Poster: Secondary Metabolism

Abs # 304: Investigation of coordinate regulation between the nicotine biosynthesis and SAM recycling pathways in roots of tobacco (Nicotiana tabacum)

Presenter:	Heim, William , wheim@vt.edu
Authors	Heim, William  (A)   Jelesko, John  (A)
Affiliations:	(A): Virginia Polytechnic Institute and State University

Putrescine N-methyltransferase (PMT) catalyzes the first committed step in the nicotine biosynthesis pathway in roots of tobacco by methylating putrescine to form N-methylputrescine. The methyl donor for this reaction is S-adenosylmethionine (SAM) and is regenerated via the SAM recycling pathway (comprised of S-adenosylhomocysteine hydrolase (SAHH), methionine synthase (MS), and S-adenosylmethionine synthase (SAMS)). SAMS is known to be upregulated during conditions that induce high levels of nicotine biosynthesis, but little is known about whether the remaining enzymes of the SAM recycling pathway are also coordinately upregulated during those same inducing conditions. To this end, we will present results from Northern and Western blot analyses that begin to address the issue of coordinate regulation of the SAM recycling pathway with nicotine biosynthesis. The implications of coordination between the two pathways will begin to lead to new insights about the integration of primary and secondary metabolism.