Modulation of carbohydrate metabolism in transgenic potato through genetic engineering and analysis of rabbits fed on wild type and transgenic potato tubers

Abstract

Previously we described generation of two types of transgenic potato plants. In one of them the 14-3-3 protein derived from Cucurbita pepo was overexpressed, in the other one respective endogenous protein was repressed. Detailed analysis of those plants suggested that the analysed 14-3-3 isoform controlled plant senescence. In this study the carbohydrate contents, adenine nucleotide level and catecholamine contents in tubers and leaves of transgenic plants grown in a greenhouse and in a field were compared. Overexpressing of 14-3-3 protein led to an increase in catecholamine and soluble sugars contents in leaves and a reduction in tubers size and starch content. The repression of 14-3-3 synthesis led to opposite effect, namely to a decrease in catecholamine and soluble sugars content in leaves and to an increase in tubers size and in starch content. It is proposed that 14-3-3 protein affects carbohydrate metabolism in potato via regulation of catecholamine synthesis. The transgenic potato tubers differing in soluble sugars to starch ratio and in carbohydrate content in tubers were used for rabbit feeding. The increase in body weight correlated with soluble sugars content in potato tubers. There were only slight changes in leucocyte and erythrocyte numbers measured in peripheral blood and also almost no change in hemoglobin content and erythrocyte volume.