ASPECTS OF THE PHOTOBIOLOGY OF POTATO VIRUS X, ITS RNA AND A HYBRID PARTICLE OF TMV PROTEIN-PVX-RNA

摘要

The inactivation of potato virus X (PVX), free PVX-RNA, and a phenotypically mixed virus particle composed of PVX-RNA and U-l TMV protein (PVXRNA : TMVPRO) by ultraviolet, radiation was studied at three wavelengths. Rate constants of inactivation and inactivation quantum yields have been determined for irradiation in H20 and D20;the kinetic isotope effect for inactivation has been calculated for the different particles. In addition, the visible light-dependent plant host mediated repair of ultraviolet damage known as photoreactivation following ir-radiation of PVX, PVX-RNA, and PVXRNA :TMVPRO at the three wavelengths in H20 and D20 has been measured. These results are compared and the implicatiors as to the inactivation mechanism are discussed. It is concluded that the constraints imposed upon PVX-RNA by the capsomer protein of PVX are less than the corresponding constraints in the case of TMV.