Purification and Analysis of Abscisic Acid-Specifically-Inducible Proteins from Rice Callus

Two ABA-specifically-inducible proteins from rice callus were isolated and purified by precipitation with 65–100% saturated (NH4)2SO4, followed by the DEAE-sepharose, TSK-gel, and two-dimension electrophoresis. Iso-electric points (pI) of the proteins with the same molecular mass (24.5 kD) were 6.1 and 6.9, respectively. The Western blot analysis indicated that the proteins expressed in different tissues were obviously different. The A1 (pI 6.1) protein was only detected in calli treated with ABA and seed embryos (SE). However, the A2 (pI 6.9) protein was found not only in the calli treated with ABA and SE, but also in the white dry callus. Thus it suggested that the two proteins might play some important roles in the processes of seed embryo (or somatic embryo) formation.