Individual and Synergic Effects of Phosphorus and Gibberellic Acid on Organic Acids Exudation Pattern, Ultra-Structure of Chloroplast and Stress Response Gene Expression in Cu-Stressed Jute (Corchorus Capsularis L.)

Copper (Cu) pollution in agricultural soils is considered as a serious health risk due to its accumulation in plants. Thus, there is an urgent need to optimize nutrient application for higher yield with lower Cu uptake to ensure food security. A pot experiment was conducted to determine the effects of single and/or combined application of different levels (0 and 80 kg ha−1) of phosphorus (P) and gibberellic acid (0 and 100 mg L−1) on Cu accumulation, morpho-physiological and antioxidative defence attributes of jute (Corchorus capsularis L.) exposed to severe Cu stress (0, 200 and 400 mg kg−1). Results revealed that C. capsularis tolerated up to 200 mg kg−1 Cu concentration without a significant (

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. Besides 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 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 RNAi holds a potential to eliminate the pest’s tolerance to insecticides and, therefore, reduce the required dosages of agrochemicals in pest control

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

Assessment of sublethal and transgenerational effects of spirotetramat, on population growth of cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae)

The cabbage aphid (Brevicoryne brassicae L.) is a devastating pest of cruciferous crops causing economic damage worldwide and notably owing to its increasing resistance to commonly used pesticides. Such resistance prompts the development of integrated pest management (IPM) programs that include novel pesticides being effective against the aphids. Spirotetramat is a novel insecticide used against sap-sucking insect pests, particularly aphids. This study evaluated the toxicity of spirotetramat to adult apterous B. brassicae after 72 h using the leaf dipping method. According to the toxicity bioassay results, the LC50 value of spirotetramat to B. brassicae was 1.304 mgL−1. However, the sublethal concentrations (LC5 and LC15) and transgenerational effects of this novel insecticide on population growth parameters were estimated using the age-stage, two-sex life table theory method. The sublethal concentrations (LC5; 0.125 mgL−1 and LC15; 0.298 mgL−1) of spirotetramat reduced the adult longevity and fecundity of the parent generation (F0). These concentrations prolonged the preadult developmental duration while decreasing preadult survival, adult longevity and reproduction of the F1 generation. The adult pre-reproductive period was also extended by spirotetramat treatment groups. Subsequently, the population growth parameters such as the intrinsic rate of increase r, finite rate of increase λ and net reproductive rate R0 of the F1 generation were decreased in spirotetramat treatment groups whereas, the mean generation time T of the F1 generation was not affected when compared to the control. These results indicated the negative effect of sublethal concentrations of spirotetramat on the performance of B. brassicae by reducing its nymphal survival, extending the duration of some immature stages and suppressing the population growth of B. brassicae. Overall, we demonstrated that spirotetramat is a pesticide showing both sublethal activities, and transgenerational effects on cabbage aphid; it may be useful for implementation in IPM programs against this aphid pest

Identification and Expression Analysis of the PIN and AUX/LAX Gene Families in Ramie (Boehmeria nivea L. Gaud)

Auxin regulates diverse aspects of growth and development. Furthermore, polar auxin transport, which is mediated by the PIN-FORMED (PIN) and AUXIN1/LIKE-AUX (AUX/LAX) proteins, plays a crucial role in auxin distribution. In this study, six PIN and four AUX/LAX genes were identified in ramie (Boehmeria nivea L.). We used qRT-PCR to characterize and analyze the two gene families, including phylogenetic relationships, intron/exon structures, cis-elements, subcellular localization, and the expression patterns in different tissues. The expression of these genes in response to indole-3-acetic acid (IAA) treatment and drought stress was also assessed; the results indicate that most of the BnAUX/LAX and BnPIN genes were regulated as a result of IAA treatment and drought stress. Our study provides insights into ramie auxin transporters and lays the foundation for further analysis of their biological functions in ramie fiber development and adaptation to environmental stresses

Lumateperone Interact with S-Protein of <i>Ebola</i> Virus and TIM-1 of Human Cell Membrane: Insights from Computational Studies

The Ebola virus outbreak in Africa is an unparalleled risk to society and to human health. Interventions that utilize the host cell receptor TIM-1 and the viral spike protein (S-protein) can be considered effective and suitable treatments. Initially, we identified Lumateperone as a candidate drug for the S-protein using the LEA3D tool; then using molecular modeling and docking, we investigated the binding efficiency of Lumateperone with the S-protein and its TIM-1 receptor. The present computational study shows that Lumateperone possesses a strong attraction to the S-protein and the TIM-1 receptor of the host as well as to their complex. It was observed that the binding energy of the S-protein/TIM-1 complex decreases in the presence of Lumateperone. A significant decrease of 395.75 kJ/mol (Lumateperone bound to the S-protein) and 517.19 kJ/mol (Lumateperone bound to the TIM-1 receptor) of binding energy was observed in the S-protein/TIM-1 complex in the presence of Lumateperone compared to their direct binding. We also noticed that Lumateperone was binding with the residues in the S-protein (Asn461) and the TIM-1 (Trp274 and Asn275) receptor that were involved in making the S-protein/TIM-1 complex. In the presence of Lumateperone, the simulation analysis also supports the above findings on the effectiveness of Lumateperone in delaying the establishment of the complex of the S-protein/TIM-1. In conclusion, this computational study predicts the possibility of Lumateperone as a therapeutic strategy against the Ebola virus