In keeping with the proposal that avenacin biosynthesis is restricted to the tips of primary roots of oat seedlings, the incorporation of radioactivity from R-[2-]mevalonic acid (MVA) into avenacins and β-amyrin by serial sections of primary roots was found to be more-or-less restricted to root tip sections. Squalene synthase (SQS) (EC 2.5.1.21) and 2,3-oxidosqualene:β-amyrin cyclase (OSβAC) (EC 5.4.99) were also most active in these sections. The incorporation of radiolabel from R-[2-]MVA into cycloartenol and 24-methylene cycloartanol by, and the 2,3-oxidosqualene:cycloartenol cyclase (OSCC) (EC 5.4.99) activity in, the various serial sections were consistent with phytosterol biosynthesis occurring in all the sections of the root with some tailing-off in the rate of synthesis in the more distal sections.
Avena sativa; Poaceae; biosynthesis; saponins; avenacins; phytosterols
NCBI PubMed ID: 10872206Publication DOI: 10.1016/s0031-9422(00)00062-5Journal NLM ID: 0151434Publisher: Elsevier
Correspondence: miranda.trojanowska@bbsrc.ac.uk
Institutions: Department of Biological Sciences, University of Hull, Hull, UK, The Sainsbury Laboratory, Norwich Research Park, Colney, UK
Methods: TLC, radiolabeling, radioactivity measurement, HPLC, extraction, CC