THE EFFECT OF A LONG-TERM WATER-STRESS ON THE METABOLISM AND EMISSIONOF TERPENES OF THE FOLIAGE OF CUPRESSUS-SEMPERVIRENS

The effects of long-term water stress on water and terpene contents of the foliage of Cupressus sempervirens were studied. A great deal of w ater was lost over 2 months before a remarkable stabilization. A stron g decrease of all the classes of terpenes accompanied this dehydration . Mono- and sesquiterpene hydrocarbons and free terpenols were almost entirely metabolized, whereas esters and terpene glycosides rose sligh tly and remained at a constant level when the water content had stabil ized. Although a significant part of the mono- and sesquiterpene hydro carbons was emitted in the early stage of stress application, the majo r part was used by the plant in response to the drought conditions.