RESUMEN
Tobacco (Nicotiana tabacum L.) is an important economic crop that is widely grown around the world. Its annual production in China is estimated at 2.2 million tons (Berbec and Matyka 2020). Since 2022, a root rot disease was sporadically observed on tobacco seedlings on cultivar Yunyan 87 in cultivated tobacco fields in the Hunan province of China. A disease incidence of about 10% occurred across 48 ha of tobacco fields. The affected tobacco plants had slow and stunted growth with yellowing leaves. The roots turned grayish brown, decayed, and died. Diseased roots were collected from six fields and cut into small pieces (5 mm ×5 mm) from the edge of the rotted portions, and then sterilized with 70% ethanol for 10 s, 0.1% HgCl2 for 1 min, and washed in sterilized water three times. All the sterilized tissue were placed on potato dextrose agar (PDA) medium and cultured at 26 â in the dark. About 3 days later, colonies with similar morphology were removed and sub-cultured on fresh PDA. A total of six strains were obtained from six tobacco samples. Strains were white and had radial growth on PDA. Hyphae were aseptate and the sporangia were filamentous. The oogonia were subglobose, smooth, 16.04 ± 0.25 µm (n=50) in diameter, and developed on unbranched stalks. The antheridia were barrel shaped and clavate. Oospores were globose, aplerotic or nearly plerotic, measuring 6.62 ± 0.33 µm (n=50). These morphological characteristics were consistent with the description of Pythium spp. (van der Plaats-Niterink 1981). For molecular identification, the internal transcribed spacer (ITS) region of rDNA and cytochrome c oxidase subunit I (Cox I) of a representative isolate, GF-3, were amplified and sequenced (GenBank accession nos. OR228424 for ITS and OR237556 for Cox I) using universal primers ITS1/ITS4 (White et al. 1990) and FM58/FM66, respectively (Villa et al. 2006). BLASTn analysis revealed that the ITS and Cox I sequences were 99.76 % (838/840 bp) and 99.85% (671/672 bp) identical to the corresponding sequences of P. dissotocum strain CBS 166.68 (AY598634.2) and UM982 (MT981147.1), respectively. A neighbor-joining phylogenetic tree based on the Cox I sequence showed that GF-3 grouped in the P. dissotocum branch. Based on morphological and molecular characteristics, GF-3 was identified to be P. dissotocum. For pathogenicity testing, four- to five-leaf-old healthy potted tobacco seedlings of the Yunyan 87 cultivar were inoculated with a zoospore suspension (1 × 105 zoospores/ml), which was induced on V8-juice medium. The zoospore suspension was introduced into the soil around plant roots and 10 mL of inoculum was used for each plant. In the control group, plants were inoculated with sterilized water. All of the treated plants were kept in humid chambers at 26°C under a 12 h/12 h photoperiod. The pathogenicity assays were performed twice, with each treatment having three replicated plants. After 5 days, tobacco seedlings inoculated with P. dissotocum showed symptoms resembling that observed in the field. However, the control plants remained healthy. Pythium dissotocum was re-isolated from the infected plants and identified by morphological and molecular methods, thus confirming Koch's postulates. Pythium dissotocum has been reported causing root rot in other plants, including hydroponic lettuce (McGehee et al. 2018) and spinach (Huo et al. 2020). Also, many Pythium species have recently been recovered from float-bed tobacco transplant production greenhouses (Zhang et al. 2022). However, to our knowledge, this is the first report of root rot on tobacco caused by P. dissotocum in China. Since this disease could greatly affect tobacco seedling establishment in the field, appropriate management strategies need to be developed to reduce further losses in tobacco planting fields.
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Here, we characterized a new mycovirus from the fungus Nigrospora chinensis, which was named "Nigrospora chinensis victorivirus 1" (NcVV1). The NcVV1 genome is 5283 bp in length, containing two continuous open reading frames (ORFs), ORF1 and ORF2. ORF1 and ORF2 were predicted to encode a putative coat protein (CP) and an RNA-dependent RNA polymerase (RdRp), respectively. The stop codon of ORF1 overlaps with the start codon of ORF2 by the tetranucleotide sequence AUGA. Phylogenetic analysis based on amino acid sequences of RdRp and CP indicated that NcVV1 clustered with members of the genus Victorivirus in the family Totiviridae. To our knowledge, this was the first report of a mycovirus infecting N. chinensis.
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Virus Fúngicos , Virus ARN , Totiviridae , Nicotiana/genética , Filogenia , Proteínas Virales/genética , Proteínas Virales/química , Virus Fúngicos/genética , Sistemas de Lectura Abierta , Genoma Viral , ARN Viral/genética , ARN Viral/química , ARN Bicatenario , Virus ARN/genéticaRESUMEN
MYB12 promotes flavonol biosynthesis in plants by targeting several early biosynthesis genes (EBGs) of this pathway. The transcriptions of these EBGs are also induced by sucrose signal. However, whether MYB12 is activated by sucrose signal and what the other roles MYB12 has in regulating plant metabolism are poorly understood. In this study, two NtMYB12 genes were cloned from Nicotiana tabacum. Both NtMYB12a and NtMYB12b are involved in regulating flavonoids biosynthesis in tobacco. NtMYB12a is further shown to inhibit the accumulation of fatty acid (FA) in tobacco leaves and seeds. Post-translational activation and chromatin immunoprecipitation assays demonstrate that NtMYB12a directly promotes the transcriptions of NtLOX6, NtLOX5, NtSFAR4 and NtGDSL2, which encode lipoxygenase (LOX) or SFAR enzymes catalyzing the degradation of FA. NtLOX6 and NtLOX5 are shown to prevent the accumulation of FA in the mature seeds and significantly reduced the percentage of polyunsaturated fatty acids (PUFAs) in tobacco. Sucrose stimulates the transcription of NtMYB12a, and loss function of NtMYB12a partially suppresses the decrease of FA content in tobacco seedlings caused by sucrose treatment. The regulation of sucrose on the expression of NtLOX6 and NtGDSL2 genes is mediated by NtMYB12a, whereas those of NtLOX5 and NtSFAR4 genes are independent of sucrose.
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Ácidos Grasos/metabolismo , Lipooxigenasa/metabolismo , Nicotiana/metabolismo , Proteínas de Plantas/metabolismo , Sacarosa/metabolismo , Factores de Transcripción/metabolismo , Inmunoprecipitación de Cromatina , Clonación Molecular , Flavonoides/metabolismo , Genes de Plantas/genética , Proteínas de Plantas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Nicotiana/enzimología , Nicotiana/genética , Factores de Transcripción/genéticaRESUMEN
Tobacco (Nicotiana tabacum L.) is a leafy, annual, solanaceous plant grown commercially for its leaves. It is one of the most important cash crops in China. In April of 2020, tobacco stems in commercial tobacco fields developed a brown to dark brown rot, in the Hunan Province of China. Almost 20% of the plants were infected. Symptoms appeared as round water-soaked spots, then turned dark black and developed into brown necrotic lesions leading to the stem becoming girdled and rotted. Diseased stem tissue was cut and sterilized with 70% ethanol for 10 s, 0.1% HgCl2 for 2 min, rinsed with sterile distilled water three times, and then plated on potato dextrose agar (PDA) and incubated at 26°C in the dark. Six isolates with similar morphology were obtained. Colonies cultured on PDA have morphological characteristics of Fusarium spp. producing white to orange-white, densely aerial mycelium with magenta to dark violet pigmentation. Macroconidia were produced on carnation leaf agar plates (Xi et al. 2019), which were slightly curved, with apical and basal cells curved, and usually contained three or five septa, 25.50 to 41.50×3.55 to 5.80 µm (n=50). Microconidia were cylindrical, ovate-oblong, straight to slightly curved, aseptate and 5.80 to 13.75 × 3.10 to 4.10 µm (n=50). For molecular identification, the translation elongation factor 1-alpha (EF1-α), the largest subunit of RNA polymerase II gene sequences (RPB2) and the mitochondrial small subunit rDNA (mtSSU) of a representative isolate CZ3-5-6 were amplified using the primer pairs ef1/ef2 (O'Donnell et al. 1998), 5F2/7Cr (O'Donnell et al. 2010) and NMS1/ NMS2 (Li et al. 1994). The obtained EF1-α, RPB2 and mtSSU sequences (GenBank accession nos. MT708482, MT708483 and MW260121, respectively) were 99.70 %, 100% and 100% identical to strains of F. commune (HM057338.1 for EF1-α, KU171700.1 for RPB2 and MG846025 for mtSSU). Moreover, Fusarium-ID database searches revealed that the EF1-α and RPB2 were 100% identical to F. commune strains (FD_01140_EF-1a and FD_02411_RPB2). Based on the morphological and molecular characteristics of the representative isolate, the fungal species was identified as F. commune. Pathogenicity testing of a representative isolate was performed by inoculating tobacco plants, which were grown for 2.5 months in a sterile pot with autoclaved soil. Each tobacco stem was injected with 20 µl of conidial suspension (105 spores/ml). Plants inoculated with sterilized water served as control. The pathogenicity tests were performed twice using three replicate plants, and all plants were kept in humid chambers (80 × 50 × 80 cm) at 26°C with a 12-h photoperiod. After 10 days, dark brown necrotic symptoms around the inoculated site, similar to those observed in natural field, were developed in all inoculated plants, whereas no symptoms were observed on the control plants. The pathogenic fungus was re-isolated from symptomatic tissue and identified as F. commune but was not recovered from the control plants. Fusarium commune has been reported to cause root rot or stalk and stem rot on some plants, such as sugarcane (Wang et al. 2018), Gentiana scabra (Guan et al. 2016) and maize (Xi et al. 2019). However, to our knowledge, this is the first report of F. commune causing stem rot on tobacco in China. Identification of F. commune as a stem rot causing pathogen might provide important insights for disease diagnosis on tobacco caused by different Fusarium species. Overall, this disease might bring a threat to tobacco production, and appropriate control measures should be adopted to reduce losses in tobacco fields.
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Antimicrobial metabolites produced by Trichoderma koningii SMF2 exhibited antimicrobial activity against a range of Gram-positive bacterial and fungal phytopathogens. Purification of these metabolites was achieved using combinations of gel filtration and high-performance liquid chromatography. Identified by liquid chromatography electrospray ionization tandem mass spectrometry, the active metabolites proved to be three known peptaibols: Trichokonin VI, VII and VIII. The Trichokonins were stable and remained biological active over a wide pH range and at every temperature tested, showing no loss of activity even after autoclaving. Trichokonins were insensitive to proteolytic enzymes. Trichokonin VI takes on typical helical structure and the structure changes only slightly at different temperatures and pH values. The present study presented the potential of Trichokonins to be used as biological control agents.
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Alameticina/análogos & derivados , Antiinfecciosos/farmacología , Plantas/microbiología , Trichoderma/química , Alameticina/química , Alameticina/aislamiento & purificación , Alameticina/farmacología , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Espectrometría de Masas , TemperaturaRESUMEN
<p><b>OBJECTIVE</b>To report a newborn infant who died of alveolar capillary dysplasia (ACD). The literature on about 20 cases of ACD was reviewed.</p><p><b>METHODS</b>A retrospective review of records of infants from Medline with a diagnosis of ACD was carried out.</p><p><b>RESULTS</b>The case was a newborn female infant who developed respiratory distress 5 hours after an uncomplicated delivery. She died at the fourth day after birth despite full ventilatory support. The lung autopsy provided a diagnosis of ACD. In the 21 infants, 7 were male and 14 were female; 19 infants were born full-term and 2 were born pre-term. The birth weight of 19 infants and Apgar score of 15 infants were normal; 16 infants developed progressing tachypnea and cyanosis within 24 hours of age, 5 developed cyanosis at 1 day to 19 days. Echocardiography demonstrated a right to left shunt in the hearts of all the 21 infants, and pulmonary hypertension in 20 infants. Twenty infants were treated with conventional mechanical ventilation, 7 infants with high-frequency oscillatory ventilation and 12 infants with extracorporeal membrane oxygenation (ECMO). Fourteen infants were also treated with inhaled nitric oxide therapy and 4 with exogenous surfactant. Diagnostic open lung biopsy was performed in 6 infants. The chest radiography showed normal findings in 3 infants, pneumothoraces in 9 infants, reticular markings, granular, patchy or diffuse opacity in lungs of 7 infants, and decreased pulmonary vascular markings in two infants. All the 21 infants died; 8 of them died within 10 days of age, 7 within 30 days of age, and one died at the age of 4 months who was the longest survivor. Fourteen infants were associated with congenital malformations, such as cardiovascular, gastrointestinal, and genitourinary systems, including one infant associated with chromosomal abnormalities, two infants of familial genetic predisposition.</p><p><b>CONCLUSIONS</b>At present, ACD is still a disease with poor prognosis, significant medical expenses and no specific treatment. When respiratory failure or persistent pulmonary hypertension (PPHN) is persistent after routine treatment in an infant, ACD should be highly suspected and conventional open-lung biopsy should be preformed to confirm the diagnosis.</p>
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Femenino , Humanos , Recién Nacido , Masculino , Síndrome de Circulación Fetal Persistente , Diagnóstico , Patología , Alveolos Pulmonares , Anomalías Congénitas , PatologíaRESUMEN
<p><b>OBJECTIVE</b>To establish a method for the content determination of protein in Sabin IPV.</p><p><b>METHODS</b>Using lowry method combined with being precipitated by trichloroacetic acid to determine the content of protein in Sabin IPV. Changing different conditions to optimize the experiment to establish a improved lowry method. And the sample recovery test was also conducted.</p><p><b>RESULTS</b>The method can exclude the interference of free aminoacid, phenols and some other additives. The calibration curve was in good linearity of protein within the range of 2.5 microg/ml-40 Microg/ml, r = 0.9998. Under the best conditions, the mean recovery was 95.32%, the CV in a batch and between batches were both < 10%.</p><p><b>CONCLUSION</b>The method can be used to determine the micro content of protein in vaccines.</p>
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Aminoácidos , Metabolismo , Calibración , Técnicas de Química Analítica , Métodos , Fenoles , Química , Vacuna Antipolio Oral , Química , Proteínas , Ácido Tricloroacético , QuímicaRESUMEN
<p><b>OBJECTIVE</b>To investigate the prevalence and risk factors of diabetic retinopathy (DR) among type 2 diabetic patients aged over 30 in Shanghai central area.</p><p><b>METHODS</b>1039 patients diagnosed with type 2 diabetes mellitus (DM) aged over 30 were investigated by randomized cluster sampling in Shanghai central area and data from 767 of those patients were analyzed.</p><p><b>RESULTS</b>(1) Among all of the 1534 digital ocular fundus images from 767 patients, 87.6% of the images from 672 patients were gradable. (2) Among all of the 672 patients with gradable ocular fundus images, the prevalence of non-proliferative diabetic retinopathy (NPDR) was 21.6%, while proliferative diabetic retinopathy (PDR) was 1.3%. The rates of mild, moderate and severe NPDR were 8.8%, 11.2% and 1.6% respectively. (3) DR patients were characterized with elder age, higher HbA1c, urea nitrogen and serum creatinine. DM duration and the level of fasting plasma glucose were risk factors for DR.</p><p><b>CONCLUSION</b>The overall prevalence of DR in type 2 diabetic patients aged over 30 in Shanghai central area was 22.9% and the DR risk factors were found to include duration of diabetes and fasting plasma glucose level.</p>
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Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , China , Epidemiología , Análisis por Conglomerados , Diabetes Mellitus Tipo 2 , Retinopatía Diabética , Epidemiología , Estudios Epidemiológicos , Prevalencia , Factores de RiesgoRESUMEN
Octenyl succinic anhydride (OSA) modified early Indica rice starch was prepared in aqueous slurry systems using response surface methodology. The paste properties of the OSA starch were also investigated. Results indicated that the suitable parameters for the preparation of OSA starch from early Indica rice starch were as follows: reaction period 4 h, reaction temperature 33.4 degrees C, pH of reaction system 8.4, concentration of starch slurry 36.8% (in proportion to water, w/w), amount of OSA 3% (in proportion to starch, w/w). The degree of substitution was 0.0188 and the reaction efficiency was 81.0%. The results of paste properties showed that with increased OSA modification, the starch derivatives had higher paste clarity, decreased retrogradation and better freeze-thaw stability.
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Bioquímica , Métodos , Fenómenos Químicos , Química Física , Congelación , Concentración de Iones de Hidrógeno , Luz , Modelos Estadísticos , Oryza , Metabolismo , Almidón , Química , Anhídridos Succínicos , Química , TemperaturaRESUMEN
<p><b>OBJECTIVE</b>To observe the inhibitory effect of Liuwei Dihuang Pill (LDP) on erythrocyte aldose reductase (EAR) activity in early diabetic nephropathy (DN) patients and to explore the clinical significance of applying LDP in prevention and treatment of DN as an inhibitor of aldose reductase.</p><p><b>METHODS</b>Seventy-two patients diagnosed as early DN with TCM Syndrome of both Qi-yin deficiency were randomly divided into the control group (31 patients) treated by conventional therapy (orally taken Gliquidone or injection of insulin) and the treated group (41 patients) treated by conventional therapy plus LDP for 3 months as one therapeutic course. Changes of symptoms, physical signs, fasting blood glucose (FBG), blood glucose 2 hrs post breakfast (2hPBG), blood total cholesterol (TC), triglyceride (TG), EAR activity, urinary albumin excretion rate (UAER), blood and urinary beta2-microglobulin (beta2-MG) in patients before and after treatment were observed.</p><p><b>RESULTS</b>LDP could improve the symptoms and signs of patients with DN, it could significantly inhibit EAR activity, to make it significantly lower than that in the control group (P < 0.05), and the levels of UAER, beta2-MG in blood and urine in the treated group after treatment were obviously lower than those in the control group (P < 0.05), and LDP showed no apparent effect on blood glucose, lipids and mean arterial pressure (P < 0.05).</p><p><b>CONCLUSION</b>LDP could obviously inhibit the activity of EAR in patients with early DN, improve various indexes of DN, so as to be helpful for its treatment.</p>
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Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aldehído Reductasa , Metabolismo , Nefropatías Diabéticas , Quimioterapia , Diagnóstico Diferencial , Medicamentos Herbarios Chinos , Usos Terapéuticos , Eritrocitos , Medicina Tradicional China , FitoterapiaRESUMEN
Objective In order to improve the understanding of Kimura's disease,the clinical features and the pathological changes of 12 patients were analyzed.Methods Twelve cases with Kimura's disease ad- mitted to Qilu Hospital of Shandong University were retrospectively reviewed.Results All 12 patients were in relatively good condition and presented as subcutaneous nodules or swelling lymph nodes.Peripheral blood eosinophilia did not occur in 5 cases,4 out of 6 patients had high-level serum IgE.Biopsies were taken in all cases and the characteristic histological presentations were discovered.Only one patient developed pulmonary inflammation and acute myocardial infarction which were rare in Kimura's disease.Conclusions Definite di- agnosis of Kimura's disease mainly relies on biopsy.A patient with Kimura's disease can suffer from severe pulmonary and cardiac diseases,but the relationship between them should be studied further.
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Objective To investigate BAALC(brain and acute leukemia cytoplasmic)gene expression in patients with de novo acute myeloid leukemia(AML)and its clinical significance. Methods BAALC expression was determined by real-time quantitative polymerase chain reaction(RQ-PCR) in 63 de novo AML patients.The association between BAALC expression and therapeutic effect was analyzed.Results The correlation coefficiencies were over 0.99 for standard curves of RQ-PCR method. BAALC expression was detected in 49(78%)AML patients.The peripheral WBC counts,hemoglobin, platelet counts and the bone mahow blast cell percentage at onset in 31 AML patients with high BAALC expression were(26.3?18.1)?10~9/L,(78.3?21.8)g/L,(76.9?64.5)?10~9/L and(61.2?22.3)% and those of 32 AML patients with low BAALC expression were(30.2?21.7)?10~9/L,(81.6?30.9)g/L, (73.9?57.2)?10~9/L,(54.3?16.3)%,respectively.No statistic differences were found between these two groups.The AML patients with normal chromosome karyotypes are more likely to have a high BAALC expression(68%)compared with those with abnormal chromosome karyotypes(23%,?~2=12.093,P= 0.001).AML patients with normal cytogenetics and high BAALC expression shows significant lower CR rate (65%)compared with those with low BAALC expression(84%,?~2=6.573,P=0.013). Conclusion High BAALC expression may define an important risk factor in AML with normal cytogenetics and predicts an adverse prognosis.
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Urine samples from 72 patients with diabetic nephropathy (DN) were analyzed and compared to those from 33 diabetic patients without albuminuria and 29 normal controls,using SELDI-TOF-MS (surface enhanced laser desorptiort/ionization time-of-flight mass spectrometry) and Biomarker Patterns Software,to identify differences in protein profile,generate a tree analysis pattern and evaluate the validity of the decision tree.The intensities of 6 peaks detected appeared upregulated,while 11 peaks downregulated,in DN group as compared to nonDN groups more than 2 folds (P