A systems biology approach identifies the biochemical mechanisms regulating monoterpenoid essential oil composition in peppermint

ABSTRACT: The integration of mathematical modeling and experimental testing is emerging as a powerful approach for improving our understanding of the regulation of metabolic pathways. In this study, we report on the development of a kinetic mathematical model that accurately simulates the developmental patterns of monoterpenoid essential oil accumulation in peppermint (Mentha x piperita). This model was then used to evaluate the biochemical processes underlying experimentally determined changes in the monoterpene pathway under low ambient-light intensities, which led to an accumulation of the branchpoint intermediate (+)-pulegone and the side product (+)-menthofuran. Our simulations indicated that the environmentally regulated changes in monoterpene profiles could only be explained when, in addition to effects on biosynthetic enzyme activities, as yet unidentified inhibitory effects of ( )-menthofuran on the branchpoint enzyme pulegone reductase (PR) were assumed. Subsequent in vitro analyses with recombinant protein confirmed that (+)-menthofuran acts as a weak competitive inhibitor of PR (Ki 300 uM). To evaluate whether the intracellular concentration of (+)-menthofuran was high enough for PR inhibition in vivo, we isolated essential oil-synthesizing secretory cells from peppermint leaves and subjected them to steam distillations. When peppermint plants were grown underlow-light conditions, (+)- menthofuran was selectively retained in secretory cells and accumulated to very high levels (up to 20 mM), whereas under regular growth conditions, (+)-menthofuran levels remained very low (<400 uM). These results illustrate the utility of iterative cycles of mathematical modeling and experimental testing to elucidate the mechanisms controlling flux through metabolic pathways.

• Autores: Turner, Glenn W.; Lee, James M.; Croteau, Rodney B.; Lange, B. Markus
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2008
• Institución: Universidad de Antioquia
• Repositorio: Repositorio UdeA
• Idioma: eng
• OAI Identifier: oai:bibliotecadigital.udea.edu.co:10495/9286
• Acceso en línea: http://hdl.handle.net/10495/9286
• Palabra clave: Biosíntesis; Biosynthesis; Pulegona reductasa; Isoprenoide Menthofurano; Modelado cinético; kinetic modeling; Sistemas biológicos; Biological systems; Biosynthesis and Biochemistry
• Rights: openAccess
• License: Atribución-NoComercial-SinDerivadas 2.5 Colombia