Single-cell and spatial RNA sequencing reveal the spatiotemporal trajectories of fruit senescence.

The senescence of fruit is a complex physiological process, with various cell types within the pericarp, making it highly challenging to elucidate their individual roles in fruit senescence. In this study, a single-cell expression atlas of the pericarp of pitaya (Hylocereus undatus) is constructed, revealing exocarp and mesocarp cells undergoing the most significant changes during the fruit senescence process. Pseudotime analysis establishes cellular differentiation and gene expression trajectories during senescence. Early-stage oxidative stress imbalance is followed by the activation of resistance in exocarp cells, subsequently senescence-associated proteins accumulate in the mesocarp cells at late-stage senescence. The central role of the early response factor HuCMB1 is unveiled in the senescence regulatory network. This study provides a spatiotemporal perspective for a deeper understanding of the dynamic senescence process in plants.

CsMYC2 is involved in the regulation of phenylpropanoid biosynthesis induced by trypsin in cucumber (Cucumis sativus) during storage.

Trypsin has a new activity of scavenging superoxide anion and generating hydrogen peroxide. Trypsin can significantly improve the storage quality of C. sativus. To illustrate the mechanism of trypsin-induced resistance in fruits and vegetables, an integrated analysis of widely targeted metabolomics and transcriptomics was carried out. Transcriptomic results showed that 1068 genes highly related to phenylpropanoid biosynthesis gathered in the brown module were obtained by WGCNA. In KEGG analysis, differentially expressed genes (DEGs) were also highly enriched in EIP (Environmental Information Processing) pathways "Plant hormone signal transduction (map04075)" and "MAPK signaling pathway-plant (map04016)". Next, 87 genes were identified as the leading edge by GSEA analysis. So far, CsMYC2 was highlighted as a key transcription factor that regulates phenylpropanoid biosynthesis identified by GSEA and WGCNA. Furthermore, the major route of biosynthesis of phenylpropanoid compounds including coumarins, lignins, chlorogenic acid, flavonoids, and derivatives regulated by trypsin was also illustrated by both transcriptomic and metabolomic data. Results of O2PLS showed that CsMYC2 was positively correlated with Rosmarinic acid-3-O-glucoside, Epigallocatechin, Quercetin-3-O-sophoroside (Baimaside), and so on. Correlation between CsMYC2, phenylpropanoid related genes, and metabolites in C. sativus was illustrated by co-expression networks. Roles of CsMYC2 were further checked in C. sativus by VIGS. The results of this study might give new insight into the exploration of the postharvest resistance mechanism of C. sativus induced by trypsin and provide useful information for the subsequent mining of resistance genes in C. sativus.

Structural Characterization, Rheological Properties, Antioxidant and Anti-Inflammatory Activities of Polysaccharides from Zingiber officinale.

The structural characteristics, rheological properties, antioxidant and anti-inflammatory activities of Zingiber officinale polysaccharides (ZOP) and ZOP-1 were studied. The total soluble sugar contents of ZOP and ZOP-1 were 78.6 ± 0.6 and 79.4 ± 0.4%, respectively. Compared with ZOP, ZOP-1 had a larger molecular weight and a more uniform distribution. There were also some differences in the monosaccharide composition between ZOP and ZOP-1. The main monosaccharide of ZOP and ZOP-1 was glucose (Glc) and galactose (Gal), respectively. Ultraviolet visible spectroscopy (UV-Vis) and fourier transform infrared spectra (FT-IR) results showed that the two polysaccharides had the characteristic absorption peaks of polysaccharides and did not contain nucleic acid and protein. They had good thermal stability, trihelix structure and amorphous sheet structure. ZOP and ZOP-1 had obvious differences in microstructure. The surface of ZOP was smooth and the broken structure was compact and stable with angular shape, while the surface of ZOP-1 was uneven with spiral accumulation and not closely arranged. Moreover, ZOP and ZOP-1 were polysaccharides molecular polymers which were entangled by van der waals' force (VDW) between polysaccharides molecules and hydrogen bond association between sugar chains, and both contain α pyranose. At different concentrations, temperature, pH and salt ion concentrations, both ZOP and ZOP-1 had the properties of non-Newtonian fluids, showed shear dilution phenomenon, which had the potential as a texture modifier or thickener in food or biomedicine. Compared with ZOP, ZOP-1 showed superior antioxidant and anti-inflammatory activities in vitro.

Transcriptome analyses and virus-induced gene silencing identify HuWRKY40 acting as a hub transcription factor in the preservation of Hylocereus undatus by trypsin.

Trypsin can significantly improve the storage quality of Hylocereus undatus (H. undatus). To verify the hub WRKY gene of H. undatus in trypsin preservation, joint analysis of transcriptome and protein-protein interaction (PPI) network was carried out, and virus-induced gene silencing (VIGS) was conducted. In the transcriptome of H. undatus, GO directed acyclic graph (DAG) showed that the GO terms of 55 WRKY genes were mainly enriched in sequence-specific DNA binding, DNA binding transcription factor activity, and so on. The GO enrichment chord diagram showed that HuWRKY40 was significantly up-regulated in the enriched top10 GO terms. KEGG enrichment analysis showed that 55 WRKY genes were mainly enriched in plant-pathogen interaction and MAPK pathway. The results of PPI network showed that HuWRKY40 was a hub protein of WRKY transcription factors (TFs) family regulated by trypsin, which was consistent with the results of transcriptome analysis. Bioinformatics analysis showed that HuWRKY40 of H. undatus had the highest homology with Beta vulgaris L. and Spinacia oleracea L. The function of the core regulatory protein HuWRKY40 was further clarified by VIGS technology. The results of VIGS showed that there was a big difference between the phenotype of the pTRV2-HuWRKY40 group and that of the control group. Finally, it was confirmed that HuWRKY40 accelerated the synthesis of flavonoids and improved the fruit quality during the storage of H. undatus. This study found that trypsin may regulate HuWRKY40 activity through the MAPK cascade pathway, affect the participation of flavonoid synthesis, and then delay fruit corruption. PRACTICAL APPLICATIONS: With attention of people to the safety and freshness of fruits and vegetables, biological preservation technology has become one of the hotspots in the field of preservation in recent years. Trypsin can significantly improve the antioxidant capacity of fruits and vegetables. As a new biological preservative, it is convenient to operate and economical. In the current work, the mechanism of trypsin on the WRKY TFs during H. undatus storage was investigated. The application of trypsin would provide a new strategy for the storage quality control of fruits and vegetables.

EuRBG10 involved in indole alkaloids biosynthesis in Eucommia ulmoides induced by drought and salt stresses.

Alkaloids are natural products with many important medicinal activities. To explore the mechanism of abiotic stress promoting alkaloid biosynthesis in Eucommia ulmoides, transcriptomic analysis and metabonomic analysis were used, virus-induced gene silencing (VIGS) lines of target gene were constructed. The results showed that drought and salt stress caused wilting and blackening of leaves, decreased chlorophyll level, and significantly induced MDA and relative conductivity. To resist the damage of stress to cells, the level of secondary metabolites such as alkaloids increased significantly with the extension of stress time. Transcriptomic results showed that, were. Six alkaloid related genes (AWGs) were gathered in five modules positively correlated with either salt stress or alkaloid contents by WGCNA. Results of GO and KEGG enrichment revealed that biosynthesis of alkaloid, especially indole alkaloid was induced, and degradation of alkaloid was inhibited under salt stress. Combining the results of transcriptome and metabolomics, it was suggested that EuRBG10 promotes the production of indole alkaloids and EuAMO5 inhibits the degradation of alkaloids, which may be the core mechanism of the indole alkaloid biosynthesis pathway (map00901) induced by salt stress. The results of these hub proteins were also consistent with the chordal graph of KEGG enrichment. Hub roles of EuRGB10 was checked in E. ulmoides by VIGS. Our findings provide a preliminary understanding of abiotic stress regulating secondary metabolites such as alkaloids, and propose hub genes that can be used to improve the level of bioactive components in medicinal plant.

Omics analyses indicate sdhC/D act as hubs of early response of E. coli to antibiotics.

In recent years, the phenomenon of microbial resistance has become increasingly serious. The generation of reactive oxygen species (ROS) during the bactericidal process of antibiotics has attracted great interest, but little research has been done on the generation of ROS in the early stage of antibiotic action. We confirmed the rapid production of ROS by flow cytometry and transmission electron microscopy (TEM). GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis indicated that the oxidative phosphorylation pathway is the key pathway of ROS production. Protein-protein interaction (PPI) network results indicate that sdhC/D are key genes in the oxidative phosphorylation pathway. The overexpression of sdhC/D resulted in a lower survival rate than the control strain after antibiotic treatments, which might be due to excess ROS induced by sdhC/D overexpression. The production of superoxide anion in the overexpress strain was significantly higher than that in the control strain, which further verified the importance of sdhC/D in the ROS release of bacteria. Current results showed that bacteria produce large amounts of ROS in the early stage of gentamicin and ampicillin action, and the regulation patterns of genes in the key pathway were consistent. sdhC/D are key genes in the early ROS release process of bacteria. Our study provides a basis for the search of ROS-related enhancers of antimicrobial action.

Lipid metabolism regulated by superoxide scavenger trypsin in Hylocereus undatus through multi-omics analyses.

To analyze the mechanism of the effect of trypsin on the preservation of Hylocereus undatus, the transcriptomic and widely targeted metabolomic profiles of H. undatus after trypsin treatment were evaluated. Among 477 genes related to lipid metabolism, 32 genes had significant expression differences. GO analysis results showed that the main enriched GO functions include pectinesterase and asparagine esterase activities, and so on. The KEGG metabolic pathway with the highest enrichment rate was fatty acid elongation. The protein-protein interaction (PPI) network analysis results showed that the PPI network of lipid metabolism is a complex biological network of scale-free cells. KCS1, QRT1, and ACC1 acted as hubs to regulate a large number of other proteins and amplify the regulatory role of trypsin to achieve a preservation effect. In addition, three unsaturated fatty acids were upregulated, while eight saturated fatty acids were downregulated. PRACTICAL APPLICATIONS: The postharvest storage of fresh fruits and vegetables brings about bottlenecks to fresh fruits and vegetables. There was also an increasing need for biopreservation techniques. Trypsin could significantly enhance the antioxidant capacity of fruits and vegetables, as a preserver for the storage of fruits and vegetables, which was convenient to operate and more economical. The regulation mechanism of trypsin on lipid metabolism in fruits and vegetables during storage of H. undatus is studied in this paper. The application of trypsin would provide a new strategy for quality control of fruit and vegetable storage.

Comprehensive evaluation of Loblolly fruit by high performance liquid chromatography four wavelength fusion fingerprint combined with gas chromatography fingerprinting and antioxidant activity analysis.

Loblolly fruit (LBF) is mainly used as raw material for beverage, but there are few researches on its quality evaluation or control. The aim of this study was to develop comprehensive evaluation methods for the quality control of Loblolly fruit. firstly, double wavelength coefficient ratio spectrum was used to identify the purity of chromatographic fingerprint peak. It is very important to identify the purity of fingerprint peaks because only the quantitative determination of pure chromatographic peaks is meaningful for its efficient quality control. Then, multi-wavelength fusion fingerprint was established to avoid one-sidedness of a single wavelength for further evaluation by systematically quantified fingerprint method (SQFM). According to the outcome of Pm, 25 batches of LBF were classified into two classifications by hierarchical cluster analysis, which was consistent with the SQFM evaluation results. Two active components, gallic acid (GAC) and ethyl gallate (EGA) in LBF, were quantitatively determined by quantitative analysis of multi-components by single marker (QAMS). In addition, the fingerprint efficacy relationship was established using an off-line antioxidant system and partial least-squares model to explore the connection between chemical components and antioxidant activities. Finally, the evaluation results of high-performance liquid chromatography and gas chromatography were integrated by the mean algorithm, which could reduce the error caused by single method. The results showed that the proposed strategy could provide a method for quality evaluation of LBF and even other traditional Chinese medicines (TCMs).

Impact of the National Centralized Drug Procurement Policy (4 + 7 policy) on the drug expenditures of patients treated in outpatient and emergency departments in a large tertiary level-A hospital in China: A single centre, interrupted time series.

WHAT IS KNOWN AND OBJECTIVE: Like many countries in the world, China is also facing growing drug expenditures year by year. In particular, the rising cost of prescription drugs has been one of the critical factors leading to the serious burden on health insurance programs. The high cost of prescription drugs not only threatens the health budget but also limits the nation's investment in other public sectors. China implemented the National Centralized Drug Procurement (NCDP) policy, also known as the "4 + 7" policy, in tertiary hospitals in various provinces and cities across the country on 18 December 2019, aiming to lessen personal and national health insurance burdens by reducing drug procurement prices. The aim of this study is to explore the impact of the implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments and on national health insurance expenditures. METHODS: This study adopts interrupted time series (ITS) to evaluate the impact of China's implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments in a tertiary hospital. The NCDP policy was officially implemented on 18 December 2019. A segmented regression model is utilized to analyse the average monthly drug expenditures of patients treated in outpatient and emergency departments from January 2018 to June 2021, including the average monthly per-visit drug expenditures of all patients and the average monthly per-visit drug expenditures of patients who paid for drugs with health insurance and those who did not use health insurance. RESULTS: After the implementation of the NCDP policy, the overall average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments were immediately reduced by 233.954 CNY (p < 0.01). Compared with the continued downward trend for drug expenditures before the implementation of the NCDP policy, the long-term trend after policy implementation was not obvious (p = 0.051973>0.05). Similarly, the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments who use health insurance to procure drugs also immediately decreased by 505.287 CNY (p < 0.01), but the long-term trends before (p = 0.469>0.05) and after policy implementation (p = 0.51>0.05) did not exhibit obvious change. For the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments who did not use health insurance, the implementation of the NCDP policy did not produce an immediate reduction in drug expenditures (p = 0.3603>0.05). Although the average monthly per-visit drug expenditures decreased by 9.078 CNY (p < 0.01) before policy implementation, this trend ended after the policy was implemented (p = 0.0735>0.05), and no other changes were triggered. WHAT IS NEW AND CONCLUSION: This study reviews the data for a period of time before and after the implementation of the NCDP policy. The policy is shown to significantly decrease the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments.

PFOA regulate adenosine receptors and downstream concentration-response cAMP-PKA pathway revealed by integrated omics and molecular dynamics analyses.

As an important pollutant, perfluorooctane acid (PFOA) has been widely concerned and reported by thousands of times, while less is known about the concentration-response pathway of PFOA. The aim of the present work was to reveal the concentration-response mechanism of PFOA in human cells. Omics results showed that calcium-related pathways play key roles in PFOA injury mechanisms. The results of GO and KEGG analyses showed that the cAMP signaling pathway was presented as the top one in all of the regulatory patterns and concentrations groups of PFOA. In the cAMP signaling pathway, the adenosine A1 receptor (ADORA1) recognized the low concentration of PFOA and induced pathway "Gi-cAMP-PKA" to decrease the concentration of cAMP. This indicated that the low concentration of PFOA may promote breast hyperplasia and inhibit lactation. While adenosine A2A receptor (ADORA2A) recognized the high concentration of PFOA and induced pathway "GS-AC-cAMP-RKA" to increase the concentration of cAMP, induce cell damage and may lead to the deterioration of breast cancer. The results of molecular dynamics simulation showed that PFOA could bind to ADORA1 and ADORA2A, thus cause subsequent signal transduction. Furthermore, considering the strong binding ability of PFOA with ADORA1, PFOA tends to bind to ADORA1 at a low concentration. On the other side, PFOA at high concentration will continue to bind to another receptor protein, ADORA2A, and activate subsequent signaling pathways. Combined analyses of transcriptomic and proteomic revealed that different concentrations of PFOA regulate cellular calcium-related pathways. The cAMP pathway showed a concentration-response effect of PFOA. After treatment with different concentrations of PFOA, ADORA1 and ADORA2A were activated respectively, showing opposite cellular effects, leading to kinds of breast lesions. In the nervous system, PFOA might induce a variety of nervous system diseases. The present work was an exploration on the toxicological mechanism of PFOA, providing important information on the health impacts of PFOA in humans.

LsrB, the hub of ABC transporters involved in the membrane damage mechanisms of heavy ion irradiation in Escherichia coli.

BACKGROUND: Ionizing radiation, especially heavy ion (HI) beams, has been widely used in biology and medicine. However, the mechanism of membrane damage by such radiation remains primarily uncharacterized. PURPOSE: Transcriptomic profiles of Escherichia coli (E. coli) treated with HI illustrated the response mechanisms of the membrane, mainly ABC transporters, related genes regulated by antibiotics treatment through enrichment analyses of GO and KEGG. The networks of protein-protein interactions indicated that LsrB was the crucial one among the ABC transporters specially regulated by HI through the calculation of plugins MCODE and cytoHubba of Cytoscape. Finally, the expression pattern, GO/KEGG enrichment terms, and the interaction between nine LuxS/AI-2 quorum sensing system members were investigated. CONCLUSIONS: Above all, results suggested that HI might perform membrane damage through regulated material transport, inhibited LuxS/AI-2 system, finally impeded biofilm formation. This work provides further evidence for the role of ABC transporters, especially LsrB, in membrane damage of E. coli to HI. It will provide new strategies for improving the precise application of HI.

Omics analyses indicate the routes of lignin related metabolites regulated by trypsin during storage of pitaya (Hylocereus undatus).

The storage quality of Hylocereus undatus was significantly improved by trypsin, a novel preservative. The transcriptomic results revealed that antioxidant signal pathways were induced, while lignin catabolic process was impeded by trypsin. In addition, the results of protein-protein interaction (PPI) network networks suggested that flavone 3'-O-methyltransferase 1 (OMT1), ferulic acid 5-hydroxylase 1 (CYP84A1), cellulose synthase isomer (CEV1), and 4-coumarate-CoA ligase 3 (4CL3) act as hubs of peroxidases, lignin related proteins, and proteins involved in the phenylpropanoid metabolism (PLPs) induced by trypsin. Trypsin also regulated the biosynthesis of lignin, chlorogenic acid, and flavonoids. Caffeic acid might be the hub in the metabolic network of the early pathways of phenylpropanoid biosynthesis. It has been hypothesized that trypsin might quickly induce lignin biosynthesis and then up-regulated bioactive metabolites to enhance storage quality of H. undatus.

Entirely control the quality consistency of Rong'e Yishen oral liquid by both quantified profiling and quantitative analysis of multi-components by single marker method.

Quantified profiling and quantitative analysis of multi-components by single marker (QAMS) method were combined to control the quality consistency of Rong'e Yishen oral liquid (REYS) in this paper. Firstly, High Performance Liquid Chromatography (HPLC) with diode array detection (DAD) was applied to collect fingerprints and establish a content determination method. Then, two methods of QAMS and the external standard method (ESM) were used for comparative study to investigate the feasibility of the former to accurately control the quality of individual marker. The results showed that there was no significant difference in quantitative determination between QAMS and ESM (t test, P＞0.05). Sodium benzoate, as an internal reference standard (IRS), can be used to simultaneously quantify Icariin, Echinacoside, and Acteoside three components of the oral liquid. Finally, the fingerprint of 15 batches of REYSs was assessed by SQFM with Hierarchical clustering analysis (HCA). The result of the quality evaluation demonstrated that 15 batches were divided into 3 levels and had good quality consistency. What's more, the content percentage of the dominant three medicinal markers and their total amount presented a close correlation with the macro quantitative similarity (Pm) of samples. Thus, quantified profiling combined with QAMS, which is systematic, simple, rigorous, and objective, could be a novel method to evaluate the quality consistency of REYS or even other traditional Chinese medicine (TCM).

Catechin gallate acts as a key metabolite induced by trypsin in Hylocereus undatus during storage indicated by omics.

Trypsin is a novel superoxide scavenger. The storage quality of H. undatus was significantly improved by trypsin. To investigate the mechanism of flavonoid metabolism regulated by trypsin, combined analysis of widely targeted metabolomic and transcriptome were performed. GO and KEGG enrichment analyses of the transcriptome profiles of H. undatus revealed that some of the flavonoid related biosynthesis pathways were regulated by up or down patterns with the treatment of trypsin. Correlation analysis of flavonoid related genes expression in H. undatus provided a rationale for the functional significance of them. Furthermore, it has been revealed that the most significantly regulated flavonoid was catechin gallate in metabolomic profiles of H. undatus. The major route of flavonoid biosynthesis regulated by trypsin was also illustrated by both transcriptomic and metabolomic data. Finally, the results of PPI network revealed that C4H, HCT, and CYP75B1 acted as hub proteins involved in flavonoid metabolism regulated by trypsin.

Transcriptomic analysis reveals hub genes and subnetworks related to ROS metabolism in Hylocereus undatus through novel superoxide scavenger trypsin treatment during storage.

BACKGROUND: It was demonstrated in our previous research that trypsin scavenges superoxide anions. In this study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. RESULTS: Trypsin significantly delayed the weight loss and decreased the levels of ROS and membrane lipid peroxidation. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of ROS genes that were up- or downregulated following trypsin treatment by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The current results showed that through the regulation of the expression of hub redox enzymes, especially thioredoxin-related proteins, trypsin can maintain low levels of endogenous active oxygen species, reduce malondialdehyde content and delay fruit aging. In addition, the results of protein-protein interaction networks suggested that the downregulated NAD(P) H and lignin pathways might be the key regulatory mechanisms governed by trypsin. CONCLUSIONS: Trypsin significantly prolonged the storage life of H. undatus through regulatory on the endogenous ROS metabolism. As a new biopreservative, trypsin is highly efficient, safe and economical. Therefore, trypsin possesses technical feasibility for the quality control of fruit storage.

Transcriptomic Analysis Reveals Cu/Zn SODs Acting as Hub Genes of SODs in Hylocereus undatus Induced by Trypsin during Storage.

It has been revealed by us that superoxide scavenging is a new activity of trypsin. In this study, the synergistic mechanisms of trypsin and superoxide dismutases (SODs) were evaluated in Hylocereus undatus (pitaya). Trypsin significantly improved the storage quality of H. undatus, including weight loss impediment and decrease of cellular injury. The regulatory mechanisms of 16 SOD genes by trypsin were revealed using transcriptomic analysis on H. undatus. Results revealed that important physiological metabolisms, such as antioxidant activities or metal ion transport were induced, and defense responses were inhibited by trypsin. Furthermore, the results of protein-protein interaction (PPI) networks showed that besides the entire ROS network, the tiny SODs sub-network was also a scale-free network. Cu/Zn SODs acted as the hub that SODs synergized with trypsin during the storage of H. undatus.

Transcriptomic analysis reveals key genes related to antioxidant mechanisms of Hylocereus undatus quality improvement by trypsin during storage.

It has been revealed in our previous studies that trypsin scavenges superoxide anions. In the current study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. Strikingly, the improvement is due not to its antibacterial or antifungal activity but to its superoxide scavenging activity. Moreover, trypsin significantly decreased the levels of ROS, cell permeability and membrane lipid peroxidation. The activities of major antioxidant enzymes were significantly improved by trypsin treatment. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of antioxidant genes up or down-regulated following trypsin treatment by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The results of protein-protein interaction networks indicated that CAT is the key among the enzymes of the complicated antioxidant system. In addition, the current results showed that the synergistic effect of trypsin with antioxidant enzymes can regulate the levels of endogenous active oxygen species, reduce malondialdehyde content, improve cell membrane integrity, alleviate cell damage and delay fruit ageing.

Ammopiptanthus mongolicus stress-responsive NAC gene enhances the tolerance of transgenic Arabidopsis thaliana to drought and cold stresses.

Drought and cold are the primary factors limiting plant growth worldwide. The Ammopiptanthus mongolicus NAC11 (AmNAC11) gene encodes a stress-responsive transcription factor. Expression of the AmNAC11 gene was induced by drought, cold and high salinity. The AmNAC11 protein was localized in the nucleus and plays an important role in tolerance to drought, cold and salt stresses. We also found that differential expression of AmNAC11 was induced in the early stages of seed germination and was related to root growth. When the AmNAC11 gene was introduced into Arabidopsis thaliana by an Agrobacterium-mediated method, the transgenic lines expressing AmNAC11 displayed significantly enhanced tolerance to drought and freezing stresses compared to wild-type Arabidopsis thaliana plants. These results indicated that over-expression of the AmNAC11 gene in Arabidopsis could significantly enhance its tolerance to drought and freezing stresses. Our study provides a promising approach to improve the tolerance of crop cultivars to abiotic stresses through genetic engineering.

Exploring the membrane toxicity of decabromodiphenyl ethane (DBDPE): Based on cell membranes and lipid membranes model.

Decabromodiphenyl ethane (DBDPE) is widely used in industry as an alternative to the decabromodiphenyl ether (BDEs). The large-scale use of DBDPE could lead to rapid growth of the human accumulation level of DBDPE. However, the biophysics of accumulation of DBDPE in cell membranes, as one of determinants of DBDPE metabolism is not clear. In the present study, detailed observations of cell lactate dehydrogenase (LDH) and reactive oxygen species (ROS) levels measurements proved that the DBDPE exposure to cell could result in significant cell membrane damage by concentration-dependent manners. The fluorescence anisotropy analysis supported the evidence that high concentration DBDPE bound decreased membrane fluidity significantly. Besides it, a detailed molecular dynamic (MD) simulation was approached to investigate the effects of DBDPE on the DPPC (dipalmitoyl phosphatidylcholine) phospholipid bilayer, which was constructed as the model of cell membrane. The molecular dynamic simulation revealed that DBDPE molecules can easily enter the membrane from the aqueous phase. Under the concentration of a threshold, the DBDPE molecules tended to aggregate inside the DPPC bilayer and caused pore formation. The bound of high concentration of DBDPE could result in significant variations in DPPC bilayer with a less dense, more disorder and rougher layer. The knowledge about DBDPEs interactions with lipid membranes is fundamentally essential to understand the in vivo process of DBDPE and the physical basis for the toxicity of DBDPE in cell membranes.

Trypsin Slows the Aging of Mice due to Its Novel Superoxide Scavenging Activity.

Trypsin is an endogenous enzyme that is generally used as a proteinase. Intriguingly, we found that trypsin had superoxide scavenging activity. In the current study, our results showed that trypsin scavenges superoxide in either intracorporal or extracorporal systems. In the light of the porcupine plots of trypsin compounds generated by ProDy, the copper ion binds to trypsin and accelerates the superoxide scavenging activity of trypsin by increasing the stability of the structure. Furthermore, the data on the age-related parameters showed that the aging of mice could be slowed by trypsin, at least in part, due to its superoxide scavenging activity. These results suggested that trypsin is an effective superoxide scavenger and has potential as a novel agent to promote health and improve aging-associated pathologies.