1. Phosphorylation and growth inhibitory activity of all ketohexose analogs
- Author
-
Kozue Okada and Hisashi Kato-Noguchi
- Subjects
Phosphorylation Process ,chemistry.chemical_compound ,Hepatic fructokinase ,chemistry ,Biochemistry ,Phosphorylation ,Glycolysis ,Growth inhibition ,Biology ,Energy source ,Agronomy and Crop Science ,Fructokinase ,Ketohexose - Abstract
Sugars are not only important energy sources and structural components, but they also act as signaling molecules that are involved in specific signal sensing. Among all ketohexose analogs (d-fructose, d-psicose, d-tagatose, d-sorbose, l-fructose, l-psicose, l-tagatose and l-sorbose), only d-psicose inhibited the growth of Arabidopsis roots. Phosphorylation by fructokinase occurred in d-fructose and d-psicose. d-Psicose-induced inhibition was relieved by adding d-fructose. Thus, the inhibition could not be attributed to the toxicity of phosphorylated d-psicose. The phosphorylation process requires ATP. After phosphorylation, d-fructose is metabolized in glycolysis and becomes energy sources and structural components, whereas d-psicose cannot contribute to the energy sources and structural components because it does not get metabolized further. However, d-psicose did not affect ATP level in the Arabidopsis roots, suggesting that the d-psicose-induced growth inhibition may not be related to the starvation of ATP. The phosphorylation of ketohexoses by fructokinase is known to a trigger signal-sensing resulting in growth inhibition. Therefore, d-psicose can be phosphorylated by fructokinase and this process may play a possible role in signal-sensing. This is probably one of the useful model systems for the study of the hexokinase-independent sugar-sensing function and for developing new types of weed-control agents.
- Published
- 2013
- Full Text
- View/download PDF