Effect of Brucea javanica Oil on the Toxicity of ß-Cypermethrin Emulsifiable Concentrate Formulation.

Enhancing the performance of traditional pesticide formulations by improving their leaf surface wetting capabilities is a crucial approach for maximizing the pesticide efficiency. This study develops an emulsifiable concentrate (EC) of 4.5% ß-cypermethrin containing Brucea javanica oil (BJO). The incorporation of BJO aims to improve the leaf-wetting properties of the EC formulation and enhance its insecticidal effectiveness. The droplet size and emulsion characteristics of ß-CYP EC emulsion with varying concentrations of the emulsifier were evaluated, and changes after incorporating BJO were assessed to develop the optimal formulation. A comprehensive comparison was conducted among commercial 4.5% ß-cypermethrin EC (ß-CYP EC-1), 4.5% ß-cypermethrin EC with BJO (ß-CYP EC-2), and 4.5% ß-cypermethrin EC without BJO (ß-CYP EC-3). This comparison encompassed various factors including storage stability, insecticidal activity, cytotoxicity, and wetting performance on cabbage leaves. The results indicated that the ideal emulsifier concentration was 15% emulsifier 0201B. ß-CYP EC-2 demonstrated superior wetting properties on cabbage leaves (the wetting performance of ß-CYP EC-2 emulsion on cabbage leaves is 2.60 times that of the ß-CYP EC-1 emulsion), heightened insecticidal activity against the third larvae of Plutella xylostella [diamondback moth (DBM)] [the insecticidal activity of the ß-CYP EC-2 emulsion against the third larvae of DBM is 1.93 times that of the ß-CYP EC-1 emulsion (12 h)], and more obvious inhibitory effects on the proliferation of DBM embryo cells than the other tested formulations. These findings have significant implications for advancing pest control strategies and promoting sustainable and effective agricultural practices.

Pectin-Coated Iron-Based Metal-Organic Framework Nanoparticles for Enhanced Foliar Adhesion and Targeted Delivery of Fungicides.

Conventional agrochemicals are underutilized due to their large particle sizes, poor foliar retention rates, and difficult translocation in plants, and the development of functional nanodelivery carriers with high adhesion to the plant body surface and efficient uptake and translocation in plants remains challenging. In this study, a nanodelivery system based on a pectin-encapsulated iron-based MOF (TF@Fe-MOF-PT NPs) was constructed to enhance the utilization of thifluzamide (TF) in rice plants by taking advantage of the pectin affinity for plant cell walls. The prepared TF@Fe-MOF-PT NPs exhibited an average particle size of 126.55 nm, a loading capacity of 27.41%, and excellent dual-stimulus responses to reactive oxygen species and pectinase. Foliar washing experiments showed that the TF@Fe-MOF-PT NPs were efficiently adhered to the surfaces of rice leaves and stems. Confocal laser scanning microscopy showed that fluorescently labeled TF@Fe-MOF-PT NPs were bidirectionally delivered through vascular bundles in rice plants. The in vitro bactericidal activity of the TF@Fe-MOF-PT NPs showed better inhibitory activity than that of a TF suspension (TF SC), with an EC50 of 0.021 mg/L. A greenhouse test showed that the TF@Fe-MOF-PT NPs were more effective than TF SC at 7 and 14 d, with control effects of 85.88 and 78.59%, respectively. It also reduced the inhibition of seed stem length and root length by TF SC and promoted seedling growth. These results demonstrated that TF@Fe-MOF-PT NPs can be used as a pesticide nanodelivery system for efficient delivery and intelligent release in plants and applied for sustainable control of pests and diseases.

Toxicity and Sublethal Effects of Autumn Crocus (Colchicum autumnale) Bulb Powder on Red Imported Fire Ants (Solenopsis invicta).

Autumn crocus (Colchicum autumnale L.) is a medicinal plant as it contains high concentrations of colchicine. In this study, we reported that the ground powder of autumn crocus bulb is highly toxic to invasive Solenopsis invicta Buren, commonly referred to as red imported fire ants (RIFAs). Ants fed with sugar water containing 5000 mg/L of bulb powder showed 54.67% mortality in three days compared to 45.33% mortality when fed with sugar water containing 50 mg/L of colchicine. Additionally, the effects of short-term feeding with sugar water containing 1 mg/L of colchicine and 100 mg/L of autumn crocus bulb powder were evaluated for RIFAs' colony weight, food consumption, and aggressiveness, i.e., aggregation, grasping ability, and walking speed. After 15 days of feeding, the cumulative colony weight loss reached 44.63% and 58.73% due to the sublethal concentrations of colchicine and autumn crocus bulb powder, respectively. The consumption of sugar water and mealworm (Tenebrio molitor L.) was substantially reduced. The aggregation rates decreased 48.67% and 34.67%, grasping rates were reduced to 38.67% and 16.67%, and walking speed decreased 1.13 cm/s and 0.67 cm/s as a result of the feeding of the two sublethal concentrations of colchicine and autumn crocus bulb powder, respectively. Our results for the first time show that powder derived from autumn crocus bulbs could potentially be a botanical pesticide for controlling RIFAs, and application of such a product could be ecologically benign due to its rapid biodegradation in the environment.

Laboratory evaluation of aqueous leaf extract of Tephrosia vogelii against larvae of Aedes albopictus (Diptera: Culicidae) and non-target aquatic organisms.

Mosquito control using insecticides has been the most successful intervention known to reduce malaria prevalence or incidence. However, vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In this research, the leaf aqueous leachate of Tephrosia vogelii was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and toward adults of the water flea, Daphnia magna (Cladocera: Crustacea) and Oreochromis niloticus, two non-target aquatic organisms that share the same ecological niche of A. albopictus. The leaf aqueous leachate of T. vogelii was evaluated against fourth-instar larvae, non-blood fed 3-5 days old laboratory strains of A. albopictus under laboratory condition. In addition, the objective of the present work was to study the environmental safety evaluation for aquatic ecosystem. Mortality was then recorded after 7d exposure. The leaf aqueous leachate of T. vogelii showed high mosquitocidal activity against larvae of A. albopictus, with a LC50=1.18µg/mL. However, it had a remarkable acute toxicity also toward adults of the non-target arthropod D. magna, with a LC50=0.47µg/L and O. niloticus with a LC50=5.31µg/L. The present findings have important implications in the practical control of mosquito larvae in the aquatic ecosystem, as the medicinal plants studied are commonly available in large quantities. The extract could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.

Association analysis of genomic loci important for grain weight control in elite common wheat varieties cultivated with variable water and fertiliser supply.

Grain weight, an essential yield component, is under strong genetic control and markedly influenced by the environment. Here, by genome-wide association analysis with a panel of 94 elite common wheat varieties, 37 loci were found significantly associated with thousand-grain weight (TGW) in one or more environments differing in water and fertiliser levels. Five loci were stably associated with TGW under all 12 environments examined. Their elite alleles had positive effects on TGW. Four, two, three, and two loci were consistently associated with TGW in the irrigated and fertilised (IF), rainfed (RF), reduced nitrogen (RN), and reduced phosphorus (RP) environments. The elite alleles of the IF-specific loci enhanced TGW under well-resourced conditions, whereas those of the RF-, RN-, or RP-specific loci conferred tolerance to the TGW decrease when irrigation, nitrogen, or phosphorus were reduced. Moreover, the elite alleles of the environment-independent and -specific loci often acted additively to enhance TGW. Four additional loci were found associated with TGW in specific locations, one of which was shown to contribute to the TGW difference between two experimental sites. Further analysis of 14 associated loci revealed that nine affected both grain length and width, whereas the remaining loci influenced either grain length or width, indicating that these loci control grain weight by regulating kernel size. Finally, the elite allele of Xpsp3152 frequently co-segregated with the larger grain haplotype of TaGW2-6A, suggesting probable genetic and functional linkages between Xpsp3152 and GW2 that are important for grain weight control in cereal plants. Our study provides new knowledge on TGW control in elite common wheat lines, which may aid the improvement of wheat grain weight trait in further research.

Adenosine A1 receptor activation as a brake on the microglial response after experimental traumatic brain injury in mice.

We reported that adenosine A(1) receptor (A(1)AR) knockout (KO) mice develop lethal status epilepticus after experimental traumatic brain injury (TBI), which is not seen in wild-type (WT) mice. Studies in epilepsy, multiple sclerosis, and neuro-oncology suggest enhanced neuro-inflammation and/or neuronal death in A(1)AR KO. We hypothesized that A(1)AR deficiency exacerbates the microglial response and neuronal damage after TBI. A(1)AR KO and WT littermates were subjected to mild controlled cortical impact (3 m/sec; 0.5 mm depth) to left parietal cortex, an injury level below the acute seizure threshold in the KO. At 24 h or 7 days, mice were sacrificed and serial sections prepared. Iba-1 immunostaining was used to quantify microglia at 7 days. To assess neuronal injury, sections were stained with Fluoro-Jade C (FJC) at 24 h to evaluate neuronal death in the hippocampus and cresyl violet staining at 7 days to analyze cortical lesion volumes. We also studied the effects of adenosine receptor agonists and antagonists on (3)H-thymidine uptake (proliferation index) by BV-2 cells (immortalized mouse microglial). There was no neuronal death in CA1 or CA3 quantified by FJC. A(1)AR KO mice exhibited enhanced microglial response; specifically, Iba-1 + microglia were increased 20-50% more in A(1)AR KO versus WT in ipsilateral cortex, CA3, and thalamus, and contralateral cortex, CA1, and thalamus (p < 0.05). However, contusion and cortical volumes did not differ between KO and WT. Pharmacological studies in cultured BV-2 cells indicated that A(1)AR activation inhibits microglial proliferation. A(1)AR activation is an endogenous inhibitor of the microglial response to TBI, likely via inhibition of proliferation, and this may represent a therapeutic avenue to modulate microglia after TBI.

Quantitative proteomics reveals the function of unconventional ubiquitin chains in proteasomal degradation.

All seven lysine residues in ubiquitin contribute to the synthesis of polyubiquitin chains on protein substrates. Whereas K48-linked chains are well established as mediators of proteasomal degradation, and K63-linked chains act in nonproteolytic events, the roles of unconventional polyubiquitin chains linked through K6, K11, K27, K29, or K33 are not well understood. Here, we report that the unconventional linkages are abundant in vivo and that all non-K63 linkages may target proteins for degradation. Ubiquitin with K48 as the single lysine cannot support yeast viability, and different linkages have partially redundant functions. By profiling both the entire yeast proteome and ubiquitinated proteins in wild-type and ubiquitin K11R mutant strains using mass spectrometry, we identified K11 linkage-specific substrates, including Ubc6, a ubiquitin-conjugating enzyme involved in endoplasmic reticulum-associated degradation (ERAD). Ubc6 primarily synthesizes K11-linked chains, and K11 linkages function in the ERAD pathway. Thus, unconventional polyubiquitin chains are critical for ubiquitin-proteasome system function.