Comparative study of protein electrophoretic patterns during embryogenesis in Coffea arabica cv Catimor.

Embryogenic and non-embryogenic calli from leaf sections of Coffea arabica cv. Catimor, were analyzed under denaturing conditions in one- and two-dimensions by polyacrylamide gel electrophoresis. The protein patterns revealed qualitative and quantitative differences in size and charge. In non-embryogenic calli, two dimensional analysis reveals seven distinctive polypeptides in the range of 15 to 70 kDa. Four of the polypeptides are acidic, three of 70 kDa and one of 15 kDa. Similarly, in embryogenic calli there are seven characteristic polypeptides with molecular weight from 23 to 35 kDa in a broad pI from acid to basic. Five of them are found in the neutral to acid pI, and are probably related to storage protein-like polypeptides detected in zygotic embryos and seeds of Coffea arabica cv. Catimor. Changes in the protein pattern appear to correlate with histological differences in embryogenic calli and with different stages of development of somatic embryos.