Monoterpene and sesquiterpene emissions of three Mediterranean species through calcareous and siliceous soils in natural conditions

Abstract

Little is known about terpene emissions released by plants in response to abiotic factors, except for climate-related factors. Standard emissions ( E S) of monoterpenes ( E SM) and sesquiterpenes ( E SS) of Rosmarinus officinalis, Pinus halepensis and Cistus albidus in siliceous and calcareous sites were examined. Their dependency on some nutrients in these soils was also analyzed. The study was carried out in the south of France at the end of March, when C. albidus exhibited a leaf growth state, while the other two species exhibited a pre-budbreak state. The results revealed that E S of all major monoterpenes released by R. officinalis and E S of α-pinene and α-humulene of P. halepensis were higher in plants growing in calcareous soils. In contrast, for C. albidus, E SM and E S of β-bourbonene and α-humulene were higher in siliceous soils. E SM of all species was mainly correlated with nitrogen ( N) and available phosphorous (P A), while dependency on Ca 2+ or K + was variable. None of these nutrients was significantly correlated with E SS, suggesting that sesquiterpene synthesis pathway requires different nutrient supplies. While higher soil nutrient content stimulated E SM of R. officinalis and P. halepensis, it had a negative effect on E SM of C. albidus, probably because C. albidus exhibited a different phenological state. Considering the soil nature, and particularly N and P A as inputs in plant terpene inventories could hence contribute to obtain more accurate terpene estimates.