Abstract
Protein and nucleic acid metabolisms in tobacco mosaic virus-infected Nicotiana glutinosa leaves were investigated. The plants were incubated at 32C for 2 or 3 days after inoculation with tobacco mosaic virus to establish a systemic infection and then some of these infected plants were transferred to 25C to induce local lesions and the others were kept 32C as controls. The leaves of each plant were detached and labeled by 14CO2. The supernatant fraction (S), mainly soluble proteins, obtained from the sap of the leaves by ultracentrifugation (105, 000×g) and the SDS-solubilized fraction (PS), mainly particulate-bound proteins, of precipitates at 10, 000×g, were electrophoresed on polyacrylamide gel columns. No difference in the proportion of protein was detected in both S and PS fractions between control and shifted plants. The incorporation of 14C from 14CO2 into the pellet fraction (P) at 105, 000×g, virus fraction, was reduced by the temperature shift. Methylated albumin kieselgur column chromatography of nucleic acid fractions obtained by phenol-SDS method showed that no significant change occurred in the proportion of molecular species of nucleic acids after temperature shift.
