ANAEROBIC CARBOHYDRATE-METABOLISM IN WHEAT AND BARLEY, 2 ANOXIA-INTOLERANT CEREAL SEEDS

Cereals such as barley and wheat are unable to germinate under anoxic conditions, Data are presented on the utilization of the soluble sugar s present in the dry seed of wheat and barley kept under strict anoxia , together with the status of the enzymes involved in the metabolism o f carbohydrates. The amount of glucose, fructose, and sucrose decrease s during the anaerobic treatment, indicating that carbohydrate metabol ism takes place in the seeds of wheat and barley kept under anoxic con ditions. The analysis of the enzymes involved in the metabolism of car bohydrates shows that the enzymatic set needed to convert sucrose, glu cose, and fructose to glucose-6P is present in the anaerobic seeds, Su crose degradation seemingly occurs through a sucrose synthase pathway with nucleoside diphosphate kinase involved in the cycling of urydilat es. However, the activity of sucrose synthase, glucokinase, and fructo kinase, all strongly induced in rice, an anoxia-tolerant cereal, are a lmost unaffected or even depressed in the two cereal seeds under inves tigation. The comparison of the results obtained and described in this paper with the published data on the metabolism of carbohydrates in r ice, indicate that the anoxia-intolerant species would rapidly suffer and eventually die from sugar starvation if kept under for a relativel y prolonged length of time (4-8 d).