A fluorometric assay for trehalose in the picomole range

Area of Science:

• Plant physiology
• Biochemistry
• Molecular biology

Background:

• Trehalose is a disaccharide with diverse roles in organisms, including potential signaling in plants.
• Trehalose 6-phosphate (Tre6P) is linked to sucrose status, but trehalose's function remains unclear.
• Measuring low trehalose levels in plants is challenging due to assay limitations.

Purpose of the Study:

• To develop a sensitive and specific assay for quantifying trehalose in plant tissues.
• To investigate the role of trehalose in plant responses to environmental stress and developmental processes.

Main Methods:

• A kinetic assay using recombinant Escherichia coli cytoplasmic trehalase (treF) was established.
• Trehalose hydrolysis was monitored fluorometrically, with quantification via an internal calibration curve.
• The assay's sensitivity and specificity were validated using plant extracts from Arabidopsis thaliana and maize.

Main Results:

• The new assay accurately measures trehalose in plant tissues, with high specificity and sensitivity.
• Arabidopsis rosettes showed increased trehalose levels under chilling conditions (8°C).
• Maize ramosa3 mutants exhibited altered trehalose levels and trehalose:Tre6P ratios in inflorescence primordia.

Conclusions:

• The developed fluorometric assay allows for precise measurement of trehalose in small plant samples.
• While chilling increases trehalose in Arabidopsis, its contribution to osmoregulation is minimal.
• Trehalose is unlikely to be a sucrose status signal; altered levels may influence maize inflorescence development.