Remarkable retardation of the senecence of tobacco leaf disks by cordycepin, an inhibitor of RNA polyadenylation

The antibiotic cordycepin (3′-deoxyadenosine), a known specific inhibitor of nucleic acid synthesis and polyadenylation of RNA, remarkably retarded decrease in the chlorophyll and protein contents of senescing tobacco leaf disks. The effectiveness of cordycepin, at its optimum concentration (ca. 4 × 10−5M), was 53% as effective as a cytokinin, benzyladenine at 10−6M. Adenosine and 2′-deoxyadenosine had no anti-senescence action.