Rapid Increase in UDP-Glucose during Early Wheat Embryo Germination.

The cellular content of UDP-glucose in isolated wheat (Triticum aestivum L.) embryo increases 8-fold during the first 40 minutes of imbibition. An additional 3-fold increase in the amount of UDP-glucose was observed in the next 5 hours of germination. This communication also describes a unique, quantitative method to achieve a high sensitivity in a direct determination of UDP-glucose with Na [(32)P]pyrophosphate and UDP-glucose pyrophosphorylase. The sensitivity of the assay for UDP-glucose is 10 picomoles.