Purification and properties of elm mottle virus |
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Authors: | A T JONES M A MAYO |
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Institution: | Scottish Horticultural Research Institute, Invergowrie, Dundee, Scotland |
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Abstract: | A virus obtained commonly from Wych elm (Ulmus glabra) in Scotland showing ringspot and line-pattern leaf symptoms was serologically related to elm mottle virus (EMotV) from East Germany. The virus was seed-borne in elm and was transmitted by inoculation of sap to elm and twenty-one herbaceous species. No symptoms developed in infected elm seedlings kept in the glasshouse. In Chenopodium quinoa sap, EMotV lost infectivity after diluting to 10-4, after 10 min at 60 oC, or 9 days at 18 oC. When purified from C. quinoa sap by clarification with n-butanol (8-5 %, v/v) and differential centrifugation, preparations contained quasi-spherical particles mostly 26–29 nm m diameter (mean = 28 nm) which sedimented as three nucleo-protein components with sedimentation coefficients (so2o, w) of 83, 88 and 1 or S; most infectivity was associated with the 101 S component but infectivity was enhanced by adding the slower sedimenting components. When centrifuged to equilibrium in caesium chloride solution at 4 oC, purified virus preparations were largely degraded and contained many non-infective particles c. 15–22 nm in diameter, and intact infective particles which formed a band of density c. 1–34 g/cm3. Polyacrylamide gel electrophoresis indicated that EMotV contained a single major protein species of estimated mol. wt. 25000 and five RNA species of estimated mol. wt. 1–30, 1.15, 0–82, 0 39 and 0–30 times106. Gel electrophoresis of RNA extracted from the separated components indicated that the 101 S component contained 1–30 x io6 mol. wt. RNA and the 83 S component 0–82 times 106 mol. wt. RNA. In these and other properties, EMotV resembles the serologically unrelated tobacco streak virus. |
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