Ralstonia solanacearum effector RipAK suppresses homodimerization of the host transcription factor ERF098 to enhance susceptibility and the sensitivity of pepper plants to dehydration.

Plants have evolved a sophisticated immune system to defend against invasion by pathogens. In response, pathogens deploy copious effectors to evade the immune responses. However, the molecular mechanisms used by pathogen effectors to suppress plant immunity remain unclear. Herein, we report that an effector secreted by Ralstonia solanacearum, RipAK, modulates the transcriptional activity of the ethylene-responsive factor ERF098 to suppress immunity and dehydration tolerance, which causes bacterial wilt in pepper (Capsicum annuum L.) plants. Silencing ERF098 enhances the resistance of pepper plants to R. solanacearum infection not only by inhibiting the host colonization of R. solanacearum but also by increasing the immunity and tolerance of pepper plants to dehydration and including the closure of stomata to reduce the loss of water in an abscisic acid signal-dependent manner. In contrast, the ectopic expression of ERF098 in Nicotiana benthamiana enhances wilt disease. We also show that RipAK targets and inhibits the ERF098 homodimerization to repress the expression of salicylic acid-dependent PR1 and dehydration tolerance-related OSR1 and OSM1 by cis-elements in their promoters. Taken together, our study reveals a regulatory mechanism used by the R. solanacearum effector RipAK to increase virulence by specifically inhibiting the homodimerization of ERF098 and reprogramming the transcription of PR1, OSR1, and OSM1 to boost susceptibility and dehydration sensitivity. Thus, our study sheds light on a previously unidentified strategy by which a pathogen simultaneously suppresses plant immunity and tolerance to dehydration by secreting an effector to interfere with the activity of a transcription factor and manipulate plant transcriptional programs.

Roles of CgEde1 and CgMca in Development and Virulence of Colletotrichum gloeosporioides.

Anthracnose, induced by Colletotrichum gloeosporioides, poses a substantial economic threat to rubber tree yields and various other tropical crops. Ede1, an endocytic scaffolding protein, plays a crucial role in endocytic site initiation and maturation in yeast. Metacaspases, sharing structural similarities with caspase family proteases, are essential for maintaining cell fitness. To enhance our understanding of the growth and virulence of C. gloeosporioides, we identified a homologue of Ede1 (CgEde1) in C. gloeosporioides. The knockout of CgEde1 led to impairments in vegetative growth, conidiation, and pathogenicity. Furthermore, we characterized a weakly interacted partner of CgEde1 and CgMca (orthologue of metacaspase). Notably, both the single mutant ΔCgMca and the double mutant ΔCgEde1/ΔCgMca exhibited severe defects in conidiation and germination. Polarity establishment and pathogenicity were also disrupted in these mutants. Moreover, a significantly insoluble protein accumulation was observed in ΔCgMca and ΔCgEde1/ΔCgMca strains. These findings elucidate the mechanism by which CgEde1 and CgMca regulates the growth and pathogenicity of C. gloeosporioides. Their regulation involves influencing conidiation, polarity establishment, and maintaining cell fitness, providing valuable insights into the intricate interplay between CgEde1 and CgMca in C. gloeosporioides.

CgCFEM1 Is Required for the Full Virulence of Colletotrichum gloeosporioides.

Colletotrichum gloeosporioides is widely distributed and causes anthracnose on many crops, resulting in serious economic losses. Common fungal extracellular membrane (CFEM) domain proteins have been implicated in virulence and their interaction with the host plant, but their roles in C. gloeosporioides are still unknown. In this study, a CFEM-containing protein of C. gloeosporioides was identified and named as CgCFEM1. The expression levels of CgCFEM1 were found to be markedly higher in appressoria, and this elevated expression was particularly pronounced during the initial stages of infection in the rubber tree. Absence of CgCFEM1 resulted in impaired pathogenicity, accompanied by notable perturbations in spore morphogenesis, conidiation, appressorium development and primary invasion. During the process of appressorium development, the absence of CgCFEM1 enhanced the mitotic activity in both conidia and germ tubes, as well as compromised conidia autophagy. Rapamycin was found to basically restore the appressorium formation, and the activity of target of rapamycin (TOR) kinase was significantly induced in the CgCFEM1 knockout mutant (∆CgCFEM1). Furthermore, CgCFEM1 was proved to suppress chitin-triggered reactive oxygen species (ROS) accumulation and change the expression patterns of defense-related genes. Collectively, we identified a fungal effector CgCFEM1 that contributed to pathogenicity by regulating TOR-mediated conidia and appressorium morphogenesis of C. gloeosporioides and inhibiting the defense responses of the rubber tree.

Association of preoperative electrocardiographic markers with sepsis in elderly patients after general surgery.

BACKGROUND: Electrocardiographic markers, as surrogates for sympathetic excitotoxicity, are widely predictive of cardiovascular adverse events, but whether these markers can predict postsurgical sepsis (SS) is unclear. METHODS: We retrospectively analyzed patients who underwent abdominal surgery from March 2013 to May 2023. We collected basic data, comorbidities, blood samples, echocardiology, electrocardiogram, and surgical data, as well as short-term outcome. The primary endpoints were postsurgical SS, in which logistic regression analyses can identify independent risk factors. The optimal cut-off value predictive postsurgical SS both P wave and PR interval were calculated in the receiver operating characteristic curve (ROC). RESULTS: A total of 1988 subjects were analyzed, and the incidence of postsurgical SS was 3.8%. The mean age at enrollment was 68.6 ± 7.1 years, and 53.2% of the participants were men. In the ROC analysis, the areas under the curve (AUC) for P wave and PR interval predictive postsurgical SS were 0.615 (95%CI, 0.548-0.683; p = 0.001) and 0.618 (95%CI, 0.554-0.682; p = 0.001), respectively. The P wave and PR interval predicted postoperative sepsis with optimal discrimination of 103 and 157 ms, with a sensitivity of 0.744 and 0.419, and a specificity of 0.427 and 0.760. P-wave less than 103 ms or PR interval less than 157 ms associated with a 2.06 or 2.33 fold increase occurred risk postsurgical SS. CONCLUSIONS: Shorter P-wave and PR intervals were both independently associated with postsurgical SS. These preoperative electrophysiological markers could have potential useful for early recognition of postoperative SS.

Impact of proton pump inhibitor management committee's multifaceted interventions on acid suppressant prescribing patterns in outpatient and emergency departments.

BACKGROUND: A nationwide campaign for rational proton pump inhibitor (PPI) use launched in 2015 had a positive impact for hospitalized patients PPI use. But there were few studies focusing on the rational use of PPIs in outpatients. In 2018, the PPI management committee conducted a year-long intervention on the appropriate use of PPIs in outpatient and emergency departments, including clinical pharmacist interventions and stewardship interventions. The purpose of this study was to examine the impact of the PPI management committee's multifaceted interventions by comparing the real-world acid suppressant prescribing patterns for outpatients before (2017) and after intervention (2019) at a Chinese tertiary teaching hospital. METHODS: Prescriptions containing any acid suppressant in outpatient and emergency departments in baseline (2017) and postintervention (2019) periods were extracted from the hospital information system and the prescription automatic screening system. Acid suppressant prescribing patterns were evaluated based on primary diagnoses and patient demographics. The prescribed acid suppressants stratified using age groups (< 7, 7-17, 18-45, 46-65, 66-85 and > 85 years) were also examined. RESULT: The utilization rate of acid suppressant in 2017 and 2019 was 2.5% (41,165/1,619,366) and 2.2% (49,550/2,236,471), respectively (P < 0.0001). 60,135 acid suppressant prescriptions were obtained in 2017 and 73,275 in 2019. The rate of acid suppressant prescriptions for the approved indications significantly increased from 62.6% (2017) to 65.4% (2019) (P < 0.0001). Prescriptions diagnosed as abnormal symptoms, signs and clinical manifestations, decreased in 2019 (13.0% vs. 16.5%, P < 0.0001). The most frequently prescribed PPIs differed between 2017 and 2019 (rabeprazole 2017 vs. esomeprazole 2019). Omeprazole was the most common PPI and cimetidine was the most common H2RA prescribed to patients aged < 18 years in 2017 and 2019. A total of CNY11.83 million was spent on acid suppressants in 2019, accounting for about 48.7% of total medication cost, increased by 11.3% from 2017 (37.4%). CONCLUSION: The proportion of acid suppressant prescriptions for approved indications was enhanced after the PPI management committee's multifaceted interventions, but there were still some problems in the selection of acid suppressants.

The CD68+ macrophages to CD8+ T-cell ratio is associated with clinical outcomes in hepatitis B virus (HBV)-related hepatocellular carcinoma.

BACKGROUND: Tumor microenvironment plays an essential role during the progression of hepatocellular carcinoma (HCC). Tumor infiltrating immune cells (TILs) was an important component of tumor microenvironment. However, whether TIL features are correlated with the prognosis of HCC patients remains unclear. METHODS: Cancer tissue and paired paracancerous tissues from 220 stage II∼III HBV-related HCC patients were collected. TILs were analyzed using a tyramide signal amplification system combined with immunohistochemistry. Kaplan-Meier survival analysis was conducted to investigate the associations between the prognosis and the infiltrating pattern of TILs. RESULTS: The patients were classified into three distinct subgroups (Clusters (C)1-3) with different overall survival (OS) and disease-free survival (DFS) according to the distribution pattern of TILs. The CD68/CD8 ratio in the cancer SA was correlated with the prognosis. Patients with a higher CD68/CD8 ratio exhibited poorer OS and DFS than those with a lower ratio. The CD68/CD8 ratio in the cancer SA was an independent factor for OS prediction but not DFS. CONCLUSION: CD68+ macrophages and CD8+ T-cells are essential immunological determinants for HBV-related HCC prognosis, and the CD68/CD8 ratio in cancer SA is a novel, prognostic factor for OS prediction in HBV-related HCC patients.

Label free proteomics and systematic analysis of secretome reveals effector candidates regulated by SGE1 and FTF1 in the plant pathogen Fusarium oxysporum f. sp. cubense tropical race 4.

BACKGROUND: Phytopathogens secreted effectors during host colonization to suppress or trigger plant immunity. Identification of new effectors is one of the research focuses in recent years. There is only a limited knowledge about effectors of Fusarium oxysporum f. sp. Cubense tropical race 4 (Foc TR4), the causal agent of wilt disease in Cavendish banana. RESULTS: Two transcription factors, SGE1 and FTF1, were constitutively over-expressed in Foc TR4 to partially mimic the in-planta state. Secreted proteins with high purity were prepared through a two-round extraction method. Then the secretome were analyzed via label free proteomics method. A total of 919 non-redundant proteins were detected, of which 74 proteins were predicted to be effector candidates. Among these candidates, 29 were up-regulated and 13 down-regulated in the strain over-expressing SGE1 and FTF1, 8 were up-regulated and 4 down-regulated in either SGE1 or FTF1 over expression strain. CONCLUSIONS: Through label free proteomics analysis, a series of effector candidates were identified in secretome of Foc TR4. Our work put a foundation for functional research of these effectors.

Toll-like receptor protein 4 monoclonal antibody inhibits mmLDL-induced endothelium-dependent vasodilation dysfunction of mouse mesenteric arteries.

Minimally modified low-density lipoprotein (mmLDL) is a risk factor for cardiovascular disease. This study was designed to investigate the effect of a Toll-like receptor 4 monoclonal antibody (TLR4 mAb) on mmLDL-induced endothelium-dependent vasodilation (EDV) impairment in mouse mesenteric arteries and to explore the underlying mechanism. Animals were divided into a normal control group, an mmLDL treatment group, and a TLR4 mAb intervention group. The serum concentrations of IL-1ß and TNF-α were detected using enzyme-linked immunosorbent assays (ELISAs). EDV function was measured using a microvascular tension tracing method. The protein levels and mRNA expression of IL-1ß and TNF-α in vascular tissue were detected using western blot analysis and reverse transcription polymerase chain reaction, respectively. TLR4 mAb improved mmLDL-induced EDV functional impairment in a dose-dependent manner. TLR4 mAb significantly upregulated KCa3.1 and KCa2.3 channel protein levels and downregulated TNF-α and IL-1ß expression. These effects were possibly associated with the competitive antagonism of TLR4 mAb on the TLR4 signaling pathway and the downstream NF-κB p65 and p38 MAPK pathways, which are activated by mmLDL. In conclusion, pretreatment with TLR4 mAb lessens mmLDL-induced EDV dysfunction and inhibits overexpression of inflammatory factors. Regulation of the TLR4 pathway, as well as its downstream NF-κB p65 and p38 MAPK pathways, may be an effective strategy for the prevention and treatment of cardiovascular diseases.

HbWRKY40 plays an important role in the regulation of pathogen resistance in Hevea brasiliensis.

KEY MESSAGE: Overexpression of HbWRKY40 induces ROS burst in tobacco and increases disease resistance in Arabidopsis; RNA-seq and ChIP assays revealed the regulatory network of HbWRKY40 in plant defense. WRKY, a family of plant transcription factors, are involved in the regulation of numerous biological processes. In rubber tree Hevea brasiliensis, the roles of WRKYs remain poorly understood. In the present study, a total of 111 genes encoding putative HbWRKY proteins were identified in the H. brasiliensis genome. Among these genes, HbWRKY40 transcripts were significantly induced by Colletotrichum gloeosporioides and salicylic acid. To assess its roles in plant defense, HbWRKY40 was over-expressed in Nicotiana benthamiana and Arabidopsis thaliana. The results showed that HbWRKY40 significantly induced reactive oxygen species burst in N. benthamiana and increased resistance of Arabidopsis against Botrytis cinerea. Transient expression in mesophyll cell protoplasts of H. brasiliensis showed that HbWRKY40 localizes at nuclei. In addition, transcripts of 145 genes were significantly up-regulated and 6 genes were down-regulated in the protoplasts over-expressing HbWRKY40 based on the RNA-seq analysis. Among these potential downstream targets, 12 genes contain potential WRKY-binding sites at the promoter regions. Further analysis through chromatin immunoprecipitation revealed that 10 of these 12 genes were the downstream targets of HbWRKY40. Taken together, our findings indicate that HbWRKY40 plays an important role in the disease resistance by regulating defense-associated genes in H. brasiliensis.

Awareness, attitude and behavior regarding proton pump inhibitor among medical staff in the Southwest of China.

BACKGROUND: Proton pump inhibitors (PPIs) are one of the most frequently prescribed classes of drug in the world and there is a growing number of publications on correct versus incorrect use of PPIs worldwide. The knowledge of PPIs among the medical staff is essential for improving the rationality of PPI application. The present study aimed to investigate awareness, attitude and behavior toward PPI use among medical staff in the Southwest of China. METHODS: The present descriptive-analytical study was conducted on 900 medical staff from three professional groups (300 doctors, 300 nurses and 300 pharmacists) in China. The study data were collected through a self-designed questionnaire which included demographics, awareness, attitude and behavior toward PPI use. The study was carried out in 22 hospitals in Luzhou between February and June 2018. RESULTS: Of 900 surveys issued, 851valid questionnaires (295doctors, 268 nurses and 288 pharmacists) were returned. Of all respondents, 33.25% were men and 66.75% were women. The score related to PPI awareness score of medical staff was low (59.47 ± 15.75). The level of awareness of pharmacist was significantly higher than that of doctors and nurses (P < 0.01), which was related to gender, age, occupation, educational level, professional title, hospital nature and hospital grade. Similarly, on the attitude towards PPI use, the pharmacists scored also significantly higher than doctors and the nurses (P < 0.01). Three hundred eighty-one of 851 medical staff had used PPI in the past 1 year, of which omeprazole was the most widely used. Among doctors, nurses and pharmacists, the usage rate of PPI was 50.85, 42.16, 40.97%, respectively. The use frequency was related to occupation and professional title. The score about the behavior toward PPIs of the nurses was also significantly lower than that of doctors and pharmacists (P < 0.01). CONCLUSIONS: The study indicated that the medical staff lack of awareness concerning rational use of PPI in China, especially nurse. Thus, it is necessary to call for action on the improvement of PPI awareness and medication-taking behaviors to reduce PPI overuse and to promote the rationality of PPI application.

AtKATANIN1 Modulates Microtubule Depolymerization and Reorganization in Response to Salt Stress in Arabidopsis.

The microtubule cytoskeleton is a dynamic system that plays vital roles in fundamental cellular processes and in responses to environmental stumili. Salt stress induced depolymerization and reorganization of microtubules are believed to function in the promotion of survival in Arabidopsis. Microtubule-severing enzyme ATKATANIN1 (AtKTN1) is recognized as a MAP that help to maintain organized microtubule structure. To date, whether AtKTN1 is involved in response to salt stress in Arabidopsis remains unknown. Here, our phenotypic analysis showed that the overexpression of AtKTN1 decreased tolerance to salt stress, whereas the knock-out of AtKTN1 increased salt tolerance in the early stage but decreased salt tolerance in the later stage. Microscopic analysis revealed that microtubule organization and dynamics are distorted in both overexpression and mutant cells which, in turn, resulted in an abnormal disassembly and reorganization under salt stress. Moreover, qRT analysis revealed that stress-responsive genes were down-regulated in overexpression and mutant cells compared to WT cells under salt stress. Taken together, our results indicated roles of AtKTN1 in modulating microtubule organization, salt-stress induced microtubule disruption and recovery, and its involvement in stress-related signaling pathways.

A Colletotrichum gloeosporioides cerato-platanin protein, CgCP1, contributes to conidiation and plays roles in the interaction with rubber tree.

Colletotrichum gloeosporioides is the causal agent of rubber tree anthracnose and leads to serious losses of natural rubber production. The pathogenesis of C. gloeosporioides on rubber tree remains unknown. Cerato-platanin proteins are small, secreted cysteine-rich proteins that contribute to virulence and function in plant-fungal interactions. A gene encoding cerato-platanin protein, CgCP1, was identified in C. gloeosporioides. In silico analysis indicated that CgCP1 belongs to a new branch of the cerato-platanin protein family. The CgCP1 knockout mutants (ΔCgCP1) and complementary strain (Res-ΔCgCP1) were generated to investigate its biological function. The results showed that the speed of growth of aerial hyphae was not significantly different among the wild-type (WT), ΔCgCP1, and Res-ΔCgCP1 strains, but conidiation of ΔCgCP1 significantly decreased in comparison with the WT. The pathogenicity test proved that the severity of symptoms caused by ΔCgCP1 was reduced significantly compared with those caused by the Res-ΔCgCP1 and WT strains. Additionally, CgCP1 induced necrosis-like cell death on tobacco leaf and accumulation of reactive oxygen species in rubber tree mesophyll protoplasts. Altogether, these data indicate the involvement of C. gloeosporioides CgCP1 in conidiation and the interaction with rubber tree.

SGE1 is involved in conidiation and pathogenicity of Fusarium oxysporum f.sp. cubense.

The ascomycete fungus Fusarium oxysporum f.sp. cubense race 4 (Foc TR4) causes vascular wilt diseases in banana (Musa spp.). In the present study, the role of SGE1 in regulating growth, conidiation, and pathogenicity of Foc TR4 was investigated. Deletion of SGE1 did not influence vegetative growth but impaired the conidiation of Foc TR4. Besides, the SGE1 deletion mutant basically lost pathogenicity on banana plantlets. Observation under the microscope indicated that the penetration and colonization processes were severely impaired in the SGE1 deletion mutant. Proteomics analysis suggested that SGE1 regulated the production of a series of proteins of Foc TR4. Taken together, our results suggest that SGE1 plays an important role in regulating conidiation and pathogenicity in fungal pathogen Foc TR4.

Changes in proton pump inhibitor prescribing trend over the past decade and pharmacists' effect on prescribing practice at a tertiary hospital.

BACKGROUND: Proton pump inhibitors (PPIs) remain one of the world's most frequently prescribed medications and there is a growing number of publications on correct versus incorrect use of PPIs worldwide. The objective of this observational retrospective study was to assess changes in PPI prescribing trends over the past decade and pharmacists' effect on optimizing PPI prescribing practice at a tertiary hospital in China. METHODS: We collected the prescriptions of PPIs in our hospital from January 2007 to December 2016. Then the rate of PPI prescribing, the defined daily doses (DDDs) and expenditures were calculated and plotted to show the change in utilization of and expenditure on PPIs. Reasons behind this change and effect of pharmacists' intervention were evaluated by investigating the rationality of PPI use through sample surveys of patients of pre-intervention (Jul.-Dec. 2015) and post-intervention (Jul.-Dec. 2016). RESULTS: In outpatient settings, the rate of PPI prescribing remained almost constant, utilization (from 135,808 DDDs to 722,943 DDDs) and expenditure (from 1.85 million CNY to 7.96 million CNY) increased for the past ten years, dominated by oral formulations and rabeprazole. In contrast, in inpatient settings, the rate of PPI prescribing (from 20.41 to 37.21%), utilization (from 132,329 DDDs to 827,747 DDDs) and expenditure (from 3.15 million CNY to 25.29 million CNY) increased from 2007 to 2015 and then decreased, dominated by injection formulations and omeprazole. Pharmacist interventions could significantly promote the rational use of PPIs (44.00% versus 26.67%), decrease PPI use and reduce patients' charges (P < 0.05). CONCLUSIONS: The utilization of and expenditure on PPIs grew due to the increase of patients and irrational use of PPI. Pharmacist interventions help to reduce PPI utilization and expenditure and enhance rationality for inpatients, but much work should be done to regulate injection and originator formulas, and improve the rationality in the future.

BAS2 Is Required for Conidiation and Pathogenicity of Colletotrichum gloeosporioides from Hevea brasiliensis.

The hemibiotrophic fungi Colletotrichum gloeosporioides can cause anthracnose in rubber trees. By searching the genome of the fungal pathogen, the BAS2 encoding a biotrophy-associated secreted protein was identified. In the present study, the knockout mutants of BAS2 were constructed and the functions of BAS2 were investigated. The in vitro assays showed that BAS2 was not necessary for vegetative growth but was important for normal asexual reproduction in C. gloeosporioides. Pathogenicity assays suggested that BAS2 was involved in the process of the pathogen penetrating into the host tissue. Subcellular localization analysis revealed that BAS2 showed secretional characteristics in the fungi, and BAS2 mainly function as a cytoplasmic protein after being secreted into the host cell. Extracellular proteomics analysis revealed that BAS2 was required for the secretion of a series of proteins, which were important for the pathogenicity of C. gloeosporioides. These data lead to a better understanding of the biotrophy-associated secreted protein in regulating the pathogenesis of C. gloeosporioides.

High Concentration of Melatonin Regulates Leaf Development by Suppressing Cell Proliferation and Endoreduplication in Arabidopsis.

N-acetyl-5-methoxytryptamine (Melatonin), as a crucial messenger in plants, functions in adjusting biological rhythms, stress tolerance, plant growth and development. Several studies have shown the retardation effect of exogenous melatonin treatment on plant growth and development. However, the in vivo role of melatonin in regulating plant leaf growth and the underlying mechanism are still unclear. In this study, we found that high concentration of melatonin suppressed leaf growth in Arabidopsis by reducing both cell size and cell number. Further kinetic analysis of the fifth leaves showed that melatonin remarkably inhibited cell division rate. Additionally, flow cytometic analysis indicated that melatonin negatively regulated endoreduplication during leaf development. Consistently, the expression analysis revealed that melatonin regulated the transcriptional levels of key genes of cell cycle and ribosome. Taken together, this study suggests that high concentration of melatonin negatively regulated the leaf growth and development in Arabidopsis, through modulation of endoreduplication and the transcripts of cell cycle and ribosomal key genes.

Dynamic variation of bioactive compounds and aflatoxins in contaminated Radix Astragali during extraction process.

BACKGROUND: Although increasing attention has been paid to the health threat caused by mycotoxins in commodities such as food or medicines, mycotoxin transfer processes from crude material to products have raised little concern so far. Radix Astragali is a commonly used edible and medicinal herbal plant that is susceptible to contamination with aflatoxins from Aspergillus flavus. There have been no studies on mycotoxin transfer into pharmaceutical preparations or derivative products. RESULTS: To facilitate the aflatoxin reduction and bioactivity retention, the dynamic variations of aflatoxins as well as herbal compounds, namely calycosin-7-glucoside, astragaloside and formononetin, in Radix Astragali contaminated by A. flavus during water decoction and ethanol refluxing treatments were evaluated simultaneously by an ultra-fast liquid chromatography-triple quadrupole linear ion trap mass spectrometry method. After the extraction processes, although the amount of alfatoxins was reduced remarkably, aflatoxin residuals in preparation still exceed recommended limits, manifesting the great need to establish a limit for aflatoxins in herbal extractions or derivative products. Meanwhile, due to the hydrolysis of glucoside, water decoction period should be no longer than 4 h. CONCLUSIONS: This investigation would benefit from the determination of the dynamic variation of aflatoxins in infected herbs in preparation treatments, in order to further develop aflatoxin limits in herbal preparations.

Simultaneous determination of four aflatoxins and ochratoxin A in ginger after inoculation with fungi by ultra-fast liquid chromatography-tandem mass spectrometry.

BACKGROUND: Aflatoxins (AFs) and ochratoxin A (OTA) have been detected frequently in food, agricultural products and traditional Chinese medicines, and their presence poses serious health and economic problems worldwide. Ginger can easily be polluted with mycotoxins. In this study, ginger samples were cultivated for 15 days after inoculation with fungi and were prepared based on ultrasound-assisted solid-liquid extraction using methanol/water followed by immunoaffinity column clean-up and analysed by ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) for AFs and OTA. RESULTS: The limits of detection and quantification of AFs and OTA were 0.04-0.30 µg mL(-1) and 0.125-1.0 µg mL(-1) , respectively. The recoveries were 82.0-100.2%. After 15 days' cultivation, no macroscopic mildew was found in ginger. But, the content of AFB1 expressed an increasing trend in ginger, peel [less than the limit of quantification (LOQ)] to the innermost layer (51.86 µ mL(-1) ), AFB2 was only detected in the innermost layer at the level of 0.87 µ mL(-1) . A small amount (

Quality evaluation of Salvia miltiorrhiza Bge. by ultra high performance liquid chromatography with photodiode array detection and chemical fingerprinting coupled with chemometric analysis.

UNLABELLED: An ultra high performance liquid chromatography with photodiode array detection method is developed for the simultaneous quantitative determination of five water-soluble compounds including danshensu, protocatechualdehyde, rosmarinic acid, salvianolic acid B, and salvianolic acid A in Salvia miltiorrhiza Bge. SAMPLES: Through method optimization, the five compounds all expressed good linearity (R(2) > 0.9990) in a wide concentration range together with satisfactory accuracy, precision, and stability. Moreover, through qualitative analysis of the chemical fingerprint combined with similarity analysis, hierarchical cluster analysis, principle component analysis, and partial least-squares discriminate analysis, we determined that the 13 batches of Salvia miltiorrhiza Bge. were similar in internal quality and the differences resulted from various cultivation environments, recovery elements, and others. Seen from the results of hierarchical cluster analysis and principle component analysis, the classification of 13 batches was in accordance, and partial least-squares discriminate analysis technique was more suitable than the principle component analysis model to provide a distinct classification of test samples on the basis of their different components. Moreover, a permutation test verified the rationality of partial least-squares discriminate analysis and variable importance plot showed that peaks 37 and 38 were the most significant variables in distinguishing the Salvia miltiorrhiza Bge. SAMPLES: The idea of the quantitative and qualitative analysis of Salvia miltiorrhiza Bge. was convenient, sensitive, and comprehensive, which could be applied to evaluate the quality of more traditional Chinese medicines.

The Xanthomonas campestris effector protein XopDXcc8004 triggers plant disease tolerance by targeting DELLA proteins.

Plants protect themselves from the harmful effects of pathogens by resistance and tolerance. Disease resistance, which eliminates pathogens, can be modulated by bacterial type III effectors. Little is known about whether disease tolerance, which sustains host fitness with a given pathogen burden, is regulated by effectors. Here, we examined the effects of the Xanthomonas effector protein XopDXcc8004 on plant disease defenses by constructing knockout and complemented Xanthomonas strains, and performing inoculation studies in radish (Raphanus sativus L. var. radiculus XiaoJinZhong) and Arabidopsis plants. XopDXcc8004 suppresses disease symptoms without changing bacterial titers in infected leaves. In Arabidopsis, XopDXcc8004 delays the hormone gibberellin (GA)-mediated degradation of RGA (repressor of ga1-3), one of five DELLA proteins that repress GA signaling and promote plant tolerance under biotic and abiotic stresses. The ERF-associated amphiphilic repression (EAR) motif-containing region of XopDXcc8004 interacts with the DELLA domain of RGA and might interfere with the GA-induced binding of GID1, a GA receptor, to RGA. The EAR motif was found to be present in a number of plant transcriptional regulators. Thus, our data suggest that bacterial pathogens might have evolved effectors, which probably mimic host components, to initiate disease tolerance and enhance their survival.