ABSTRACT
Coffee (Coffea arabica L.) is currently grown in many tropical and subtropical areas countries and is a major traded commodity for the developing world. Coffee leaf blight, caused by Phomopsis heveicola, is one of the most important fungal diseases dangerous to coffee crops in China. This study aimed to develop a PCR-based diagnostic method for detecting P. heveicola in planta. Specific primers (CPHF/CPHR) were designed based on sequence data of region of internal transcribed spacer (ITS1 and ITS4) of P. heveicola. The efficiency and specificity of CPHF/CPHR were established by PCR analysis of DNA from P. heveicola strains isolated from China and fungal isolates of other genera. A single amplification product of 318 bp was detected from DNA P. heveicola isolates. No amplification product was observed with any of the other fungal isolates tested. The specific primers designed and employed in PCR detected P. heveicola up to 3 pg from DNA isolated. This is the first report on the development of a species-specific PCR assay for identification and detection of P. heveicola. Thus, the PCR-based assay developed was very specific, rapid and sensitive tool for the detection of pathogen P. heveicola.
Subject(s)
Coffea/microbiology , DNA, Fungal/genetics , Phomopsis/genetics , Phomopsis/isolation & purification , Plant Diseases/microbiology , China , Coffee , DNA Primers/genetics , Nucleic Acid Amplification Techniques , Phomopsis/metabolism , Polymerase Chain Reaction/methodsABSTRACT
We obtained a strain of Bacillus subtilis, which we named Czk1, from the aerial roots of rubber trees. This bacterial isolate exhibits strong antagonistic activity against Ganoderma pseudoferreum, Phellinus noxius, Helicobasidium compactum, Rigidoporus lignosus, Sphaerostilbe repens, and Colletotrichum gloeosporioides. Our earlier research has shown that the antagonistic activity of a fermentation supernatant Czk1 isolate produces a complex mixture of lipopeptides. In this study, we used methanol to extract crude lipopeptides, purified them using a Sephadex G-25 column, cloned the lipopeptide genes, and analyzed purified fractions by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) to identify the lipopeptides from B. subtilis strain Czk1. The cloned lipopeptide genes included those that encode the enzymes lpa, ituD, sfp, and fenB. The crude lipopeptides were purified and found in five fractions. Further analysis revealed that five fractions of the purified composition contained members of the surfactin, iturin, fengycin, and bacillomycin families of antibiotics. This suggests that these lipopeptides from strain Czk1 have potential as plant disease biocontrol agents.
Subject(s)
Bacillus subtilis/metabolism , Bacterial Proteins/metabolism , Hevea/microbiology , Lipopeptides/metabolism , Plant Roots/microbiology , Bacillus subtilis/genetics , Bacillus subtilis/isolation & purification , Bacterial Proteins/genetics , Bacterial Proteins/isolation & purification , Cloning, Molecular , Colletotrichum/drug effects , Colletotrichum/physiology , Lipopeptides/genetics , Lipopeptides/pharmacology , Methanol , Peptides, Cyclic/genetics , Peptides, Cyclic/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Spores, Fungal/drug effects , Spores, Fungal/physiologyABSTRACT
The in vitro sensitivity of AvrPik allele isolates of Magnaporthe oryzae to isoprothiolane was examined and the virulence fitness costs of AvrPik allele isolates to isoprothiolane were assessed. Isoprothiolane was found to suppress the radial growth of AvrPik allele isolates at all concentrations (1, 5, 10, 15, and 20 µg/mL). Generally, a higher isoprothiolane concentration has a stronger inhibitory effect on mycelial growth in AvrPik allele isolates at 6 and 10 days after inoculation. The inhibitory effect of isoprothiolane also increased with treatment time. To determine whether a correlation existed between the in vitro sensitivity of AvrPik allele isolates and virulence, the half-maximal inhibitor concentration and 75% of the maximum inhibitor concentration were calculated for each mutation isolate and wild-type isolate. Based on these values and virulence, no significant correlation between the susceptibility of AvrPik allele isolates and virulence was detected. In summary, no fitness costs were associated with sensitivity of blast isolates carrying specific AvrPik alleles to different virulence.
Subject(s)
Genetic Fitness/drug effects , Magnaporthe/drug effects , Mutation , Mycelium/drug effects , Thiophenes/pharmacology , Alleles , Dose-Response Relationship, Drug , Genotype , Magnaporthe/genetics , Magnaporthe/pathogenicity , Mycelium/genetics , Mycelium/pathogenicity , Oryza/microbiology , Plant Diseases/microbiology , Time Factors , VirulenceABSTRACT
This study assessed the clinical efficacy of lamivudine and adefovir dipivoxil combined with autologous bone marrow stem cell transplantation as treatment for patients with hepatitis B and decompensated liver cirrhosis. In total, 77 patients with hepatitis B and decompensated liver cirrhosis were randomly divided into two groups. Under general symptomatic and supportive treatment, the patients in group A (37 cases) were treated with lamivudine and adefovir dipivoxil, whereas those in group B (40 cases) were treated with autologous bone marrow stem cell transplantation in combination with lamivudine and adefovir dipivoxil. After 4 weeks of treatment, the liver function indicators and clinical signs and symptoms of the patients in group B improved more significantly than those of patients in group A. Lamivudine and adefovir dipivoxil in combination with autologous bone marrow stem cell transplantation effectively prevented hepatitis B virus infection and bone marrow stem cell damage. This combination treatment facilitates the differentiation of bone marrow stem cells into normal liver cells to restore liver structure and improve liver function, thereby improving the quality of life of patients.
