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1.
New Phytol ; 243(4): 1329-1346, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38898642

RESUMEN

Drought-induced xylem embolism is a primary cause of plant mortality. Although c. 70% of cycads are threatened by extinction and extant cycads diversified during a period of increasing aridification, the vulnerability of cycads to embolism spread has been overlooked. We quantified the vulnerability to drought-induced embolism, pressure-volume curves, in situ water potentials, and a suite of xylem anatomical traits of leaf pinnae and rachises for 20 cycad species. We tested whether anatomical traits were linked to hydraulic safety in cycads. Compared with other major vascular plant clades, cycads exhibited similar embolism resistance to angiosperms and pteridophytes but were more vulnerable to embolism than noncycad gymnosperms. All 20 cycads had both tracheids and vessels, the proportions of which were unrelated to embolism resistance. Only vessel pit membrane fraction was positively correlated to embolism resistance, contrary to angiosperms. Water potential at turgor loss was significantly correlated to embolism resistance among cycads. Our results show that cycads exhibit low resistance to xylem embolism and that xylem anatomical traits - particularly vessels - may influence embolism resistance together with tracheids. This study highlights the importance of understanding the mechanisms of drought resistance in evolutionarily unique and threatened lineages like the cycads.


Asunto(s)
Cycadopsida , Sequías , Hojas de la Planta , Agua , Xilema , Xilema/fisiología , Xilema/anatomía & histología , Hojas de la Planta/anatomía & histología , Hojas de la Planta/fisiología , Cycadopsida/fisiología , Cycadopsida/anatomía & histología , Especificidad de la Especie
2.
Ecotoxicol Environ Saf ; 276: 116301, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38599159

RESUMEN

To study the heavy metal accumulation and its impact on insect exterior and chromosome morphology, and reveal the molecular mechanism of insects adapting to long-term heavy metal compound pollution habitats, this study, in the Diaojiang river basin, which has been polluted by heavy metals(HMs) for nearly a thousand years, two Eucriotettix oculatus populations was collected from mining and non-mining areas. It was found that the contents of 7 heavy metals (As, Cd, Pb, Zn, Cu, Sn, Sb) in E. oculatus of the mining area were higher than that in the non-mining 1-11 times. The analysis of morphology shows that the external morphology, the hind wing type and the chromosomal morphology of E. oculatus are significant differences between the two populations. Based on the heavy metal accumulation,morphological change, and stable population density, it is inferred that the mining area population has been affected by heavy metals and has adapted to the environment of heavy metals pollution. Then, by analyzing the transcriptome of the two populations, it was found that the digestion, immunity, excretion, endocrine, nerve, circulation, reproductive and other systems and lysosomes, endoplasmic reticulum and other cell structure-related gene expression were suppressed. This shows that the functions of the above-mentioned related systems of E. oculatus are inhibited by heavy metal stress. However, it has also been found that through the significant up-regulation of genes related to the above system, such as ATP2B, pepsin A, ubiquitin, AQP1, ACOX, ATPeV0A, SEC61A, CANX, ALDH7A1, DLD, aceE, Hsp40, and catalase, etc., and the down-regulation of MAPK signalling pathway genes, can enhanced nutrient absorption, improve energy metabolism, repair damaged cells and degrade abnormal proteins, maintain the stability of cells and systems, and resist heavy metal damage so that E. oculatus can adapt to the environment of heavy metal pollution for a long time.


Asunto(s)
Saltamontes , Metales Pesados , Contaminantes Químicos del Agua , Animales , Metales Pesados/toxicidad , Contaminantes Químicos del Agua/toxicidad , Saltamontes/efectos de los fármacos , Saltamontes/anatomía & histología , Monitoreo del Ambiente/métodos , Minería , China , Adaptación Fisiológica/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Ríos/química
3.
J Appl Clin Med Phys ; 25(6): e14279, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38259194

RESUMEN

BACKGROUND: Local recurrence in locally advanced pancreatic cancer (LAPC) after carbon-ion radiotherapy (CIRT) may partly attribute to low dose-averaged linear energy transfer (LETd), despite high CIRT dose. PURPOSE: This study aimed to investigate the approaches to up-modulate the CIRT LETd and to evaluate the corresponding oxygen enhancement ratio (OER) reduction. METHODS: 10 LAPCs that had been irradiated by CIRT with 67.5 Gy (RBE) in 15 fractions were selected. Their original plans were taken as the control plan for the LETd and OER investigations. Our considerations for up-modulating LETd were: (1) to deliver high doses to gross tumor volume core (GTVcore), while keeping dose constraints of the gastrointestinal (GI) tract in tolerance; (2) to put more Bragg-peak (BP) within the modulated targets; (3) to increase the BP density, high doses were necessary; (4) CIRT LETd could be effectively increased to small volumes; and (5) simultaneous integrated boost technique (SIB) could achieve the aforementioned tasks. The LETd and the corresponding OER distributions of each type of SIB plan were evaluated. RESULTS: We delivered up to 100 Gy (RBE) to GTVcore using SIB. The mean LETd of GTV increased significantly by 21.3% from 47.8 to 58.0 keV/µm (p < 0.05). Meanwhile, the mean OER of GTVcore decreased by 6.6%, from 1.51 to 1.41 (p < 0.05). The GI LETdS in all modulated plans were not more than those in the original plans. CONCLUSIONS: SIB could effectively increase CIRT LETd to LAPC, thus producing reduced OER, which may effectively overcome the radioresistance of LAPCs.


Asunto(s)
Radioterapia de Iones Pesados , Transferencia Lineal de Energía , Neoplasias Pancreáticas , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia de Intensidad Modulada , Neoplasias Pancreáticas/radioterapia , Humanos , Radioterapia de Iones Pesados/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Órganos en Riesgo/efectos de la radiación , Pronóstico
4.
Artículo en Inglés | MEDLINE | ID: mdl-39129076

RESUMEN

BACKGROUND: Gallstone disease (GSD), nonalcoholic fatty liver disease (NAFLD), metabolic dysfunction-associated fatty liver disease (MAFLD), and metabolic syndrome (MetS) are common medical disorders worldwide. This study aimed to ascertain how NAFLD, MAFLD, MetS, and other factors affect the development of GSD, and how the GSD-associated factors influence patient recovery after laparoscopic cholecystectomy (LC). METHODS: We included 200 patients who were diagnosed with GSD and underwent LC between January 2017 and February 2022. A total of 200 subjects without GSD and "non-calculous causes" during the same period were also included as controls. We compared the metabolic disorder differences between GSD patients and controls. Furthermore, we sub-grouped patients based on the comorbidities of preoperative NAFLD, MAFLD, and MetS, and compared the impacts of these comorbidities on short-term post-LC functional recovery of the patients. RESULTS: The prevalence of NAFLD and MetS were higher in GSD patients (P < 0.05). Based on multivariate logistic regression analysis, hyperglycemia [odds ratio (OR) = 2.2, 95% confidence interval (CI): 1.4-3.4, P = 0.001] and low high-density lipoprotein cholesterol (HDL-C) level (OR = 1.8, 95% CI: 1.1-3.1, P = 0.048) were linked to GSD. NAFLD and MetS linked to liver enzymes after LC (P < 0.05). MetS also linked to the levels of inflammatory indicators after LC (P < 0.05). The obesity, hyperlipidemia, low HDL-C level, and hyperglycemia linked to liver enzymes after LC (P < 0.05). Hyperlipidemia, low HDL-C level, and hypertension linked to inflammation after LC (P < 0.05). CONCLUSIONS: The prevalence of GSD may be linked to NAFLD and MetS. Hyperglycemia and low HDL-C level were independent risk factors of GSD.

5.
Artículo en Inglés | MEDLINE | ID: mdl-39019667

RESUMEN

BACKGROUND: The rate of distant metastasis in patients with pancreatic neuroendocrine tumors (PNETs) is 20%-50% at the time of initial diagnosis. However, whether tumor size can predict distant metastasis for PNETs remains unknown up to date. METHODS: We used Surveillance, Epidemiology, and End Results (SEER) population-based data to collect 6089 patients with PNETs from 2010 to 2019. The optimal cut-off point of tumor size to predict distant metastasis was calculated by Youden's index. Multivariate logistic regression analysis was used to figure out the association between tumor size and distant metastasis patterns. RESULTS: The most common metastatic site was liver (27.2%), followed by bone (3.0%), lung (2.3%) and brain (0.4%). Based on an optimal cut-off value of tumor size (25.5 mm) for predicting distant metastasis determined by Youden's index, patients were categorized into groups of tumor size < 25.5 mm and ≥ 25.5 mm. Multivariate logistic regression analyses showed that, compared with < 25.5 mm, tumor size ≥ 25.5 mm was an independent risk predictor of overall distant metastasis [odds ratio (OR) = 4.491, 95% confidence interval (CI): 3.724-5.416, P < 0.001] and liver metastasis (OR = 4.686, 95% CI: 3.886-5.651, P < 0.001). CONCLUSIONS: Tumor size ≥ 25.5 mm was significantly associated with more overall distant and liver metastases. Timely identification of distant metastasis for tumor size ≥ 25.5 mm may provide survival benefit for timely and precise treatment.

6.
J Integr Plant Biol ; 66(7): 1408-1426, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38578160

RESUMEN

Structural variations (SVs) are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress. In this study, we employed woolly grape (Vitis retordii), a species native to the tropical and subtropical regions of East Asia with both coastal and inland habitats, as a valuable model for examining the impact of SVs on local adaptation. We assembled a haplotype-resolved chromosomal reference genome for woolly grape, and conducted population genetic analyses based on whole-genome sequencing (WGS) data from coastal and inland populations. The demographic analyses revealed recent bottlenecks in all populations and asymmetric gene flow from the inland to the coastal population. In total, 1,035 genes associated with plant adaptive regulation for salt stress, radiation, and environmental adaptation were detected underlying local selection by SVs and SNPs in the coastal population, of which 37.29% and 65.26% were detected by SVs and SNPs, respectively. Candidate genes such as FSD2, RGA1, and AAP8 associated with salt tolerance were found to be highly differentiated and selected during the process of local adaptation to coastal habitats in SV regions. Our study highlights the importance of SVs in local adaptation; candidate genes related to salt stress and climatic adaptation to tropical and subtropical environments are important genomic resources for future breeding programs of grapevine and its rootstocks.


Asunto(s)
Vitis , Vitis/genética , Adaptación Fisiológica/genética , Genoma de Planta/genética , Genética de Población , Polimorfismo de Nucleótido Simple/genética , Tolerancia a la Sal/genética , Variación Estructural del Genoma/genética , Genómica , Genes de Plantas
7.
Trends Biotechnol ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38734565

RESUMEN

RNA sensing in vivo evaluates past or ongoing endogenous RNA disturbances, which is crucial for identifying cell types and states and diagnosing diseases. Recently, the CRISPR-driven genetic circuits have offered promising solutions to burgeoning challenges in RNA sensing. This review delves into the cutting-edge developments of CRISPR-powered RNA sensors in vivo, reclassifying these RNA sensors into four categories based on their working mechanisms, including programmable reassembly of split single-guide RNA (sgRNA), RNA-triggered RNA processing and protein cleavage, miRNA-triggered RNA interference (RNAi), and strand displacement reactions. Then, we discuss the advantages and challenges of existing methodologies in diverse application scenarios and anticipate and analyze obstacles and opportunities in forthcoming practical implementations.

8.
Huan Jing Ke Xue ; 45(3): 1665-1673, 2024 Mar 08.
Artículo en Zh | MEDLINE | ID: mdl-38471878

RESUMEN

Changes in soil nitrogen components in tea gardens affect the soil nitrogen supply capacity and nitrogen cycle. In this study, soil samples were collected from forest land, cultivated land, and tea gardens with different plantation ages (30, 50, and 70 years) to explore the changes in soil nitrogen components and their relationship with physicochemical properties and enzyme activities. The results showed that:① with the increase in tea plantation age, the silt, total phosphorus, and urease and catalase activities gradually increased, whereas the sand, clay, pH, electrical conductivity, soil organic carbon, and the activities of invertase gradually decreased. The alkaline phosphatase activity increased first and then decreased with the increase in tea plantation age, and no significant differences were observed in soil water content and acid phosphatase activity. ② With the increase in tea plantation age, the contents of acid ammonia nitrogen, amino acid nitrogen, and nitrate nitrogen (NO3--N) increased significantly, and the contents of total nitrogen, acid ammonia nitrogen, hydrolyzable unknown nitrogen, and non-hydrolyzable nitrogen in tea gardens were significantly higher than those in forest land. ③ The total phosphorus, alkaline phosphatase, and urease were the main factors affecting soil nitrogen components. Among them, organic nitrogen components were significantly correlated with total phosphorus and alkaline phosphatase, and inorganic nitrogen components were significantly correlated with alkaline phosphatase, whereas total nitrogen had significant correlations with sand, silt, total phosphorus, urease, and alkaline phosphatase.


Asunto(s)
Fosfatasa Alcalina , Suelo , Suelo/química , Arena , Nitrógeno/análisis , Carbono , Ureasa , Amoníaco , Fósforo/análisis , , Microbiología del Suelo , China
9.
Front Plant Sci ; 15: 1374925, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38606078

RESUMEN

Bud sport is a common and stable somatic variation in perennial fruit trees, and often leads to significant modification of fruit traits and affects the breeding value. To investigate the impact of bud sport on the main metabolites in the fruit of white-fleshed loquat, we conducted a multi-omics analysis of loquat fruits at different developmental stages of a white-fleshed bud sport mutant of Dongting loquat (TBW) and its wild type (TBY). The findings from the detection of main fruit quality indices and metabolites suggested that bud sport resulted in a reduction in the accumulation of carotenoids, fructose, titratable acid and terpenoids at the mature stage of TBW, while leading to the accumulation of flavonoids, phenolic acids, amino acids and lipids. The comparably low content of titratable acid further enhances the balanced and pleasent taste profile of TBW. Expression patterns of differentially expressed genes involved in fructose metabolism exhibited a significant increase in the expression level of S6PDH (EVM0006243, EVM0044405) prior to fruit maturation. The comparison of protein sequences and promoter region of S6PDH between TBY and TBW revealed no structural variations that would impact gene function or expression, indicating that transcription factors may be responsible for the rapid up-regulation of S6PDH before maturation. Furthermore, correlation analysis helped to construct a comprehensive regulatory network of fructose metabolism in loquat, including 23 transcription factors, six structural genes, and nine saccharides. Based on the regulatory network and existing studies, it could be inferred that transcription factors such as ERF, NAC, MYB, GRAS, and bZIP may promote fructose accumulation in loquat flesh by positively regulating S6PDH. These findings improve our understanding of the nutritional value and breeding potential of white-fleshed loquat bud sport mutant, as well as serve as a foundation for exploring the genes and transcription factors that regulate fructose metabolism in loquat.

10.
Huan Jing Ke Xue ; 45(1): 386-395, 2024 Jan 08.
Artículo en Zh | MEDLINE | ID: mdl-38216488

RESUMEN

Spatial prediction of the concentrations of soil heavy metals (HMs) in cultivated land is critical for monitoring cultivated land contamination and ensuring sustainable eco-agriculture. In this study, 32 environmental variables from terrain, climate, soil attributes, remote-sensing information, vegetation indices, and anthropogenic activities were used as auxiliary variables, and random forest (RF), regression Kriging (RK), ordinary Kriging (OK), and multiple linear regression (MLR) models were proposed to predict the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in cultivated soils. In comparison to those of RK, OK, and MLR, the RF model had the best prediction performance for As, Cd, Cr, Hg, Pb, and Zn, whereas the OK and RK models had highest prediction performance for Cu and Ni, respectively, showing that R2 was the highest, and mean absolute error (MAE) and root mean square error (RMSE) were the lowest. The prediction performance of the spatial distribution of soil HMs under different prediction methods was basically consistent. The high value areas of eight HMs concentrations were all distributed in the southern plain area. However, the RF model depicted the details of spatial prediction more prominently. Moreover, the importance ranking of influencing factors derived from the RF model indicated that the spatial variation in concentrations of the eight HMs in Lanxi City were mainly affected by the combined effects of Se, TN, pH, elevation, annual average temperature, annual average rainfall, distance from rivers, and distance from factories. Given the above, random forest models could be used as an effective method for the spatial prediction of soil heavy metals, providing scientific reference for regional soil pollution investigation, assessment, and management.

11.
Exp Ther Med ; 28(4): 390, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39161620

RESUMEN

Endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y gastrectomy and an intact major duodenal papilla is challenging and difficult, with unsatisfactory outcomes using various endoscopes. Limited data are available regarding the outcomes of ERCP using a pediatric colonoscope in such patients. To evaluate the efficacy of a pediatric colonoscope in patients with Roux-en-Y gastrectomy and an major duodenal intact papilla, 93 consecutive patients with Roux-en-Y gastrectomy and an intact major duodenal papilla who underwent ERCP using a pediatric colonoscope at the Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, (Nanjing, China) between January 2018 and December 2022 were retrospectively reviewed. Following the failure of bile duct cannulation, a double-guidewire or precut technique was utilized for advanced cannulation. Interventions were performed using standard ERCP therapeutic accessories. The results indicated that distal gastrectomy with Roux-en-Y reconstruction was performed in 38 out of 93 patients, while 55 patients underwent total gastrectomy with Roux-en-Y reconstruction. The success rates associated with endoscope insertion, endoscopic cannulation and therapeutic ERCP were 88.17% (82/93), 85.37% (70/82) and 95.71% (67/70), respectively, while the clinical intervention success and complication rates were 72.04% (67/93) and 7.53% (7/93), respectively. The endoscope insertion time was 40.78±10.04 min, and the ERCP procedure time was 88.55±16.38 min. Student's t-test showed that the endoscope insertion time and the ERCP procedure time in patients undergoing distal gastrectomy were longer than those in patients undergoing total gastrectomy (P<0.05). Binary logistic regression analysis showed that age and number of previous abdominal surgeries were independent risk factors associated with endoscope insertion failure. In conclusion, the present study demonstrated that the use of a pediatric colonoscope is efficacious and safe for patients with Roux-en-Y gastrectomy and an intact major duodenal papilla undergoing ERCP.

12.
EBioMedicine ; 100: 104962, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38184937

RESUMEN

BACKGROUND: Liver cirrhosis (LC) is the highest risk factor for hepatocellular carcinoma (HCC) development worldwide. The efficacy of the guideline-recommended surveillance methods for patients with LC remains unpromising. METHODS: A total of 4367 LCs not previously known to have HCC and 510 HCCs from 16 hospitals across 11 provinces of China were recruited in this multi-center, large-scale, cross-sectional study. Participants were divided into Stage Ⅰ cohort (510 HCCs and 2074 LCs) and Stage Ⅱ cohort (2293 LCs) according to their enrollment time and underwent Tri-phasic CT/enhanced MRI, US, AFP, and cell-free DNA (cfDNA). A screening model called PreCar Score was established based on five features of cfDNA using Stage Ⅰ cohort. Surveillance performance of PreCar Score alone or in combination with US/AFP was evaluated in Stage Ⅱ cohort. FINDINGS: PreCar Score showed a significantly higher sensitivity for the detection of early/very early HCC (Barcelona stage A/0) in contrast to US (sensitivity of 51.32% [95% CI: 39.66%-62.84%] at 95.53% [95% CI: 94.62%-96.38%] specificity for PreCar Score; sensitivity of 23.68% [95% CI: 14.99%-35.07%] at 99.37% [95% CI: 98.91%-99.64%] specificity for US) (P < 0.01, Fisher's exact test). PreCar Score plus US further achieved a higher sensitivity of 60.53% at 95.08% specificity for early/very early HCC screening. INTERPRETATION: Our study developed and validated a cfDNA-based screening tool (PreCar Score) for HCC in cohorts at high risk. The combination of PreCar Score and US can serve as a promising and practical strategy for routine HCC care. FUNDING: A full list of funding bodies that contributed to this study can be found in Acknowledgments section.


Asunto(s)
Carcinoma Hepatocelular , Ácidos Nucleicos Libres de Células , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/epidemiología , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/epidemiología , alfa-Fetoproteínas , Estudios Transversales , Detección Precoz del Cáncer/métodos , Ultrasonografía/métodos , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/complicaciones , Biomarcadores de Tumor
13.
J Hepatocell Carcinoma ; 10: 2411-2420, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38260186

RESUMEN

Purpose: Although laparoscopic splenectomy and azygoportal disconnection (LSD) can significantly decrease portal vein pressure and even the incidence of hepatocellular carcinoma (HCC) in patients with cirrhotic portal hypertension (CPH), postoperative HCC inevitably occurs in certain patients. The purpose of this study was to seek a novel preoperative non-invasive predictive indicator to predict the occurrence of postoperative HCC. Patients and Methods: From April 2012 to April 2022, we collected clinical data of 178 hepatitis B virus (HBV)-related CPH patients. Based on inverse treatment probability weighting, candidate variables for predicting postoperative HCC were determined by means analysis. Then, a novel preoperative non-invasive prediction indicator (ie, type IV collagen-alpha fetoprotein-fibrosis-4 score [IVAF-FIB-4]) was established based on candidate variables, and its predictive ability was explored. Results: Postoperative HCC occurred in 9 (5.1%) patients. Correlation analyses showed that the IVAF-FIB-4 had a significant positive correlation with HCC (r = 0.835, P < 0.001). IVAF-FIB-4 showed a high accuracy (the area under the receiver operating characteristic curve: 0.939, 95% confidence interval [CI]: 0.818-1.000; sensitivity: 88.9%; specificity: 93.5%). At the end of follow-up, the incidence density of HCC in patients with IVAF-FIB-4 (1) was significant higher than that in patients with IVAF-FIB-4 (0) (138.1/1000 vs 1.1/1000 person-years; rate ratio: 130.475, 95% CI: 16.318-1043.227). In logistic regression, IVAF-FIB-4 was an independent risk factor for HCC (odds ratio: 668.000, 95% CI: 53.895-8279.541; P < 0.001). Conclusion: IVAF-FIB-4 is a novel preoperative noninvasive predictive indicator for predicting postoperative HCC in HBV-related CPH patients after LSD, with satisfactory predictive ability.

18.
Braz. j. microbiol ; 44(3): 945-952, July-Sept. 2013. ilus, graf, tab
Artículo en Inglés | LILACS | ID: lil-699825

RESUMEN

It is well known that the type III secretion system (T3SS) and type III (T3) effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc) is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2) which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2) is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME). Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.


Asunto(s)
Sistemas de Secreción Bacterianos , Proteínas Bacterianas , Medios de Cultivo/química , Factores de Virulencia/metabolismo , Xanthomonas campestris/crecimiento & desarrollo , Xanthomonas campestris/metabolismo
19.
Braz. j. microbiol ; 44(3): 949-952, July-Sept. 2013.
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1469599

RESUMEN

It is well known that the type III secretion system (T3SS) and type III (T3) effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc) is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2) which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2) is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME). Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.


Asunto(s)
Receptores de Hormona Tiroidea , Western Blotting , Xanthomonas campestris , Glucuronidasa , Triyodotironina
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