAT) and oxidase tests, and 16S rRNA sequence analyses. The three PGPR isolates were Planomicrobium chinense (accession no. NR042259), Bacillus cereus (accession no. CP003187) and Pseudomonas fluorescens (accession no. GU198110). The isolates solubilized phosphate and exhibited antibacterial activities against pathogenic bacteria i.e., Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Klebsiella pneumoniae and Escherichia coli and antifungal activities against Helminthosporium sativum and Fusarium solani. The untreated MW irrigation as well as Ag nanoparticle treatment resulted in significant accumulation of Ni in the rhizosphere soil. PGPR induced accumulation of Ni and Pb in the rhizosphere soil and maize shoot. Ag nanoparticle also caused Ni and Pb accumulation in maize shoot. Combined treatment with PGPR, Ag nanoparticle and MW resulted in decreased accumulation of Pb and Ni both in the rhizosphere soil and maize shoot. Combined treatment of Ag nanoparticle, MW and PGPR decreased Na accumulation and increased K accumulation. Ag nanoparticle increased Fe and Co accumulation but decreased Zn and Cu accumulation in MW treatment; in combined treatment, it reduced PGPR-induced accumulation of Co and Fe in the rhizosphere and Co accumulation in shoot. PGPR significantly increased root weight, shoot weight, root length, shoot length, leaf area, and proline, chlorophyll and carotenoid content of the maize plant. Ag nanoparticle also enhanced the leaf area, fresh weight, root length and antioxidant activities of maize. Treatment with Ag nanoparticle increased the gibberellic acid (GA) and abscisic acid (ABA) content of maize leaves but decreased the accumulation of GA in the presence of PGPR and MW.

The response of maize (Zea mays L.) plant assisted with bacterial consortium and fertilizer under oily sludge.

The objective of this study was to evaluate the role of PGPR consortium and fertilizer alone and in combination on the physiology of maize grown under oily sludge stress environment as well on the soil nutrient status. Consortium was prepared from Bacillus cereus (Acc KR232400), Bacillus altitudinis (Acc KF859970), Comamonas (Delftia) belonging to family Comamonadacea (Acc KF859971) and Stenotrophomonasmaltophilia (Acc KF859973). The experiment was conducted in pots with complete randomized design with four replicates and kept in field. Oily sludge was mixed in ml and Ammonium nitrate and Diammonium phosphate (DAP) were added at 70 ug/g and 7 ug/g at sowing. The plant was harvested at 21 d for estimation of protein, proline and antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD). To study the degradation, total petroleum hydrocarbon was extracted by soxhelt extraction and extract was analyzed by GC-FID at different period after incubation. Combined application of consortium and fertilizer enhanced the germination %, protein and, proline content by 90,130 and 99% higher than untreated maize plants. Bioavailability of macro and micro nutrient was also enhanced with consortium and fertilizer in oily sludge. The consortium and fertilizer in combined treatment decreased the superoxide dismutase (SOD), peroxidase dismutase (POD) of the maize leaves grown in oily sludge. Degradation of total petroleum hydrocarbon (TPHs) was 59% higher in combined application of consortium and fertilizer than untreated maize at 3 d. The bacterial consortium can enhanced the maize tolerance to oily sludge and enhanced degradation of total petroleum hydrocarbon (TPHs). The maize can be considered as tolerant plant species to remediate oily sludge contaminated soils.

Bioinoculants: A sustainable approach to maximize the yield of Ethiopian mustard (Brassica carinata L.) under low input of chemical fertilizers.

This study aimed to find out the effect of plant growth-promoting rhizobacteria (PGPR; Azospirillum brasilense and Azotobacter vinelandii) either alone or in combination with different doses of nitrogen and phosphate fertilizers on growth, seed yield, and oil quality of Brassica carinata (L.) cv. Peela Raya. PGPR were applied as seed inoculation at 10(6) cells/mL(-1) so that the number of bacterial cells per seed was 2.6 × 10(5) cells/seed. The chemical fertilizers, namely, urea and diammonium phosphate (DAP) were applied in different doses (full dose (urea 160 kg ha(-1) + DAP 180 kg ha(-1)), half dose (urea 80 kg ha(-1) + DAP 90 kg ha(-1)), and quarter dose (urea 40 kg ha(-1) + DAP 45 kg ha(-1)). The chemical fertilizers at full and half dose significantly increased the chlorophyll, carotenoids, and protein content of leaves and the seed yield (in kilogram per hectare) but had no effect on the oil content of seed. The erucic acid (C22:1) content present in the seed was increased. Azospirillum performed better than Azotobacter and its effect was at par with full dose of chemical fertilizers (CFF) for pigments and protein content of leaves when inoculated in the presence of half dose of chemical fertilizers (SPH). The seed yield and seed size were greater. Supplementing Azospirillum with SPH assisted Azospirillum to augment the growth and yield, reduced the erucic acid (C22:1) and glucosinolates contents, and increased the unsaturation in seed oil. It is inferred that A. brasilense could be applied as an efficient bioinoculant for enhancing the growth, seed yield, and oil quality of Ethiopian mustard at low fertilizer costs and sustainable ways.

Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea mays L.) on growth and germination of succeeding crop wheat (Triticum aestivum L.) and associated weed (Avena fatua L.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatua L.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control.

Isolation of plant-growth-promoting rhizobacteria from rhizospheric soil of halophytes and their impact on maize (Zea mays L.) under induced soil salinity.

The present investigation was aimed to scrutinize the salt tolerance potential of plant-growth-promoting rhizobacteria (PGPR) isolated from rhizospheric soil of selected halophytes (Atriplex leucoclada, Haloxylon salicornicum, Lespedeza bicolor, Suaeda fruticosa, and Salicornica virginica) collected from high-saline fields (electrical conductivity 4.3-5.5) of District Mardan, Pakistan. Five PGPR strains were identified using 16S rRNA amplification and sequence analysis. Bacillus sp., isolated from rhizospheric soil of Atriplex leucoclada, and Arthrobacter pascens, isolated from rhizospheric soil of Suaeda fruticosa, are active phosphate solubilizers and bacteriocin and siderophore producers; hence, their inoculation and co-inoculation on maize ('Rakaposhi') under induced salinity stress enhanced shoot and root length and shoot and root fresh and dry mass. The accumulation of osmolytes, including sugar and proline, and the elevation of antioxidant enzymes activity, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, were enhanced in the maize variety when inoculated and co-inoculated with Bacillus sp. and Arthrobacter pascens. The PGPR (Bacillus sp. and A. pascens) isolated from the rhizosphere of the mentioned halophytes species showed reliability in growth promotion of maize crop in all the physiological parameters; hence, they can be used as bio-inoculants for the plants growing under salt stress.

Chromium toxicity tolerance of Solanum nigrum L. and Parthenium hysterophorus L. plants with reference to ion pattern, antioxidation activity and root exudation.

Chromium (Cr), being a highly toxic metal, adversely affects the mineral uptake and metabolic processes in plants when present in excess. The current study was aimed at investigating the Cr accumulation in various plant tissues and its relation to the antioxidation activity and root exudation. Plants were grown in soil spiked with different concentrations of Cr for three weeks in pots and analysed for different growth, antioxidants and ion attributes. Furthermore, plants treated with different concentrations of Cr in pots were shifted to rhizobox-like system for 48h and organic acids were monitored in the mucilage dissolved from the plant root surface, mirroring rhizospheric solution. The results revealed that the Cr application at 1mM increased the shoot fresh and dry weight and root dry weight of Solanum nigrum, whereas the opposite was observed for Parthenium hysterophorus when compared with lower levels of Cr (0.5mM) or control treatment. In both plant species, Cr and Cl concentrations were increased while Ca, Mg and K concentrations in root, shoot and root exudates were decreased with increasing levels of Cr. Higher levels of Cr treatments enhanced the activities of SOD, POD and proline content in leaves of S. nigrum, whereas lower levels of Cr treatment were found to have stimulatory effects in P. hysterophorus. P. hysterophorus exhibited highest exudation of organic acid contents. With increasing levels of Cr treatments, citric acid concentration in root exudates increased by 35% and 44% in S. nigrum, whereas 20% and 76% in P. hysterophorus. Cr toxicity was responsible for the shoot growth reduction of S. nigrum and P. hysterophorus, however, shoot growth response was different at different levels of applied Cr. Consequently, Cr stress negatively altered the plant physiology and biochemistry. However, the enhanced antioxidant production, Cl uptake and root exudation are the physiological and biochemical indicators for the plant adaptations in biotic systems polluted with Cr.

Role of plant growth promoting rhizobacteria in modulating the efficiency of poultry litter composting with rock phosphate and its effect on growth and yield of wheat.

The present study was aimed to evaluate the role of Plant Growth Promoting Rhizobacteria (PGPR) in P solubilisation from rock phosphate through composting with poultry litter, and further to study the effects of prepared enriched composts on growth, yield, and phosphorus uptake of wheat crop. Various phosphorus-enriched composts were prepared from rock phosphate and poultry litter (1:10) with and without inoculation of plant growth promoting rhizobacterias (Pseudomonas sp. and Proteus sp.). Results showed that the rock-phosphate-added poultry litter had higher total phosphorus, available (Mehlic-3 extracted) phosphorus, microbial biomass (carbon and phosphorus), and lower total organic carbon, total nitrogen, and carbon/nitrogen ratio over poultry litter alone. Inoculation of Pseudomonas sp. with rock phosphate-added poultry litter showed maximum increase in available phosphorus (41% of total phosphorus) followed by Proteus sp. inoculation (30% of total phosphorus) over uninoculated treatment (23% of total phosphorus) on the 120th day of composting. Microbial biomass (carbon and phosphorus) increased up to Day 45 and tended to decrease till the 120th day of composting, irrespective of the treatments. However, in pot experiments, wheat seeds receiving inoculation with plant growth promoting rhizobacterias, subsequently treated with rock phosphate-enriched compost proved highly stimulatory to plant height, phosphorus uptake, grain yield, and seed phosphorus content over uninoculated untreated control. The plant growth promoting rhizobacterias inoculation can be a sustainable source releasing phosphorus from low grade rock phosphate through composting and application of rock phosphate-enriched compost can be an alternative to chemical fertilisers for better crop production.

Synthesis, chemical characterization, DNA binding, antioxidant, antibacterial, and antifungal activities of ferrocence incorporated selenoureas.

Ferrocene-incorporated selenoureas 1-(4-methoxybenzoyl)-3-(4-ferrocenylphenyl)selenourea (P4Me), 1-(3-methoxybenzoyl)-3-(4-ferrocenylphenyl)selenourea (P3Me), and 1-(2-methoxybenzoyl)-3-(4-ferrocenylphenyl)selenourea (P2Me) were synthesized and characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, atomic absorption spectroscopy, CHNS, and single-crystal X-ray diffraction. DNA interaction of the compounds was investigated with cyclic voltammetry, UV-visible spectroscopy, and viscometry, which is a prerequisite for anticancer agents. Drug-DNA binding constant was found to vary in the sequence: K(P4Me) (4.9000 × 104 M⁻¹) > K(P2Me) (2.318 × 104 M⁻¹) > K(P3Me) (1.296 × 104 M⁻¹). Antioxidant (1,1-diphenyl-2-picrylhydrazyl), antifungal (against Faussarium solani and Helmentosporium sativum), and antibacterial (against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis) activities have also been reported in addition.