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Degradation of RNA of Partially Uncoated Tobacco Mosaic Virus During Extraction from Tobacco Leaves
Author(s) -
Onda Haruo,
Hirai Tokuzo
Publication year - 1970
Publication title -
japanese journal of microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0021-5139
DOI - 10.1111/j.1348-0421.1970.tb00513.x
Subject(s) - tobacco mosaic virus , centrifugation , rna , rnase p , sucrose , differential centrifugation , chemistry , virus , tobacco leaf , extraction (chemistry) , ribonuclease , tobamovirus , chromatography , biology , virology , biochemistry , agricultural engineering , gene , engineering
Extracts of tobacco leaves, 3 to 22 hr after infection with 32 P‐labeled tobacco mosaic virus (TMV), were analysed by sucrose density‐gradient centrifugation. As reported previously, a shoulder appeared on the lighter side of the main peak representing intact parent viruses. The shoulder was shown to contain partially uncoated virus particles with sedimentation constants of about 140–150 S, which withstood dialysis against a phosphate buffer. RNA from the uncoated particles was isolated on the sucrose density‐gradient, and its sedimentation constant was estimated at 16–18 S. Intact TMV‐RNA and RNA having 16–18 S were also obtained directly from homogenates of tobacco leaves infected with 32 P‐TMV. 32 P‐TMV was partially stripped by SDS and was added to tobacco leaf sap to test the RNase activity in tobacco leaves. A part of RNA which was exposed by SDS was digested and the 32 P‐radioactivity in the top zone of the centrifugation tube increased. This finding supported the idea that the partially uncoated virus particles in infected leaves lost a portion of their RNA during extraction by the action of the RNase contained in the homogenate.