Inhibition of protein degradation increases the Bt protein concentration in Bt cotton

Bacillus thuringiensis(Bt)cotton production is challenged by two main problems,i.e.,the low concentration of Bt protein at the boll setting stage and the lowest insect resistance in bolls among all the cotton plant’s organs.Therefore,increasing the Bt protein concentration at the boll stage,especially in bolls,has become the main goal for increasing insect resistance in cotton.In this study,two protein degradation inhibitors(ethylene diamine tetra acetic acid(EDTA)and leupeptin)were sprayed on the bolls,subtending leaves,and whole cotton plants at the peak flowering stage of two Bt cultivars(medium maturation Sikang 1(SK1))and early maturation Zhongmian 425(ZM425)in 2019 and 2020.The Bt protein content and protein degradation metabolism were assessed.The results showed that the Bt protein concentrations were enhanced by 21.3 to 38.8%and 25.0 to 38.6%in the treated bolls of SK1 and ZM425 respectively,while they were decreased in the subtending leaves of these treated bolls.In the treated leaves,the Bt protein concentrations increased by 7.6 to 23.5%and 11.2 to 14.9%in SK1 and ZM425,respectively.The combined application of EDTA and leupeptin to the whole cotton plant increased the Bt protein concentrations in both bolls and subtending leaves.The Bt protein concentrations in bolls were higher,increasing by 22.5 to 31.0%and 19.6 to 32.5%for SK1 and ZM425,respectively.The organs treated with EDTA or/and leupeptin showed reduced free amino acid contents,protease and peptidase activities and significant enhancements in soluble protein contents.These results indicated that inhibiting protein degradation could improve the protein content,thus increasing the Bt protein concentrations in the bolls or/and leaves of cotton plants.Therefore,the increase in the Bt protein concentration without yield reduction suggested that these two protein degradation inhibitors may be applicable for improving insect resistance in cotton production.

Analysis of the Mechanism and Effectiveness of Lignin in Improving the High-Temperature Thermal Stability of Asphalt

The use of lignin,which is a by-product of the pulp and paper industry,in the development of asphalt binders would contribute to waste reduction,providing environmental,economic,and social benefits.In this study,samples of lignin-modified asphalt binder samples with different content of lignin(3%,6%,9%,12%,and 15%)and unmodified asphalt(control)were tested using Fourier transform infrared spectroscopy(FTIR),dynamic shear rheometer(DSR),and thermogravimetry.The mechanism and effectiveness of lignin in improving the thermal stability of asphalt at high temperatures were analyzed.The FTIR analysis shows that no new characteristic absorption peak is seen in the infrared spectral of the lignin-modified asphalt binder samples,and some bands characteristic of lignin-related peaks gradually increased with the increase of lignin content.This suggests that the modification of lignin-modified asphalt binder samples was due to physical blending rather than chemical modification.The increase of lignin content in the lignin-modified asphalt samples increases the complex shear modulus G*of the samples and decreases the phase angles of the samples.Similarly,the anti-rutting performance(G*/sinδ)of the samples improves with the increase in lignin content,but this is not significant after any addition of lignin that exceeds 12%of asphalt mass.Thermal characterizations show that the thermal decomposition rate of lignin is lower,and its residual amount is higher compared to that of asphalt,which is a major reason for the improved stability of lignin-modified asphalt binders at high temperatures.The effect of lignin on the thermal stability of asphalt is dependent on both lignin content and temperature.It has a positive effect on the thermal stability of asphalt at high temperatures within the range of asphalt service temperature(25℃–200℃).Additionally,from the pyrolysis viewpoint,it was explained that excessive lignin addition is not beneficial to the thermal stability of asphalt at high temperatures,which is consistent with the DSR test result conducted high temperatures.

Red light-driven generation of reactive oxygen species for the targeted oxidation of glioma cells and thiols over covalent organic framework

Reactive oxygen species(RoS)are essential for biological processes like cell signaling and chemical processes like organic oxidation.Moreover,the sufficient generation of RoS plays a significant role in targeted tumor treatments or oxidation of organics.Herein,a hydrazone-linked porphyrin covalent organic framework(Por-DETH-COF)is developed for red light-induced generation of ROS like singlet oxygen(^(1)O_(2))or superoxide(O_(2)·^(-))to undertake different but targeted oxidations.First,^(1)O_(2)is adopted in photodynamic therapy(PDT)for the oxidation of glioma cells.The PDT efficiency of Por-DETH-COF on the apoptosis of glioma cells is explored through flow cytometry and western blot assay.The apoptosis rate of glioma cells significantly increases over Por-DETH-COF under 660nm red light illumination,suggestive of the potency of^(1)O_(2).Second,O_(2)^(·-)is employed for the targeted oxidation of thiols.A series of thiols could be efficiently oxidized to corresponding disulfides over Por-DETH-COF under 660 nm red light illumination,indicative of the significance of O_(2)^(·-).This work highlights the potential of covalent organic frameworks in generating Ros for precise medical applications of complex chemical environments.

Analysis of the effects of antifungal peptide P-1 from Bacillus pumilus HN-10 on energy metabolism of Trichothecium roseum

This study investigated the antifungal activity and possible mode of action of Bacillus pumilus HN-10 antifungal peptide P-1 against Trichothecium roseum.The results showed that the antifungal peptide P-1 at a concentration of 1.0μg mL^(-1)had strong antifungal activity against T.roseum.P-1 inhibited the tricarboxylic acid cycle(TCA)pathway and the transporter pathway of NADH to coenzyme Q on the electron transport chain.P-1 significantly reduced succinate dehydrogenase(SDH),malate dehydrogenase(MDH),ATPase,mitochondrial complex enzymes I,II and IV enzyme activities on the electron transport chain,and 5'-triphosphate(ATP),5'-diphosphate(ADP),5'-monophosphate(AMP)content,and energy charge(EC);significantly increased 6-phosphofructokinase(PFK)enzyme activity.The release of Ca^(2+)(OD_(680))from the inner mitochondrial membrane and the openness of the mitochondrial permeability transition pore(MPTP)were analysed,and microscopy was performed following staining of mitochondria with JC-1.The results indicated that P-1 significantly increased the release of Ca^(2+) and the openness of MPTP,decreased the mitochondrial membrane potential,and produced green fluorescence;transcriptomics data analysis showed that there were 39 differentially expressed genes(DEGs)related to energy metabolism enzymes.The results verified by qRT-PCR were basically consistent with the transcriptome sequencing results.Thus,P-1 achieved its inhibitory effect mainly by regulating genes related to energy metabolism.