Evaluation of SDS-Polyacrylamide gel electrophoresis and immunostrip technique for detection of Tobacco mosaic virus and Cucumber mosaic virus in IRAQ


his study was carried out to evaluate the efficiency of electrophoresis on SDS- poly acrylamide slap gel and immunostrip techniques for detection of Tobacco mosaic virus (TMV, genus Tobamovirus) and Cucumber mosaic virus (CMV, genus Cucumovirus, family Bromoviridae), compared with symptoms on diagnostic plants for the two viruses. The results obtained showed that the two methods were effective. The analysis of samples of purified CMV, total proteins from infected cucumber plants, and extracts from infected plants with or without chlorophyll, by electrophoresis on 10% polyacrylamide slap gel containing 0.1% SDS showed two bands of 24 and 26 kd in size, and absent in samples of total protein or extracts of healthy plants. These two proteins represent the coat protein (CP) of CMV. In addition, one 18 kd protein band appeared on SDS- polyacrylamide gel profile which represent the CP of TMV, when samples of purified virus, total protein of infected plants, and plant extracts with or without chlorophyll were analyzed. This band was absent in similar samples from healthy plants. The test of immunostrip specific for CMV showed positive reaction with extracts from melon, cucumber, winter squash, and zucchini infected plants. Similarly, a positive reaction with immunostrip specific for TMV appeared with extracts from tobacco, tomato infected with TMV. No reaction was obtained with healthy plants extract. These results were similar to those obtained from indicator plants for the two viruses.