title: Mode of action of the antiphytoviral compound 2,4-dioxohexahydro-1,3,5-triazine (5-azadihydrouracil).
abstract: The time course of inhibition of potato virus X ( PVX ) synthesis by the newly developed antiphytoviral compound 2,4- dioxohexahydro -1,3,5-triazine (DHT) was determined in mechanically inoculated leaves of Nicotiana tabacum L. cv. ' Samsun '. At the permissive temperature (22 +/- 3 degrees) DHT inhibited the synthesis of PVX almost 100% within 8 h postinoculation, after which the inhibition declined. In leaves maintained at a temperature of 5 +/- 2 degrees for 5 days, DHT inhibited PVX synthesis about 65% immediately after the shift to permissive temperature. This time course of inhibition was almost identical to that of 2-thiouracil. Uracil completely overcame the inhibition of PVX replication caused by DHT when added within 2 h after incubation of leaf disks with DHT. These results indicate that DHT acts as an analogue of the pyrimidine base uracil.
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004347:Drug Interactions; D010935:Plant Diseases; D010942:Plant Viruses / Q000187:drug effects* / Q000254:growth & development; D010947:Plants, Toxic; D013696:Temperature; D013889:Thiouracil / Q000494:pharmacology; D014026:Nicotiana / Q000382:microbiology*; D014227:Triazines / Q000494:pharmacology*; D014498:Uracil; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D014227:Triazines; C020894:dioxohexahydrotriazine; D014498:Uracil; D013889:Thiouracil; D003513:Cycloheximide