Deciphering the mechanistic role of Bacillus paramycoides (PM51) and Bacillus tequilensis (PM52) in bio-sorption and phyto-assimilation of Cadmium via Linum usitatissimum L. Seedlings.

Three Cd2+ resistant bacterium's minimal inhibition concentrations were assessed and their percentages of Cd2+ accumulation were determined by measurements using an atomic absorption spectrophotometer (AAS). The results revealed that two isolates Bacillus paramycoides (PM51) and Bacillus tequilensis (PM52), identified by 16S rDNA gene sequencing, showed a higher percentage of Cd2+ accumulation i.e., 83.78% and 81.79%, respectively. Moreover, both novel strains can tolerate Cd2+ levels up to 2000 mg/L isolated from district Chakwal. Amplification of the czcD, nifH, and acdS genes was also performed. Batch bio-sorption studies revealed that at pH 7.0, 1 g/L of biomass, and an initial 150 mg/L Cd2+ concentration were the ideal bio-sorption conditions for Bacillus paramycoides (PM51) and Bacillus tequilensis (PM52). The experimental data were fit to Langmuir isotherm measurements and Freundlich isotherm model R2 values of 0.999 for each of these strains. Bio sorption processes showed pseudo-second-order kinetics. The intra-diffusion model showed Xi values for Bacillus paramycoides (PM51) and Bacillus tequilensis (PM52) of 2.26 and 2.23, respectively. Different surface ligands, was investigated through Fourier-transformation infrared spectroscopy (FTIR). The scanning electron microscope SEM images revealed that after Cd2+ adsorption, the cells of both strains became thick, adherent, and deformed. Additionally, both enhanced Linum usitatissimum plant seed germination under varied concentrations of Cd2+ (0 mg/L, 250 mg/L,350 mg/L, and 500 mg/L). Current findings suggest that the selected strains can be used as a sustainable part of bioremediation techniques.

Bacillus safensis filtrate-based ZnO nanoparticles control black heart rot disease of apricot fruits by maintaining its soluble sugars and carotenoids.

Black heart rot is a serious disease of apricot and it has been reported to be caused by Alternaria solani, around the world. The present research was designed to control this disastrous disease using zinc oxide nanoparticles (b-ZnO NPs). These NPs were synthesized in the filtrate of a useful bacterium (Bacillus safensis) and applied to control black heart rot of apricot. After synthesis, the reduction of b-ZnO NPs was confirmed by UV-visible spectroscopy, at 330 nm. Fourier transform infrared (FTIR) spectra ensured the presence of multiple functional groups (alcohols, phenols, carboxylic acids, nitro compounds and amines) on the surface of b-ZnO NPs. X-Ray diffraction (XRD) analysis elucidated their average size (18 nm) while scanning electron microscopy (SEM) micrograph described the spherical shape of b-ZnO NPs. The synthesized b-ZnO NPs were applied in four different concentrations (0.25 mg/ml, 0.50 mg/ml, 0.75 mg/ml, 1.0 mg/ml) under both in vitro and in vivo conditions. These NPs were very efficient in inhibiting mycelial growth (85.1%) of A. solani at 0.75 mg/ml concentration of NPs, in vitro. Same concentration also performed best, in vivo, and significantly reduced disease incidence (by 67%) on self-inoculated apricot fruit. Apart from this, application of b-ZnO NPs helped apricot fruit to maintain its quality under fungal-stress conditions. The decay of apricot fruit was reduced and they maintained greater firmness and higher weight. Moreover, b-ZnO NPs treated fruits controlled black heart rot disease by maintaining higher contents of ascorbic acid, soluble sugars and carotenoids. These b-ZnO NPs were produced in powder form for their easy carriage to the farmers' fields.

Spherical Fe2O3 nanoparticles inhibit the production of aflatoxins (B1 and B2) and regulate total soluble solids and titratable acidity of peach fruit.

Aflatoxin is a group I carcinogen and causes significant public health and food safety risks, throughout the world. This study was carried out to assess the levels of aflatoxin contamination in diseased peach (Prunus persica L.) fruit and their control using myco-synthesized iron oxide nanoparticles (Fe2O3 NPs). Diseased peach fruit were diagnosed to be infected with Aspergillus flavus. The isolated pathogen was cultured under UV light (365 nm) and exposed to ammonium hydroxide (31 %) vapors, which confirmed its ability to produce aflatoxin. For the control of this disease, Fe2O3 NPs were synthesized in the filtrate of a biocontrol fungus (Trichoderma harzianum) and characterized before analyzing their potential in disease control. FTIR spectrum described the presence of capping and reducing agents (secondary amines, alcohol, alkyne and aromatic compounds) on the surface of Fe2O3 NPs. X-ray Diffraction (XRD) described the crystalline size (7.78), while the spherical shape of Fe2O3 NPs was described by the SEM analysis. The EDX spectrum indicated the successful formation of Fe2O3 NPs by showing strong signals of iron (74.38 %). All concentrations displayed mycelial growth inhibition, in vitro and the greatest growth reduction (65.4 %) was observed at 1 mg/ml concentration of NPs. At the same concentration of Fe2O3 NPs, significant control of fruit rot of peach was also observed, in vivo. Treatment of Fe2O3 NPs maintained higher soluble solids, sucrose, total sugar, ascorbic acid, titratable acidity and firmness of peach fruit. Diseased fruit were further investigated for the presence and detection of aflatoxins. All three methods viz. thin layer chromatography (TLC), enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) confirmed a higher production of aflatoxins in control plants, while this production was significantly reduced in Fe2O3 NPs-treated peach fruit.

Impact of bacterial synthesized nanoparticles on quality attributes and postharvest disease control efficacy of apricot and loquat.

Postharvest fungal attacks on fruits such as apricots and loquats are common. Diseased fruit samples were collected from Murree's local fruit markets. The disease-causing pathogens were identified utilizing molecular, microscopic, and morphological characteristics. Alternaria alternata and Aspergillus niger were identified as the pathogens responsible for brown rot in loquat and black rot in apricot. To combat these fruit diseases, iron oxide (Fe2 O3 ) nanoparticles were synthesized using Bacillus subtilis and were characterized using various techniques. X-ray diffraction examination validated the size of iron oxide nanoparticles. The presence of several capping agents in the synthesized nanoparticles was confirmed by Fourier transform infrared analysis. Scanning electron microscopy revealed the spherical morphology of nanoparticles, whereas energy-dispersive X-ray proved the presence of different elemental compositions. After completing antifungal activities in vitro and in vivo, it was discovered that a nanoparticle concentration of 1.0 mg/mL efficiently suppressed the growth of fungal mycelia. Fungi growth was effectively inhibited in fruit samples treated with 1.0 mg/mL nanoparticles. The results of successful in vitro and in vivo antifungal activities imply that iron oxide (Fe2 O3 ) nanoparticles play an important role in ensuring fruit quality against pathogenic attacks. Bacterial-mediated iron oxide can be widely used because it is less expensive and less harmful to the environment than chemically manufactured fertilizers.

Concurrent application of bacterial-mediated and mycosynthesized ZnO nanofungicides to maintain high ascorbic acid and delay postharvest decay of apricot.

Quality of apricot fruit is affected by different biotic stresses during growth, harvesting and storage. Due to fungal attack, huge losses of its quality and quantity are observed. The present research was designed for the diagnoses and management of postharvest rot disease of apricot. Infected apricot fruit were collected, and the causative agent was identified as A. tubingensis. To control this disease, both bacterial-mediated nanoparticles (b-ZnO NPs) and mycosynthesized nanoparticles (f-ZnO NPs) were used. Herein, biomass filtrates of one selected fungus (Trichoderma harzianum) and one bacterium (Bacillus safensis) were used to reduce zinc acetate into ZnO NPs. The physiochemical and morphological characters of both types of NPs were determined. UV-vis spectroscopy displayed absorption peaks of f-ZnO NPs and b-ZnO NPs at 310-380 nm, respectively, indicating successful reduction of Zinc acetate by the metabolites of both fungus and bacteria. Fourier transform infrared (FTIR) determined the presence of organic compounds like amines, aromatics, alkenes and alkyl halides, on both types of NPs, while X-ray diffraction (XRD) confirmed nano-size of f-ZnO NPs (30 nm) and b-ZnO NPs (35 nm). Scanning electron microscopy showed flower-crystalline shape for b-ZnO NPs and spherical-crystalline shape for f-ZnO NPs. Both NPs showed variable antifungal activities at four different concentrations (0.25, 0.50, 0.75 and 1.00 mg/ml). Diseases control and postharvest changes in apricot fruit were analyzed for 15 days. Among all treatments, 0.50 mg/ml concentration of f-ZnO NPs and 0.75 mg/ml concentration of b-ZnO NPs exhibited the strongest antifungal activity. Comparatively, f-ZnO NPs performed slightly better than b-ZnO NPs. Application of both NPs reduced fruit decay and weight, maintained higher ascorbic acid contents, sustained titratable acidity, and preserved firmness of diseased fruit. Our results suggest that microbial synthesized ZnO NPs can efficiently control fruit rot, extend shelf life, and preserve the quality of apricot.

Effect of green Fe2O3 nanoparticles in controlling Fusarium fruit rot disease of loquat in Pakistan.

The subtropical fruit known as the loquat is prized for both its flavour and its health benefits. The perishable nature of loquat makes it vulnerable to several biotic and abiotic stressors. During the previous growing season (March-April 2021), loquat in Islamabad showed signs of fruit rot. Loquat fruits bearing fruit rot symptoms were collected, and the pathogen that was causing the disease isolated and identified using its morphology, microscopic visualisation, and rRNA sequence. The pathogen that was isolated was identified as Fusarium oxysporum. Green synthesized metallic iron oxide nanoparticles (Fe2O3 NPs) were employed to treat fruit rot disease. Iron oxide nanoparticles were synthesized using a leaf extract of the Calotropis procera. Characterization of NPs was performed by different modern techniques. Fourier transform infrared spectroscopy (FTIR) determined the existence of stabilizing and reducing compounds like phenol, carbonyl compounds, and nitro compounds, on the surface of Fe2O3 NPs. X-ray diffraction (XRD) explained the crystalline nature and average size (~49 nm) of Fe2O3 NPs. Energy dispersive X-ray (EDX) exhibited Fe and O peaks, and scanning electron microscopy (SEM) confirmed the smaller size and spherical shape of Fe2O3 NPs. Following both in vitro and in vivo approaches, the antifungal potential of Fe2O3 NPs was determined, at different concentrations. The results of both in vitro and in vivo analyses depicted that the maximum fungal growth inhibition was observed at concentration of 1.0 mg/mL of Fe2O3 NPs. Successful mycelial growth inhibition and significantly reduced disease incidence suggest the future application of Fe2O3 NPs as bio fungicides to control fruit rot disease of loquat.

Exploration of plant growth promoting traits and regulatory mechanisms of Bacillus anthracis PM21 in enhancing salt stress tolerance in maize.

Bacillus species have been reported to reduce the negative effects of salt stress on plants; the involvement of Bacillus anthracis PM21 and the internal mechanisms involved in this process are unclear. The effects of PM21 inoculation on maize plants under salt stress were investigated in this study. The study aimed to assess the ability of Bacillus anthracis PM21 to endure high levels of salinity stress while preserving the concentration of plant growth regulators. The biomass, photosynthetic pigments, relative water content (RWC), antioxidants, osmoprotectants, inorganic ion contents, regulation of plant hormones and expression of antioxidants enzyme encoded genes were investigated under normal and salinity stress conditions. Bacillus anthracis PM21 produced a significant amount of 1-aminocyclopropane-1-carboxylate deaminase enzyme (ACC deaminase) and exopolysaccharides (EPS) under salt stress and normal conditions. PM21 also produced plant growth stimulants including indole acetic acid, gibberellic acid (GA3), kinetin, and siderophore under salinity stress and normal conditions. Under salt stress, PM21 inoculation markedly increased plant growth indices, stimulate antioxidant enzyme mechanisms, osmoprotectants, and chlorophyll content. The use of qRT-PCR to analyze the transcription of targeted genes indicated greater expression of antioxidant-encoded genes and inferred their possible function in salinity stress tolerance. Our findings shed light on the functions of PM21 and its regulatory mechanisms in plant salt stress tolerance, as well as the importance of PM21 in this process. This study will provide a thorough analysis of the theoretical framework for adopting PM21 in agricultural production as an eco-friendly method to enhance crop growth and yield under salinity stress.

Health risk assessment and bioaccumulation of potentially toxic metals from water, soil, and forages near coal mines of district Chakwal, Punjab, Pakistan.

Water, forages, and soil contamination with potentially toxic metals (PTMs) through anthropogenic activities has become a significant environmental concern. It is crucial to find out the level of PTMs in water, soil, and forages near industrial areas. The PTMs enter the body of living organisms through these sources and have become a potential risk for humans and animals. Therefore, the present study aims at the health risk assessment of PTMs and their accumulation in soil, water, and forages of three tehsils (Kallar Kahar, Choa Saidan Shah, and Chakwal) in district Chakwal. Samples of wastewater, soil, and forages were collected from various sites of district Chakwal. PTMs detected in the present study were cadmium (Cd), chromium (Cr), lead (Pb), zinc (Zn), cobalt (Co), copper (Cu), and nickel (Ni), and their levels were measured through atomic absorption spectrophotometer (AAs GF95 graphite furnace auto sampler). Pollution load index (PLI), bio concentration factor (BCF), soil enrichment factors (EF), daily intake value (DIM), and health risk index (HRI) in sheep, cow, and buffalo were also analyzed. The results revealed that the mean concentration (mg/L) of Cd (0.72-0.91 mg/L), Cr (1.84-2.23 mg/L), Pb (0.95-3.22 mg/L), Co (0.74-2.93 mg/L), Cu (0.84-1.96 mg/L), and Ni (1.39-4.39 mg/L) in wastewater samples was higher than permissible limits set by WHO, NEQS, WWF, USEPA, and Pakistan in all three tehsils of district Chakwal. Similarly, in soil samples, concentrations of Cd (1.21-1.95 mg/kg), Cr (38.1-56.4 mg/kg), and Ni (28.3-55.9 mg/kg) were higher than their respective threshold values. The mean concentration of PTMs in forage samples (Parthenium hysterophorus, Mentha spicata, Justicia adhatoda, Calotropis procera, Xanthium strumarium, Amaranthaceae sp.) showed that maximum values of Cd (5.35-7.55 mg/kg), Cr (5.47-7.51 mg/kg), Pb (30-36 mg/kg), and Ni (12.6-57.5 mg/kg) were beyond their safe limit set for forages. PLI, BCF, and EF were > 1.0 for almost all the PTMs. The DIM and HRI for sheep were less than < 1.0 but for cows and buffalo were > 1.0. The current study showed that soil, water, and forages near coal mines area are contaminated with PTMs which enter the food chain and pose significant harm to humans and animals. In order to prevent their dangerous concentration in the food chain, regular assessment of PTMs present in soil, forages, irrigating water, and food is recommended.

Bio-fabrication of zinc oxide nanoparticles from Picea smithiana and their potential antimicrobial activities against Xanthomonas campestris pv. Vesicatoria and Ralstonia solanacearum causing bacterial leaf spot and bacterial wilt in tomato.

Due to an inevitable disadvantage of chemical or physical synthesis routes, biosynthesis approach to nanoparticles, especially metallic oxide is attractive nowadays. Metallic oxides nanoparticles present a new approach to the control of plant pathogens. ZnO nanoparticles (ZNPs) have very important role in phytopathology. In current study, biosynthesized ZNPs were tested against two devastating bacterial pathogens including Xanthomonas campestris pv. vesicatoria and Ralstonia solanacearum causing bacterial leaf spot and bacterial wilt in tomato. ZNPs were produced using a new extract from the plant Picea smithiana using an environmentally friendly, cost-effective and simple procedure. Zinc acetate was added to P. smithiana extract, stirred and heated to 200 °C. The white precipitation at the bottom were clear indication of synthesis of nanoparticles, which were further dried by subjecting them at 450 °C. X-ray diffraction pattern determined that the ZNPs had a crystallite size of about 26 nm, Fourier transform infrared spectroscopy indicated a peak between 450 and 550 cm-1 and the particle size estimated by dynamic light scattering was about 25 nm on average. Scanning electron microscopic analysis indicated that the particles were hexagonal in shape 31 nm in diameter. Antibacterial tests showed ZNPs synthesized by P. smithiana resulted in clear inhibition zones of 20.1 ± 1.5 and 18.9 ± 1.5 mm and 44.74 and 45.63% reduction in disease severity and 78.40 and 80.91% reduction in disease incidence in X. compestris pv. vesicatoria and R. solanacearum respectively at concentration of 100 µg/ml. Our findings reveal that the concentration of ZNPs was important for their efficient antibacterial activity. Overall, the biosynthesized ZNPs have been found to have effective antimicrobial activities against bacterial wilt and bacterial leaf spot in tomato.

Biofilm formation and flocculation potential analysis of halotolerant Bacillus tequilensis and its inoculation in soil to mitigate salinity stress of chickpea.

Application of beneficial microbes in soil is an important avenue to control plant stresses. In this study, the salinity tolerance of halotolerant bacteria (Bacillus tequilensis) was investigated and the bacterium was inoculated in the soil to mitigate salinity stress. The results revealed the highest floc yield and biofilm formation ability of B. tequilensis at 100 mM NaCl concentration. Fourier transformed infrared spectroscopy depicted the presence of carbohydrates and proteins which binds with sodium ions (Na+) and provide tolerance against salinity. Using PCR, plant growth-promoting bacterial genes viz., 1-aminocyclopropane-1-carboxylate deaminase and pyrroloquinoline quinone were successfully amplified from the genome of B. tequilensis. In the saline soil, B. tequilensis was inoculated and chickpea plants were grown. The bacterial strain improved the physiology, biochemistry, and antioxidant enzyme activities of the chickpea plant under salt stress. Plants inoculated with B. tequilensis exhibited higher relative water content, higher photosynthetic pigments, lower levels of hydrogen peroxide (H2O2) and malondialdehyde, and improved enzymatic activity for the scavenging of reactive oxygen species. The findings of this study suggest the sustainable use of B. tequilensis to mitigate the salinity stress of chickpea and other crops. This bacterium not only helps in the alleviation of the toxic effects of salt but also increases plant growth along with a reduction in crop losses due to salinity. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01280-1.

Biodegradation of monocrotophos by Brucella intermedia Msd2 isolated from cotton plant.

Widespread and inadequate use of Monocrotophos has led to several environmental issues. Biodegradation is an ecofriendly method used for detoxification of toxic monocrotophos. In the present study, Msd2 bacterial strain was isolated from the cotton plant growing in contaminated sites of Sahiwal, Pakistan. Msd2 is capable of utilizing the monocrotophos (MCP) organophosphate pesticide as its sole carbon source for growth. Msd2 was identified as Brucella intermedia on the basis of morphology, biochemical characterization and 16S rRNA sequencing. B. intermedia showed tolerance of MCP up to 100 ppm. The presence of opd candidate gene for pesticide degradation, gives credence to B. intermedia as an effective bacterium to degrade MCP. Screening of the B. intermedia strain Msd2 for plant growth promoting activities revealed its ability to produce ammonia, exopolysaccharides, catalase, amylase and ACC-deaminase, and phosphorus, zinc and potassium solubilization. The optimization of the growth parameters (temperatures, shaking rpm, and pH level) of the MCP-degrading isolate was carried out in minimal salt broth supplemented with MCP. The optimal pH, temperature, and rpm for Msd2 growth were observed as pH 6, 35 °C, and 120 rpm, respectively. Based on optimization results, batch degradation experiment was performed. Biodegradation of MCP by B. intermedia was monitored using HPLC and recorded 78% degradation of MCP at 100 ppm concentration within 7 days of incubation. Degradation of MCP by Msd2 followed the first order reaction kinetics. Plant growth promoting and multi-stress tolerance ability of Msd2 was confirmed by molecular analysis. It is concluded that Brucella intermedia strain Msd2 could be beneficial as potential biological agent for an effective bioremediation for polluted environments.

Elucidating molecular characterization of chlorpyrifos and profenofos degrading distinct bacterial strains for enhancing seed germination potential of Gossypium arboreum L.

Chlorpyrifos (CP) and profenofos (PF) are organophosphate pesticides (OPs) widely used in agriculture and are noxious to both fauna and flora. The presented work was designed to attenuate the toxicity of both pesticides in the growth parameters of a cotton crop by applying plant growth-promoting rhizobacteria (PGPR), namely Pseudomonas aeruginosa PM36 and Bacillus sp. PM37. The multifarious biological activities of both strains include plant growth-promoting traits, including phosphate solubilization; indole-3-acetic acid (IAA), siderophore, and HCN production; nitrogen fixation; and enzymatic activity such as cellulase, protease, amylase, and catalase. Furthermore, the molecular profiling of multi-stress-responsive genes, including acdS, ituC, czcD, nifH, and sfp, also confirmed the plant growth regulation and abiotic stress tolerance potential of PM36 and PM37. Both strains (PM36 and PM37) revealed 92% and 89% of CP degradation at 50 ppm and 87% and 81% at 150 ppm within 7 days. Simultaneously 94% and 98% PF degradation was observed at 50 ppm and 90% and 92% at 150 ppm within 7 days at 35 °C and pH 7. Biodegradation was analyzed using HPLC and FTIR. The strains exhibited first-order reaction kinetics, indicating their reliance on CP and PF as energy and carbon sources. The presence of opd, mpd, and opdA genes in both strains also supported the CP and PF degradation potential of both strains. Inoculation of strains under normal and OP stress conditions resulted in a significant increase in seed germination, plant biomass, and chlorophyll contents of the cotton seedling. Our findings indicate that the strains PM36 and PM37 have abilities as biodegraders and plant growth promoters, with potential applications in crop sciences and bioremediation studies. These strains could serve as an environmentally friendly, sustainable, and socially acceptable solution to manage OP-contaminated sites.

Biological Applications of Ball-Milled Synthesized Biochar-Zinc Oxide Nanocomposite Using Zea mays L.

Nanotechnology is one of the vital and quickly developing areas and has several uses in various commercial zones. Among the various types of metal oxide-based nanoparticles, zinc oxide nanoparticles (ZnO NPs) are frequently used because of their effective properties. The ZnO nanocomposites are risk-free and biodegradable biopolymers, and they are widely being applied in the biomedical and therapeutics fields. In the current study, the biochar-zinc oxide (MB-ZnO) nanocomposites were prepared using a solvent-free ball-milling technique. The prepared MB-ZnO nanocomposites were characterized through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray powder diffraction (XRD), and thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet-visible (UV) spectroscopy. The MB-ZnO particles were measured as 43 nm via the X-ray line broadening technique by applying the Scherrer equation at the highest peak of 36.36°. The FTIR spectroscope results confirmed MB-ZnO's formation. The band gap energy gap values of the MB-ZnO nanocomposites were calculated as 2.77 eV by using UV-Vis spectra. The MB-ZnO nanocomposites were tested in various in vitro biological assays, including biocompatibility assays against the macrophages and RBCs and the enzymes' inhibition potential assay against the protein kinase, alpha-amylase, cytotoxicity assays of the leishmanial parasites, anti-inflammatory activity, antifungal activity, and antioxidant activities. The maximum TAC (30.09%), TRP (36.29%), and DPPH radicals' scavenging potential (49.19%) were determined at the maximum dose of 200 µg/mL. Similarly, the maximum activity at the highest dose for the anti-inflammatory (76%), at 1000 µg/mL, alpha-amylase inhibition potential (45%), at 1000 µg/mL, antileishmanial activity (68%), at 100 µg/mL, and antifungal activity (73 ± 2.1%), at 19 mg/mL, was perceived, respectively. It did not cause any potential harm during the biocompatibility and cytotoxic assay and performed better during the anti-inflammatory and antioxidant assay. MB-ZnO caused moderate enzyme inhibition and was more effective against pathogenic fungus. The results of the current study indicated that MB-ZnO nanocomposites could be applied as effective catalysts in various processes. Moreover, this research provides valuable and the latest information to the readers and researchers working on biopolymers and nanocomposites.

ZnO Nanoparticle-Mediated Seed Priming Induces Biochemical and Antioxidant Changes in Chickpea to Alleviate Fusarium Wilt.

Chickpea (Cicer arietinum L.) is one of the main pulse crops of Pakistan. The yield of chickpea is affected by a variety of biotic and abiotic factors. Due to their environmentally friendly nature, different nanoparticles are being synthesized and applied to economically important crops. In the present study, Trichoderma harzianum has been used as a stabilizing and reducing agent for the mycosynthesis of zinc oxide nanoparticles (ZnO NPs). Before their application to control Fusarium wilt of chickpea, synthesized ZnO NPs were characterized. X-ray diffraction (XRD) analysis revealed the average size (13 nm) of ZnO NPs. Scanning electron microscopy (SEM) indicated their spherical structure, and energy dispersive X-ray analysis (EDX) confirmed the oxide formation of ZnO NPs. Transmission electron microscopy (TEM) described the size and shape of nanoparticles, and Fourier transform infrared (FTIR) spectroscopy displayed the presence of reducing and stabilizing chemical compounds (alcohol, carboxylic acid, amines, and alkyl halide). Successfully characterized ZnO NPs exhibited significant mycelial growth inhibition of Fusarium oxysporum, in vitro. In a greenhouse pot experiment, the priming of chickpea seeds with ZnO NPs significantly increased the antioxidant activity of germinated plants and they displayed 90% less disease incidence than the control. Seed priming with ZnO NPs helped plants to accumulate higher quantities of sugars, phenol, total proteins, and superoxide dismutase (SOD) to create resistance against wilt pathogen. These nanofungicides were produced in powder form and they can easily be transferred and used in the field to control Fusarium wilt of chickpea.

Dimethoate residues in Pakistan and mitigation strategies through microbial degradation: a review.

Organophosphate pesticides (OPs) are used extensively for crop protection worldwide due to their high water solubility and relatively low persistence in the environment compared to other pesticides, such as organochlorines. Dimethoate is a broad-spectrum insecticide that belongs to the thio-organophosphate group of OPs. It is applied to cash crops, animal farms, and houses. It has been used in Pakistan since the 1960s, either alone or in a mixture with other OPs or pyrethroids. However, the uncontrolled use of this pesticide has resulted in residual accumulation in water, soil, and tissues of plants via the food chain, causing toxic effects. This review article has compiled and analyzed data reported in the literature between 1998 and 2021 regarding dimethoate residues and their microbial bioremediation. Different microorganisms such as bacteria, fungi, and algae have shown potential for bioremediation. However, an extensive role of bacteria has been observed compared to other microorganisms. Twenty bacterial, three fungal, and one algal genus with potential for the remediation of dimethoate have been assessed. Active bacterial biodegraders belong to four classes (i) alpha-proteobacteria, (ii) gamma-proteobacteria, (iii) beta-proteobacteria, and (iv) actinobacteria and flavobacteria. Microorganisms, especially bacterial species, are a sustainable technology for dimethoate bioremediation from environmental samples. Yet, new microbial species or consortia should be explored.

Deciphering distinct root exudation, ionomics, and physio-biochemical attributes of Serratia marcescens CP-13 inoculated differentially Cd tolerant Zea mays cultivars.

Cadmium (Cd) being a non-essential, mobile, and toxic heavy metal, negatively affects the plant growth and physiology. Current work investigated the impact of Serratia marcescens CP-13 inoculation on root organic acids and nutrient exudates of two maize cultivars varying in Cd tolerance under induced Cd toxicity. Seedlings of Cd-sensitive (Sahiwal-2002) and Cd-tolerant (MMRI-Yellow) cultivars were grown either inoculated or non-inoculated with CP-13 in Petri plates having various Cd stress levels (0, 6, 12, 18, 24, 30 µM). Seedlings were transferred to rhizoboxes for the collection of root exudates and analysis of physio-biochemical traits. Both maize cultivars exuded higher organic acids and nutrient exudates under non-inoculated conditions as compared to inoculated ones. Non-inoculated tolerant cultivar exhibited higher nutrient accumulation, biomass, antioxidants, total chlorophyll, Cd release meanwhile reduced Cd uptake, lipid peroxidation, exudation of organic acids, and nutrients than the sensitive one. However, under CP-13 inoculation, Cd sensitive cultivar exhibited less exudation of organic acids (citric acid, acetic acid, malic acid, glutamic acid, formic acid, succinic acid, and oxalic acid), nutrients mobilization (K, Na, Zn, Ca, and Mg), total chlorophyll, antioxidants (APX, SOD, POD), total soluble sugar, diminished MDA, and Cd uptake. The significant reduction in release of root exudates by both cultivars was likely due to the plant growth promoting traits of CP-13 which confer Cd tolerance. The maximum release of rhizospheric root exudates were documented at 30 µM applied Cd stress. Therefore, the Serratia sp. CP-13 was proposed as a potential inoculant for bioremediation of Cd together with maize cultivars.

Omics: a tool for resilient rice genetic improvement strategies.

Rice is pivotal pyramid of about half of the world population. Bearing small genome size and worldwide utmost food crop rice has been known as ideal cereal crop for genome research. Currently, decreasing water table and soil fatigue are big challenges and intense consequences in changing climate. Whole sequenced genome of rice sized 389 Mb of which 95% is covered with excellent mapping order. Sequenced rice genome helps in molecular biology and transcriptomics of cereals as it provides whole genome sequence of indica and japonica sub species. Through rice genome sequencing and functional genomics, QTLs or genes, genetic variability and halophyte blocks for agronomic characters were identified which have proved much more useful in molecular breeding and direct selection. There are different numbers of genes or QTLs identified for yield related traits i.e., 6 QTLs/genes for plant architecture, 6 for panicle characteristics, 4 for grain number, 1 gene/QTL for tiller, HGW, grain filling and shattering. QTLS/genes for grain quality, biotic stresses and for abiotic stresses are 7, 23 and 13 respectively. Low yield, inferior quality and susceptibility to biotic and abiotic stresses of a crop is due to narrow genetic background of new evolving rice verities. Wild rice provides genetic resources for improvement of these characters, molecular and genomics tool at different stages can overcome these stresses and improve yield and quality of rice crop.

Antifungal activity of Zinc nitrate derived nano Zno fungicide synthesized from Trachyspermum ammi to control fruit rot disease of grapefruit.

Grapefruit (Citrus paradisi) is a widely grown citrus and its fruit is affected by a variety of biotic and abiotic stress. Keeping in view the hazardous effects of synthetic fungicides, the recent trend is shifting towards safer and eco-friendly control of fruit diseases. The present study was aimed to diagnose the fruit rot disease of grapefruit and its control by using zinc oxide green nanoparticles (ZnO NPs). Fruit rot symptoms were observed in various grapefruit growing sites of Pakistan. Diseased samples were collected, and the disease-causing pathogen was isolated. Following Koch's postulates, the isolated pathogen was identified as Rhizoctonia solani. For eco-friendly control of this disease, ZnO NPs were prepared in the seed extract of Trachyspermum ammi and characterized. Fourier transform infrared spectroscopy (FTIR) of these NPs described the presence of stabilizing and reducing compounds such as phenols, aldehyde and vinyl ether, especially thymol (phenol). X-ray diffraction (XRD) analysis revealed their crystalline nature and size (48.52 nm). Energy dispersive X-ray (EDX) analysis elaborated the presence of major elements in the samples, while scanning electron microscopy (SEM) confirmed the morphology of bio fabricated NPs. ZnO NPs exhibited very good anti-fungal activity and the most significant fungal growth inhibition was observed at 1.0 mg/ml concentration of green NPs, in vitro and in vivo. These findings described that the bioactive constituents of T. ammi seed extract can effectively reduce and stabilize ZnO NPs. It is a cost-effective method to successfully control the fruit rot disease of grapefruit.

Mycosynthesized Fe2 O3 nanoparticles diminish brown rot of apple whilst maintaining composition and pertinent organoleptic properties.

AIMS: Iron oxide nanoparticles (Fe2 O3 NPs) were mycosynthesized using Trichoderma harzianum and applied to control brown rot of apple. The influence of Fe2 O3 NPs on the quality of fruit was also studied. METHODS AND RESULTS: Diseased apple fruits with brown rot symptoms were collected, and the disease-causing pathogen was isolated and identified as Fusarium oxysporum. To control this disease, mycosynthesis of Fe2 O3 NPs was executed using T. harzianum. FTIR spectroscopy revealed the occurrence of stabilizing and reducing agents on NPs. X-ray diffraction (XRD) analysis determined their average size (17.78 nm) and crystalline nature. Energy-dispersive X-ray (EDX) showed strong signals of iron, and scanning electron microscopy (SEM) displayed a high degree of polydispersity of synthesized NPs. Foliar application of NPs significantly reduced brown rot and helped fruits to maintain biochemical and organoleptic properties. Firmness and higher percentage of soluble solids, sugars and ascorbic acid depicted its good quality. CONCLUSION: Environment-friendly mycosynthesized Fe2 O3 NPs can be effectively used to control brown rot of apple. SIGNIFICANCE AND IMPACT OF THE STUDY: Trichoderma harzianum is a famous biocontrol agent, and the synthesis of NPs in its extract is an exciting avenue to control fungal diseases. Due to its nontoxic nature to human gut, it can be applied on all edible fruits.

Microbial detoxification of dimethoate through mediated hydrolysis by Brucella sp. PS4: molecular profiling and plant growth-promoting traits.

High toxicity of dimethoate requires efficient ways for detoxification and removal of its residues in contaminated environments. Microbial remediation is a process that utilizes the degradation potential of microbes to provide a cost-effective and reliable approach for pesticide abatement. For this purpose, a dimethoate-degrading bacterium Brucella sp. was isolated from a contaminated agricultural soil sample in Multan, Pakistan. This isolate was found to tolerate up to 100 ppm of dimethoate in minimal salt medium and was further evaluated for plant growth-promoting traits. The strain gave positive results for amylase, ammonia, and catalase production, while other traits such as indole acetic acid production and potassium solubilization were also confirmed. Thus, the strain could play an important role for plant nutrient transmission in the plant rhizosphere. Optimization of growth parameters (i.e., pH and temperature) depicted the potential of PS4 to be best tolerating dimethoate, with maximum cell density at λ 600 nm. Optimum pH and temperature for growth were found to be 6 and 35 °C, respectively. Based on optimization results as well as different attributes, the rhizospheric bacterial isolate PS4 was further subjected to a batch degradation experiment under different concentrations of dimethoate (25, 50, 75, and 100 ppm). This promising dimethoate-degrading isolate was found to degrade 83% of dimethoate (at 100 ppm) within a period of 7 days. In addition, it degraded 88% of dimethoate at 50 ppm, indicating that the bacterial isolate utilized dimethoate solely as a source of energy. The strain followed the first order reaction kinetics, depicting its dependence on dimethoate as energy and carbon source. Molecular profiling further supported its role in plant growth promotion and multi-stress tolerance. This research showed that Brucella sp. is capable of degrading dimethoate, and therefore, it would be useful in the investigation of novel bioremediation techniques at pesticide-polluted sites.