Fungal-mediated synthesis of silver nanoparticles: a novel strategy for plant disease management.

Various traditional management techniques are employed to control plant diseases caused by bacteria and fungi. However, due to their drawbacks and adverse environmental effects, there is a shift toward employing more eco-friendly methods that are less harmful to the environment and human health. The main aim of the study was to biosynthesize silver Nanoparticles (AgNPs) from Rhizoctonia solani and Cladosporium cladosporioides using a green approach and to test the antimycotic activity of these biosynthesized AgNPs against a variety of pathogenic fungi. The characterization of samples was done by using UV-visible spectroscopy, SEM (scanning electron microscopy), FTIR (fourier transmission infrared spectroscopy), and XRD (X-ray diffractometry). During the study, the presence of strong plasmon absorbance bands at 420 and 450 nm confirmed the AgNPs biosynthesis by the fungi Rhizoctonia solani and Cladosporium cladosporioides. The biosynthesized AgNPs were 80-100 nm in size, asymmetrical in shape and became spherical to sub-spherical when aggregated. Assessment of the antifungal activity of the silver nanoparticles against various plant pathogenic fungi was carried out by agar well diffusion assay. Different concentration of AgNPs, 5 mg/mL 10 mg/mL and 15 mg/mL were tested to know the inhibitory effect of fungal plant pathogens viz. Aspergillus flavus, Penicillium citrinum, Fusarium oxysporum, Fusarium metavorans, and Aspergillus aflatoxiformans. However, 15 mg/mL concentration of the AgNPs showed excellent inhibitory activity against all tested fungal pathogens. Thus, the obtained results clearly suggest that silver nanoparticles may have important applications in controlling various plant diseases caused by fungi.

Microcystin levels in irrigation water and field-vegetable plants, and food safety risk assessment: A case study from Egypt.

Microcystin (MC), a hepatotoxin that is harmful to human health, has frequently increased in freshwaters worldwide due to the increase in toxic cyanobacterial blooms. Despite many studies reported the human exposure to MC through drinking water, the potential transfer of this toxin to human via consumption of vegetables grown on farmlands that are naturally irrigated with contaminated water has not been largely investigated. Therefore, this study investigates the presence of MC in irrigation water and its potential accumulation in commonly consumed vegetables from Egyptian farmlands. The results of toxin analysis revealed that all irrigation water sites contained high MC concentrations (1.3-93.7 µg L-1) along the study period, in association with the abundance of dominant cyanobacteria in these sites. Meanwhile, MCs were detected in most vegetable plants surveyed, with highest levels in potato tubers (1100 µg kg-1 fresh weight, FW) followed by spinach (180 µg kg-1 FW), onion (170 µg g-1 FW), Swiss chard (160 µg kg-1 FW) and fava bean (46 µg kg-1 FW). These MC concentrations in vegetables led to estimated daily intake (EDI) values (0.08-1.13 µg kg bw-1 d-1 for adults and 0.11-1.5 µg kg bw-1 d-1 for children), through food consumption, exceeding the WHO recommended TDI (0.04 µg kg bw-1 d-1) for this toxin. As eutrophic water is widely used for irrigation in many parts of the world, our study suggests that cyanotoxins in irrigation waters and agricultural plants should be regularly monitored to safeguard the general public from inadvertent exposure to harmful toxins via food consumption.

High doses of clethodim-based herbicide GrassOut Max poses reproductive hazard by affecting male reproductive function and early embryogenesis in Swiss albino mice.

Clethodim is a widely used and approved class II herbicide, with little information about its impact on the reproductive system. Herein, we investigated the male reproductive toxicity of clethodim using a mouse model. GrassOut Max (26% clethodim-equivalent) or analytical grade clethodim (≥90%) were given orally to male mice for 10 d in varying doses. All parameters were assessed at 35 d post-treatment. Significant decrease in testicular weight, decreased germ cell population, elevated DNA damage in testicular cells and lower serum testosterone level was observed post clethodim based herbicide exposure. Epididymal spermatozoa were characterized with significant decrease in motility, elevated DNA damage, abnormal morphology, chromatin immaturity and, decreased acetylated-lysine of sperm proteins. In the testicular cells of clethodim-based herbicide treated mice, the expression of Erß and Gper was significantly higher. Proteomic analysis revealed lower metabolic activity, poor sperm-oocyte binding potential and defective mitochondrial electron transport in spermatozoa of clethodim-based herbicide treated mice. Further, fertilizing ability of spermatozoa was compromised and resulted in defective preimplantation embryo development. Together, our data suggest that clethodim exposure risks male reproductive function and early embryogenesis in Swiss albino mice via endocrine disrupting function.

Chemical Characterization of Honey and Its Effect (Alone as well as with Synthesized Silver Nanoparticles) on Microbial Pathogens' and Human Cancer Cell Lines' Growth.

The antibacterial, anticancer, and wound-healing effects of honey can vary according to the type, geographical region, honey bee species, and source of the flowers. Nanotechnology is an innovative and emerging field of science with an enormous potential role in medical, cosmetics, and industrial usages globally. Metal nanoparticles that derived from silver and range between 1 nm and 100 nm in size are called silver nanoparticles (AgNPs). Much advanced research AgNPs has been conducted due to their potential antibacterial and anticancer activity, chemical stability, and ease of synthesis. The purpose of the present study was to explore the physicochemical properties of honey and the potential to use forest honey to synthesize AgNPs as well as to appraise the nanoparticles' antimicrobial and anticancer effects. Here, we used three different percentages of forest honey (20%, 40%, and 80%) as biogenic mediators to synthesize AgNPs at room temperature. The development of AgNPs was confirmed by color change (to the naked eye) and ultraviolet-visible spectroscopy studies, respectively. The absorbance peak obtained between 464 to 4720 nm validated both the surface plasmon resonance (SPR) band and the formation of AgNPs. Regarding the sugar profile, the contents of maltose and glucose were lower than the content of fructose. In addition, the results showed that the SPR band of AgNPs increased as the percentage of forest honey increased due to the elevation of the concentration of the bio-reducing agent. A bacterial growth kinetic assay indicated the strong antibacterial efficacy of honey with silver nanoparticles against each tested bacterial strain. Honey with nanotherapy was the most effective against hepatocellular carcinoma (HepG2) and colon cancer (HCT 116) cells, with IC50s of 23.9 and 27.4 µg/mL, respectively, while being less effective against breast adenocarcinoma cells (MCF-7), with an IC50 of 32.5 µg/mL.

Prediction Models Based on Soil Characteristics for Evaluation of the Accumulation Capacity of Nine Metals by Forage Sorghum Grown in Agricultural Soils Treated with Varying Amounts of Poultry Manure.

Predictive models were generated to evaluate the degree to which nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were absorbed by the leaves, stems and roots of forage sorghum in growing media comprising soil admixed with poultry manure concentrations of 0, 10, 20, 30 and 40 g/kg. The data revealed that the greatest contents of the majority of the metals were evident in the roots rather than in the stems and leaves. A bioaccumulation factor (BAF) < 1 was calculated for Cr, Fe, Ni, Pb and Zn; BAF values for Co, Cu, Mn and Cd were 3.99, 2.33, 1.44 and 1.40, respectively, i.e., > 1. Translocation factor values were < 1 for all metals with the exception of Co, Cr and Ni, which displayed values of 1.20, 1.67 and 1.35 for the leaves, and 1.12, 1.23 and 1.24, respectively, for the stems. The soil pH had a negative association with metal tissues in plant parts. A positive relationship was observed with respect to plant metal contents, electrical conductivity and organic matter quantity. The designed models exhibited a high standard of data precision; any variations between the predicted and experimentally observed contents for the nine metals in the three plant tissue components were nonsignificant. Thus, it was concluded that the presented predictive models constitute a pragmatic tool to establish the safety from risk to human well-being with respect to growing forage sorghum when cultivating media fortified with poultry manure.

Biotransformation and detoxification of saxitoxin by Bacillus flexus in batch experiments.

Saxitoxins (STXs) are carbamate alkaloid neurotoxins produced by some species of cyanobacteria. They are water soluble and relatively stable in the natural environment, and thereby represent a risk to animal and human health through a long-time exposure. STXs cannot be sufficiently removed by conventional water treatment methods. Therefore, this study investigates the potential STX biodegradation and detoxification by bacteria as a promising method for toxin removal. STX biodegradation experiments were conducted using Bacillus flexus SSZ01 strain in batch cultures. The results revealed that SSZ01 strain grew well and rapidly detoxified STX, with no lag phase observed. STX detoxification by SSZ01 strain was initial-toxin-concentration-dependent. The highest biotransformation rate (10 µg STX L-1 day-1) the pseudo-first-order kinetic constant (0.58 d-1) were obtained at the highest initial toxin concentration (50 µg L-1) and the lowest ones (0.06 µg STX L-1 day-1 and 0.14 d-1, respectively) were recorded at the lowest initial concentration (0.5 µg L-1). STX biotransformation rate increased with temperature, with highest occurred at 30 ºC. This rate was also influenced by pH, with highest obtained at pH8 and lowest at higher and lower pH values. HPLC chromatograms showed that STX biotransformation peak is corresponding to the least toxic STX analog (disulfated sulfocarbamoyl-C1 variant). The Artemia-based toxicity assay revealed that this biotransformation byproduct was nontoxic. This suggests the potential application of this bacterial strain in slow sand filters for cyanotoxin removal in water treatment plants. Being nontoxic, this byproduct needs to be assayed for its therapeutic effects toward neurodegenerative diseases.

Population Genetics and Anastomosis Group's Geographical Distribution of Rhizoctonia solani Associated with Soybean.

Rhizoctonia solani is a species complex composed of many genetically diverse anastomosis groups (AG) and their subgroups. It causes economically important diseases of soybean worldwide. However, the global genetic diversity and distribution of R. solani AG associated with soybean are unknown to date. In this study, the global genetic diversity and distribution of AG associated with soybean were investigated based on rDNA-ITS sequences deposited in GenBank and published literature. The most prevalent AG, was AG-1 (40%), followed by AG-2 (19.13%), AG-4 (11.30%), AG-7 (10.43%), AG-11 (8.70%), AG-3 (5.22%) and AG-5 (3.48%). Most of the AG were reported from the USA and Brazil. Sequence analysis of internal transcribed spacers of ribosomal DNA separated AG associated with soybean into two distinct clades. Clade I corresponded to distinct subclades containing AG-2, AG-3, AG-5, AG-7 and AG-11. Clade II corresponded to subclades of AG-1 subgroups. Furthermore, AG and/or AG subgroups were in close proximity without corresponding to their geographical origin. Moreover, AG or AG subgroups within clade or subclades shared higher percentages of sequence similarities. The principal coordinate analysis also supported the phylogenetic and genetic diversity analyses. In conclusion, AG-1, AG-2, and AG-4 were the most prevalent AG in soybean. The clade or subclades corresponded to AG or AG subgroups and did not correspond to the AG's geographical origin. The information on global genetic diversity and distribution will be helpful if novel management measures are to be developed against soybean diseases caused by R. solani.

First Record of Clonostachys rosea (Ascomycota: Hypocreales) Entomopathogenic Fungus in the Mango Hopper Amritodus atkinsoni (Hemiptera: Cicadellidae).

Mango hopper (Amritodus atkinsoni Lethierry) causes devastations in the early vegetative stage of the mango crop. The classical management of mango hopper is with systemic insecticides but their overuse has caused environmental pollution. Here, we have evaluated the entomopathogenic role of Clonostachys rosea through bioassay and optimized media for its large-scale culturing. The current study reveals the potentiality of C. rosea as entomopathogenic on A. atkinsoni. Initially, morphological and molecular characterization was used to validate local isolates' identity as C. rosea. Further, we have evaluated the entomopathogenic role of C. rosea through a bioassay, where the highest mean mortality in A. atkinsoni was observed at a treatment concentration of 3 × 108 conidia/mL, with 96.67% mortality after 168 h of infection. This work also provides insight into the laboratory-based media standardization for C. rosea, resulting in oatmeal agar media and broth as the most suitable artificial media, and 20 °C temperature for its mass culture. Thus, C. rosea is a novo-entomopathogenic fungus on A. atkinsoni and has a high potency to be included in the management of mango hopper pests.

Green Chemistry Based Synthesis of Zinc Oxide Nanoparticles Using Plant Derivatives of Calotropis gigantea (Giant Milkweed) and Its Biological Applications against Various Bacterial and Fungal Pathogens.

Nanotechnology is a burning field of scientific interest for researchers in current era. Diverse plant materials are considered as potential tool in green chemistry based technologies for the synthesis of metal nanoparticles (NPs) to cope with the hazardous effects of synthetic chemicals, leading to severe abiotic climate change issues in today's agriculture. This study aimed to determine the synthesis and characterization of metal-based nanoparticles using extracts of the selected plant Calotropis gigantea and to evaluate the enzyme-inhibition activities and antibacterial and antifungal activity of extracts of metal-based zinc nanoparticles using C. gigantea extracts. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). C. gigantea was examined for antimicrobial activity against clinical isolates of bacteria and fungi. The water, ethanolic, and acetone extracts of C. gigantea were studied for their antagonistic action against bacterial strains (E. coli, S. aureus, P. multocida, and B. subtilis) and selected fungal strains (A. paracistic, F. solani, A. niger, S. ferrugenium, and R. nigricans). In vitro antimicrobial activity was determined by the disc diffusion method, where C. gigantea wastested for AChE and BChE inhibitory activity using Ellman's methodology. The kinetic analysis was performed by the proverbial Berthelot reaction for urease inhibition. The results showed that out of all the extracts tested, ethanolic and water extracts possessed zinc nanoparticles. These extracts showed the maximum zone of inhibition against F. solani and P. multocida and the lowest against S. ferrugenium and B. subtilis. A potential source of AChE inhibitors is certainly provided by the abundance of plants in nature. Numerous phyto-constituents, such as AChE and BChE inhibitors, have been reported in this communication. Water extract was active and has the potential for in vitro AChE and BChE inhibitory activity. The urease inhibition with flower extracts of C. gigantea revealed zinc nanoparticles in water extracts that competitively inhibited urease enzymes. In the case of cholinesterase enzymes, it was inferred that the water extract and zinc nanoparticles have more potential for inhibition of BChE than AChE and urease inhibition. Furthermore, zinc nanoparticles with water extract are active inthe inhibition of the bacterial strains E. coli, S. aureus, and P. multocida and the fungal strains A. paracistic, F. solani, and A. niger.

Exposure of Pisum sativum L. Seeds to Methomyl and Imidacloprid Cause Genotoxic Effects in Pollen-Mother Cells

Pesticides are commonly used in modern agricultural systems to protect the plants from pests. Even though they potentially increase the crop yield, they have undesirable toxic effects on the consumers of plant products and nontarget host plants. However, there are limited studies to demonstrate the cytological changes induced by pesticides on plant cells. In the present study, we assess the cytological changes induced by two most commonly used insecticides, methomyl (ME) and imidacloprid (IM), using Pisum sativum L. as model plant system. P. sativum seeds were exposed to various concentrations of ME and IM (0.1, 0.2, 0.3, 0.4 and 0.5%) for 1, 3, and 6 h, and their effects on seed germination (SG), radicle length (RL), mitotic index (MI), chromosomal aberrations frequency (CAF), and micronucleus frequency (MNF) were studied. The results indicate that these insecticides decrease MI in root-tip cells, and increase in the MNF in pollen-mother cells in a dose-dependent manner. Additionally, insecticide-treated groups showed a dose- and time-dependent increase in the percentage of aberrant meiotic cells. Clumped nuclei (CNU), stickiness (STC), bridges (BRs), laggards (LGs), secondary association (SA), and precocious separation (PS) were among the frequently observed anomalies. The findings of this study indicate that commonly used insecticides ME and IM have substantial genotoxic effects on the root-tip and pollen-mother cells of P. sativum L.

Methomyl, imbraclaobrid and clethodim induced cytomixis and syncytes behaviors in PMCs of Pisum sativum L: Causes and outcomes.

Cytomixis is a common phenomenon observed in meiotic cells such as anther which is influenced by various factors. Use of pesticides is a common practice in agriculture. However, it is not known whether pesticides can induce cytomixis in plant cells and induce genetic variation. To understand this, the present study was planned to assess the cytomixis and syncytes behaviors in PMCs of Pisum sativum L. Seeds of P. sativum (Family: Fabaceae) were treated with different concentrations of commonly used pesticides methomyl (ME), imbraclaobrid (IM) and clethodim (CL). Seeds were treated with various concentrations (0.1, 0.2, 0.3, 0.4 and 0.5% of ME, IM and CL prepared in water) for 1 and 3 h. Effect of pesticides on pollen fertility, frequency of cytomixis, and kind of cytomixis cells was assessed. In the cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), and various stages of meiosis (PI, MI, AI and TI) with cytomixis cells were observed. In addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) was assessed. During the microsporogenesis in P. sativum, the occurrence of cytomixis and syncytes at various stages of meiosis I were seen. The formation of cytoplasmic channels and direct fusing of pollen mother cells (PMCs) were both seen to cause cytomixis, with the former being more common than the latter. The percentage of PMCs with cytomixis and syncytes cells increased with increase in the concentration of pesticides. The result of the present investigation indicates that commonly used pesticides ME, IM, and CL have a significant effect on pollen fertility, frequency of cytomixis, and kind of cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), in addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) on P. sativum.

Optimization of Monascus purpureus for Natural Food Pigments Production on Potato Wastes and Their Application in Ice Lolly.

During potato chips manufacturing, large amounts of wastewater and potato powder wastes are produced. The wastewater obtained at washing after cutting the peeled potatoes into slices was analyzed, and a large quantity of organic compounds and minerals such as starch (1.69%), protein (1.5%), total carbohydrate (4.94%), reducing sugar (0.01%), ash (0.14%), crude fat (0.11%), Ca (28 mg/L), Mg (245 mg/L), Fe (45.5 mg/L), and Zn (6.5 mg/L) were recorded; these wastes could be considered as valuable by-products if used as a fermentation medium to increase the value of the subsequent products and to exceed the cost of reprocessing. In this study, we used wastewater and potato powder wastes as a growth medium for pigment and biomass production by Monascus purpureus (Went NRRL 1992). The response surface methodology was used to optimize total pigment and fungal biomass production. The influence of potato powder waste concentration, fermentation period, and peptone concentration on total pigment and biomass production was investigated using the Box-Behnken design method with 3-factors and 3-levels. The optimal production parameters were potato powder waste concentration of 7.81%, fermentation period of 12.82 days, and peptone concentration of 2.87%, which produced a maximum total pigment of 29.86 AU/ml that include, respectively, a maximum biomass weight of 0.126 g/ml and the yield of pigment of 236.98 AU/g biomass. The pigments produced were used as coloring agents for ice lolly. This study has revealed that the ice lolly preparations supplemented with these pigments received high acceptability. Finally, we recommend using wastewater and potato powder wastes for pigment and biomass production, which could reduce the cost of the pigment production process on an industrial scale in the future.

Foliar use of TiO2-nanoparticles for okra (Abelmoschus esculentus L. Moench) cultivation on sewage sludge-amended soils: biochemical response and heavy metal accumulation.

Considering its richness in organic and inorganic mineral nutrients, the recycling of sewage sludge (SS) is highly considered as a soil supplement in agriculture. However, the fate of hazardous heavy metal accumulation in the crops cultivated in SS amended soils is always a source of concern. Since nanoparticles are widely recognized to reduce heavy metal uptake by crop plants; thus, the present experiment deals with okra (Abelmoschus esculentus L. Moench) cultivation under the combined application of SS and TiO2-nanoparticles (NPs). Triplicated pot experiments were conducted using different doses of SS and TiO2-NPs such as 0 g/kg SS (control), 50 g/kg SS, 50 g/kg SS + TiO2, 100 g/kg SS, and 100 g/kg SS + TiO2, respectively. The findings of this study indicated that among the doses of treatment combinations investigated, 100 g/kg SS + TiO2 showed a significant (p < 0.05) increase in the okra plant yield (287.87 ± 4.06 g/plant) and other biochemical parameters such as fruit length (13.97 ± 0.54 cm), plant height (75.05 ± 3.18 cm), superoxide dismutase (SOD: 110.68 ± 3.11 µ/mg), catalase (CAT: 81.32 ± 3.52 µ/mg), and chlorophyll content (3.12 ± 0.05 mg/g fwt.). Also, the maximum contents of six heavy metals in the soil and cultivated okra plant tissues (fruit, stem, and root regions) followed the order of Fe > Mn > Cu > Zn > Cr > Cd using the same treatment. Bioaccumulation and health risk assessment indicated that foliar application of TiO2-NPs significantly reduced the fate of heavy metal accumulation under higher doses of SS application. Therefore, the findings of this study suggested that the combined use of SS and TiO2-NPs may be useful in ameliorating the negative consequences of heavy metal accumulation in cultivated okra crops.

Klebsiella oxytoca: an efficient pyrene-degrading bacterial strain isolated from petroleum-contaminated soil.

Polycyclic aromatic hydrocarbons (PAHs) are the hazardous xenobiotic agents of oil production. One of the methods to eliminate hazardous compounds is bioremediation, which is the most efficient and cost-effective method to eliminate the harmful byproducts of crude petroleum processing. In this study, five pure bacterial isolates were isolated from petroleum-contaminated soil, four of which showed a robust growth on the PAH pyrene, as a sole carbon source. Various methods viz mass spectroscopy, biochemical assays, and 16S RNA sequencing employed to identify the isolates ascertained the consistent identification of Klebsiella oxytoca by all three methods. Scanning electron microscopy and Gram staining further demonstrated the characterization of the K. oxytoca. High-performance liquid chromatography of the culture supernatant of K. oxytoca grown in pyrene containing media showed that the cells started utilizing pyrene from the 6th day onwards and by the 12th day of growth, 70% of the pyrene was completely degraded. A genome search for the genes predicted to be involved in pyrene degradation using Kyoto Encyclopedia of Genes and Genomes (KEGG) confirmed their presence in the genome of K. oxytoca. These results suggest that K. oxytoca would be a suitable candidate for removing soil aromatic hydrocarbons.

Host Resistance to Uromyces appendiculatus in Common Bean Genotypes.

Rust, induced by the fungus Uromyces appendiculatus, is one of the most serious bean diseases. The involved mechanisms in rust resistance were evaluated in 10 common bean genotypes during the 2019/2020 and 2020/2021 growing seasons. The disease parameters such as final rust severity (FRS%), area under the disease progress curve (AUDPC) and disease increase rate (r-value) were lower in the resistant genotypes than in highly susceptible genotypes. Biochemical compounds such as total phenols and the activity of antioxidant enzymes such as catalase, peroxidase and polyphenol oxidase were increased in the resistant genotypes compared to susceptible genotypes. In the resistance genotypes, the levels of oxidative stress markers such as hydrogen peroxide (H2O2) and superoxide (O2•-) increased dramatically after infection. The electrolyte leakage percentage (EL%), was found to be much greater in susceptible genotypes than resistant genotypes. The resistant gene SA14, which was found in genotypes Nebraska and Calypso at 800 bp, had an adequate level of resistance to bean rust with high grain yield potential. After infection, the transcriptions levels of 1,3-D-glucanases and phenylalanine ammonia lyase) were higher in the resistant genotypes than susceptible genotypes. In conclusion, the resistant genotypes successfully displayed desirable agronomic traits and promising expectations in breeding programs for improving management strategies of common bean rust disease. The resistance was mediated by antioxidant enzymes, phenolic compounds, and defense gene expressions, as well as the resistant gene SA14.

Mechanism of Wheat Leaf Rust Control Using Chitosan Nanoparticles and Salicylic Acid.

Wheat leaf rust is one of the world's most widespread rusts. The progress of the disease was monitored using two treatments: chitosan nanoparticles and salicylic acid (SA), as well as three application methods; spraying before or after the inoculation by 24 h, and spraying both before and after the inoculation by 24 h. Urediniospore germination was significantly different between the two treatments. Wheat plants tested for latent and incubation periods, pustule size and receptivity and infection type showed significantly reduced leaf rust when compared to untreated plants. Pucciniatriticina urediniospores showed abnormalities, collapse, lysis, and shrinkage as a result of chitosan nanoparticles treatment. The enzymes, peroxidase and catalase, were increased in the activities. In both treatments, superoxide (O2-) and hydrogen peroxide (H2O2), were apparent as purple and brown discolorations. Chitosan nanoparticles and SA treatments resulted in much more discoloration and quantitative measurements than untreated plants. In anatomical examinations, chitosan nanoparticles enhanced thickness of blade (µ), thickness of mesophyll tissue, thickness of the lower and upper epidermis and bundle length and width in the midrib compared to the control. In the control treatment's top epidermis, several sori and a large number of urediniospores were found. Most anatomical characters of flag leaves in control plants were reduced by biotic stress with P. triticina. Transcription levels of PR1-PR5 and PR10 genes were activated in chitosan nanoparticles treated plants at 0, 1 and 2 days after inoculation. In light of the data, we suggest that the prospective use of chitosan nanoparticles might be an eco-friendly strategy to improve growth and control of leaf rust disease.

Sustainable Use of Sewage Sludge as a Casing Material for Button Mushroom (Agaricus bisporus) Cultivation: Experimental and Prediction Modeling Studies for Uptake of Metal Elements.

The present study focused on the use of sewage sludge (SS) as a casing material amendment and the potential uptake of metal elements by the cultivated white button (Agaricus bisporus: MS-39) mushroom. Laboratory experiments were performed under controlled environmental conditions to grow A. bisporus on the composted wheat straw substrate for 50 days. Different treatments (0, 50, 100, 150, and 200 g/kg) of casing material were prepared by mixing garden and dried SS and applied on the mushroom substrate after proper sterilization. The results revealed that SS application was significant (p < 0.05) in accelerating mushroom yield with a biological efficiency of 65.02% for the mixing rate of 200 g/kg. Moreover, the maximum bioaccumulation of selected metal elements (Cu, Cr, Cd, Fe, Mn, and Zn) was observed using the same treatment. Additionally, the multiple regression models constructed for the uptake prediction of metal elements showed an acceptable coefficient of determination (R2 > 0.9900), high model efficiency (ME > 0.98), and low root mean square error (RMSE < 0.410) values, respectively. The findings of this study represent sustainable use of SS for the formulation of mushroom casing material contributing toward synergistic agro-economy generation and waste management.

PCR-DGGE Analysis Proves the Suppression of Rhizoctonia and Sclerotium Root Rot Due to Successive Inoculations.

The soil-borne pathogens Rhizoctonia solani and Sclerotium rolfsii have emerged as major pathogens of radish (Raphanus sativus) worldwide. The induction of soil suppressive of radish root rot disease was evaluated in soil repeatedly inoculated with R. solani, nonpathogenic binucleate Rhizoctonia sp. AG-A W1 (BNR) and S. rolfsii. The repeated inoculations of soil with R. solani and BNR significantly suppressed the disease severity of R. solani and S. rolfsii compared to the control. In contrast, the repeated inoculation of soil with S. rolfsii significantly suppressed only the pathogen, S. rolfsii. The community structure was examined using PCR-DGGE (polymerase chain reaction denaturing gradient gel electrophoresis) method. The bands of Trichoderma sp. were observed in the first, second and third inoculations of the soil with BNR. Similarly, bands of Trichoderma sp. were observed in the second and third inoculations of the soil with S. rolfsii and R. solani. Compared to the control, disease severity was significantly reduced in the soil repeatedly inoculated with S. rolfsii and R. solani . In conclusion, Trichoderma species were accumulated in specific patterns depending on the applied fungal inoculum in the suppressive soil.

A safe haven of SARS-CoV-2 in the environment: Prevalence and potential transmission risks in the effluent, sludge, and biosolids.

The novel coronavirus, SARS-CoV-2, which has caused millions of death globally is recognized to be unstable and recalcitrant in the environment, especially in the way it has been evolving to form new and highly transmissible variants. Of particular concerns are human-environment interactions and the handling and reusing the environmental materials, such as effluents, sludge, or biosolids laden with the SARS-CoV-2 without adequate treatments, thereby suggesting potential transmission and health risks. This study assesses the prevalence of SARS-CoV-2 RNA in effluents, sludge, and biosolids. Further, we evaluate the environmental, ecological, and health risks of reusing these environmental materials by wastewater/sludge workers and farmers. A systematic review of literature from the Scopus database resulted in a total of 21 articles (11 for effluents, 8 for sludge, and 2 for biosolids) that met the criteria for meta-analysis, which are then subdivided into 30 meta-analyzed studies. The prevalence of SAR-CoV-2 RNA in effluent and sludge based on random-effect models are 27.51 and 1012.25, respectively, with a 95% CI between 6.14 and 48.89 for the effluent, and 104.78 and 1019.71 for the sludge. However, the prevalence of SARS-CoV-2 RNA in the biosolids based on the fixed-effect model is 30.59, with a 95% CI between 10.10 and 51.08. The prevalence of SARS-CoV-2 RNA in environmental materials indicates the inefficiency in some of the treatment systems currently deployed to inactivate and remove the novel virus, which could be a potential health risk concern to vulnerable wastewater workers in particular, and the environmental and ecological issues for the population at large. This timely review portends the associated risks in handling and reusing environmental materials without proper and adequate treatments.