Possible role of light and polyamines in the onset of somatic embryogenesis of Coffea canephora.

The concentration of free and bound polyamines was studied during the somatic embryogenesis induction process in Coffea canephora explants. In the present study we show that when the induction of somatic embryogenesis in C. canephora is carried out under light conditions and in the presence of the plant growth regulator, benzylaminopurine, a cytokinin, a faster response to induction is obtained. In the darkness, the response is delayed for more than 20 days, and the number of embryos is smaller. In the absence of benzylaminopurine no embryogenic response was observed. The pronounced changes in the levels of putrescine, spermidine, and spermine, both free and bound, found in C. canephora suggest that a close correlation exists between polyamine biosynthesis and somatic embryogenesis in C. canephora during a period of cellular differentiation associated with the induction of somatic embryogenesis.