Recovery of tobacco mosaic virus RNA Replication after incubation at 40 degrees.

Incubation of tobacco mosaic virus (TMV)-infected tissue at 40 degrees for 12 h destroyed the capacity for TMV RNA replication. Upon shift of the tissue from 40 to 25 degrees, synthesis of TMV RNA did not resume. Incubation at 40 degrees for 1 h did not destory the TMV RNA replicase, because viral RNA synthesis resumed upon return to 25 degrees. However, upon further incubation at 25 degrees, the synthesis rate of TMV RNA gradually declined. Upon still further incubation at 25 degrees (16-20 h), the synthesis of TMV RNA in tissue incubated at 40 degrees for either 1 or 12 h recovered. This recovery was inhibited by cycloheximide but not by 2-thiouracil.