An electron microscope study of tobacco mosaic virus at different stages of infection.
An electron microscope study of tobacco mosaic virus at different stages of infection.
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烟草花叶病毒感染不同阶段的电子显微镜研究。
DOI：
10.1002/j.1537-2197.1946.tb10385.x
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发表时间：
1946
影响因子：
3
通讯作者：
Nedra M. Utech
中科院分区：
文献类型：
--
作者：
T. Rawlins;Catherine Roberts;Nedra M. Utech
电子显微镜研究证实了斯宾塞的沉降研究，表明从感染5天的叶子中提取的纯化烟草花叶病毒制剂通常比从感染20天的叶子中提取的类似病毒制剂含有更高比例的双长颗粒。目前还无法证明双长度颗粒是由于病毒颗粒在宿主体内逐渐伸长还是由于两个长度约为300 μ m的典型颗粒的端到端聚集造成的。大多数证据显然支持后一种解释。5天病毒中颗粒长度超过450 μ m的普遍现象可以解释Stanley和Spencer的结果，他们发现，给定重量的纯化7天和5天病毒产生的局部病变比相同重量的28天和20天病毒产生的局部病变少。我们的结果表明，当病毒悬浮在稀磷酸盐- hcl溶液中时，采用高速和低速交替离心纯化的病毒比悬浮在蒸馏水中的类似纯化的病毒产生更少的端到端聚集。很大比例的烟草花叶病毒颗粒长度通常在300 μ m左右。这些粒子的长度显然受到某些因素的非常精确的控制，这些因素使粒子的长度保持在很窄的范围内，但并没有产生完全相同长度的粒子。所有现有证据表明，这种长度的颗粒存在于寄主植物中。这些颗粒长度变化如此之小，似乎不太可能是由较短的病毒颗粒端到端聚集形成的。纯化病毒在1℃蒸馏水中保存12个月左右。未能引起可检测的粒子聚集。
Electron microscope studies confirm Spencer's sedimentation studies indicating that purified tobacco mosaic virus preparations from leaves infected for five days usually contain a higher proportion of double-length particles than do similar virus preparations from leaves infected 20 days. It has not been possible to prove whether the double length particles resulted from gradual elongation of virus particles while in the host or from end-to-end aggregation of two typical particles having a length around 300 mμ. Most of the evidence apparently favors the latter explanation. The prevalence of particles longer than 450 mμ in 5-day virus may explain the results of Stanley and of Spencer in which they found fewer local lesions produced by a given weight of purified 7- and 5-day virus than by the same weight of 28- and 20-day virus. Our results indicate that purification by alternate high and low speed centrifugation while the virus is suspended in dilute phosphate-HCl solution causes less end-to-end aggregation than similar purification of virus suspended in distilled water. A very high proportion of tobacco mosaic virus particles regularly have a length around 300 mμ. The length of these particles has apparently been very accurately controlled by some factors which have kept the length within narrow limits but have not produced particles of exactly the same length. All of the available evidence indicates that particles of this length were present in the host plant. It does not appear probable that these particles, showing so little variation in length, have been formed by the end-to-end aggregation of shorter virus particles. Storage of purified virus around 12 months in distilled water at 1⚬C. failed to cause detectable aggregation of particles.