The Effect of Benzimidazole and Red Light on the Senescence of Detached Leaves of Oryza sativa cv. Ratna

Excised rice leaves (Oryza sativa L. cv. Ratna) werefloated on a 10–3M solution of benzirnidazole under dark or continuous red light. Compared to the water control a degradation of chlorophyll, protein, RNA, DNA and a decrease in the activity of alkaline inorganic pyrophosphatase was delayed at the same time as an increase of α‐amino nitrogen and the activity of acid inorganic pyrophosphatase occurred, Benzimidazole was more effective under red light than in the dark in retarding senescence. The possible role of inorganic pyrophosphatases is discussed with respect to biosynthesis during leaf senescence.