Changes in Pyruvic Acid Content and GPT Activity in Chilling-sensitive and Nonsensitive Crops

Abstract

This study investigated the mechanism of alanine accumulation observed as a common factor in chilling-sensitive crops [cucumber (Cucumis sativus L.) and eggplant (Solanum melongena L.)] during cold storage. Pyruvic acid in acids increased rapidly during the storage of these crops at 1C. However, in sensitive crops at 20C or in a chilling-resistant crop [carrot (Daucus carota L.)] at 1C, the increase was not found. No significant changes in glutamate-pyruvate transaminase (GPT) activity closely related to the biosynthesis of alanine were found in chilling-sensitive or chilling-resistant crops during storage at 1, 5, or 20C. We suggest that the accumulated alanine found in chilling-sensitive crops may be produced by GPT from accumulated pyruvic acid during cold storage.