Impact of climatic disturbances on the chemical compositions and metabolites of Salvia officinalis

Abstract

Aromatic and medicinal plants in ecosystems are subject to various climatic disturbances that impact their morphological and physiological processes. Although plants have mechanisms to adapt to their climatic conditions, such as periods of drought and lack of precipitation, their metabolism is still affected. This study aimed to predict and evaluate the behavior of Salvia officinalis under climatic disturbances. Over a period of 4 years in a controlled environment, three treatments were applied to the plant: Treatment 1 with normal monthly average temperature and precipitation in the first year; Treatment 2 with a temperature increase of 5°C and a 50% reduction in water supply in the second year; and Treatment 3 with a temperature increase of 10°C and a 75% reduction in water supply in the fourth year. The results show that the percentage of primary metabolites, including nutritional values, changed with increasing temperature and decreasing precipitation. Treatment 1 had 7.13% protein, 6.21% carbohydrate, 1.35% lipid, and 4% dietary fiber, while Treatment 2 had 7.05% protein, 5.12% carbohydrate, 1.01% lipid, and 3.01% dietary fiber, and Treatment 3 had 6.86% protein, 3.02% carbohydrate, 0.52% lipid, and 2.34% dietary fiber. The mineral composition of the plant also changed with each treatment, with Mg decreasing from 10.02 to 8.55 to 0.05%, Fe decreasing from 8.18 to 8 to 7.62%, K decreasing from 5.55 to 5.05 to 4.02%, Mn decreasing from 5.54 to 5.11 to 3.48%, Ca decreasing from 4.65 to 2.75 to 1.23%, and P decreasing from 3.37 to 3.05 to 2.25%. Regarding secondary metabolites, the percentage of alkaloids, flavonoids, saponins, coumarins, tannins, and essential oil yield changed as well. Treatment 2 showed an increase in secondary metabolites, while Treatment 3 showed a decrease. Alkaloids increased from 9.56 to 13.68 to 11.3%, flavonoids increased from 7.53 to 13.48 to 10.49%, saponins increased from 5.23 to 7.44 to 6%, coumarins increased from 3.35 to 4.85 to 3.99%, tannins increased from 2.26 to 3.22 to 2.62%, and essential oil yield increased from 0.53 to 0.80 to 0.62%. Gas chromatography analysis revealed that the major compounds of the essential oils of Salvia officinalis, such as α-thujone, manool, β-caryophyllene, α-humulene, viridiflorol, 1,8-cineol, and camphor, were also modified by temperature and water stress.