Characterization of starch produced by suspension cell cultures of Indica rice (Oryza sativa L.)

Suspension cultures of rice (Oryza sativa L.), initiated from seed, produced significant amounts of starch. Starch accumulated in the cultured cells throughout the growth phase and reached a maximum of 7% of the cell dry weight at stationary phase. Starch was present in compound granules which were birefringent under polarized light. Suspension culture starch had a higher amylose content and a lower gelatinization temperature than rice grain starch. Additionally, starch branching enzyme, an enzyme involved in starch biosynthesis, was characterized by anion exchange chromatography in culture cells and endosperm. Culture cells had at least one major form of starch branching enzyme which differed from the multiple enzyme forms present in endosperm.