“…Since monoterpene biosynthesis in peppermint is confined to the secretory cells of glandular trichomes (Gershenzon et al, 1989;McCaskill et al, 1992), to obtain extracts enriched in monoterpene biosynthetic enzymes, purified preparations of secretory cells were isolated by modification of a previously described surface abrasion protocol . Freshly harvested leaves were soaked in deionized water for 1 h at 4°C, and their surfaces abraded using a cell disrupter (Bead-Beater, Biospec Products, Bartlesville, OK) filled with 20 g of plant material, 120 g of 0.5-mm-diameter glass beads, 20 g of XAD-4 polystyrene resin beads, and a buffer comprised of 25 mm 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), pH 7.4, containing 200 mm sorbitol, 2 mm Suc, 10 mm KCl, 5 mm MgCl 2 , 5 mm dithiothreitol, 0.5 mm KH 2 PO 4 , 0.1 mm Na 2 P 2 O 7 , 1% (w/v) polyvinylpyrrolidone (M r ϭ 40,000), and 0.6% (w/v) methyl cellulose.…”