ABSTRACT
By the end of 2021, the pear yield in Xinjiang reached 1,795,900 tons, accounting for 1/9 of the country. Pear black spot, caused by Alternaria gaisen disease, has had a significant impact on the pear industry. A. gaisen can infect nearly all pear plants, resulting in black spots on the fruit that negatively affect both yield and quality. This study focused on the TRM76323 strain of Streptomyces, which was isolated from the soil of Tamarix chinensis in Xinjiang Province. Through a multiphase classification and identification method, the genetic classification status of the antagonistic strains was determined. The study also identified the antibacterial active components of streptochlorin using modern isolation and purification techniques. The antagonistic activity of Streptomyces against Alternaria was analyzed through in vitro and in vivo experiments. This research not only expanded the resource bank of antagonistic microorganisms in extreme environments in Xinjiang, but also identified active components that could contribute to the development of new drug lead compounds. Additionally, this study presents a novel approach for the prevention and control of pear black spot disease.
ABSTRACT
This paper aimed to investigate the role of Duhuo Jisheng decotion (DHJSD) in delaying human disc degeneration and its possible molecular mechanism. The intervertebral disc specimens were divided into normal and degenerated groups according to Pfirrmann classfication. The expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in intervertebral disc tissue were detected by Western blot and PCR. Then degenerated human primary NPCs were cultured in vitro, the viability of NPCs treated with stromal cell-derived factor-1 (SDF-1，10 μg·L⁻¹)and various concentrations of DHJSD was assessed by the CCK-8 assay, and the appropriate concentration was screened. The experiment was divided into three groups, control group, SDF-1 group and DHJSD plus SDF-1 group. The levels of TNF-α, IL-1β, Agg, coIⅡ, MMP-3 and MMP-13 were detected. The levels of CXCR4, NF-κB major groups P65 phosphorylation (p-P65) and nuclear translocation, after treated with CXCR4 siRNA and NF-κB inhibitor (BAY11-7082) were measured by Western blot and immunofluorescence. At the same time, the expression of cell inflammatory factors and extracellular matrix were also measured. The expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in the degenerated intervertebral disc tissue were significantly increased. In vitro study, the results of CCK-8 indicated that the viability of NPCs was significantly increased when DHJSD concentration was 300 mg·L⁻¹. After the experiment was divided into three groups, compared with SDF-1 group, the expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in DHJSD group were significantly decreased, but the expressions of Agg, coIⅡ were significantly increased. When CXCR4-siRNA was transfected into NPCs, SDF-1 increased expressions of CXCR4 and p-P65 and inhibited nuclear translocation of P65, whose effect was suppressed by CXCR4-siRNA and DHJSD. In addition, when BAY11-7082 was used to treat NPCs, the expression of TNF-α, IL-1β, MMP-3 and MMP-13 were significantly decreased. DHJSD could inhibit the production of inflammatory factors and promote the synthesis of extracellular matrix. The potential mechanism may be related to the SDF-1/CXCR4/NF-κB signaling pathway.
