Stimulation of RNA synthesis in Cicer arietinum seedlings by cyclic 3':5' adenosine monophosphate.

IAA induces tryptophan oxygenase (EC 1.13.1.12) in Cicer arietinum seedlings and CAMP mimics this action [I]. In seedlings preincubated with IAA, there is also a 3-3.5fold activation of adenyl cyclase as evident from increased incorporation of [8-14C]adenine into [14C]cAMP [2]. Furthermore, the inhibitory effect on germination of C. arietinum caused by inclusion of 8-azadenine in the imbibition medium is readily reversed by either IAA or CAMP [3]. These findings are suggestive of a regulatory role played by IAA in the early phase of seed germination. Evidence presented now demonstrates that CAMP and IAA stimulate in vitro RNA and protein synthesis in C. arietinum without affecting DNA synthesis.