Differential expression of the proteins in endosperms of rice with different chromosome sets

The present paper compared the major storage proteins in starchy endosperm of four autotetraploid rice lines with that of their corresponding diploid rice lines. The content of albumin, globulin, prolamin and glutelin in each sample was determined respectively. The structure and expression pattern of each storage protein was investigated using one-dimensional SDS-PAGE. Our results showed that the protein content of each fraction in endosperm of autotetraploid rice line is mostly higher than that of its corresponding diploid rice line. However, the SDS-PAGE analysis showed that the subunit types of each storage protein of autotetraploid rice line was generally homologous to that of its corresponding diploid rice line, except for one differential band observed on SDS-PAGE gels of total protein fraction and another on the SDS-PAGE gels of albumin and globulin fraction. These results indicated that duplicated genes in autotetraploid rice ac-quired the same expression patterns as that seen in its corresponding diploid rice. It was suggested that the doubling of chromosome sets did not change the protein expression profile but the protein expression level in the starchy endosperm of autotetraploid rice.