Functional characterization of Kid-Kis and MazF-MazE in Sf9 cells and Mythimna separata embryos.

Toxin-antitoxin (TA) systems are comprised of a toxin and its antidote antitoxin and are widely present in bacterial and in eukaryotic systems. However, no work regarding TA systems has been reported in insects. We characterized the Kid-Kis and MazF-MazE TA systems in Spodoptera frugiperda cells and Mythimna separata embryos and observed that the Kid and MazF toxins were highly toxic. In Sf9 cells transfected with Kid plasmid and MazF alone, the apoptosis rate was 24.37% and 29.47%, respectively. Whereas the toxicity of their cognate antitoxins were limited. Both apoptosis and necrosis were induced by the two toxins. Both the Kis and MazE antitoxins partly neutralized toxicity in a dose-dependent manner, with MazE accomplishing almost full neutralization at a 1:4 toxin:antitoxin ratio, the cell survival rate was 81% and 97%, respectively. Our results indicate that MazF-MazE is a good candidate module for application in insects, such as in developing new sterile insect technique (SIT).

RNA interference-mediated knockdown of a cytochrome P450 gene enhanced the toxicity of α-cypermethrin in xanthotoxin-fed larvae of Spodoptera exigua (Hübner).

The beet armyworm (Spodoptera exigua) is a highly polyphagous agricultural pest that is distributed worldwide. However, the adaptive mechanisms of S. exigua for various insecticides and defensive substances in host plants are unknown. Insect P450 monooxygenases play an important role in the detoxification of plant toxins and insecticides, leading to insecticides resistance. We investigated the induced effects of xanthotoxin exposure on detoxification enzyme activity and larval tolerance to α-cypermethrin in S. exigua. Our results showed that the lethal concentration (LC50) of α-cypermethrin for xanthotoxin-exposed larvae was 2.1-fold higher than in the control. Moreover, cytochrome P450 enzyme activity was significantly elevated by upregulation of P450 genes in treated larvae. RT-qPCR results showed that CYP9A10 expression level was significantly increased in all treatments, while maximal expression level was observed in xanthotoxin+α-cypermethrin-fed larvae. RNAi-mediated silencing of CYP9A10 further increased mortality by 18%, 26% and 35% at 48 h and by 27%, 43% and 55% at 72 h when larvae were exposed to diets containing chemicals as compared to the control. The results show that CYP9A10 might play an important role in xanthotoxin and α-cypermethrin detoxification in S. exigua. RNAi-mediated silencing could provide an effective synergistic agent for pest control or insecticide resistance management.

Enhanced effects of dietary tannic acid with chlorantraniliprole on life table parameters and nutritional physiology of Spodoptera exigua (Hübner).

The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) is a highly polyphagous pest which causes considerable economic losses to cotton and many vegetable crops. Tannins are among the most important secondary metabolites in cotton plants. We show that tannic acid enhances the toxic effect of chlorantraniliprole on S. exigua when presented in combination. Bioassays using third-instar S. exigua larvae on an artificial diet showed that consumption of tannic acid with chlorantraniliprole at the concentration of (2 mg/g and LC50 0.018 mg/L) had higher toxicity when compared to either chlorantraniliprole or tannic acid alone (LC50 0.027 mg/L). The diet containing tannic acid with chlorantraniliprole significantly prolonged larval and pupal developmental time and extended mean generation time and total pre-oviposition period compared to either chemical alone. Moreover, fecundity, survival rate, reproductive value, intrinsic rate of increase, finite rate of increase and net reproduction rate declined significantly when exposed to the combined treatment. No difference was observed between tannic acid and the control. Meanwhile, tannic acid with chlorantraniliprole had markedly antifeedant effects; causing significant decline in the relative growth rate (RGR), the relative consumption rate (RCR), the efficiency of conversion of ingested food (ECI), the efficiency of conversion of digested food and an increase in the approximate digestibility (AD) compared to either chemical alone. Tannic acid with chlorantraniliprole also decreased the insect's carbohydrate, lipid and protein contents significantly. The results showed that the interaction between tannic acid and chlorantraniliprole on the growth inhibition of larvae was additive and tannic acid increased the toxicity of chlorantraniliprole to insects. The results of this study provide information useful in integrated pest management programs for S. exigua and show that tannic acid combined with chlorantraniliprole may be a route to reducing the use of synthetic pesticides.

Knock-Down of Gossypol-Inducing Cytochrome P450 Genes Reduced Deltamethrin Sensitivity in Spodoptera exigua (Hübner).

Plants employ an intricate and dynamic defense system that includes physiological, biochemical, and molecular mechanisms to counteract the effects of herbivorous attacks. In addition to their tolerance to phytotoxins, beet armyworm has quickly developed resistance to deltamethrin; a widely used pyrethroid insecticide in cotton fields. The lethal concentration (LC50) required to kill 50% of the population of deltamethrin to gossypol-fed Spodoptera exigua larvae was 2.34-fold higher than the control group, suggesting a reduced sensitivity as a consequence of the gossypol diet. Piperonyl butoxide (PBO) treatment was found to synergize with deltamethrin in gossypol-fed S. exigua larvae. To counteract these defensive plant secondary metabolites, beet armyworm elevates their production of detoxification enzymes, including cytochrome P450 monooxygenases (P450s). Gossypol-fed beet armyworm larvae showed higher 7-ethoxycoumarin-O-deethylase (ECOD) activities and exhibited enhanced tolerance to deltamethrin after 48 and 72 h when compared to the control. Moreover, gossypol pretreated S. exigua larvae showed faster weight gain than the control group after transferring to a deltamethrin-supplemented diet. Meanwhile, gossypol-induced P450s exhibited high divergence in the expression level of two P450 genes: CYP6AB14 and CYP9A98 in the midgut and fat bodies contributed to beet armyworm tolerance to deltamethrin. Knocking down of CYP6AB14 and CYP9A98, via double-stranded RNAs (dsRNA) in a controlled diet, rendered the larvae more sensitive to the insecticide. These data demonstrate that generalist insects can exploit secondary metabolites from host plants to enhance their defense systems against other toxic chemicals. Impairing this defense pathway by RNA interference (RNAi) holds a potential to eliminate the pest's tolerance to insecticides and, therefore, reduce the required dosages of agrochemicals in pest control.

Molecular charactarization of wheat advanced lines for leaf rust resistant genes using SSR markers.

A total of fifty seven wheat advanced lines were screened to detect the existence of leaf rust resistant genes (Lr9, Lr13, Lr19, Lr24, Lr26, Lr28, Lr32, Lr34, Lr35, Lr36, Lr37, Lr39 and Lr46) using thirteen SSR markers. Only four markers for Lr13, Lr32, Lr34 and Lr35 produced separate, reproducible bands which indicated the positive linkage of leaf rust resistance with these SSR markers. The highest frequency was observed for Lr32 (100%), as it was detected in all fifty seven lines, followed by Lr34 (89.4%) in 51 lines, Lr35 (87.7%) in 50 lines and Lr13 (31.5%) in 18 lines respectively. All the four resistant genes were identified in fifteen lines which is only 26% of the studied population. These results indicate that there are limited number of variant genes for leaf rust resistance in the studied wheat advanced lines. Therefore, strategies for arraying these genes to lengthen infection resistance are advised to eliminate wheat rust diseases. In addition, more reliable and capable markers are essential to be settled for marker assisted selection of these and other genes.

Impact of cement waste on soil fertility and crop productivity: a serious concern for food security.

The rapid expansion of urbanization and construction activities has led to a significant increase in cement production worldwide, resulting in a surge in cement waste generation. This study aims to provide a comprehensive analysis of the repercussions of cement waste on soil fertility and crop productivity, emphasizing its critical implications for global food security. Through a multidisciplinary approach, encompassing field surveys, laboratory experiments, and statistical modeling, we assess the physicochemical alterations induced by cement waste in agricultural soils. Our findings reveal substantial declines in crucial soil parameters, including pH levels, organic matter content, and nutrient availability, which directly translate into diminished crop yields. Furthermore, the study identifies key mechanisms underlying these detrimental effects, including altered microbial communities and disrupted nutrient cycling processes. In addition, the findings underscore the severity of the issue, revealing substantial declines in soil fertility and crop yields in areas affected by cement waste contamination. Additionally, we discuss potential mitigation strategies and policy interventions aimed at mitigating the adverse effects of cement waste on agricultural systems. By quantifying the extent of soil degradation and crop yield reduction attributed to cement waste, this research underscores the urgency for sustainable waste management practices and highlights the need for policy interventions to safeguard agricultural productivity and ensure global food security in the face of escalating urbanization and construction activities.

The synergistic potential of biochar and nanoparticles in phytoremediation and enhancing cadmium tolerance in plants.

Cadmium (Cd) is classified as a heavy metal (HM) and is found into the environment through both natural processes and intensified anthropogenic activities such as industrial operations, mining, disposal of metal-laden waste like batteries, as well as sludge disposal, excessive fertilizer application, and Cd-related product usage. This rising Cd disposal into the environment carries substantial risks to the food chain and human well-being. Inadequate regulatory measures have led to Cd bio-accumulation in plants, which is increasing in an alarming rate and further jeopardizing higher trophic organisms, including humans. In response, an effective Cd decontamination strategy such as phytoremediation emerges as a potent solution, with innovations in nanotechnology like biochar (BC) and nanoparticles (NPs) further augmenting its effectiveness for Cd phytoremediation. BC, derived from biomass pyrolysis, and a variety of NPs, both natural and less toxic, actively engage in Cd removal during phytoremediation, mitigating plant toxicity and associated hazards. This review scrutinizes the application of BC and NPs in Cd phytoremediation, assessing their synergistic mechanism in influencing plant growth, genetic regulations, structural transformations, and phytohormone dynamics. Additionally, the review also underscores the adoption of this sustainable and environmentally friendly strategies for future research in employing BC-NP microaggregates to ameliorate Cd phytoremediation from soil, thereby curbing ecological damage due to Cd toxicity.

Entropy-based grid approach for handling outliers: a case study to environmental monitoring data.

Grid-based approaches render an efficient framework for data clustering in the presence of incomplete, inexplicit, and uncertain data. This paper proposes an entropy-based grid approach (EGO) for outlier detection in clustered data. The given hard clusters obtained from a hard clustering algorithm, EGO uses entropy on the dataset as a whole or on an individual cluster to detect outliers. EGO works in two steps: explicit outlier detection and implicit outlier detection. Explicit outlier detection is concerned with those data points that are isolated in the grid cells. They are either far from the dense region or maybe a nearby isolated data point and therefore declared as an explicit outlier. Implicit outlier detection is associated with the detection of outliers that are perplexedly deviated from the normal pattern. The determination of such outliers is achieved using entropy change of the dataset or a specific cluster for each deviation. The elbow based on the trade-off between entropy and object geometries optimizes the outlier detection process. Experimental results on CHAMELEON datasets and other similar datasets suggested that the proposed approach(es) detect the outliers more precisely and extend the capability of outliers detection to an additional 4.5% to 8.6%. Moreover, the resultant clusters became more precise and compact when the entropy-based gridding approach is applied on top of hard clustering algorithms. The performance of the proposed algorithms is compared with well-known outlier detection algorithms, including DBSCAN, HDBSCAN, RE3WC, LOF, LoOP, ABOD, CBLOF and HBOS. Finally, a case study for detecting outliers in environmental data has been carried out using the proposed approach and results are generated on our synthetically prepared datasets. The performance shows that the proposed approach may be an industrial-oriented solution to outlier detection in environmental monitoring data.

The Multifaceted Role of Jasmonic Acid in Plant Stress Mitigation: An Overview.

Plants, being sessile, have developed complex signaling and response mechanisms to cope with biotic and abiotic stressors. Recent investigations have revealed the significant contribution of phytohormones in enabling plants to endure unfavorable conditions. Among these phytohormones, jasmonic acid (JA) and its derivatives, collectively referred to as jasmonates (JAs), are of particular importance and are involved in diverse signal transduction pathways to regulate various physiological and molecular processes in plants, thus protecting plants from the lethal impacts of abiotic and biotic stressors. Jasmonic acid has emerged as a central player in plant defense against biotic stress and in alleviating multiple abiotic stressors in plants, such as drought, salinity, vernalization, and heavy metal exposure. Furthermore, as a growth regulator, JA operates in conjunction with other phytohormones through a complex signaling cascade to balance plant growth and development against stresses. Although studies have reported the intricate nature of JA as a biomolecular entity for the mitigation of abiotic stressors, their underlying mechanism and biosynthetic pathways remain poorly understood. Therefore, this review offers an overview of recent progress made in understanding the biosynthesis of JA, elucidates the complexities of its signal transduction pathways, and emphasizes its pivotal role in mitigating abiotic and biotic stressors. Moreover, we also discuss current issues and future research directions for JAs in plant stress responses.

Development of an easy and cost-effective method for non-invasive genotyping of insects.

Non-invasive genotyping methods provide valuable information on insect populations. However, poor DNA amplification and time-consuming sampling procedures limit these methods, especially for small insects. An efficient and convenient method was developed for non-invasive, non-lethal genotyping of a large insect, Mythimna separata, and a small insect, Drosophila melanogaster, by amplification of endogenous and exogenous, nuclear and mitochondrial genes from insect frass, exuviae, and food waste. For M. separata, the chitin synthesis gene MsCHSB and the COI gene were successfully detected by PCR from exuviae DNA. However, a COI fragment could not be detected directly by PCR from frass, probably due to DNA degradation. To improve the detection rate, DNA from frass was first amplified by Multiple Displacement Amplification with phi29 DNA polymerase, after which the COI fragment was detected from all samples by PCR. For D. melanogaster, second instar larvae were reared individually for three days and then DNA was extracted from food waste of each individual. The endogenous fragment serendipity α (sryα), exogenous transgene ΦC31 integrase, and the kl-5 gene, a Y-chromosome-located male-specific marker gene were successfully detected from most samples. We developed a simple, non-invasive, non-lethal method to determine gender and identify transgenic individuals early in the larval stage. This universal method is applicable to most insects and has potential application in genetic and ecological studies of insects and other arthropods.

Sub-lethal effects of lufenuron exposure on spotted bollworm Earias vittella (Fab): key biological traits and detoxification enzymes activity.

Spotted bollworm, Earias vittella, is one of the most serious and devastating insect pests of vegetables and cotton. Currently, insecticides are necessary for its control in nearly all crop systems. In this paper, we evaluate the sub-lethal effects of lufenuron on biological traits and activity of detoxification enzymes: cytochrome P450 monooxygenases, esterase, and glutathione S-transeferase (GST) in second instar larvae of E. vittella. Results showed that sub-lethal concentrations (LC15 and LC40 of lufenuron), prolonged larval period (at LC40 = 13.86 ± 1.22 day, LC15 = 13.14 ± 1.15 day, control = 12.28 ± 0.7), pupal duration (LC40 = 11.1 ± day, LC15 = 11.8 ± 0.28 day, control = 9.40 ± 0.52), and extended mean generation time (LC40 = 27.3 ± 0.43 LC15 = 29.0 ± 1.19 day, control = 26.0 ± 0.65). Sub-lethal exposure significantly prolonged the pre-adult stage, decreased pupal weight, and reduced adult longevity in the parent (F0) and F1 generation. Moreover, the fecundity and egg viability were significantly lowered in parental and F1 generations at both sub-lethal concentrations compared to the control. While no significant effects were noted on reproductive parameters such as the intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0) of F1 generation when compared to the control. Only mean generation time (T) in F1 at LC15 was significantly longer compared to the LC40 and control (LC40 = 3.79 ± 0.37, LC15 = 32.28 ± 1.55 day, control = 29.79 ± 0.55). Comparatively, the activities of cytochrome P450 monooxygenases and esterase were higher than GST in treated populations. The increase in resistance development against insecticides may possibly because of elevated activity of detoxification enzymes. These results provide useful information for monitoring resistance in integrated pest management (IPM) programs for E. vittella.

Gossypol-induced fitness gain and increased resistance to deltamethrin in beet armyworm, Spodoptera exigua (Hübner).

BACKGROUND: In plant-insect interactions, phytotoxins such as gossypol, exert a defensive role on behalf of the plant by interfering with the essential metabolic, biochemical and physiological pathways of herbivorous insects. The beet armyworm, Spodoptera exigua (Hübner), is a key pest for many important crops including a range of vegetables, ornamentals, and cotton. In this study, we investigated how resistance to deltamethrin relates to enzyme activity in gossypol-pretreated larvae of S. exigua. RESULTS: Following selection with deltamethrin insecticides on gossypol-pretreated larvae for 10 generations, the Gos-SEL population developed a 113.29-fold resistance. Under the same conditions, the Delta-SEL selected population showed a 69.76-fold increase in resistance along with corresponding levels of xenobiotic defense enzyme activity. Similarly, the fecundity of the Delta-SEL population together with male and female longevity were found to be significantly lower when compared with the Gos-SEL population and the laboratory susceptible-strain group (SS-Strain). In addition, the activities of cytochrome P450s in S. exigua were significantly enhanced when the insects were fed on a deltamethrin and gossypol-pretreated diet compared with being fed on deltamethrin alone. CONCLUSION: The reproductive capacity of S. exigua is significantly reduced in Delta-SEL and Gos-SEL populations compared with the control group (SS-Strain). Elevation of the major detoxification enzyme cytochrome P450 monooxygenase and esterase might have an important role in inducing tolerance to deltamethrin in gossypol-fed S. exigua populations. This study enhances our understanding of detoxification enzyme pathways for S. exigua gene expression and their role in responses to insecticides and plant secondary metabolites. © 2018 Society of Chemical Industry.

Biostatistical Options for Quantitative Diet Analysis.

Sufficient statistics knowledge is crucial for the correct design of a research plan. The elucidations of results are interpretive only if appropriate statistical methods are applied. Statistical strategies are a particular approach to demonstrate complicated information in broad and explicable conclusions. The emergence of biostatistical approaches for diet evaluation has improved the accuracy of diet estimation, and different methodologies of data integration promise to magnify our understanding of ecological communities. The present study aimed to compile multiple statistical methods used for diet analysis. More specifically, the significant analysis used in diet assessment, central expectations, and preferences related to each measure was conceptualized. In addition, the ability of each test to evaluate diversity, richness, differentiation, fluctuation, similarity, and quantification of multiple diet items was summarized. Moreover, different options were proposed for researchers to select the appropriate statistical tests. This study covers a framework, aim, and understanding of the statistical test methods of diet analysis.

Dermal fibroblasts from different layers of human skin are heterogeneous in expression of collagenase and types I and III procollagen mRNA.

We have previously shown that the expression of collagenase mRNA and activity are suppressed in fibroblasts derived from postburn hypertrophic scar. Although it is known that differential synthesis of collagen and collagenase in postburn hypertrophic scar is one of the main reasons for the excessive accumulation of collagen, it is not clear why the expression of collagenase in hypertrophic scar fibroblasts is suppressed relative to that in normal fibroblasts. In this study, we hypothesized that dermal fibroblasts from deeper layers of skin, which normally migrate toward the wound site, have a different capacity to express key extracellular matrix proteins such as collagenase and types I and III procollagen. To test this hypothesis, we established four different pairs of hypertrophic and site-matched normal cell strains from four different patients with postburn hypertrophic scarring. In another set of experiments, ten different cell strains from two normal human skin samples that were horizontally sectioned into five different layers (layers 1-5 correspond to upper to deeper layers, respectively) were established in culture. Cells at the same passages were harvested, total RNA was extracted, and Northern analysis was conducted to determine the level of collagenase and types I and III procollagen mRNA expression in each cell strain. The results of Northern blot analysis showed two transcripts each for the pro alpha1(I) collagen chain (5.8 and 4.8 kb) and for the pro alpha1(III) collagen chain (5.4 and 4.8 kb) in all cell strains examined. The intensity of the pro alpha1(I) chain of type I procollagen mRNA varied, ranging from 50.8 to 137.1 and 44.4 to 131.5 densitometry units among either normal or hypertrophic scar cells examined, respectively. Similarly, the relative quantity of type III procollagen transcript also varied, ranging from 10.4 to 91.1 and 28.7 to 116.1 among normal and hypertrophic scar cells, respectively. When five different skin layers from each tissue sample were evaluated for functional cell heterogeneity, the results showed a marked variation in expression of mRNA for type I and III procollagen. Although the level of collagenase mRNA also varied among different cell strains examined, the expression of collagenase mRNA was lower in fibroblasts derived from deeper layers of each skin sample. In conclusion, cells from different layers of normal skin samples are heterogeneous in their constitutive expression of some key extracellular matrix components such as collagenase and types I and III procollagen.