Watts J W, Dawson J R
John Innes Institute, Colney Lane, Norwich NR4 7UH, United Kingdom.
Virology. 1980 Sep;105(2):501-7. doi: 10.1016/0042-6822(80)90050-1.
Mixed infections of tobacco protoplasts with Cowpea chlorotic mottle virus (CCMV) and brome mosaic virus (BMV) have been studied. Fluorescent antibody staining showed that capsids of both viruses were made in doubly infected protoplasts but only infectious BMV could be recovered, i.e., BMV dominated in mixed infections and prevented synthesis of infectious CCMV. Healthy protoplasts could be infected after several hours in culture but the susceptibility to infection decreased with time in culture; the decrease was much faster with BMV than with CCMV, probably because the difference in electrical charge of the two viruses affects the method of entry into the protoplasts. If inoculation with the second virus was delayed there was an increasing resistance to superinfection (interference or cross-protection) so that when the delay between inoculations was more than 8 hr BMV was no longer able to infect protoplasts previously infected with CCMV and vice versa. No recombinants between BMV and CCMV were observed. Attempts to rescue a temperature-sensitive strain of CCMV with BMV under restrictive conditions (35 degrees ) were unsuccessful; dominance by BMV prevented synthesis of infectious CCMV RNA.
已对烟草原生质体与豇豆褪绿斑驳病毒（CCMV）和雀麦花叶病毒（BMV）的混合感染进行了研究。荧光抗体染色显示，两种病毒的衣壳在双重感染的原生质体中均有产生，但只能回收有感染性的BMV，即BMV在混合感染中占主导地位，并阻止了有感染性的CCMV的合成。健康的原生质体在培养数小时后可被感染，但随着培养时间的延长，其感染易感性会降低；BMV的降低速度比CCMV快得多，这可能是因为两种病毒电荷的差异影响了进入原生质体的方式。如果延迟接种第二种病毒，则对再次感染（干扰或交叉保护）的抗性会增加，因此当接种间隔超过8小时时，BMV就不再能够感染先前已被CCMV感染的原生质体，反之亦然。未观察到BMV和CCMV之间的重组体。在限制条件（35摄氏度）下用BMV拯救CCMV的温度敏感株的尝试未成功；BMV的主导地位阻止了有感染性的CCMV RNA的合成。
