STIMULATION OF ACCUMULATION OF TERPENOIDS BY CELL-SUSPENSIONS OF LAVANDULA-ANGUSTIFOLIA FOLLOWING PRETREATMENT OF PARENT CALLUS

Lines of callus of Lavandula angustifolia have been established that contained up to 20% of the levels of mono- and sesquiterpenoids found in foliage but in contrast, negligible quantities of these lower terpenoids accumulated in derived cell suspensions. Pretreatment of callus by pulse-feeding of mevalonate had little effect on terpenoid accumulation but now the derived cell suspensions stored monoterpenoids at levels ca 10(3)-fold those of controls and these accumulations could be magnified a further 10(2)-fold by use of a two-phase culture medium. Cell-free extracts of both productive and non-accumulating lines of callus converted [C-14]isopentenyl pyrophosphate into predominently 2E,6E- and 2Z,6E-farnesols together with the sesquiterpenoids humulene and caryophyllene; the pattern of predominating monoterpenoids characteristic of the productive callus lines was not observed. Preincubation of the extracts with NADPH or NADP(+) increased the accumulations of the sesquiterpenoids by up to 20-fold. Reasons for these unexpected patterns of products are discussed.