Glucose Metabolism of Embryos and Endosperms from Deteriorating Barley and Wheat Seeds

Changes in glucose utilization into CO(2) and ethanol-insoluble material were followed in whole seeds, embryos, and endosperms of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) which had reached different levels of deterioration through accelerated aging treatments. Excised embryos from deteriorated wheat seeds had reduced respiration and glucose utilization into ethanol-insoluble material but not into CO(2). These treatments had no effect on respiration of excised endosperms, although they reduced utilization of glucose into ethanol-insoluble material and CO(2). Changes in metabolic activity of whole seeds in response to deterioration treatments are difficult to interpret because they represent the sum of the changes that take place in the embryos and endosperms. Changes in respiration and glucose utilization in these two tissues neither proceed at the same rate nor go in the same direction during deterioration.Incubation of excised embryos and endosperms in glucose-(14)C under N(2), as compared to air, affects the utilization but not the uptake of glucose. Embryos produce more (14)CO(2) and less labeled ethanol-insoluble material under N(2) as compared to air. The responses of endosperms to N(2) are of a much lower magnitude than those of embryos.