Related Experiment Video
Updated: Oct 18, 2026

Evaluating Leaf Responses to Microbial Secondary Metabolites Using A High-Throughput Format
Published on: December 5, 2025
Enhanced Formation of alpha-Tocopherol and Highly Oxidized Abietane Diterpenes in Water-Stressed Rosemary Plants
1Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona, Spain.
Abstract:
The lipid-soluble antioxidants alpha-tocopherol and carnosic acid were studied in field-grown rosemary (Rosmarinus officinalis L.) plants subjected to drought. During summer in the Mediterranean region, the predawn water potential decreased to -3 MPa and the relative water content to 42%, which caused a depletion of the maximum diurnal CO(2) assimilation rate by 80%. Meanwhile, the maximum efficiency of photosystem II photochemistry and the chlorophyll content of leaves remained unaltered, indicative of the absence of photooxidative damage. The concentration of alpha-tocopherol increased by 15-fold and that of carotenoids by approximately 26% in response to water stress. Enhanced formation of the highly oxidized abietane diterpenes isorosmanol (by 25%) and dimethyl isorosmanol (by 40%) was observed during the summer as result of the oxidation of carnosic acid, which decreased by 22%. The large amounts of carnosic acid, alpha-tocopherol, and carotenoids present in rosemary leaves might contribute to the prevention of oxidative damage in plants exposed to drought.
Related Concept Videos
Radical Autoxidation
Adaptations that Reduce Water Loss
Responses to Drought and Flooding
Responses to Salt Stress
Responses to Heat and Cold Stress
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

