The effects of water deficit on the expression of monoterpene synthases and essential oils composition in Salvia ecotypes

Abstract

The medicinal sage plant (Salvia spp.), belonging to Lamiaceae family, is one of the most important medicinal and aromatic plants. The members of this genus are globally known due to its antimicrobial, antioxidant, astringent, spasmolytic, antihidrotic and specific sensorial properties. In this study, we investigated the potential impact of water deficit on transcript abundance, and essential oil composition of five major metabolites, i.e. 1-8 cineole, a-b-thujone, camphor, and borneol in three genotypes of Salvia spp. Results showed that relative expression of three genes and their corresponding metabolites increased together at three stages under drought condition, but the CS gene transcript decreased independently from 1,8-cineole in garden sage. Furthermore, borneol changed differently compared to the BS gene expression in control and drought treatment plants of S. reuterana (Yasuj). The competitive synthesis of ß-thujone, and a-thujone by SS gene were demonstrated in S. officinalis and Yasuj ecotype of S. reuterana; whereas, no change was observed for Urmia ecotype of S. reuterana. There was no precursor shortage to synthesis of borneol and camphor in garden sage; however increasing the BS led to high production of borneol and low camphor in S. reuterana under drought stress. As a mechanism, secondary metabolites enable the plants to cope with unfavorable conditions, but genetic differences might affect the quantity and quality of these compounds.

How climate change-related abiotic factors affect the production of industrial valuable compounds in Lamiaceae plant species: a review

“…are among the most important MAPs, and several studies have been conducted to evaluate their ability to respond to drought stress. Ramezani et al. (2020) investigated the effect of water deficit on the EO composition, namely, the five main metabolites (1,8-cineole, camphor, borneol, α- and β-thujone), in three genotypes of Salvia spp.…”

Influence of Climate-Related Environmental Stresses on Economically Important Essential Oils of Mediterranean Salvia sp.

“…Changes in monoterpene content can be correlated to upregulated expression of monoterpene synthase and bornyl diphosphate synthase ( Radwan et al, 2017 ). Drought stress affects different growing stages of sage and the associated increase in production of monoterpenes under water deficit is a result of upregulation of 1,8-cineole synthase and bornyl diphosphate synthase in different growth stages of sage resulting in increased production of 1,8-cineole and camphor ( Ramezani et al, 2020 ; Figure 3 ). In the context of reoccurring stress in S. officinalis increase in α-pinene has been recorded under repetitive drought stress ( Kulak, 2020 ).…”

“…There is a significant number of papers on the effects of environmental factors on Salvia species. Research shows that the composition and concentration of volatile compounds in Salvia are dependent not only on genetic and seasonal factors but also on environmental factors ( Ramezani et al, 2020 ). Climate change is, with no doubt, one of the concerning, human-induced, environmental threats for plant biodiversity.…”

Climate Influence and Essential Oils Composition of Salvia Officinalis in Populations of Southern Albania

“…In addition, it is well known that the composition of essential oils and concentration of volatile compounds in Salvia sp. depends not only on genetic and seasonal factors but also on environmental conditions (Ramezani et al, 2020), although with the accelerating climate change this can potentially be problematic for the future production and use of these oils in the pharmaceutical and food industry (Karalija et al, 2022). There are limited reports on the variation of chemical oil composition of medicinal plants under different climatic conditions.…”