Biochemical and genetic mechanisms in Pieris rapae (Lepidoptera: Pieridae) resistance under emamectin benzoate stress.

Pieris rapae (Lepidoptera: Pieridae) poses a significant threat to Brassicaceae crops, leading to substantial losses annually. Repeated insecticide applications are widely used to protect crops and increase the resistance of P. rapae. Exploring the biochemical and molecular basis of insecticide tolerance in P. rapae is crucial for achieving effective insect suppuration and implementing resistance control strategies. In our research, emamectin benzoate (EBZ) resistance was developed in P. rapae strain through selective pressure over 15 generations. Moreover, the biochemical mechanisms underlying resistance to EBZ and its potential cross-resistance to other insecticides were studied. Additionally, the expression levels of cytochrome P450 (CYP450) and glutathione-s-transferase (GST) genes in P. rapae were quantitatively assessed upon exposure to EBZ using real-time PCR. Our data exhibited that the LC50 value of susceptible strain (Sus) and EBZ resistance strain (EBZ-R) were 0.009 and 8.09 mg/L, with a resistance ratio (RR) reaching 898.8-fold. The EBZ-R stain displayed notably low cross-resistance to lambda-cyhalothrin, spinetoram, and cypermethrin. However, it demonstrated a moderate level of cross-resistance to deltamethrin. Conversely, no cross-resistance was noted to chlorantraniliprole and indoxacarb. Notably, enzyme inhibitors of detoxification enzymes revealed that piperonyl butoxide (PBO) and diethyl maleate (DEM) enhanced the EBZ toxicity to the resistant strain, indicating the potential involvement of CYP450 and GST in avermectin resistance. A remarkable enhancement in CYP450 and GST activity was observed in the EBZ-R stain. CYP450 and GST genes are upregulated in the EBZ-R stain compared to the Sus strain, which serves as a basis for comprehending the mechanism behind P. rapae resistance to EBZ. The molecular docking analysis demonstrated that EBZ has a high binding affinity with CYP6AE120 and PrGSTS1 with docking energy values of -20.19 and -22.57 kcal/mol, respectively. Our findings offer valuable insights into crafting efficient strategies to monitor and manage resistance in P. rapae populations in Egypt.

Cinnamon nanoemulsion mitigates acetamiprid-induced hepatic and renal toxicity in rats: biochemical, histopathological, immunohistochemical, and molecular docking analysis.

Acetamiprid (ACDP) is a widely used neonicotinoid insecticide that is popular for its efficacy in controlling fleas in domestic settings and for pets. Our study aims to offer a comprehensive examination of the toxicological impacts of ACDP and the prophylactic effects of cinnamon nanoemulsions (CMNEs) on the pathological, immunohistochemical, and hematological analyses induced by taking ACDP twice a week for 28 days. Forty healthy rats were divided into four groups (n = 10) at random; the first group served as control rats; the second received CMNEs (2 mg/Kg body weight); the third group received acetamiprid (ACDP group; 21.7 mg/Kg body weight), and the fourth group was given both ACDP and CMNEs by oral gavage. Following the study period, tissue and blood samples were extracted and prepared for analysis. According to a GC-MS analysis, CMNEs had several bioactive ingredients that protected the liver from oxidative stress by upregulating antioxidant and anti-inflammatory agents. Our findings demonstrated that whereas ACDP treatment considerably boosted white blood cells (WBCs) and lymphocytes, it significantly lowered body weight gain (BWG), red blood cells (RBCs), hemoglobin (Hb), hematocrit (HCT), and platelets (PLT). ACDP notably reduced antioxidant enzyme activities: superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) and elevated hydrogen peroxide and malondialdehyde levels compared with other groups. ACDP remarkably raised alanine aminotransferase (ALT), aspartate amino transaminase (AST), and alkaline phosphatase (ALP) levels.Moreover, the histopathological and immunohistochemistry assays discovered a severe toxic effect on the liver and kidney following ACDP delivery. Furthermore, cyclooxygenase 2 (COX-2) + immunoexpression was enhanced after treatment with CMNEs. All of the parameters above were returned to nearly normal levels by the coadministration of CMNEs. The molecular docking of cinnamaldehyde with COX-2 also confirmed the protective potential of CMNEs against ACDP toxicity. Our findings highlighted that the coadministration of CMNEs along with ACDP diminished its toxicity by cutting down oxidative stress and enhancing antioxidant capacity, demonstrating the effectiveness of CMNEs in lessening ACDP toxicity.

Decontamination of Chlorpyrifos Residue in Soil by Using Mentha piperita (Lamiales: Lamiaceae) for Phytoremediation and Two Bacterial Strains.

This study utilizes Mentha piperita (MI) for the first time to investigate the uptake and translocation of chlorpyrifos (CPF; 10 µg g-1) from soil, introducing a new approach to improve the efficacy of this technique, which includes using biosurfactants (Bacillus subtilis and Pseudomonas aeruginosa) at 107 CFU/mL to degrade CPF under greenhouse conditions. Moreover, antioxidant enzymes, including superoxide dismutase (SOD) and peroxidase (Prx), and oxidative stress due to hydrogen peroxide (H2O2) and malondialdehyde (MDA) in MI roots and leaves were evaluated under CPF stress. Our results demonstrated that amending soil with MI and B. subtilis followed by P. aeruginosa significantly reduced CPF levels in the soil (p > 0.05) and enhanced CPF concentrations in MI roots and leaves after 1, 3, 7, 10, and 14 days of the experiment. Furthermore, CPF showed its longest half-life (t1/2) in soil contaminated solely with CPF, lasting 15.36 days. Conversely, its shortest half-life occurred in soil contaminated with CPF and treated with MI along with B. subtilis, lasting 4.65 days. Soil contaminated with CPF and treated with MI and P. aeruginosa showed a half-life of 7.98 days. The half-life (t1/2) of CPF-contaminated soil with MI alone was 11.41 days. A batch equilibrium technique showed that B. subtilis is better than P. aeruginosa for eliminating CPF from soil in In vitro experiments. Notably, CPF-polluted soil treated with coadministration of MI and the tested bacteria improved the activities of SOD and Prx and reduced H2O2 and MDA compared with CPF-polluted soil treated with MI alone. Our findings demonstrated that using B. subtilis and P. aeruginosa as biosurfactants to augment phytoremediation represents a commendable strategy for enhancing the remediation of CPF contamination in affected sites while reducing the existence of harmful pesticide remnants in crop plants.

Contrasting fertilization response of soil phosphorus forms and functional bacteria in two newly reclaimed vegetable soils.

Fertilization is a pervasive approach to agricultural production enhancing vegetable nutrients such as phosphorus (P) absorption. However, unreasonable fertilization strategies result in high levels of residual P in vegetable planting systems. To better understand the mechanisms of soil phosphorus dynamics responding to inorganic/organic fertilization, we conducted a 3-year field experiment in two newly reclaimed vegetable fields in southern China. The results revealed that soil Olsen-P in CF (mineral fertilization) and OF (Combined application of organic and inorganic fertilizers) increased by approximately 210.6 % and 183.6 %, respectively, while stable P proportion decreased by approximately 9.2 % and 18.1 %, respectively, compared with CK. Combined application of organic and inorganic fertilizer increased the proportion of moderately labile P (NaOH-P) by 1-6 % in comparison with chemical fertilizer and facilitated the conversion from diester-P to monoester-P, indicating that applying pig manure enhanced the potential soil P bioavailability. Besides, organic-inorganic fertilization shaped a bacterial community with more connectivity and stability and changed keystone taxa related to the P transformation of the network. Phenylobacterium, Solirubrobacter, and Modestobacter were regarded as core genera for mobilizing soil phosphorus. However, residual P content in newly reclaimed soils under fertilization, especially for chemical fertilizer, remained non-negligible and may cause potential environmental risks. The partial least squares path modeling results demonstrated that fertilization management had both direct and indirect positive effects on P fraction through the improvement of soil nutrients e.g. total N and soil organic carbon, and bacterial community, while soil properties mainly determined the variation of soil P species. Our results provide comprehensive insights into the current status of legacy P forms and the vital role of fertilizer, key soil properties and bacteria in P dynamics in newly reclaimed vegetable field.

A comprehensive overview of eco-friendly bio-fertilizers extracted from living organisms.

Currently, sustainable agriculture involves ecofriendly techniques, which include biofertilization. Biofertilizers increase plant productivity by improving soil fertility and nutrient content. A wide range of living organisms can be applied as biofertilizers and increase soil fertility without causing pollution due to their biodegradability. The organisms can be microorganisms like bacteria, microalgae, and micro fungi or macro organisms like macroalgae, macro fungi, and higher plants. Biofertilizers extracted from living organisms or their residues will be increasingly used rather than chemical fertilizers, which cause heavy metal accumulation in soil. Biofertilizer use aims for sustainable development in agriculture by maintaining the soil. This will mitigate climate change and related impacts and will also lower many serious diseases resulting from pollution such as cancer, liver and renal failure, and immune diseases. This review is a comprehensive overview of biofertilizers extracted from a range of living organisms from the Kingdoms Monera to Plantae and included bacteria, algae, fungi, and higher plants. Organisms that play a vital role in elevating soil nutrients in a safe, cheap, and ecofriendly manner are included in the review to promote their potential commercial application.

Editorial for the Special Issue "Detoxification Mechanisms in Insects".

Insects are faced with numerous toxins (xenobiotics) as they go through life, some produced naturally by plants (sometimes called allelochemicals) and some produced by humans (insecticides) [...].

Identification and Characterization of Glutathione S-transferase Genes in Spodoptera frugiperda (Lepidoptera: Noctuidae) under Insecticides Stress.

Insect glutathione S-transferases (GSTs) serve critical roles in insecticides and other forms of xenobiotic chemical detoxification. The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a major agricultural pest in several countries, especially Egypt. This is the first study to identify and characterize GST genes in S. frugiperda under insecticidal stress. The present work evaluated the toxicity of emamectin benzoate (EBZ) and chlorantraniliprole (CHP) against the third-instar larvae of S. frugiperda using the leaf disk method. The LC50 values of EBZ and CHP were 0.029 and 1.250 mg/L after 24 h of exposure. Moreover, we identified 31 GST genes, including 28 cytosolic and 3 microsomal SfGSTs from a transcriptome analysis and the genome data of S. frugiperda. Depending on the phylogenetic analysis, sfGSTs were divided into six classes (delta, epsilon, omega, sigma, theta, and microsomal). Furthermore, we investigated the mRNA levels of 28 GST genes using qRT-PCR under EBZ and CHP stress in the third-instar larvae of S. frugiperda. Interestingly, SfGSTe10 and SfGSTe13 stood out with the highest expression after the EBZ and CHP treatments. Finally, a molecular docking model was constructed between EBZ and CHP using the most upregulated genes (SfGSTe10 and SfGSTe13) and the least upregulated genes (SfGSTs1 and SfGSTe2) of S. frugiperda larvae. The molecular docking study showed EBZ and CHP have a high binding affinity with SfGSTe10, with docking energy values of -24.41 and -26.72 kcal/mol, respectively, and sfGSTe13, with docking energy values of -26.85 and -26.78 kcal/mol, respectively. Our findings are important for understanding the role of GSTs in S. frugiperda regarding detoxification processes for EBZ and CHP.

Enhancing the Toxicity of Cypermethrin and Spinosad against Spodoptera littoralis (Lepidoptera: Noctuidae) by Inhibition of Detoxification Enzymes.

The extensive use of wide-ranging insecticides in agricultural activities may develop resistance in insects. The dipping technique was utilized for examining changes in detoxifying enzyme levels in Spodoptera littoralis L. induced by cypermethrin (CYP) and spinosad (SPD) with and without a combination of three enzyme inhibitors: triphenyl phosphate (TPP), diethyl maleate (DEM), and piperonyl butoxide (PBO), at 70 µg/mL. PBO, DEM, and TPP showed 50% mortality against larvae at 236.2, 324.5, and 245.8 µg/mL, respectively. The LC50 value of CYP on S. littoralis larvae reduced from 2.86 µg/mL to 1.58, 2.26, and 1.96 µg/mL, while the LC50 value of SPD declined from 3.27 µg/mL to 2.34, 2.56, and 2.53, with the addition of PBO, DEM, and TPP, respectively, 24 h after treatment. Moreover, the activity of carboxylesterase (CarE), glutathione S-transferase (GST), and cytochrome P450 monooxygenase (Cyp 450) was significantly inhibited (p < 0.05) by TPP, DEM, PBO plus CYP, and SPD in S. littoralis larvae in comparison with tested insecticides alone. These findings suggested that three enzyme inhibitors play a major role in increasing the toxicity of CYP and SPD in S. littoralis and will provide insight into how to overcome insecticide resistance in insects.

Effects of periplocoside T isolated from Periploca sepium on behavior and sensory-CNS-motor circuits in Drosophila melanogaster larvae.

Periplocoside T (PST) from Periploca sepium has insecticidal activity against some lepidopterans, which can significantly inhibit the activity of vacuolar-type H+-ATPases (V-ATPase). V-ATPase is involved in the release of neurotransmitters in vesicles during nerve signal transduction. However, there are actions of PST on behavior and sensory-central nervous system (CNS)-motor neural circuit which are commonly overlooked. After exposure to 500 mg/L PST for 48 h, the difference of the proportion of larvae responding to stimuli in the four Drosophila strains was not significant as compared to controls, but larval mouth hook movement and body wall motion were significantly decreased as compared to controls, and the decrease was more obvious in parats1; DSC1-/- and DSC1-/- strains, especially in parats1; DSC1-/- strain. Compared with control (DMSO), the excitatory junction potential (EJP) frequencies of sensory-CNS-motor circuits in the four Drosophila strains after PST or bafiloymcin A1 (BA1, a V-ATPase specific inhibitor) treatment gradually decreased with time, and the decreasing amplitude of BA1 treatment was greater than that of PST treatment, but both were higher than that of the control. The decay amplitude of EJP frequency in two strains with DSC1 channel knockout was lower than that of w1118 and parats1 strains without DSC1 channel knockout. Thus, the results indicated that PST, similar to BA1, could inhibit the transmission of sensory-CNS-motor circuit excitability of Drosophila larvae by inhibiting the activity of V-ATPase, and DSC1 channel play a role of in regulating the stability of nervous system.

Functional validation of CYP304A1 associated with haedoxan A detoxification in Aedes albopictus by RNAi and transgenic drosophila.

BACKGROUND: Insect cytochrome P450 monooxygenases play important roles in the detoxification metabolism of endogenous and exogenous compounds. Haedoxan A (HA) from Phryma leptostachya L. is a highly efficient natural pesticide used to control houseflies and mosquitos. CYP4C21 and CYP304A1 were previously demonstrated to be transcriptionally increased in Aedes albopictus in response to HA exposure, but their involvement in HA metabolism is unknown. RESULTS: Our data showed that CYP304A1 expression levels in A. albopictus were highest in third-instar larvae, and the expression level of CYP4C21 decreased significantly with the growth of instars, with the lowest occurring in the pupal stage. Compared with the control, the silencing of CYP304A1 and CYP4C21 genes by chitosan nanoparticle-mediated RNA interference could deplete 58.2% and 54.0% of the expression of corresponding genes, respectively. The bioassay data showed that knocking down the expression of CYP304A1 increased the mortality of A. albopictus when exposed to HA at LC30 and LC50 doses, but did not significantly increase mortality after silencing CYP4C21. Our data demonstrated that CYP304A1, but not CYP4C21, may be involved in HA detoxification. Moreover, the resistance ratio of CYP304A1 overexpressing flies was approximately 2-fold higher than that of the control line. The metabolized product of HA by CYP304A1 needs to be further confirmed by in vitro expression. CONCLUSION: This finding showed that inducibility was not always linked to detoxifying capabilities, and enhanced our understanding of the molecular basis of HA metabolic detoxification in A. albopictus. © 2022 Society of Chemical Industry.

In vivo and in vitro antifungal activities of five alkaloid compounds isolated from Picrasma quassioides (D. Don) Benn against plant pathogenic fungi.

Highly active and novel antifungal compounds are continuously researched from natural products for pesticide development. Picrasma quassioides (D. Don) Benn, a species of Simaroubaceae, is used in traditional Chinese medicine to treat colds and upper respiratory infections. In this study, the active ingredients of P. quassioides and their antifungal activities against plant pathogenic fungi are investigated to explore the practical application of the plant in the agricultural field. The results showed that the extracts of P. quassioides exhibited highly significant preventive and curative effects on apple valsa canker (AVC) with a reduction of lesion diameter were 80.28% and 83.63%, respectively, and can improve the resistance of apple trees to a pathogen. Five antifungal compounds, namely, canthin-6-one (T1), nigakinone (T2), 4,5-dimethoxycanthin-6-one (T3), 1-methoxycarbonyl-ß-carboline (T4), and 1-methoxycarbonyl-3-methoxyl-ß-carboline (T5), are isolated from P. quassioides using the bioassay-guided method. This is the first report of 1-methoxycarbonyl-3-methoxyl-ß-carboline as a natural product. Canthin-6-one shows strong in vitro inhibitory activity against 11 species of plant pathogenic fungi, and their EC50 values range from 1.49 to 8.80 mg/L. The control efficacy of canthin-6-one at 2000 mg/L are 87.88% and 94.37% against AVC and 80.10% and 84.73% against apple anthracnose (C. gloeosporioides), respectively. Additionally, V. mali is observed after treatment with cannin-6-one, although microscopic. This is the first study on the control of the secondary metabolites of P. quassioides against plant fungal diseases. The results show that P. quassioides is a potential resource for the development of botanical fungicides.

A Genetic Compensation Phenomenon and Global Gene Expression Changes in Sex-miR-2766-3p Knockout Strain of Spodoptera exigua Hübner (Lepidoptera: Noctuidae).

MicroRNAs (miRNAs) drive the post-transcriptional repression of target mRNAs and play important roles in a variety of biological processes. miR-2766-3p is conserved and abundant in Lepidopteran species and may be involved in a variety of biological activities. In this study, Sex-miR-2766-3p was predicted to potentially bind to the 3' untranslated region (UTR) of cap 'n' collar isoform C (CncC) in Spodoptera exigua, and Sex-miR-2766-3p was confirmed to regulate the expression of SeCncC through screening with a luciferase reporter system. Although CRISPR/Cas9 has been extensively utilized to examine insect gene function, studies of miRNA function are still relatively uncommon. Thus, we employed CRISPR/Cas9 to knock out Sex-miR-2766-3p from S. exigua. However, the expression of SeCncC was not significantly altered in the knockout strain (2766-KO) compared with that of the WHS strain. This result suggested that a miRNA knockout might lack phenotypes because of genetic robustness. Additionally, we used transcriptome analysis to examine how the global gene expression patterns of the Sex-miR-2766-3p knockout strain varied. RNA-seq data revealed 1746 upregulated and 2183 downregulated differentially expressed genes (DEGs) in the 2766-KO strain, which might be the result of Sex-miR-2766-3p loss or DNA lesions as the trigger for transcriptional adaptation. GO function classification and KEGG pathway analyses showed that these DEGs were enriched for terms related to binding, catalytic activity, metabolic process, and signal transduction. Our findings demonstrated that S. exigua could compensate for the missing Sex-miR-2766-3p by maintaining the expression of SeCncC by other pathways.

Ameliorating effect of the biological Zinc nanoparticles in abamectin induced hepato-renal injury in a rat model: Implication of oxidative stress, biochemical markers and COX-2 signaling pathways.

Extensive use of abamectin (ABM) as an anthelmintic in veterinary systems adversely affects the health and welfare of animals and humans. Zinc nanoparticles (ZnNPs) have therapeutic benefits and ameliorate the effect of environmental pollutants. In this study, we assessed the ameliorative effect of ZnNPs against the sub-lethal toxicity of ABM in rats. Forty healthy rats were randomly selected into four groups (n = 10); the control received normal saline and test rats were treated orally twice weekly with ABM (1 mg/kg bwt), ZnNPs (10 mg/kg bwt) and ABM + ZnNPs for 28 days. Upon completion of the study period, blood and tissue samples were collected and prepared for hematological, biochemical, pathological, and immunohistochemical analysis. Our results showed that ABM treatment significantly decreased body weight gain (BWG), red blood cells (RBCs), hemoglobin (Hb), hematocrit (HC), and platelet (PLT); while it significantly increased white blood cells (WBCs) and lymphocytes. ABM also significantly decreased antioxidant enzyme activities: superoxide dismuthase (SOD), glutathione peroxidase (GPx), and catalase (CAT) and increased hydrogen peroxide and malondialdehyde levels compared with other groups. ABM significantly raised alanine aminotransferase (ALT), aspartate amino transaminase (AST), and alkaline phosphatase (ALP) levels, which was restored by co-administration of ZnNPs. Moreover, ZnNPs ameliorated ABM-mediated negative histopathological changes in the liver and kidney tissues, exhibiting a significant protective effect. Cyclooxygenase 2 (COX-2) + immuno-expression were reduced after pretreatment with ZnNPs. These findings suggested that co-administration of ZnNPs with ABM mitigated its toxicity by combating oxidative stress and boosting antioxidant capacity, indicating the efficacy of ZnNPs in attenuating ABM toxicity.

Response of faba bean to intercropping, biological and chemical control against broomrape and root rot diseases.

Multispecies cropping systems contribute to sustainable agriculture with multiple ecosystem services. Effects of intercropping of various crops with faba beans on growth and yield parameters and disease severity of root rot, damping off and broomrape were investigated. This study was implemented in the laboratory, greenhouse and field to investigate the effect of the intercropping systems (fenugreek + faba bean, lupine + faba bean, garlic + faba bean and sole faba bean). The intercropping systems were combined with the application of arbuscular mycorrhiza fungi (AMF) and yeast as bio-control agents, compared to chemical application of herbicides (Glyphosate) and fungicides (Rizolex-T50), to control rot root diseases and broomrape weeds, Orobanche spp., of faba bean plants in vivo and under the naturally infested field. In vitro, yeast and Rizolex-T50 significantly inhibited mycelial growth of root pathogenic fungi. Intercropping with garlic and/or application of Rizolex-T, significantly decreased the incidence and disease index of root rot and damping-off diseases, meanwhile increased percentage of survival plants. In vivo, intercropping with fenugreek and/or application of Glyphosate, significantly reduced the number/weight of spikes/plot of broomrapes. Intercropping with fenugreek combined with AMF application promoted crop growth and significantly increased yield components. The AMF enhanced seed yield/ha when applied to the intercropping of faba bean + fenugreek and faba bean + garlic, showing the highest seed yield/ha with 3.722 and 3.568 ton/ha, respectively. Intercropping of faba bean with garlic integrated with AMF revealed the highest values of LER, 2.45, and net return, 2341 US$/ha. Our results suggested that using faba bean-garlic intercrop along with AMF inoculation can reduce root rot disease, damping off and broomrapes, as well as enhance the profitability of Egyptian farmer and sustainable production.

Evidence for Multiple Origins of Knockdown Resistance (kdr) in Spodoptera exigua (Hübna) (Lepidoptera: Noctuidae) From China.

The beet armyworm, Spodoptera exigua (Hübna) is a serious agricultural pest that is challenging to control due to resistance to most pesticides, including pyrethroids. This resistance has previously been linked to the knockdown resistance (kdr) mutation (L1014F) of the voltage-gated sodium channel (VGSC) in S. exigua. To better understand the frequencies of the kdr mutation of SeVGSC and identify the evolutionary origins of kdr mutation in S. exigua, seven populations of S. exigua were collected in China, and partial SeVGSC genomic sequences for each individual were acquired. The bioassays showed that the survival rates of seven populations of S. exigua larvae exposed to the discriminating dose of beta-cypermethrin (0.05 mg/cm2) ranged from 91.66% to 100%, indicating that all seven populations had evolved resistance to beta-cypermethrin. The frequencies of kdr mutation (CTT to TTT) of SeVGSC of field populations ranged China were from 60% to 89.6%. The CTT to CAT substitution at this coding position resulting in the L1014H (kdr-H) mutation was found in only one individual from the QP18 population. Based on the phylogeny of SeVGSC alleles, it appeared that the kdr mutation in S. exigua populations had multiple origins, which has major consequences for pyrethroid effectiveness in the field. Thus, it is recommended to limit the use of pyrethroid and encourage rotation of insecticides with different modes of action for control of S. exigua to alleviate resistance development.

Algae as Bio-fertilizers: Between current situation and future prospective.

Bio-fertilization is a sustainable agricultural practice that includes using bio-fertilizers to increase soil nutrient content resulting in higher productivity. Soil micro-flora has been exposed to improve soil fertility and increase biomass productivity and identified as a correct environmentally friendly bio-based fertilizer for pollution-free agricultural applies. The majority of cyanobacteria can fix nitrogen from the atmosphere and several species including Anabaena sp., Nostoc sp., and Oscillatoria angustissima is known to be effective cyanobacterial based bio fertilizers. Acutodesmus dimorphus, Spirulina platensis Chlorella vulgaris, Scenedesmus dimorphus, Anabaena azolla, and Nostoc sp. are some of the green microalgae and cyanobacteria species that have been successfully used as bio fertilizers to boost crop growth. Also, Chlorella vulgaris is one of the most commonly used microalgae in bio fertilizer studies. The addition of seaweed species that are Sargassum sp. and Gracilaria verrucosa leads to chemical changes as a soil fertility indicator on clay and sandy soils, and the addition of seaweed conditioner to soil can improve its organic content, return pH to normal, and reduce C/N ratio in both sandy and clay soil. This review provides an effective approach to increase soil fertility via environmentally friendly bio-based fertilizer using micro and macro algae. Instead of the usage of inorganic and organic fertilizers that have polluted impacts to soil as aggregation of heavy metals, in addition to there their human carcinogenic effects.

Controlling of Meloidgyne incognita (Tylenchida: Heteroderidae) using nematicides, Linum usitatissimum extract and certain organic acids on four peppers cultivars under greenhouse conditions.

Organic acids and plant extracts, which have a nemacidal action and may be used instead of nematicides that pollute the environment, are one way for controlling the pepper root-knot nematode. We provide in this study for a first time a new strategy for management Meloidgyne incognita (Kofoid and White) by using organic acids and plant extract compared to nematicides on four peppers cultivars (Super amarr, Super mard, Super noura and Werta) under greenhouse conditions compared to nematicides. This study aimed to evaluate 0.1% of organic acids (humic and salicylic acid) and 0.1% of Linum usitatissimum extract on plant parameters of pepper varieties (Super amarr, Super mard, Super noura and Werta) and control of M. incognita under greenhouse conditions compared to four nematicides (Oxamyl 24% SL, Fosthiazates 75% EC, Ethoprophos N40% EC and Fenamiphos 40% EC). Our data obtained four nematicides were more effectiveness than other treatments in reduced galls and egg masses of M. incognita. Whilst, humic and salicylic acids have remarkably higher nematicidal activity than L. usitatissimum in all lines of pepper. Therefore, plant extract and organic acids may be used a best alternative of nematicides to control PPNs and caused the longitudinal growth of plant. Also, ultimately reduce environmental risk from nematicide pollution.

Knockin of the G275E mutation of the nicotinic acetylcholine receptor (nAChR) α6 confers high levels of resistance to spinosyns in Spodoptera exigua.

Spinosyns, including spinosad and spinetoram, act on the insect central nervous system, gradually paralyzing or destroying the target insect. Spinosad resistance is associated with loss-of-function mutations in the nicotinic acetylcholine receptor (nAChR) α6 subunit in a number of agricultural pests. Using gene editing, nAChR α6 has been verified as a target for spinosyns in five insect species. Recently, a point mutation (G275E) in exon 9 of nAChR α6 was identified in spinosad-resistant strains of Thrips palmi and Tuta absoluta. To date, no in vivo functional evidence has been obtained to support that this mutation is involved in spinosyn resistance in lepidopteran pests. In this study, the G275E mutation was introduced into the nAChR of Spodoptera exigua using clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated protein 9 (Cas9) gene-editing technology. Reverse transcriptase-polymerase chain reaction and sequencing confirmed that this mutation was present in exon 9 of the nAChR transcripts in the edited 275E strain. The results of bioassays showed that the 275E strain was highly resistant to spinosad (230-fold) and spinetoram (792-fold) compared to the unedited background strain, directly confirming that the G275E mutation of the nAChR α6 subunit confers high levels of spinosyn resistance in S. exigua. Inheritance analysis showed that the resistance trait is autosomal and incompletely recessive. This study employs a reverse genetics approach to validate the functional role played by the G275E mutation in nAChR α6 of S. exigua in spinosyns resistance and provides another example of the use of CRISPR/Cas9 gene-editing technology to confirm the role played by candidate target site mutations in insecticide resistance.

Negative cross-resistance of a pyrethroid-resistant Drosophila mutant to Phryma leptostachya-derived haedoxan A.

Voltage-gated sodium channels are the primary target of pyrethroid insecticides. Mutations in sodium channel confer knockdown resistance (kdr) to pyrethroids in various arthropod pests. Haedoxan A (HA) is the major insecticidal component from Phryma leptostachya. It has been shown that HA alters electrical responses at the Drosophila neuromuscular junction and modifies the gating properties of cockroach sodium channels expressed in Xenopus oocytes. However, whether sodium channel mutations that confer pyrethroid resistance also affect the action of HA is unknown. In this study, we conducted bioassays using HA and permethrin in two Drosophila melanogaster strains: w1118 , an insecticide-susceptible strain, and parats1 , a pyrethroid-resistant strain due to a I265N mutation in the sodium channel, and identified a new case of negative cross-resistance (NCR) between permethrin and HA. Both parats1 larvae and adults were more resistant to permethrin, as expected. However, both parats1 larvae and adults were more sensitive to HA compared to w1118 . We confirmed that the I265N mutation reduced the sensitivity to permethrin of a Drosophila sodium channel variant, DmNav 22, expressed in Xenopus oocytes. Interestingly, the I265N mutation also abolished the effect of HA on sodium channels. Further characterization showed that I265 on the sodium channels is critical for the action of both pyrethroids and HA on sodium channels, pointing to an overlapping mode of action between pyrethroids and HA on the sodium channel. Overall, our results suggest an I265N-independnt mechanism(s) in parats1 flies that is responsible for the NCR between permethrin and HA at the whole insect level.

In vivo and in vitro management of Meloidogyne incognita (Tylenchida: Heteroderidae) using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. compared with oxamyl.

Biological control using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. is a prospective alternative technique to overcome plant parasitic nematodes infection. So, the current study was conducted in vitro on five egg-masses, 100 free eggs and 100 infective juveniles (IJs) of Meloidogyne incognita as well as greenhouse treatments on Luffa aegyptiaca L. to evaluate the nematicidal potential of six strains belong to Pseudomonas spp. and Serratia spp. as compared to oxamyl. Results showed that the inhibitory effect and juvenile mortality varied according to bacteria species, strains and exposure time. All the tested bacteria significantly (P ≤ 0.05) inhibited egg hatching and increased juvenile mortality in vitro. After 3 days of treatment, Pseudomonas spp. were more effective against eggs (48.31to 55.15%) and IJs (20.98 to 25.30%) than Serratia spp. (44.55 to 49.75% with eggs) and (19.06 to 21.61% with IJs), respectively. In the pot experiment, Luffa aegyptiaca L. treated with Serratia spp. and Pseudomonas spp. displayed significantly higher (P ≤ 0.05) levels of growth (as indicated by root length, fresh roots weight and fresh shoots weight) compared to control plants and significantly (P ≤ 0.05) suppressed galling (number of galls) and reproduction (as indicated by number of egg-masses on roots and number of eggs and juveniles in pot soil). Meanwhile, among the treated plants, Serratia spp. and Pseudomonas spp. gave the best results in shoot weight of pots infected by eggs of M. incognita than those infected with IJs as compared with positive control. While, oxamyl treatment gave the best results in pots infected by eggs and IJs. The lowest galling (gall index), number of eggs and juveniles in soil was observed in the treatment with mixture of Serratia spp. and Pseudomonas spp. as well as, enhanced growth of sponge gourd more than application each of them alone. Pots treated with oxamyl overwhelmed those treated with mixture of Serratia spp. and Pseudomonas spp.