Effect of glgB/GASBD fusion gene expression on increased branching degree of potato starch and changes in physicochemical properties of starch

The objective of this study was to investigate the influence of granule-bound starch-binding domain fusion gene expression on the structure and properties of potato starch. The glgB/GASBD fusion gene and the glgB gene for control were transferred into the potato cultivar Desiree using Agrobacterium-mediated method, which were expressed in potato tubers driven by the potato granule-bound starch synthase gene promoter. The accumulation of glgB/GASBD fusion protein in starch granules was analyzed by Western blot hybridization. A large amount of glgB/GASBD fusion protein was found to accumulate in the starch granules, and the position of the GASBD in the fusion protein (at the N-terminus or at the C-terminus) had no significant effect on the accumulation of the fusion protein in the starch granules. An increase in the degree of branching of the starch results in a specific change in the physical and chemical properties and functional properties of the starch.