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2.
Pathogens ; 12(7)2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37513816

RESUMEN

In October 2020, samples of walnut branch blight were collected from Longnan. Pathogens were isolated and identified based on morphological and molecular features, and their characteristics were analyzed by pathogenicity. Pathogenicity testing revealed that seven strains (LN-1, LN-3, LN-6, LN-19, LN-27, QY3-1, and QY9-1) induced symptoms of walnut branch blight that were consistent with those observed in the field after inoculation. Furthermore, some Fusarium-type conidia and spherical chlamydospores were visible indicating that they were Fusarium spp. A molecular characterization including sequence and phylogenetic analysis of the ITS, TEF-1α, ßTUB, Fu, and LSU gene regions revealed that LN-1 and LN-19 belonged to F. avenaceum, LN-3 and LN-6 to F. acuminatum, LN-27 to F. sporotrichioides, and QY3-1 and QY9-1 to F. tricinctum. This is the first time that F. acuminatum-, F. sporotrichioides-, and F. tricinctum-caused walnut branch blight has been reported in China.

4.
Front Oncol ; 13: 1080910, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36816977

RESUMEN

Background: Hypoxia-inducible factor 1-alpha (HIF-1α) stability and transcriptional action are reduced by the hypoxia-inducible factor 1-alpha subunit suppressor (HIF1AN). Its inappropriate expression is associated with the development of cancer and immune control. It is yet unknown how HIF1AN, clinical outcomes, and immune involvement in breast cancer (BC) are related. Methods: Using the GEPIA, UALCAN, TIMER, Kaplan-Meier plotter, and TISIDB datasets, a thorough analysis of HIF1AN differential expression, medical prognosis, and the relationship between HIF1AN and tumor-infiltrating immune cells in BC was conducted. Quantitative real-time PCR (qRT-PCR) analysis of BC cells were used for external validation. Results: The findings revealed that, as compared to standard specimens, BC cells had significantly lower levels of HIF1AN expression. Good overall survival (OS) for BC was associated with higher HIF1AN expression. Additionally, in BC, the expression of HIF1AN was closely associated with the chemokines and immune cell infiltration, including neutrophils, macrophages, T helper cells, B cells, Tregs, monocytes, dendritic cells, and NK cells. A high correlation between HIF1AN expression and several immunological indicators of T-cell exhaustion was particularly revealed by the bioinformatic study. Conclusions: HIF1AN is a predictive indicator for breast tumors, and it is useful for predicting survival rates.

5.
Nat Commun ; 13(1): 7629, 2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36494373

RESUMEN

The ongoing COVID-19 pandemic has demonstrated that viral diseases represent an enormous public health and economic threat to mankind and that individuals with compromised immune systems are at greater risk of complications and death from viral diseases. The development of broad-spectrum antivirals is an important part of pandemic preparedness. Here, we have engineer a series of designer cells which we term autonomous, intelligent, virus-inducible immune-like (ALICE) cells as sense-and-destroy antiviral system. After developing a destabilized STING-based sensor to detect viruses from seven different genera, we have used a synthetic signal transduction system to link viral detection to the expression of multiple antiviral effector molecules, including antiviral cytokines, a CRISPR-Cas9 module for viral degradation and the secretion of a neutralizing antibody. We perform a proof-of-concept study using multiple iterations of our ALICE system in vitro, followed by in vivo functionality testing in mice. We show that dual output ALICESaCas9+Ab system delivered by an AAV-vector inhibited viral infection in herpetic simplex keratitis (HSK) mouse model. Our work demonstrates that viral detection and antiviral countermeasures can be paired for intelligent sense-and-destroy applications as a flexible and innovative method against virus infection.


Asunto(s)
COVID-19 , Virosis , Virus , Humanos , Ratones , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , Replicación Viral , Pandemias
6.
Nat Commun ; 13(1): 6357, 2022 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-36289204

RESUMEN

Surgical resection is the main treatment option for most solid tumors, yet cancer recurrence after surgical resection remains a significant challenge in cancer therapy. Recent advances in cancer immunotherapy are enabling radical cures for many tumor patients, but these technologies remain challenging to apply because of side effects related to uncontrollable immune system activation. Here, we develop far-red light-controlled immunomodulatory engineered cells (FLICs) that we load into a hydrogel scaffold, enabling the precise optogenetic control of cytokines release (IFN-ß, TNF-α, and IL-12) upon illumination. Experiments with a B16F10 melanoma resection mouse model show that FLICs-loaded hydrogel implants placed at the surgical wound site achieve sustainable release of immunomodulatory cytokines, leading to prevention of tumor recurrence and increased animal survival. Moreover, the FLICs-loaded hydrogel implants elicit long-term immunological memory that prevents against tumor recurrence. Our findings illustrate that this optogenetic perioperative immunotherapy with FLICs-loaded hydrogel implants offers a safe treatment option for solid tumors based on activating host innate and adaptive immune systems to inhibit tumor recurrence after surgery. Beyond extending the optogenetics toolbox for immunotherapy, we envision that our optogenetic-controlled living cell factory platform could be deployed for other biomedical contexts requiring precision induction of bio-therapeutic dosage.


Asunto(s)
Recurrencia Local de Neoplasia , Optogenética , Ratones , Animales , Factor de Necrosis Tumoral alfa , Inmunoterapia , Factores Inmunológicos , Hidrogeles , Citocinas , Interleucina-12/genética
7.
Exp Ther Med ; 24(5): 665, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36168421

RESUMEN

Adenomyotic cysts are small cysts with a diameter of <5 mm, usually containing hemorrhagic material. The present study reported on a patient with a large adenomyotic cyst with abnormally high serum levels of CA19-9 (>1,000 U/ml) and CA125 (642 U/ml) and a complaint of pelvic pain. MRI scans were critical in diagnosing the case. Adhering to the principle of tumor-free implantation, a laparotomy was performed. After the operation, six weeks were required to normalize the serum level of CA19-9 and four weeks for CA125. Elevated tumor markers are frequently observed in malignancies, but the outcome reported in the present case was a benign lesion and the prognosis was favorable. In the present case, it was unusual that CA19-9 was elevated in addition to CA125, as it is commonly reported that only CA125 is elevated in cases of large adenomyotic cyst.

8.
Biomolecules ; 12(9)2022 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-36139022

RESUMEN

Breast cancer (BC) is one of the most common types of malignancies in women and greatly threatens female health. KRT17 is a member of the keratin (KRT) protein family that is abundant in the outer layer of the skin, where it protects epithelial cells from damage. Although KRT17 has been studied in many types of cancer, the expression of KRT17 in specific subtypes of BC remains to be determined. In our study, we explored the expression and prognostic implications of KRT17 in BC patients using mRNA transcriptome data and clinical BC data from The Cancer Genome Atlas (TCGA). Receiver operating characteristic (ROC) curves and the chi-square test were used to assess the diagnostic value of KRT17 expression. Quantitative real-time PCR (qRT-PCR) analysis of BC cells and tissues and immunohistochemistry (IHC) analysis of clinical tissues were used for external validation. Furthermore, the relationship between KRT17 and immune function was studied by using the CIBERSORT algorithm to predict the proportions of tumor-infiltrating immune cells (TIICs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the potential mechanisms by which KRT17 expression influences patient survival. We found that KRT17 expression was significantly lower in BC tissues than in normal tissues, especially in the luminal-A, luminal-B and human epidermal growth factor receptor-2 (HER2)+ subtypes of BC. ROC analysis revealed that KRT17 expression had moderate diagnostic value. Interestingly, decreased expression of KRT17 was significantly correlated with poor prognosis in BC patients, especially in HER2high and ERhigh patients. This trend was also verified by tissue microarray (TMA) analysis. KRT17 was found to be involved in some antitumor immune pathways, especially the IL-17 signaling pathway, and associated with multiple immune cells, such as natural killer (NK) and CD4+ T cells. In conclusion, high expression of KRT17 predicted favorable prognosis in BC patients with higher HER2 expression. This result may indicate that KRT17 plays a different role depending on the level of HER2 expression and could serve as a promising and sensitive biomarker for the diagnosis and prognostication of HER2high BC.


Asunto(s)
Neoplasias de la Mama , Queratina-17 , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Femenino , Humanos , Interleucina-17/genética , Queratina-17/genética , ARN Mensajero
9.
Technol Cancer Res Treat ; 21: 15330338221121086, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36000314

RESUMEN

Background and Objects: Malignant phyllodes tumor of the breast (MPTB) is a rare tumor for which surgery or surgery combined with radiotherapy (RT) is the primary treatment method. However, recently, the therapeutic effect of RT on MPTB has been controversial. We aimed to explore the role of RT, chemotherapy (CT), and surgical modalities in patients with MPTB. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to select patients with MPTB who met the criteria between 2010 and 2018. Kaplan-Meier curves and Cox proportional risk regression models were used to analyze the effects of RT on MPTB patients. Based on this, we compared the effects of breast-conserving surgery (BSC) and mastectomy on the postoperative survival of MPTB. Results: A total of 298 patients with MPTB were included in this study. RT was received by 22.1% (n = 66) of the patients while 77.9% (n = 232) did not receive RT. CT was received by 4.7% (n = 14) patients while 95.3% (n = 284) did not receive CT. According to Kaplan-Meier curves, RT and CT combined resulted in a decrease in breast cancer-specific survival (BCSS) and overall survival (OS) compared to patients who did not receive RT. Mastectomy improved the OS and BCSS of the patients more than BCS). The findings of univariate and multivariate Cox regression analyses suggested that "distant metastasis", "tumor grade" and "number of positive lymph node biopsies" affected OS of breast cancer, while "distant metastasis", "tumor grade", "surgery combined with radiotherapy/surgery", and "radiotherapy/chemotherapy or not", had a significant effect on BCSS. Conclusion: RT and CT did not significantly improve the long-term survival of MPTB patients. Mastectomy improved OS and BCSS of the patient more than BCS. RT in an early stage improved early prognosis moderately in MPTB patients with tumor diameter less than 50 mm.


Asunto(s)
Neoplasias de la Mama , Mastectomía , Mama/patología , Neoplasias de la Mama/patología , Femenino , Humanos , Mastectomía/métodos , Mastectomía Segmentaria/métodos , Radioterapia Adyuvante , Programa de VERF
10.
Exp Ther Med ; 24(3): 576, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35949328

RESUMEN

Approximately one in four myocardial infarctions occur in older patients. The majority of therapeutic advances are either not appropriate or not tested in elderly patients. The main reasons for deviating from the guidelines are justified concerns regarding the effectiveness of the recommended forms of therapy, fear of adverse drug reactions and ethical concerns. Targeting interleukin 6 (IL-6) for ventricular remodeling after cardiovascular damage is a feasible alternative to standard polypharmaceutics, but the underlying molecular mechanisms are not well understood. Continuous activation of the IL-6-associated cytokine receptor gp130 leads to cardiomyopathic hypertrophy. TGFß1 is involved in forming fibrosis in various organs, and its overexpression can cause myocardial hypertrophy and fibrosis. Il-6 has been hypothesized to be indirectly involved in cardiac remodeling via the TGFß1/Smad signaling transduction pathway. In the present study, a rat model of acute myocardial ischemia, IL-6 and IL-6 receptor blockers were injected directly into the necrotic myocardium. Changes in cardiac function, myocardial infarction area, myocardial collagen, necrotic myocardial fibrosis and levels of TGFß1, IL-6 and MMP2/9 were quantified in myocardial tissue fibrosis by ELISA. The present study demonstrated that IL-6 stimulated myocardial fibrosis through the TGFß1-Smad-MM2/9 signaling transduction pathway. Overall, this provided a solid foundation for understanding the relationship between IL-6 and ventricular remodeling.

11.
Front Oncol ; 12: 964934, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36003773

RESUMEN

Breast cancer is the most common cancer in women worldwide with increasing incidence. Significant therapeutics advances in the field of breast cancer have resulted in a growing number of treatment options, whereas de novo or acquired resistance is still a persistent clinical challenge. Drug resistance involves a variety of mechanisms, and hypoxia is one of the many causes. Hypoxia-inducible Factor-1 Alpha (HIF-1α) is a key transcription factor which can regulate the response of cells to hypoxia. HIF-1α can trigger anaerobic glycolysis of tumor cells, induce angiogenesis, promote the proliferation, invasion, and migration of tumor cells, and lead to multidrug resistance. This review mainly discusses the role of HIF-1α in the drug-resistant breast cancer and highlighted the potential of HIF-1α -targeted therapy.

12.
Oncol Lett ; 24(2): 285, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35814828

RESUMEN

Breast cancer (BC) is one of the most common malignant cancers in females worldwide and greatly threatens women's health. The C-type lectin domain family 10 member A (CLEC10A) is a member of the C-type lectin receptor family that has been previously reported to promote the antitumor activity of immune cells. In the present study, the potential prognostic value of CLEC10A expression in BC was assessed using data from The Cancer Genome Atlas online database. Differences in the mRNA expression levels of CLEC10A between BC and normal tissues were then analyzed using the Tumor Immune Estimation Resource (TIMER) platform and the University of Alabama at Birmingham Cancer data analysis portal. Reverse transcription-quantitative PCR was performed to validate the results of this analysis. The Kaplan-Meier plotter database was used to evaluate the association between the mRNA expression levels of CLEC10A and clinical prognosis of BC. Based on the association between the mRNA expression levels of CLEC10A and the tumor immune microenvironment, the TIMER platform and the Tumor and Immune System Interaction Database website were utilized to assess the correlation between CLEC10A expression and the degree of tumor immune cell infiltration. The present study revealed that CLEC10A expression was significantly lower in BC tissues compared with that in normal tissues, which was in turn associated with poorer clinical outcomes. This suggested that lower CLEC10A expression levels were associated with unfavorable prognosis in BC. In addition, the expression level of CLEC10A was found to be positively associated with the level of different tumor-infiltrating immune cells in BC, including CD8 T cells, B cells, macrophages and NK cells which, was in turn closely correlated with some gene markers such as CD19, CD8A, KIR2DS4 and PTGS2. These results suggest that the relationship between lower CLEC10A expression level and poor prognosis in BC may be due to the role of CLEC10A in the tumor immune microenvironment. In conclusion, CLEC10A may be a potential biomarker that can be used to efficiently predict prognosis in patients with BC.

13.
Microb Pathog ; 166: 105537, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35430269

RESUMEN

Anthracnose disease has harmed walnut in recent years, resulting in yield losses in China. As a results, both morphological and molecular techniques must be used to confirm the etiology of anthracnose on walnut. In May 2020, walnut branches with indications of anthracnose were gathered in Ganquan, China (N33°56'/E105°44'). A strain named JT20 was isolated and morphologically characterized as a Colletotrichum specie. Pathogenicity tests further confirmed that the strain caused apparent anthracnose symptoms on walnut which were consistent with those seen in the field. On PDA, colonies were gray, cotton wool-like on the surface and pale gray to pale orange on the dorsal side. Conidia were aseptate, hyaline, fusiform to cylindrical with rounded to pointy ends and a length of 5.52-9.30 × 2.18-4.61 µm. PDA, lactose, yeast extract, pH 6-8, temperature of 25 °C and complete darkness were shown to be the optimum culture conditions for surface mycelium growth while PSA, lactose, urea, pH 9, temperature of 30 °C and complete darkness were found to be the best conditions for pathogen sporulation. The isolate was deduced as based on phylogenetic analysis with 3 genes (ribosomal DNA-ITS, ACT and GAPDH) as well as morphological characteristics and cultural features, the isolate was identified C. nymphaeae. This is the first report of C. nymphaeae causing walnut anthracnose in China.


Asunto(s)
Colletotrichum , Juglans , Colletotrichum/genética , Lactosa , Filogenia , Enfermedades de las Plantas
14.
Microb Pathog ; 163: 105382, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34974122

RESUMEN

To obtain a potential biocontrol agent for potato scab, 75 endophytic bacteria were isolated from the healthy potato tubers and strain 3-5 was selected as an optimal antagonistic bacterium against Streptomyces griseoplanus (Streptacidiphilus griseoplanus) causing potato scab. Strain 3-5 was identified as Bacillus amyloliquefaciens based on its morphological characteristics, 16S rDNA and gyrB gene sequence analysis. B. amyloliquefaciens 3-5 has biological functions of indole-3-acetic acid (IAA) production and nitrogen fixation. Polymerase chain reaction (PCR) detection revealed that B. amyloliquefaciens 3-5 had 6 diverse antibacterial substance synthesis genes, named bacD, bacAB, ituD, ituC, sfP and albF, which resulted in the production of bacilysin, iturin, surfactin and subtilosin. Field efficacy evaluation revealed that B. amyloliquefaciens 3-5 (solid fermentation) was successful in controlling potato scab with a 38.90 ± 3.2140% efficiency which is higher than other chemical bactericides except zhongshengmycin·oligosaccharins and kasugamycin·zhongshengmycin. The endophytic bacterium B. amyloliquefaciens 3-5 could be used as a biocontrol agent against potato scab due its control efficacy and environmental safety.


Asunto(s)
Bacillus amyloliquefaciens , Solanum tuberosum , Enfermedades de las Plantas
16.
Sci Adv ; 7(50): eabh2358, 2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34890237

RESUMEN

The CRISPR-Cas12a has been harnessed as a powerful tool for manipulating targeted gene expression. The possibility to manipulate the activity of CRISPR-Cas12a with a more precise spatiotemporal resolution and deep tissue permeability will enable targeted genome engineering and deepen our understanding of the gene functions underlying complex cellular behaviors. However, currently available inducible CRISPR-Cas12a systems are limited by diffusion, cytotoxicity, and poor tissue permeability. Here, we developed a far-red light (FRL)­inducible CRISPR-Cas12a (FICA) system that can robustly induce gene editing in mammalian cells, and an FRL-inducible CRISPR-dCas12a (FIdCA) system based on the protein-tagging system SUperNova (SunTag) that can be used for gene activation under light-emitting diode­based FRL. Moreover, we show that the FIdCA system can be deployed to activate target genes in mouse livers. These results demonstrate that these systems developed here provide robust and efficient platforms for programmable genome manipulation in a noninvasive and spatiotemporal fashion.

17.
Front Oncol ; 11: 654428, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34381705

RESUMEN

Breast cancer (BC) is the most frequent cancer among women worldwide and is the leading cause of cancer-related deaths in women. Cancer cells with stem cell-like features and tumor-initiating potential contribute to drug resistance, tumor recurrence, and metastasis. To achieve better clinical outcomes, it is crucial to eradicate both bulk BC cells and breast cancer stem cells (BCSCs). Salinomycin, a monocarboxylic polyether antibiotic isolated from Streptomyces albus, can precisely kill cancer stem cells (CSCs), particularly BCSCs, by various mechanisms, including apoptosis, autophagy, and necrosis. There is increasing evidence that salinomycin can inhibit cell proliferation, invasion, and migration in BC and reverse the immune-inhibitory microenvironment to prevent tumor growth and metastasis. Therefore, salinomycin is a promising therapeutic drug for BC. In this review, we summarize established mechanisms by which salinomycin protects against BC and discuss its future clinical applications.

18.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34404729

RESUMEN

Chimeric antigen receptor (CAR)-engineered T cell therapies have been recognized as powerful strategies in cancer immunotherapy; however, the clinical application of CAR-T is currently constrained by severe adverse effects in patients, caused by excessive cytotoxic activity and poor T cell control. Herein, we harnessed a dietary molecule resveratrol (RES)-responsive transactivator and a transrepressor to develop a repressible transgene expression (RESrep) device and an inducible transgene expression (RESind) device, respectively. After optimization, these tools enabled the control of CAR expression and CAR-mediated antitumor function in engineered human cells. We demonstrated that a resveratrol-repressible CAR expression (RESrep-CAR) device can effectively inhibit T cell activation upon resveratrol administration in primary T cells and a xenograft tumor mouse model. Additionally, we exhibit how a resveratrol-inducible CAR expression (RESind-CAR) device can achieve fine-tuned and reversible control over T cell activation via a resveratrol-titratable mechanism. Furthermore, our results revealed that the presence of RES can activate RESind-CAR T cells with strong anticancer cytotoxicity against cells in vitro and in vivo. Our study demonstrates the utility of RESrep and RESind devices as effective tools for transgene expression and illustrates the potential of RESrep-CAR and RESind-CAR devices to enhance patient safety in precision cancer immunotherapies.


Asunto(s)
Citotoxicidad Inmunológica/inmunología , Inmunoterapia Adoptiva/métodos , Leucemia Eritroblástica Aguda/inmunología , Activación de Linfocitos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Animales , Apoptosis , Proliferación Celular , Modelos Animales de Enfermedad , Femenino , Humanos , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/terapia , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
19.
Front Oncol ; 11: 652253, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34150621

RESUMEN

Circulating Tumor Cells (CTCs) are cancer cells that split away from the primary tumor and appear in the circulatory system as singular units or clusters, which was first reported by Dr. Thomas Ashworth in 1869. CTCs migrate and implantation occurs at a new site, in a process commonly known as tumor metastasis. In the case of breast cancer, the tumor cells often migrate into locations such as the lungs, brain, and bones, even during the early stages, and this is a notable characteristic of breast cancer. Survival rates have increased significantly over the past few decades because of progress made in radiology and tissue biopsy, making early detection and diagnosis of breast cancer possible. However, liquid biopsy, particularly that involving the collection of CTCs, is a non-invasive method to detect tumor cells in the circulatory system, which can be easily isolated from human plasma, serum, and other body fluids. Compared to traditional tissue biopsies, fluid sample collection has the advantages of being readily available and more acceptable to the patient. It can also detect tumor cells in blood earlier and in smaller numbers, possibly allowing for diagnosis prior to any tumor detection using imaging methods. Because of the scarcity of CTCs circulating in blood vessels (only a few CTCs among billions of erythrocytes and leukocytes), thorough but accurate detection methods are particularly important for further clinical applications.

20.
Plant Dis ; 2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-33973812

RESUMEN

Fennel (Foeniculum vulgare Mill.) is herbaceous plant commonly cultivated for culinary and medicinal uses in China (Shi et al. 2016 ). In May 2019, disease of fennel was observed in Yumen City, Gansu Province, China (N 40°28'/E 97°05'). The incidence across the fields (about 0.23 hectare) was about 4.5%. The outer leaves of diseased fennel wilted, the rhizome changed color from brown to dark brown,necrosis and rot symptoms developed on the root. Finally, the whole plant wilted and died. When pulling up, it was easy to break the root. To identify the pathogen, 15 samples of diseased plants were collected and symptomatic rhizome tissues were surface disinfected with 0.1% HgCl solution for 30 s, rinsed in sterilized water 3 times, placed on potato dextrose agar (PDA), and incubated at 25℃ in the dark. About 7 days, hyphal tips from the tissue edge were transferred to a new PDA for purification. Three isolates obtained were named as hxa, hxb and hxc. To confirm their pathogenicity, two-month old fennel seedings planted in pots, three seedings per pot, with sterilized nutrient soil were inoculated by pouring 50 ml of conidial suspension (107 conidium/mL) produced from the three isolates. Plants inoculated with sterilized water only were included as controls. Six pots of inoculated plants were maintained in climatic cabinet / chamber (> 85% RH, 25°C). The pathogenicity tests were conducted twice. After 7 days, the plants inoculated with conidial suspension of hxa developed brown necrosis and wilt symptoms resembling those originally observed in the field, whereas the controls and the plants inoculated with the other two isolates had no symptoms. Furthermore, hxa was reisolated from rhizome of these diseased plants. The results indicated that isolate hxa was the pathogen causing root rot of fennel. The colonies of hxa on PDA were white-to-cream, slimy, mycelium appressed, aerial mycelium absent. Mycelium was hyaline, septate and formed hyphal coils. Conidiophores were solitary, hyaline, sometimes crooked or sinuous, widest at the base, gradually tapering to the apex. Conidia were smooth, hyaline, aseptate, elliptical and ovoid, measuring 5.97 to 9.51 × 2.13 to 3.58 um (avg. 7.58×2.78, n=100). These morphological characters of the fungal isolates were identical to those of Plectosphaerella cucumerina (Carlucci et al. 2012). For molecular identification, genomic DNA was extracted from the mycelium, and the rDNA internal transcribed spacer (ITS) region, portions of the 28S ribosomal RNA (LSU), calmodulin (CaM) and translation elongation factor 1α (Ef-1α) gene were amplified using primer pairs ITS1/ITS4, LROR/LR5, CMD5/CMD6 and 688f/1251R (White et al., 1990; Hopple et al., 1999; Hong et al., 2005; Alves et al., 2008), respectively. The sequences of these genes were deposited in GenBank (accessions: ITS as MW426266, LSU as MW433724, CaM as MW448071 and EF-1a as MW459981) and used in analysis to generate a phylogenetic tree. These sequences showed 100, 100, 96 and 97.32% homology to the sequences of P. cucumerina (GenBank accession no. EU594566, MH867359, KY416911 and KY964491), respectively. According to morphological characteristics and phylogenetic analysis, isolate hxa was identified as P. cucumerina. To our knowledge, this is the first report of P. cucumerina causing root rot of fennel in China as well as worldwide. This finding may help to take effective control measures of root rot on fennel.

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