Glutamine Metabolism in Corn Kernels Cultured In Vitro

Abstract

The fate of glutamine, the major source of N supplied to the developing maize endosperm, was examined in endosperm tissues of corn caryopsis grown udner sterile conditions. In the culture system, [U-14C]glutamine was included in the medium or was injected directly into the endosperm. Samples were harvested at intervals up to 168 h. Protein and starch fractions were then separated and analyzed for their 14C content. At 168 h, 31% of the total label incorporated in the endosperm was in zein, 15% in glutelin and 24% in starch. When individual amino acids and sugars in the endosperm powders were analyzed, the 14C still remaining in the glutamine accounted for only 12-14% of the total radioactivity.