Enhancing Sucrose Synthase Activity in Transgenic Potato (Solanum tuberosum L.) Tubers Results in Increased Levels of Starch, ADPglucose and UDPglucose and Total Yield
- 16 July 2009
- journal article
- Published by Oxford University Press (OUP) in Plant and Cell Physiology
- Vol. 50 (9), 1651-1662
- https://doi.org/10.1093/pcp/pcp108
Abstract
Sucrose synthase (SuSy) is a highly regulated cytosolic enzyme that catalyzes the conversion of sucrose and a nucleoside diphosphate into the corresponding nucleoside diphosphate glucose and fructose. To determine the impact of SuSy activity in starch metabolism and yield in potato (Solanum tuberosum L.) tubers we measured sugar levels and enzyme activities in tubers of SuSy-overexpressing potato plants grown in greenhouse and open field conditions. We also transcriptionally characterized tubers of SuSy-overexpressing and -antisensed potato plants. SuSy-overexpressing tubers exhibited a substantial increase in starch, UDPglucose and ADPglucose content when compared with controls. Tuber dry weight, starch content per plant and total yield of SuSy-overexpressing tubers increased significantly over those of control plants. In contrast, activities of enzymes directly involved in starch metabolism in SuSy-overexpressing tubers were normal when compared with controls. Transcriptomic analyses using POCI arrays and the MapMan software revealed that changes in SuSy activity affect the expression of genes involved in multiple biological processes, but not that of genes directly involved in starch metabolism. These analyses also revealed a reverse correlation between the expressions of acid invertase and SuSy-encoding genes, indicating that the balance between SuSy- and acid invertase-mediated sucrolytic pathways is a major determinant of starch accumulation in potato tubers. Results presented in this work show that SuSy strongly determines the intracellular levels of UDPglucose, ADPglucose and starch, and total yield in potato tubers. We also show that enhancement of SuSy activity represents a useful strategy for increasing starch accumulation and yield in potato tubers.This publication has 62 references indexed in Scilit:
- Plastidial Localization of a Potato ‘Nudix’ Hydrolase of ADP-glucose Linked to Starch BiosynthesisPlant and Cell Physiology, 2008
- ABA Is an Essential Signal for Plant Resistance to Pathogens Affecting JA Biosynthesis and the Activation of Defenses in ArabidopsisTHE PLANT CELL ONLINE, 2007
- QTLs for enzyme activities and soluble carbohydrates involved in starch accumulation during grain filling in maizeJournal of Experimental Botany, 2005
- Evidence That Sucrose Loaded into the Phloem of a Poplar Leaf Is Used Directly by Sucrose Synthase Associated with Various β-Glucan Synthases in the StemPlant Physiology, 2004
- mapman: a user‐driven tool to display genomics data sets onto diagrams of metabolic pathways and other biological processesThe Plant Journal, 2004
- Glucose and mannose regulate the expression of a major sucrose synthase gene in Arabidopsis via hexokinase-dependent mechanismsPlant Physiology and Biochemistry, 2002
- Expression of a bacterial sucrose phosphorylase in potato tubers results in a glucose‐independent induction of glycolysisPlant, Cell & Environment, 2001
- Starch synthesis in amyloplasts purified from developing potato tubersThe Plant Journal, 1997
- Sink- and vascular-associated sucrose synthase functions are encoded by different gene classes in potato.THE PLANT CELL ONLINE, 1995
- Gene expression during tuber development in potato plantsFEBS Letters, 1990