Toward Arabidopsis thaliana hydrophilic metabolome: assessment of extraction methods and quantitative 1H NMR.

Our goal was to establish the hydrophilic metabolome of heterotrophic Arabidopsis thaliana cells grown in suspension, a cellular model of plant sink tissues. Water-soluble metabolites were extracted using four protocols: perchloric acid, boiling ethanol, methanol and methanol/chloroform (M/Chl). They were detected and quantified using (1)H nuclear magnetic resonance (NMR) spectroscopy at 400 MHz.

A metabolic study of the regulation of proteolysis by sugars in maize root tips: effects of glycerol and dihydroxyacetone.

Sugars, the main growth substrates of plants, act as physiological signals in the complex regulatory network of sugar metabolism. To investigate the function of different glycolytic steps in sugar sensing and signaling we compared the effects of carbon starvation with those of glucose, glycerol and dihydroxyacetone on carbon metabolism, proteolysis, and protease expression in excised maize (Zea mays L.) root tips.

In plants, 3-o-methylglucose is phosphorylated by hexokinase but not perceived as a sugar.

In plants, sugars are the main respiratory substrates and important signaling molecules in the regulation of carbon metabolism. Sugar signaling studies suggested that sugar sensing involves several key components, among them hexokinase (HXK). Although the sensing mechanism of HXK is unknown, several experiments support the hypothesis that hexose phosphorylation is a determining factor.

Sucrose cycling in heterotrophic plant cell metabolism: first step towards an experimental model.

Sucrose is the cornerstone of higher plant metabolism. Produced by photosynthesis, sucrose is the main substrate for respiration and biosynthesis. The emerging idea is that sucrose may act as regulator of its own metabolism, characterized in particular by a permanent process of degradation and formation.