Effect of abscisic acid and slow drying on soluble carbohydrate content in developing embryoids of carrot (<i>Daucus carota</i> L.) and alfalfa (<i>Medicago sativa</i> L.)

Abstract

Abstract In the presence of abscisic acid (ABA), contents of glucose and fructose decreased in carrot embryoids, whereas umbelliferose increased during dehydration. The acquisition of desiccation tolerance was tested by scoring germinated embryoids. It did not keep pace with the changes in soluble carbohydrate contents during development, which suggests that in these somatic embryoids di- and oligosaccharides are not the determining factors for anhydrobiosis. However, on slow dehydration, umbelliferose increased, while sucrose decreased and the monosaccharides declined completely. These changes were positively correlated with increased desiccation tolerance. A similar analysis of slowly dried, ABA-treated alfalfa embryoids showed that stachyose and sucrose increased and the monosaccharides declined with the acquisition of desiccation tolerance. These data support the contention that carbohydrates are involved in anhydrobiosis.