Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Plant Dis ; 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35522954

RESUMEN

Bellis perennis L., commonly known as the daisy or sun chrysanthemum, belonging to the family Asteraceae, is a perennial herb and is usually used as an ornamental plant worldwide for its vibrant flowers. Simultaneously, B. perennis has been proved to have therapeutic effects used on common colds, wound healing, anti-tumor, anxiolytic and antioxidant (Karakas et al. 2017). In July 2021, typical leaf spot was observed on B. perennis with about 50% disease incidence in Ruyue lake wetland park of Zibo (36.71°N, 118.01°E), Shandong Province, China. We surveyed more than 1000 square meters of planting area, and the diseased leaves were mostly concentrated in the lower location of plants, where the humidity was higher under the forest. Symptoms on the initially diseased leaves appeared as light yellow, round or oval lesions with light or brown borders. With the development of the disease, the area of the lesion gradually expands, the color deepens, and the shape is becoming irregular. To identify the causal pathogen, small pieces of 15 tissues collected from the infected leaves were sterilized with 75% ethanol for 30 s and then 2% sodium hypochlorite (NaClO) for 60 s, finally rinsed with sterile water three times. All the tissues were placed on potato dextrose agar (PDA) and incubated at 25 ℃ in the dark for 5 days (Zhu et al. 2013). A total of 13 isolates were obtained from the above diseased leaves. The cultures were initially grayish white, then a light green halo appeared in the middle of the medium after 5 days, with numerous gray aerial hyphae. For molecular identification, the RNA polymerase II beta subunit (PRB2), Tsr ribosome biogenesis protein, partial coding sequences of chitin synthase, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and major allergen Alt a 1 were amplified from genomic DNA extracted from four representative single isolates using the primers PRB2DF/PRB2DR, Tsr1F/Tsr1R, CHSDF1/CHSDR1, GDF1/GDR1, and AltF/AltR (Damn et al. 2019; Lawrence et al. 2013), respectively, and sequenced (GenBank accession nos. OL416000, OL416001, OL416002, OL416003, and OL416004). These genes had more than 99.9% nucleotide identity with the corresponding sequences (KY131957.1, KY131958.1, KY996470.1, MN657411.1, and KY923227.1) of the reference strains of Alternaria alternata in GenBank. For pathogenicity tests, five healthy B. perennis plants each with three living leaves were inoculated with mycelial plugs of A. alternata from a 5-day-old culture grown on PDA. After inoculation, the plants were placed in a greenhouse with 85% relative humidity at 25 ℃ and monitored daily for symptom development. After 3 days, all inoculated leaves with mycelial plugs of A. alternata appeared symptoms similar to those observed in the field previously, while no symptoms appeared on negative controls which were inoculated with sterile PDA plugs. Cultures re-isolated from diseased leaves had the same morphological and molecular results as those isolated in the field, confirming Koch's postulates. The causal agent on B. perennis was confirmed as A. alternata on the basis of morphological and molecular results (Simmons 2007). To our knowledge, this is the first report on the presence of A. alternata affecting B. perennis plants in China. The discovery of this new disease is beneficial to the application and protection of B. perennis, which is a popular landscape and medicinal plant.

2.
Plant Dis ; 2022 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-36089683

RESUMEN

Gaillardia pulchella Foug., belonging to the family Asteraceae, is an annual herb commonly seen in tropical America and China. It is often used as ornamental flowers because of its bright color, long flowering period and simple cultivation and management. In June 2021, leaf spot on G. pulchella with ∼40% disease incidence was observed in Laoshan scenic spot of Qingdao, Shandong Province, China. Initial symptoms on leaves appeared as light yellow to brown round or oval spots with dark brown borders, and the lesion area gradually expanded and the color deepened with the development of the disease. Small tissue samples collected from the infected lesions were surface-sterilized with 70% ethanol for 30 s, then rinsed with 2% sodium hypochlorite (NaClO) for 60 s, and finally rinsed with sterilized water three times. All the samples were transferred to potato dextrose agar (PDA) medium and incubated at 25℃ in the dark for 5 days (Zhu et al. 2013). A total of 9 isolates were obtained from the 11 selected tissues of symptomatic leaves. Afterward, all the single spore isolates were transferred onto potato carrot agar (PCA) plates (Mirkova 2003). After 7 to 10 days of incubation on PCA at 25℃ in the dark, colonies had a cottony mycelium with round margins, colored in white to gray. To test pathogenicity, six healthy G. pulchella plants were inoculated with mycelial plugs of the above pure cultures from a 7-day-old culture grown on PCA, while six germfree PCA plugs were served as negative controls. All the inoculated plants were set in greenhouse incubator at 25℃ and 80% relative humidity. Following 5 days incubation, brown spots began to appear on the sites of all inoculated leaves with mycelial plugs, while all the negative controls inoculated with sterile PCA plugs remained healthy. Infected lesions were separated and cultured as the same as those isolated in the field, and the same isolate was again microscopically identified, fulfilling Koch's postulates. 5 isolates were characterized, the colony margins of single spore isolate were round with gray or black aerial mycelia. Conidia were clustered and unbranched with 1 to 4 septa, colored in light or dark brown, shaped in obclavate or ellipsoid with short conical beak at the tip, dimensions varied from 14 to 51 µm (length) × 4.5 to 11 µm (width). The described morphological characteristics were consistent with Alternaria alternata (Simmons 2007). For further identification of molecular characterization, the genes of Chitin synthase (CHSD), RNA polymerase II second largest subunit (PRB2), Tsr1 ribosome biogenesis protein (Tsr1) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were obtained by PCR amplification with the primer pairs CHSDF1/CHSDR1, PRB2DF/PRB2DR, Tsr1F/Tsr1R and GAPDHF1/GAPDHR1 (Damn et al. 2019; Lawrence et al. 2013), respectively. The sequenced genes (GenBank accession nos. ON660874, ON660875, ON660876 and ON660877) had more than 99% nucleotide identity with the corresponding genes (GenBank accession nos. KY996470.1, MN304718.1, KY996472.1 and MN158133.1) of the reference strains of A. alternata in GenBank, and the re-inoculated and re-isolated strains have the same results which were repeated three times. The causal agent occurred on G. pulchella was identified as A. alternata based on the morphological and molecular characteristics. To our knowledge, this is the first record causing leaf spot on G. pulchella by A. alternata in China.

3.
Plant Dis ; 105(5): 1356-1364, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33258433

RESUMEN

Photinia (Photinia × fraseri Dress) is a well-known green plant that has high ornamental value and is widely distributed around the world. An outbreak of typical bud blight disease was observed between May and August in photinia in 2017 in Qingdao, China. The causal agent for this blight was subsequently isolated from symptomatic samples and identified as Nothophoma quercina based on morphological characterization and molecular analyses (ITS, LSU, RPB2, and TUB2). Results of pathogenicity tests on isolated fungi also supported the conclusion that N. quercina is the pathogen responsible for this condition. To our knowledge, this is the first report of bud blight on P. fraseri caused by N. quercina in China.


Asunto(s)
Ascomicetos , Photinia , Ascomicetos/genética , China
4.
Plant Dis ; 2020 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-32762323

RESUMEN

Celtis sinensis Pers. (Chinese hackberry), belonging to the family Ulmaceae, is widely used as a street tree or landscape plant because of its longevity and aesthetic growth habit. Additionally, C. sinensis is of economic importance due to its medicinal properties. Roots and bark of the plant can be used in natural medicine for the treatment of lumbago, measles, tumor, etc (Zhang et al. 2016). In July 2019, symptoms of leaf spot were observed on C. sinensis in Yuanshan national forest park of Zibo, Shandong Province, China (36.48°N, 117.84°E). We surveyed more than 500 square meters of forest area, and more than 80% of the acreage was affected with the leafspot disease. Symptoms on infected leaves appeared as regular round or oval spots, colored in yellow with brown borders, which coalesced into larger spots as the disease progressed. To investigate the cause, 20 leaves of infected tissues were cut into ~2 mm pieces and surface disinfected with 75% ethanol for 30 s, rinsed three times with sterile deionized water. These were air dried and placed on potato dextrose agar (PDA) and incubated at 25℃ for 5 to 7 days. A minimum of 15 isolates were obtained and cultures were initially white, gradually becoming gray green to dark after 1 week, producing copious amounts of gray aerial mycelium. Three representative single isolates were used for molecular identification, which were verified based on the amplification of DNA sequences of internal transcribed spacer region, translation elongation factor 1 alpha and beta-tubulin genes, using the primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and BT-2a/BT-2b (Glass and Donaldson 1995), respectively. The sequenced genes (GenBank accession no. MT367874, MT385087, MT374083) exhibited 99.63% (Identity=545/547), 99.00% (Identity=297/300), and 100.00% (Identity=451/451) homology with the corresponding genes of type specimen of Botryosphaeria dothidea strain CBS110302 (GenBank accession no. AY259092, AY573218, EU673106), respectively. Morphological and molecular results showed that the isolates were B. dothidea (Slippers et al. 2014; Zhai et al. 2014). Pathogenicity was confirmed using five living, healthy C. sinensis plants with three leaves were wound inoculated with mycelial plugs (about 4 mm in diameter) of B. dothidea from a 7-day-old culture grown on PDA, while inoculated with sterile PDA plugs on the same leaves were served as negative controls. All the plants were covered by plastic sheeting and keep high relative humidity by adding water in time. Seven days later, all inoculated leaves appeared as round dark brown spots, which were larger than observed in the field. The pathogenicity test was repeated three times. No symptoms were observed on negative controls. Fungi re-isolated from inoculated leaves were confirmed as B. dothidea on the basis morphology and molecular characterization as described above. To our knowledge, this is the first report on the presence of B. dothidea affecting C. sinensis plants in China. This discovery is important to ensure the sustainable production of C. sinensis, an important landscaping and medicinal tree.

5.
Plant Dis ; 2020 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-32896214

RESUMEN

Physostegia virginiana Benth. (false dragon head flower), belonging to the family Lamiaceae, is a perennial plant and is usually used as landscape plant in parks and wetlands in China. It is also widely used as an ornamental plant for cut-flower all over the world (Cardin et al. 2007). In June 2019, leaf spot symptoms were observed on P. virginiana in Zibo botanical garden of Shandong Province, China (36.79°N, 118.02°E). We surveyed about 200 square meters of planting area, and most of the infected plants were close to the water or wet places, with ~20% disease incidence which were concentrated in the lower leaves of plants. The symptoms appeared on leaves were mostly round or oval spots, light to dark brown in color, and 3 to 8 mm in diameter. Severe leaf lesions were linked together, causing early fall of leaves. Small pieces of 15 infected leaves were collected to confirm the causal pathogen. The samples were sterilized by 70% ethanol for 30 s, 5% NaClO for 1 min, then rinsed in sterile water three times, plated on potato dextrose agar (PDA) and incubated at 25℃ in the dark for 7 days (Zhu et al. 2013), and 7 isolates were obtained from 10 diseased samples. The stroma of fungal mycelium was initially white, gradually turning dark green to black, while the margin of colony was regular, with concentric rings which were black sporodochia aggregates. Conidiophore hyaline, produce 2-3 order complex branches, arising as 3-4 conidiogenous cells from the tip of the branches, conidiogenous cells ampulliform to cylindrical. Conidia were aseptate, unicellular, hyaline, cylindrical, and their dimensions varied from 4.8 to 8.2 × 1.7 to 2.4 µm with rounded tips. The morphological characteristics of the isolates matched features described for Paramyrothecium roridum (Tode) L. Lombard & Crous, comb. nov. (Lombard et al. 2016). For molecular identification, genomic DNA was extracted from five representative single spore isolates. The partial coding genes of internal transcribed spacer (ITS) and calmodulin (cmdA) from the original isolates were amplified with primers ITS1/ITS4 and CALDF1/CALDR1 (White et al. 1990; Lawrence et al. 2013), respectively. The sequenced genes (GenBank accession no. MT318535, and MT454826) exhibited 98.71%, and 100.00% homology with type specimen of P. roridum strain CBS372.50 (GenBank accession no. MH856665.1, and KU846271.1), respectively, confirming the morphological identification. Pathogenicity of the fungus was tested indoor by inoculating 5 living, healthy P. virginiana plants with 3 leaves, which were inoculated with 10 µl of conidial suspension (2 × 105 conidia/ml) from a 10-day-old cultures on PDA, while 5 other inoculated plants with 10 µl of sterile water were served as controls. Treated plants with the inoculated leaves were covered by plastic bags in the greenhouse of 14 h light/10 h dark with ~80% relative humidity at 25℃. As time went by (about 3-7 days), the leaves inoculated with conidial suspension appeared similar symptoms as described above, whereas negative controls were still healthy. The same pathogens were isolated from the diseased leaves and repeated three times with same results as those that were obtained previously from the outdoor plants, including morphological and molecular results which confirm Koch's postulates. To our knowledge, this is the first record of P. roridum causing leaf spot on P. virginiana in China. The finding is beneficial to the better application of P. virginiana, a very common ornamental plant.

7.
Stroke ; 45(8): 2385-90, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25005441

RESUMEN

BACKGROUND AND PURPOSE: Stroke system of care plays key roles both in providing effective therapies and in improving the overall outcome of patients with stroke. Our purpose was to develop and evaluate the system in Chinese rural areas. METHODS: A stroke system of care was developed from November 2009 to November 2010 in 3 townships in Ganyu County. An additional 3 matched townships were invited as controls. We first investigated stroke management in these townships and then implemented stroke system of care and an education campaign in the 3 intervention townships. The effectiveness of the system was then evaluated. RESULTS: There were 1036 patients with new stroke among 344 345 subjects in the 6 rural communities. The incidence of stroke in the rural areas was 301/100 000, and the mortality rate was 55/100 000. The proportions significantly increased in the intervention communities after the implementation of the stroke system of care and education campaign when compared with the control communities, including patients presenting at rural hospitals within 3 hours of symptom onset (13.6% versus 8.7%; P=0.017), diagnosed by computed tomographic scanning within 24 hours of admission (65.3% versus 58.5%; P=0.034), and received thrombolytic treatment (3.9% versus 1.7%; P=0.038). During the 1-year follow-up, 32 (6.5%) patients with stroke in the intervention communities and 48 (10.1%) in the control communities died. The disability rate of stroke was significantly reduced in the intervention communities at postintervention (38.4% versus 48.1%; P=0.001). CONCLUSIONS: A stroke system of care would be reliable and practical in Chinese rural areas. CLINICAL TRIAL REGISTRATION URL: http://www.chictr.org. Unique identifier: ChiCTR-RCH-13003408.


Asunto(s)
Accidente Cerebrovascular/terapia , Anciano , China/epidemiología , Manejo de la Enfermedad , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Población Rural , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Activador de Tejido Plasminógeno/uso terapéutico
8.
Front Plant Sci ; 15: 1343793, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38828225

RESUMEN

The Unmanned Aerial Vehicle (UAV) sprayer has the advantages of high work efficiency, simple operation, and high safety factor, and has broad application prospects UAV sprayer are widely used in the agricultural field, and the application of UAV sprayer spraying technology in agriculture has provided convenience and increased profits for farmers, and has also become a research hotspot in the field of agriculture. In recent years, although research has been conducted on the feasibility and application effects of UAV sprayer spraying crown shaped plants, there have been no experiments or studies in the field of garden plants. This experiment conducted a droplet deposition experiment of UAV sprayer spraying garden plants, exploring the droplet deposition effect of UAV sprayer in the field of garden plants, and conducting experiments on the influence of spray volume and nozzle type on droplet deposition. The experimental results showed that the canopy performance of small and medium-sized garden plants was better at a flight altitude of 1.5m, a spray volume of 180L/hm2, and a flight speed of 2m/s. Reducing flight altitude, increasing spray volume, and reducing flight speed can improve the distribution of droplets in the canopy. This experiment lays the foundation for the application of UAV sprayer for the prevention and control of pests and diseases in garden plants, as well as for the application of growth regulators, and provides a basis for further innovative research in the field of garden plant application technology.

9.
Pest Manag Sci ; 2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38703046

RESUMEN

BACKGROUND: Effective utilization of plant protection UAVs in peanut cultivation management necessitates a comprehensive grasp of how application volume rates and pesticides influence peanut leaf spot and rust control. This study aimed to compare the effects of application volume rates and pesticides on droplet deposition, disease, leaf retention rate and peanut yield. A T20 plant protection unmanned aerial vehicle (UAV) sprayer was used to apply four various pesticide doses. In comparison, a knapsack sprayer was used to spray with an application volume rate of 450 L ha-1. RESULTS: The results showed a significant difference in droplet deposition between the plant protection UAVs and the electric knapsack sprayer. In the pesticide treatment with an application volume rate of 15.0 L ha-1, there was no significant difference in the deposition on the peanut canopy of each pesticide treatment, but there was a significant difference in the deposition on the ground in the treatment with adding vegetable oil adjuvant. The treatment with added vegetable oil additives showed the worst performance. The treatment with an application volume rate of 22.5 L ha-1 showed the best performance, with the leaf spot control effect being only 0.3% lower than that of the electric knapsack sprayer. CONCLUSION: Plant protection UAV spraying is feasible to control peanut diseases. Considering the operational effectiveness of the plant protection UAV and application volume rate, it is recommended to use an application volume rate of 22.5 L ha-1 without adding vegetable oil adjuvants for field operations. © 2024 Society of Chemical Industry.

10.
Front Plant Sci ; 14: 1303669, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38093990

RESUMEN

Plant protection drone spraying technology is widely used to prevent and control crop diseases and pests due to its advantages of being unaffected by crop growth patterns and terrain restrictions, high operational efficiency, and low labor requirements. The operational parameters of plant protection drones significantly impact the distribution of spray droplets, thereby affecting pesticide utilization. In this study, a field experiment was conducted to determine the working modes of two representative plant protection drones and an electric backpack sprayer as a control to explore the characteristics of droplet deposition with different spray volumes in the citrus canopy. The results showed that the spraying volume significantly affected the number of droplets and the spray coverage. The number of droplets and the spray coverage area on the leaf surface were significantly increased by increasing the spray volume from 60 L/ha to 120 L/ha in plant protection drones. Particularly for the DJI T30, the mid-lower canopy showed a spray coverage increase of 52.5%. The droplet density demonstrated the most significant variations in the lower inner canopy, ranging from 18.7 droplets/cm2 to 41.7 droplets/cm2 by XAG V40. From the deposition distribution on fruit trees, the plant protection drones exhibit good penetration ability, as the droplets can achieve a relatively even distribution in different canopy layers of citrus trees. The droplet distribution uniformity inside the canopy is similar for XAG V40 and DJI T30, with a variation coefficient of approximately 50%-100%. Compared to the plant protection drones, the knapsack electric sprayer is suitable for pest and disease control in the mid-lower canopy, but they face challenges of insufficient deposition capability in the upper canopy and overall poor spray uniformity. The distribution of deposition determined in this study provides data support for the selection of spraying agents for fruit trees by plant protection drones and for the control of different pests and diseases.

11.
Artículo en Inglés | MEDLINE | ID: mdl-22505426

RESUMEN

MaoC-like hydratase (MaoC) is a recently identified enzyme involved in the biosynthetic pathway of polyhydroxyalkanoates (PHAs), which are completely biodegradable polymers used to produce green plastics. The inactive mutant D194N-MaoC was crystallized in the presence of the substrate crotonyl-CoA. Crystals were grown in a number of conditions, but only those produced using 20%(v/v) ethylene glycol were suitable for structural studies. Data were collected to 2.10 Å resolution using X-radiation and the crystal belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 81.40, b = 82.58, c = 123.99 Å.


Asunto(s)
Acilcoenzima A/química , Enoil-CoA Hidratasa/química , Phytophthora/enzimología , Acilcoenzima A/metabolismo , Cristalización , Cristalografía por Rayos X , Enoil-CoA Hidratasa/metabolismo , Activación Enzimática , Mutación , Especificidad por Sustrato
12.
BMC Biotechnol ; 11: 32, 2011 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-21470403

RESUMEN

BACKGROUND: Pectate lyases (PELs) play an important role in the infection process of plant pathogens and also have a commercial significance in industrial applications. Most of the PELs were expressed as soluble recombinant proteins, while a few recombinant proteins were insoluble. The production of a large-scale soluble recombinant PEL would allow not only a more detailed structural and functional characterization of this enzyme but also may have important applications in the food industry. RESULTS: We cloned a new pectate lyase gene (Pcpel2) from Phytophthora capsici. Pcpel2 was constructed by pET system and pMAL system, and both constructs were used to express the PCPEL2 in Escherichia coli BL21 (DE3) pLysS. The expressed products were purified using affinity chromatography and gel filtration chromatography. The purity, specific activity and pathogenicity of the purified PCPEL2 expressed by the pMAL system were higher than the purified PCPEL2 expressed by the pET system. In addition, some other characteristics of the purified PCPEL2 differed from the two systems, such as crystallographic features. Purified PCPEL2 expressed by the pMAL system was crystallized by the hanging-drop vapour-diffusion method at 289 K, and initial crystals were grown. CONCLUSION: The two different methods and comparison presented here would be highly valuable in obtaining an ideal enzyme for the downstream experiments, and supply an useful alternative to purify some insoluble recombinant proteins.


Asunto(s)
Proteínas Fúngicas/metabolismo , Phytophthora/enzimología , Polisacárido Liasas/metabolismo , Proteínas Recombinantes/metabolismo , Western Blotting , Cromatografía de Afinidad/métodos , Cromatografía en Gel/métodos , Cristalización , Tecnología de Alimentos/métodos , Proteínas Fúngicas/genética , Proteínas Fúngicas/aislamiento & purificación , Phytophthora/genética , Hojas de la Planta/virología , Polisacárido Liasas/genética , Polisacárido Liasas/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Esporas Fúngicas/crecimiento & desarrollo
13.
Artículo en Inglés | MEDLINE | ID: mdl-20208158

RESUMEN

MaoC-like dehydratase (MaoC) plays an important role in supplying (R)-3-hydroxyacyl-CoA from the fatty-acid oxidation pathway to polyhydroxyalkanoate (PHA) biosynthetic pathways. PHAs have been attracting much attention as they can be used in the biosynthesis of synthetic plastics. Crystals of MaoC from Phytophora capsici were grown by the hanging-drop vapour-diffusion method at 289 K in a number of screening conditions. An MaoC crystal diffracted to 1.93 A resolution using X-ray radiation and belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 81.458, b = 82.614, c = 124.228 A, alpha = beta = gamma = 90 degrees.


Asunto(s)
Hidroliasas/química , Phytophthora/enzimología , Biocatálisis , Cristalización , Cristalografía por Rayos X , Expresión Génica , Hidroliasas/genética , Hidroliasas/aislamiento & purificación , Hidroliasas/metabolismo
14.
Biotechnol Lett ; 32(11): 1719-23, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20640873

RESUMEN

A new monoamine oxidase type C-like dehydratase gene (MaoC) supplying (R)-3-hydroxyacyl-CoA from the fatty acid oxidation pathway to polyhydroxyalkanoates (PHAs) biosynthetic pathways was identified from Phytophthora capsici. MaoC was over-expressed in Escherichia coli and the recombinant MaoC was purified. The purified tagged MaoC shows the enoyl-CoA hydratase activity of 58 U/mg towards crotonyl-CoA. MaoC may not fold properly above 40°C which was revealed by circular dichroism analysis. Crystal of MaoC diffracts to 1.93 with unit-cell parameters of a = 81.458 Å, b = 82.614 Å, c = 124.228 [corrected] Å, α = ß = γ = 90°.


Asunto(s)
Hidroliasas/genética , Hidroliasas/metabolismo , Monoaminooxidasa/genética , Monoaminooxidasa/metabolismo , Phytophthora/enzimología , Polihidroxialcanoatos/metabolismo , Acilcoenzima A/metabolismo , Dicroismo Circular , Clonación Molecular , Cristalografía por Rayos X , ADN de Hongos/química , ADN de Hongos/genética , Escherichia coli/genética , Ácidos Grasos/metabolismo , Hidroliasas/química , Hidroliasas/aislamiento & purificación , Datos de Secuencia Molecular , Monoaminooxidasa/química , Monoaminooxidasa/aislamiento & purificación , Oxidación-Reducción , Conformación Proteica , Pliegue de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Análisis de Secuencia de ADN , Temperatura
15.
PLoS One ; 8(11): e80024, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24244597

RESUMEN

BACKGROUND: Polyhydroxyalkanoates (PHAs) have attracted increasing attention as "green plastic" due to their biodegradable, biocompatible, thermoplastic, and mechanical properties, and considerable research has been undertaken to develop low cost/high efficiency processes for the production of PHAs. MaoC-like hydratase (MaoC), which belongs to (R)-hydratase involved in linking the ß-oxidation and the PHA biosynthetic pathways, has been identified recently. Understanding the regulatory mechanisms of (R)-hydratase catalysis is critical for efficient production of PHAs that promise synthesis an environment-friendly plastic. METHODOLOGY/PRINCIPAL FINDINGS: We have determined the crystal structure of a new MaoC recognized from Phytophthora capsici. The crystal structure of the enzyme was solved at 2.00 Å resolution. The structure shows that MaoC has a canonical (R)-hydratase fold with an N-domain and a C-domain. Supporting its dimerization observed in structure, MaoC forms a stable homodimer in solution. Mutations that disrupt the dimeric MaoC result in a complete loss of activity toward crotonyl-CoA, indicating that dimerization is required for the enzymatic activity of MaoC. Importantly, structure comparison reveals that a loop unique to MaoC interacts with an α-helix that harbors the catalytic residues of MaoC. Deletion of the loop enhances the enzymatic activity of MaoC, suggesting its inhibitory role in regulating the activity of MaoC. CONCLUSIONS/SIGNIFICANCE: The data in our study reveal the regulatory mechanism of an (R)-hydratase, providing information on enzyme engineering to produce low cost PHAs.


Asunto(s)
Acilcoenzima A/química , Enoil-CoA Hidratasa/química , Phytophthora/química , Polihidroxialcanoatos/biosíntesis , Acilcoenzima A/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Biocatálisis , Dominio Catalítico , Cristalografía por Rayos X , Enoil-CoA Hidratasa/genética , Enoil-CoA Hidratasa/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Oxidación-Reducción , Phytophthora/enzimología , Multimerización de Proteína , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad por Sustrato
16.
Cancer Lett ; 269(1): 18-25, 2008 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-18501504

RESUMEN

We evaluated the incidence, age, gender, and anatomical distribution of gastric cancers in 65,284 cases of upper GI endoscopies. A total of 5253 gastric cancer cases were identified. Cancers of the cardia, fundus, body and antrum account for 33.6%, 2.7%, 23.6% and 34.0% of all cases, respectively. The mean age for gastric cancers was 56.9+/-10.2 years and 69.7% of the cancer cases were found in the 50-69 year age group. Subjects with cardia cancer were slightly older than subjects with non-cardia cancer. Over the 12-year period, the incidence of the gastric antrum cancer had significantly declined, whereas the incidence of the gastric cancer in the cardia and body had risen steadily. Thus, there was a rising trend of cardia cancers and a decreasing trend of most non-cardia cancers.


Asunto(s)
Cardias , Neoplasias Gástricas/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , China/epidemiología , Unión Esofagogástrica/patología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Distribución por Sexo , Neoplasias Gástricas/patología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA