Abstract
Fruit trees in Rosaceae family, such as apple, have a unique metabolic pathway, that is, Rosaceae trees synthesize sorbitol in source leaves and transport sorbitol to sink organs in addition to sucrose. Sorbitol synthesis leads higher photosynthesis rate comparing with plants, which synthesize sucrose as a sole translocate sugar. Sorbitol is known to be a compatible solute against water and cold stresses and it promote boron movement in plant body. To add sorbitol synthetic ability to non-sorbitol synthetic plants, sorbitol-6-phosphate dehydrogenase (S6PDH) from apple was transformed to Arabidopsis thaliana under the control of source leaf specific promoter, i.e. chlorophyll a/b binding protein (cab) promoter. 6 transformants were obtained. Although one transformant has trace level of sorbitol, other transformants synthesize certain amount of sorbitol. Growth of transformants deteriorated and the plants dead easily. The transformants have small, tick and rough leaves and their flowering time is slightly earlier than wild type.
