Abstract.
The aim of this work was to investigate the extent to which starch synthesis in potato (Solanum tuberosum L.) tubers is controlled by the activity of ADPglucose pyrophosphorylase (EC 2.7.7.27; AGPase). In order to do this, fluxes of carbohydrate metabolism were measured in tubers that had reduced AGPase activity as a result of the expression of a cDNA encoding the B subunit in the antisense orientation. Reduction in AGPase activity led to a reduction in starch accumulation, and an increase in sucrose accumulation. The control coefficient of AGPase on starch accumulation in intact plants was estimated to be around 0.3. The fluxes of carbohydrate metabolism were measured in tuber discs from wild-type and transgenic plants by investigating the metabolism of [U-14C]glucose. In tuber discs, the control coefficient of AGPase over starch synthesis was estimated as 0.55, while the control coefficient of the enzyme over sucrose synthesis was −0.47. The values obtained suggest that AGPase activity exerts appreciable control over tuber metabolism in potato.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 24 February 1999 / Accepted: 8 April 1999
Rights and permissions
About this article
Cite this article
Sweetlove, L., Müller-Röber, B., Willmitzer, L. et al. The contribution of adenosine 5′-diphosphoglucose pyrophosphorylase to the control of starch synthesis in potato tubers. Planta 209, 330–337 (1999). https://doi.org/10.1007/s004250050640
Issue Date:
DOI: https://doi.org/10.1007/s004250050640