Comparative Study on Coat Proteins of an Attenuated, a Temperature Sensitive and Their Parent Strains of Tobacco Mosaic Virus

Abstract

AbstractAn attenuated strain (L11A) of tobacco mosaic virus (TMV) induces no remarkable symptoms on tomato plants (Goto and Nemoto 1971) and has been used to protect tomato against virulent strains of TMV (Oshima 1981), A temperature sensitive strain (Ls1) of TMV was isolated and found to have a malfunction of virus movement from cell to cell (NISHI‐GUCHI et al. 1978, 1980). Those two strains are derived from a wild virulent strain (L). Coat proteins of them were compared with one another and with that of Dahlemense (D) strain of TMV, in order to see whether coat protein was associated with their respective characters.The coat proteins of the four strains behaved similar in both SDS‐polyacrylamide gel and 8 M urea polyacrylamide gel electrophoresis, suggesting that they are similar in molecular weight and charging effect in the gels. There was no significant difference in chromatographic pattern of tryptic peptides among the four strains. Amino acid compositions of tryptic peptides revealed that three strains, L11A, Ls1 and L, were identical to one another and that they differed from D slightly. These results suggest that coat protein is related neither to virus attenuation of L11A nor to the malfunction of Ls1.