Abstrato

Role of Endogenous Nucleic Acids and Proteins in Adventitious Root Formation in Mung Bean Cuttings

S. Nag, A. Paul and M. A. Choudhuri

Nucleic acid, proteins and their degradative enzymes (DNase omitted) associated with adventitious root formation (ARF) were determined in different phases at the base of hypocotyl cuttings of mung bean (Vigna radiata L. cv. 105). DNA and RNA contents in mung bean hypocotyls showed that there was a marked change in nucleic acid contents (DNA and RNA) during the early inductive phase (0-24h). However, there was a gradual accumulation of DNA and RNA after 24h up to the early expression phase (24-96h). Although the rise in the content of RNA was markedly greater than that of DNA. The synthesis of new DNA and RNA might have a role during new root initial formation in mung bean hypocotyls. The pattern of RNase activity was inversely correlated with endogenous RNA content during the induction and early initiation phase (0-48h). The total protein contents tally with RNA content suggesting that high protein synthesis is preceded by RNA synthesis. Soluble protein increased during early phase (0- 72h) but insoluble protein was remarked low during this early phase. However, the greater activities of proteases (acidic and neutral) at the expression phase (72-120h) rather than at the induction phase (0-24h) may indicate that they are involved in protein turnover during root development at the later phase in mung bean hypocotyls explants