nicotiana tabacum, nuclear run-on, transcriptional and post-transcriptional regulation, Biology (General), QH301-705.5, Plant ecology, QK900-989

The present work aims to examine the underlying molecular mechanism(s) for the reduced transcriptions and activities of DNA methyltransferases (NtDNMTs) by gibberellin A3 (GA3) in tobacco (Nicotiana tabacum L). Nuclear run-on and cordycepin chase assays demonstrated a significant reduction in the transcriptional rate and transcript half-lives of NtMET1 and NtCMT3 by GA3. Lineweaver-Burk plot analysis revealed a non-competitive mode of inhibition of NtDNMTs activity by GA3. Taken together, both in vivo and in vitro studies clearly demonstrated the altered transcriptional and post-transcriptional regulation as a mechanism of inhibition in expression and activity of NtDNMTs by GA3.