Abstract
Many organisms have developed mechanisms to sense and respond to internal or external soluble sugars for the maintenance of growth and metabolism. In higher plants, the soluble sugars act as important signaling molecules that affect a wide range of biological functions, including flowering time, seed, and early seedling development. Although these sugars act in concert with various cellular components, only few are currently known. Trehalose is present in many prokaryotic and eukaryotic organisms. Its function as an energy source or cellular protectant under stress conditions has been well studied in yeast and Escherichia coli. In plants, however, there is only limited knowledge of the functions of endogenous trehalose and its hydrolytic enzyme trehalase. Therefore, we isolated a T-DNA knockout plant, Attre1, with impaired trehalase activity. The Attre1 mutant contained elevated levels of endogenous trehalose, and exhibited phenotypic abnormalities in both vegetative and reproductive organ development, including growth retardation, abnormal leaf and flower morphologies, and impaired pollen production. Interestingly, a disruption of AtTRE1 resulted in alterations in trehalose synthesis and expression of hexokinase genes. The presented results indicate that Arabidopsis contains a trehalose-signaling network which might be functionally coupled to a hexokinase-dependent signaling pathway, consequently controlling plant metabolism and development.
Acknowledgements
This study was supported by grants 30801005 and 60900405 to H.-J.C. from the Technology Development Program for Agriculture and Forestry, Ministry of Food, Agriculture, Forestry and Fisheries, Republic of Korea.