Bio-nanosilver synthesized by the entomopathogenic nematode-symbiotic bacterium as bio-insecticide for the red flour beetle (Tribolium castaneum): Poster

Biological control can be another important way to manage post-harvest insect pests. Some organisms that showed biological control activity against some soil pests are insect-parasitic nematodes. There are two different species of nematodes, steinernematids and heterorhabditids, who carry within their bodies insect-pathogenic bacteria. Xenorhabdus spp are bacteria which infest steinernematids and Photorhabdus spp. bacteria infect heterorhabditids. The study aimed to develop pesticide alternatives by synthesizing silver bio-nanoparticles (AgNPs) using Xenorhabdus indica bacterial filtrate. The nanoparticles synthesized by the bacterial strains were purified and its cytotoxicity and bioactivity was examined against the larvae of the Tribolium castaneum. AgNPs were characterized by Scanning Electron Microscopy and X-Ray diffraction analysis, and the results revealed that the obtained nanoparticles are nanosilver with sizes ranging from 30 to 70 nm, with spherical shape and nonsmoothed surface. Insect larvae were initially exposed to descending concentrations (100, 50, 25, 10 and 5 µg/ml) of the biosynthesized nanosilver for 48 hours. Results of the bioassay showed that mortality of treated larvae was concentration-dependent with LC50 of 25 µg/ml. Higher mortality percentage (89%) was observed with the concentration 100 ug/ml and the lower one was obtained by the concentration 5 µg/ml (60%). Subsequently, data of the present study suggest these bio-AgNPs-bacterial filtrate complexes could be used as potentially effective eco-friend bio-control candidates. However, testing other types of bio-synthesized nanomaterials, and its vital effect as bio-insecticide for storage insect species are still under investigation.Biological control can be another important way to manage post-harvest insect pests. Some organisms that showed biological control activity against some soil pests are insect-parasitic nematodes. There are two different species of nematodes, steinernematids and heterorhabditids, who carry within their bodies insect-pathogenic bacteria. Xenorhabdus spp are bacteria which infest steinernematids and Photorhabdus spp. bacteria infect heterorhabditids. The study aimed to develop pesticide alternatives by synthesizing silver bio-nanoparticles (AgNPs) using Xenorhabdus indica bacterial filtrate. The nanoparticles synthesized by the bacterial strains were purified and its cytotoxicity and bioactivity was examined against the larvae of the Tribolium castaneum. AgNPs were characterized by Scanning Electron Microscopy and X-Ray diffraction analysis, and the results revealed that the obtained nanoparticles are nanosilver with sizes ranging from 30 to 70 nm, with spherical shape and nonsmoothed surface. Insect larvae were initially exposed to descending concentrations (100, 50, 25, 10 and 5 µg/ml) of the biosynthesized nanosilver for 48 hours. Results of the bioassay showed that mortality of treated larvae was concentration-dependent with LC50 of 25 µg/ml. Higher mortality percentage (89%) was observed with the concentration 100 ug/ml and the lower one was obtained by the concentration 5 µg/ml (60%). Subsequently, data of the present study suggest these bio-AgNPs-bacterial filtrate complexes could be used as potentially effective eco-friend bio-control candidates. However, testing other types of bio-synthesized nanomaterials, and its vital effect as bio-insecticide for storage insect species are still under investigation

Mulberry based zinc nano-particles mitigate salinity induced toxic effects and improve the grain yield and zinc bio-fortification of wheat by improving antioxidant activities, photosynthetic performance, and accumulation of osmolytes and hormones

Salinity stress (SS) is a challenging abiotic stress that limits crop growth and productivity. Sustainable and cost effective methods are needed to improve crop production and decrease the deleterious impacts of SS. Zinc (Zn) nanoparticles (NPs) have emerged as an important approach to regulating plant tolerance against SS. However, the mechanisms of SS tolerance mediated by Zn-NPs are not fully explained. Thus, this study was performed to explore the role of Zn-NPs (seed priming and foliar spray) in reducing the deleterious impacts of SS on wheat plants. The study comprised different SS levels: control, 6 and 12 dS m−1, and different Zn-NPs treatments: control, seed priming (40 ppm), foliar spray (20 ppm), and their combination. Salinity stress markedly reduced plant growth, biomass, and grain yield. This was associated with enhanced electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2), sodium (Na), chloride (Cl) accumulation, reduced photosynthetic pigments, relative water contents (RWC), photosyntetic rate (Pn), transpiration rate (Tr), stomata conductance (Gs), water use efficiency (WUE), free amino acids (FAA), total soluble protein (TSP), indole acetic acid (IAA), gibberellic acid (GA), and nutrients (Ca, Mg, K, N, and P). However, the application of Zn-NPs significantly improved the yield of the wheat crop, which was associated with reduced abscisic acid (ABA), MDA, H2O2 concentration, and EL, owing to improved antioxidant activities, and an increase in RWC, Pn, Tr, WUE, and the accumulation of osmoregulating compounds (proline, soluble sugars, TSP, and FAA) and hormones (GA and IAA). Furthermore, Zn-NPs contrasted the salinity-induced uptake of toxic ions (Na and Cl) and increased the uptake of Ca, K, Mg, N, and P. Additionally, Zn-NPs application substantially increased the wheat grain Zn bio-fortification. Our results support previous findings on the role of Zn-NPs in wheat growth, yield, and grain Zn bio-fortification, demonstrating that beneficial effects are obtained under normal as well as adverse conditions, thanks to improved physiological activity and the accumulation of useful compounds. This sets the premise for general use of Zn-NPs in wheat, to which aim more experimental evidence is intensively being sought. Further studies are needed at the genomic, transcriptomic, proteomic, and metabolomic level to better acknowledge the mechanisms of general physiological enhancement observed with Zn-NPs application

The potential of endophytic fungi as bio-control agents against the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Abstract Endophytes are promising bio-control agents and rich sources of secondary metabolites known for their biological activities. Two medicinal plants, Pelargonium graveolens and Melia azedarach, and two weeds, Chenopodium album and Malva parviflora, were selected to isolate endophytic fungi. Spore suspension of Alternaria alternata (MG786545), Alternaria solani (MG786543), Curvularia lunata (MF113056), Nigrospora sphaerica (MF113055), and Stemphylium sp. endophytes was tested for their pathogenicity to the third-instar larvae of the cotton leaf worm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Two techniques were used: dipping in spore suspension and residual film assay. Secondary metabolites were extracted, and ethyl acetate extracts of A. alternata (MG786545), C. lunata (MF113056), and N. sphaerica (MF113055) were tested for their insecticidal activity by both techniques. C. lunata (MF113056) showed the most potent pathogenicity causing 60% mortality after 7 days by dipping bioassay, while A. solani (MG7865453) and A. alternata (MG786545) caused 40 and 33.3% mortality, respectively. All tested endophytes showed no effect against S. littoralis by residual film method. N. sphaerica ethyl acetate extract activated larval feeding on castor leaves causing 25% mortality by residual film at 2000 mg/l

Utilizing bio-synthesis of nanomaterials as biological agents for controlling soil-borne diseases in pepper plants: root-knot nematodes and root rot fungus

Abstract The utilization of Trichoderma longibrachiatum filtrate as a safe biocontrol method for producing zinc nanoparticles is a promising approach for managing pests and diseases in agricultural crops. The identification of Trichoderma sp. was achieved through PCR amplification and sequencing of 18s as ON203115, while the synthesis of ZnO-NPs was accomplished by employing Trichoderma filtration. The presence of ZnO-NPs was confirmed by observing a color change to dark green, along with the use of visible and UV spectrophotometers, and the formation and chemical structure of ZnO-NPs were examined. Direct exposure to ZnO-NPs exhibited a significant inhibitory effect on the growth of Fusarium oxysporum at 80.73% compared with control. Also, the percent mortality of Meloidogyne incognita second juveniles stage (J2s) results showed 11.82%, 37.63%, 40.86%, and 89.65% after 6, 12, 24, and 72 h, respectively in vitro. Disease resistance was assessed in the greenhouse against M. incognita and F. oxysporum using the drench application of ZnO-NPs. The application of ZnO-NPs significantly reduced the disease severity of F. oxysporum and improved the quality and quantity of sweet pepper yield. In addition, the application of ZnO-NPs to M. incognita resulted in a significant reduction in the number of nematode galls, egg masses per root, eggs/egg mass, and females by 98%, 99%, 99.9%, and 95.5% respectively. Furthermore, it was observed that the application of ZnO-NPs to pepper plants not only inhibited the growth of F. oxysporum and M. incognita, but also promoted the recovery of pepper plants as indicated by improvements in stem length by 106%, root length 102%, fresh weight 112%, root fresh weight 107%, and leaf area 118% compared to healthy control plants. Additionally, real-time PCR application and DD-PCR technique revealed that the application of ZnO-NPs stimulated the secretion of certain enzymes. These findings suggest that the biosynthesized ZnO-NPs possess anti-nematode and antifungal properties, making them effective for protecting plants against M. incognita and F. oxysporum invasion in soil. This study significantly contributes to our understanding of the nematicidal and fungicidal activities of ZnO-NPs in suppressing soil-borne diseases

Cross-linked chitosan/gelatin beads loaded with Chlorella vulgaris microalgae/zinc oxide nanoparticles for absorbing carcinogenic bisphenol-A pollutant from water

Water polluted by phenolic compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent biological system from a chitosan (CS), gelatin (GT), an

Melatonin: A Vital Pro-Tectant for Crops against Heat Stress: Mechanisms and Prospects

Heat stress (HS) is a serious environmental stress that negatively affects crop growth and productivity across the globe. The recent increase in atmospheric temperature caused by global warming has increased its intensity, which is a serious challenge that needs to be addressed. Plant growth and development involves a series of physiological, metabolic, and biochemical processes that are negatively affected by heat-induced oxidative stress, disorganization of cellular membranes and disturbed plant water relations, nutrient uptake, photosynthetic efficiency, and antioxidant activities. Plant tolerance to abiotic stresses can be substantially increased by the application of bio-stimulants, without posing a threat to the ecosystem. Melatonin (MT) is a multi-functional signaling molecule that has the potential to protect plants from the adverse impacts of HS. MT protects the cellular membranes, maintains the leaf water content, and improves the water use efficiency (WUE) and nutrient homeostasis; thereby, improving plant growth and development under HS. Moreover, MT also improves gene expression, crosstalk of hormones, and osmolytes, and reduces the accumulation of reactive oxygen species (ROS) by triggering the antioxidant defense system, which provides better resistance to HS. High endogenous MT increases genes expression and antioxidant activities to confer HS tolerance. Thus, it is important to understand the detailed mechanisms of both exogenous and endogenous MT, to induce HS tolerance in plants. This review highlights the versatile functions of MT in various plant responses, to improve HS tolerance. Moreover, we also discussed the MT crosstalk with other hormones, antioxidant potential of MT, and success stories of engineering MT to improve HS tolerance in plants. Additionally, we also identified various research gaps that need to be filled in future research using this important signaling molecule. Thus, this review will help the readers to learn more about MT under changing climatic conditions and will provide knowledge to develop heat tolerance in crops

Melatonin: A Vital Pro-Tectant for Crops against Heat Stress: Mechanisms and Prospects

Heat stress (HS) is a serious environmental stress that negatively affects crop growth and productivity across the globe. The recent increase in atmospheric temperature caused by global warming has increased its intensity, which is a serious challenge that needs to be addressed. Plant growth and development involves a series of physiological, metabolic, and biochemical processes that are negatively affected by heat-induced oxidative stress, disorganization of cellular membranes and disturbed plant water relations, nutrient uptake, photosynthetic efficiency, and antioxidant activities. Plant tolerance to abiotic stresses can be substantially increased by the application of bio-stimulants, without posing a threat to the ecosystem. Melatonin (MT) is a multi-functional signaling molecule that has the potential to protect plants from the adverse impacts of HS. MT protects the cellular membranes, maintains the leaf water content, and improves the water use efficiency (WUE) and nutrient homeostasis; thereby, improving plant growth and development under HS. Moreover, MT also improves gene expression, crosstalk of hormones, and osmolytes, and reduces the accumulation of reactive oxygen species (ROS) by triggering the antioxidant defense system, which provides better resistance to HS. High endogenous MT increases genes expression and antioxidant activities to confer HS tolerance. Thus, it is important to understand the detailed mechanisms of both exogenous and endogenous MT, to induce HS tolerance in plants. This review highlights the versatile functions of MT in various plant responses, to improve HS tolerance. Moreover, we also discussed the MT crosstalk with other hormones, antioxidant potential of MT, and success stories of engineering MT to improve HS tolerance in plants. Additionally, we also identified various research gaps that need to be filled in future research using this important signaling molecule. Thus, this review will help the readers to learn more about MT under changing climatic conditions and will provide knowledge to develop heat tolerance in crops

Preparation of Polyvinylidene Fluoride Nano-Filtration Membranes Modified with Functionalized Graphene Oxide for Textile Dye Removal

Water scarcity has become one of the most significant problems globally. Membrane technology has gained considerable attention in water treatment technologies. Polymeric nanocomposite membranes are based on several properties, with enhanced water flux, high hydrophilicity and anti-biofouling behavior, improving the membrane performance, flexibility, cost-effectiveness and excellent separation properties. In this study, aminated graphene oxide (NH2-GO)-based PVDF membranes were fabricated using a phase-inversion method for textile dye removal. These fabricated membranes showed the highest water flux at about 170.2 (J/L.h−1.m−2) and 98.2% BSA rejection. Moreover, these membranes removed about 96.6% and 88.5% of methylene blue and methyl orange, respectively. Aminated graphene oxide-based polyvinylidene fluoride (PVDF) membranes emerge as a good membrane material that enhances the membrane performance

Data_Sheet_1_Genetic basis and principal component analysis in cotton (Gossypium hirsutum L.) grown under water deficit condition.docx

Cotton is considered as the main crop in the agricultural sector of Pakistan. Water deficiency in this region in recent years has reduced the chances of high yields of cotton. Selection and creation of high-yielding varieties of cotton, even in water deficit conditions, is one of urgent tasks of today. For this purpose, 40 diverse genotypes of upland cotton were screened in normal and water deficit conditions in triplicate arrangement under split plot in a randomized complete block design. All the genotypes showed significant difference under both water regimes. Ten upland cotton accessions were screened out as water deficit tolerant (VH-144, IUB-212, MNH-886, VH-295, IR-3701, AA-802, NIAB-111, NS-121, FH-113, and FH-142) and five as water deficit sensitive (IR-3, CIM-443, FH-1000, MNH-147, and S-12) based on seed cotton yield and stress susceptibility index. These tolerant and sensitive genotypes were crossed in line × tester mating design. For further evaluation of genetic material, the seed of 50 F1 crosses and their 15 parents were field planted under normal and water deficit conditions during next cotton growing season. Traits related to yield under the study showed significant variations among the accessions and their half sibs. The results of the principal component analysis (PCA) exhibited that total variation exhibited by factors 1 and factor 2 were 55.55 and 41.95%, respectively. PCA transformed the variables into three factors, and only two factors (F1 and F2) had eigenvalue > 1. The degree of dominance revealed that all parameters were highly influenced by non-additive gene action under both water regimes. Furthermore, the line VH-295 and tester CIM-443 had better yield performance under water deficit stress. The cross-combinations, viz., VH-144 × S-12, NIAB-111 × IR-3, and VH-295 × MNH-147, were the best for yield contributing traits. These combinations may be helpful for germplasm enhancement on large scale under water scarcity. All the studied traits have non-additive types of gene action suggesting the usage of these genotypes in cotton hybrid development program against water deficit tolerance.</p

Table_1_Determination of morpho-physiological and yield traits of maize inbred lines (Zea mays L.) under optimal and drought stress conditions.DOCX

Globally, climate change could hinder future food security that concurrently implies the importance of investigating drought stress and genotype screening under stressed environments. Hence, the current study was performed to screen 45 diverse maize inbred lines for 18 studied traits comprising phenological, physiological, morphological, and yield characters under optimum and water stress conditions for two successive growing seasons (2018 and 2019). The results showed that growing seasons and water regimes significantly influenced (p < 0.01) most of the studied traits, while inbred lines had a significant effect (p < 0.01) on all of the studied traits. The findings also showed a significant increase in all studied characters under normal conditions compared to drought conditions, except chlorophyll content, transpiration rate, and proline content which exhibited higher levels under water stress conditions. Furthermore, the results of the principal component analysis indicated a notable distinction between the performance of the 45 maize inbred lines under normal and drought conditions. In terms of grain yield, the drought tolerance index (DTI) showed that Nub60 (1.56), followed by Nub32 (1.46), Nub66 (1.45), and GZ603 (1.44) were the highest drought-tolerant inbred lines, whereas Nub46 (0.38) was the lowest drought-tolerant inbred line. These drought-tolerant inbred lines were able to maintain a relatively high grain yield under normal and stress conditions, whereas those drought-sensitive inbred lines showed a decline in grain yield when exposed to drought conditions. The hierarchical clustering analysis based on DTI classified the forty-five maize inbred lines and eighteen measured traits into three column- and row-clusters, as inbred lines in cluster-3 followed by those in cluster-2 exhibited greater drought tolerance in most of the studied traits. Utilizing the multi-trait stability index (MTSI) criterion in this study identified nine inbred lines, including GZ603, as stable genotypes in terms of the eighteen studied traits across four environments. The findings of the current investigation motivate plant breeders to explore the genetic potential of the current maize germplasm, especially in water-stressed environments.</p