ARS | Publication request: ALTERING THE PHYSICAL ENVIRONMENT AFFECTS GROWTH, MORPHOGENESIS AND ESSENTIAL OIL PRODUCTION IN MENTHA SPICATA L. SHOOTS IN VITRO

Submitted to: Phytochemical Society of North America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 3, 2005
Publication Date: August 3, 2005
Citation: Tisserat, B., Vaughn, S.F. 2005. Altering the physical environment affects growth, morphogenesis and essential oil production in mentha spicata l. shoots in vitro [abstract]. Phytochemical Society of North America. p. 33.

Technical Abstract: Altering the physical environment profoundly alters the growth (fresh weight), morphogenesis (leave, root and shoot numbers) and secondary metabolism [i.e., production of the monoterpene (-)-carvone] of Mentha spicata L. (spearmint) shoots cultured on Murashige and Skoog medium. The type of physical support (e.g., agar, liquid, sponge, platform, or glass) employed within Magenta vessels were tested. Mint shoots grown on the liquid medium produced 3-x fold greater fresh weights than shoots grown on the agar medium. However, carvone concentrations in shoots grown on agar were higher than in shoots grown on liquid medium. Replacing culture media more frequently within Magenta vessels during an 8 week culture period significantly increased growth and morphogenesis without affecting carvone concentrations. The influence of culture vessel capacity on spearmint shoots was tested by culturing shoots on a variety of culture vessels including: culture tubes, Magenta vessels and 1.89 l jars. Positive correlations occurred between culture vessel capacities and shoot growth, morphogenesis and carvone concentrations. A comparative study was conducted testing growth, morphogenesis and secondary metabolism occurring with 3 different spearmint cultivars grown on either culture tubes containing 25 ml agar medium or in an automated plant culture system (APCS, a sterile hydroponics system) employing a one-l medium reservoir. The APCS allowed for the production of greater biomass (e.g., ~12 to 15-x fold increase in fresh weight), and morphogenesis to occur compared to that obtained within culture tubes. However, shoots grown in the APCS produced less carvone compared to shoots grown in agar medium. Increasing the number of media culture immersions (4, 8, 12, or 16 immersions day-1) employing the APCS increased growth and morphogenesis responses while lowering carvone levels. Optimum growth rates is not necessarily associated with optimum secondary metabolism in vitro.