嘧肽霉素抗烟草花叶病毒作用机理初步研究

 以烟草花叶病毒(TMV)/烟草为测试体系,用³H-尿苷和³H-亮氨酸2种同位素示踪的方法研究了4%嘧肽霉素水剂抗TMV的作用机理。通过³H-尿苷示踪实验发现:无论是叶盘法还是整株法测定,嘧肽霉素均能抑制病毒对³H-尿苷的利用,抑制率分别为72.43%和68.95%;而对寄主植物RNA合成,2种方法的抑制率分别为8.09%和11.02%。通过³H-亮氨酸示踪结果可以看出:嘧肽霉素较强地抑制了病毒对³H-亮氨酸的吸收,但能促进寄主对³H-亮氨酸的吸收。³H-尿苷和³H-亮氨酸分别是RNA和蛋白质合成的前体物,因此,嘧肽霉素通过抑制病毒RNA复制和蛋白质的合成来扰乱病毒的增殖,从而减弱病害的发生。

Action mechanism of Cytosinpeptidemycin against Tobacco mosaic virus

Antiviral mechanism of Cytosinpeptidemycin against Tobacco mosaic virus(TMV)was tested by means of tracing ~3H-uridine and ~3H-leucine.Cytosinpeptidemycin is a newly reported antiphytoviral agricul-(tural) antibiotic.The results of ~3H-uridine tracing showed that Cytosinpeptidemycin inhibited the use of ~3H-uridine in synthesis of TMV-RNA and the inhibition rates were 72.43% and 68.95% respectively in testing methods of leaf discs and whole seedlings.Cytosinpeptidemycin had a little inhibition on the use of ~3H-uridine in synthesis of tobacco RNA.The result of ~3H-leucine tracing indicated that Cytosinpeptidemycin inhibited the use of synthetic precursor in synthesis of TMV coat protein,but it could promote the hosts' absorption of protein precursor.All results indicated that Cytosinpeptidemycin reduced damage of the virus on plants by inhibiting TMV-RNA replication and coat protein synthesis.