Original Research ARTICLE
PHOSPHOSERINE AMINOTRANSFERASE1 is Part of the Phosphorylated Pathways for Serine Biosynthesis and Essential for Light and Sugar-Dependent Growth Promotion
- 1Botanischen Institut, Universität zu Köln, Germany
The phosphorylated pathway of serine biosynthesis represents an important pathway in plants. The pathway consist of three reactions catalyzed by the phosphoglycerate dehydrogenase, the phosphoserine aminotransferase and the phosphoserine phosphatase, and the genes encoding for all enzymes of the pathway have been identified. Previously, the importance of the phosphoglycerate dehydrogenase and phosphoserine phosphatase for plant metabolism and development has been shown, but due to the lack of T-DNA insertion mutants, a physiological characterization of the phosphoserine aminotransferase is still missing. Hence, we generated silencing lines specifically down-regulated in the expression of the major PSAT1 gene. The morphological characterization of the obtained PSAT1-silenced lines revealed a strong inhibition of shoot and root growth. In addition, these lines are hypersensitive to the inhibition of the photorespiratory serine biosynthesis, when growing the plants at elevated CO2. Metabolic analysis of PSAT1-silenced lines, showed a strong accumulation of certain amino acids, most likely due to an enhanced ammonium assimilation. Furthermore, phenotypic analysis under low and high-light conditions and in the presence of sucrose revealed, that the phosphorylated pathway of serine biosynthesis is essential for light and sugar-dependent growth promotion in plants.
Keywords: Serine biosynthesis, primary metabolism, photorespiration, amino acid metabolism, growth promotion, Arabidopsis thaliana
Received: 18 Sep 2018;
Accepted: 05 Nov 2018.
Edited by:DEYU XIE, North Carolina State University, United States
Reviewed by:André O. Hudson, Rochester Institute of Technology, United States
Leszek A. Kleczkowski, Umeå University, Sweden
Copyright: © 2018 Krueger and Wulfert. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Stephan Krueger, Botanischen Institut, Universität zu Köln, Cologne, Germany, firstname.lastname@example.org