The Action Mechanism Of Cytosinpeptidemycin On Tobacco Mosaic Virus

Cytosinpeptidemycin is a newly reported antiphytoviral agricultural antibiotic. It was produced by fermentation broth of Streptomyces achygroscopicus var.liaoningensis, which was isolated from soil of Tianzhu hill in Shenyang. Cytosinpeptidemycin has no harmful effects to animals and environment. It can be used to inhibit plant disease caused by tobacco mosaic virus (TMV), and it has gained the pesticide register. Physiological, biochemical and molecular biological methods were adopted to study the action mechanism of cytosinpeptidemycin on TMV thoroughly by TMV/tobacco system. The results are as follows:1. According to its physical and chemical properties and known techniques of extraction and purification, a set of suitable craft was chosen to separate and purify the antibiotic,which is both economic and practical. Cytosinpeptidemycin was separated and purified using methods of adsorption with active charcoal and ion-exchange chromatography combining with the method of TLC, and the effects were obvious. Cytosinepeptide as an effective compoment was used for this research.2. Cytosinpeptidemycin is a kind of extensive antiphytoviral agricultural antibiotics, and it can prevent and cure virus diseases of various kinds of hosts caused by TMV effectively. The influence of cytosinpeptidemycin on the concentration of TMV in Plant with different treatments were tested by several methods, such as biological methods, UV absorption, and ELISA. Results indicated that cytosinpeptidemycin could decrease the concentration of TMV in plants. The effect of spraying 4% cytosinpeptidemycin 24h before TMV inoculation is better than that of spraying after inoculation. The treatment which virus was mixed with the 4% cytosinpeptidemycin for lh at the equal volume before inoculation got the best effect, and the rate of inhibition reached 96%;Theeffect of spraying 4% cytosinpeptidemycin 24h after inoculation was not distinct.3. The inhibition of cytosinpeptidemycin on TMV was studied by biological and Electronic Microscope method combining with UV absorption analytic method. The results showed that cytosinpeptidemycin could inactive strongly virions of TMV in vitro and in viro, and the inhibition rate reached 92.1% and 32.8%, respectively. The infectivity of TMV was not resumable by diluting the mixture of TMV and cytosinpeptidemycin. The virions treated with cytosinpeptidemycin appeared ruptures and abnormalities through Electron Microscopy, which showed that cytosinpeptidemycin destructed the structure of the TMV.4. Cytosinpeptidemycin degraded strongly TMV-RNA in vitro. TMV-RNA was treated with cytosinpeptidemycin before inoculation and the inhibition rate reached 92.6%.Tracing of ~3H-uridine was used to test the antiviral mechanism of cytosinpeptidemycin against tobacco mosaic virus also. The result showed that cytosinpeptidemycin inhibited the use of the precursor of viral RNA in the test of leaf discs and seedlings. A new method, quantitative competitive PCR with software of Image Master ED was used in quantitative detecting TMV-RNA in infected plant tissues and those treated with 4% cytosinpeptidemycin. Three different treatments were adopted. The results indicated that in all treatments TMV-RNA accumulation was reduced in TMV-infected tobacco leaves treated with 4% cytosinpeptidemycin. TMV-RNA accumulation was reduced greatly when TMV was mixed with cytosinpeptidemycin at the equal volume. The results were also confirmed by Indi-ELISA technique. Cytosinpeptidemycin inhibited the replication of TMV-RNA to reduce the harm to host caused by TMV. In conclusion, cytosinpeptidemycin inhibited the infection of TMV by reducing RNA accumulation in infected plants. The effect of cytosinpeptidemycin on the RNase activity was studied in order to find the action mode of cytosinpeptidemycin on replication of TMV-RNA. The results indicted that cytosinpeptidemycin inhibited replication of TMV-RNA by increasing RNase...