Age-dependent responses in cellular mechanisms and essential oil production in sweet Ferula assafoetida under prolonged drought stress

The effect of environmental conditions at different developmental ages on the vegetative growth phase was investigated in sweet Ferula assa-foetida in order to identify the defensive mechanisms and essential oil production. Younger plants had more potential for producing the essential oil. Sulfur and sesquiterpenoid compounds were detected as the main groups of components. Monoterpene production was limited to camphene that particularly appeared in older plants. Thiourea as the main sulfur-containing component in fresh tissues helped plants to tolerate abiotic stresses due to scavenging activity of reactive oxygen species (ROS). Three isoforms of SOD and one isoform of catalase were identified in the plants subjected to environmental stresses. The significant enhancement in protein level and reduction in H2O2 level during the period of growth with strong induction in antioxidant enzymes' activities in older plants indicated that they have more functional defensive mechanisms in comparing to younger plants.