Production of high‐starch, low‐glucose potatoes through over‐expression of the metabolic regulator SnRK1
- 15 May 2006
- journal article
- Published by Wiley in Plant Biotechnology Journal
- Vol. 4 (4), 409-418
- https://doi.org/10.1111/j.1467-7652.2006.00190.x
Abstract
Transgenic potato (Solanum tuberosum cv. Prairie) lines were produced over-expressing a sucrose non-fermenting-1-related protein kinase-1 gene (SnRK1) under the control of a patatin (tuber-specific) promoter. SnRK1 activity in the tubers of three independent transgenic lines was increased by 55%-167% compared with that in the wild-type. Glucose levels were decreased, at 17%-56% of the levels of the wild-type, and the starch content showed an increase of 23%-30%. Sucrose and fructose levels in the tubers of the transgenic plants did not show a significant change. Northern analyses of genes encoding sucrose synthase and ADP-glucose pyrophosphorylase, two key enzymes involved in the biosynthetic pathway from sucrose to starch, showed that the expression of both was increased in tubers of the transgenic lines compared with the wild-type. In contrast, the expression of genes encoding two other enzymes of carbohydrate metabolism, alpha-amylase and sucrose phosphate synthase, showed no change. The activity of sucrose synthase and ADP-glucose pyrophosphorylase was also increased, by approximately 20%-60% and three- to five-fold, respectively, whereas the activity of hexokinase was unchanged. The results are consistent with a role for SnRK1 in regulating carbon flux through the storage pathway to starch biosynthesis. They emphasize the importance of SnRK1 in the regulation of carbohydrate metabolism and resource partitioning, and indicate a specific role for SnRK1 in the control of starch accumulation in potato tubers.Keywords
This publication has 34 references indexed in Scilit:
- Enhanced seed phytosterol accumulation through expression of a modified HMG‐CoA reductasePlant Biotechnology Journal, 2005
- Carbon metabolite sensing and signallingPlant Biotechnology Journal, 2003
- Role of the Arabidopsis Glucose Sensor HXK1 in Nutrient, Light, and Hormonal SignalingScience, 2003
- Starch Synthesis in Potato Tubers Is Regulated by Post-Translational Redox Modification of ADP-Glucose PyrophosphorylasePlant Cell, 2002
- Sucrose to starch: a transition in molecular plant physiologyTrends in Plant Science, 2002
- Two SNF1-Related Protein Kinases from Spinach Leaf Phosphorylate and Inactivate 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase, Nitrate Reductase, and Sucrose Phosphate Synthase in Vitro1Plant Physiology, 1999
- Evidence of the crucial role of sucrose synthase for sink strength using transgenic potato plants (Solanum tuberosum L.)The Plant Journal, 1995
- Transgenic tobacco plants expressing yeast‐derived invertase in either the cytosol, vacuole or apoplast: a powerful tool for studying sucrose metabolism and sink/source interactionsThe Plant Journal, 1991
- Sugar metabolism in developing tubers of Solanum tuberosumPhytochemistry, 1986
- Enzymic Assay of 10−7 to 10−14 Moles of Sucrose in Plant TissuesPlant Physiology, 1977