Excess Zinc Supply Reduces Cadmium Uptake and Mitigates Cadmium Toxicity Effects on Chloroplast Structure, Oxidative Stress, and Photosystem II Photochemical Efficiency in Salvia sclarea Plants

Salvia sclarea L. is a Cd2+ tolerant medicinal herb with antifungal and antimicrobial properties cultivated for its pharmacological properties. However, accumulation of high Cd2+ content in its tissues increases the adverse health effects of Cd2+ in humans. Therefore, there is a serious demand to lower human Cd2+ intake. The purpose of our study was to evaluate the mitigative role of excess Zn2+ supply to Cd2+ uptake/translocation and toxicity in clary sage. Salvia plants were treated with excess Cd2+ (100 μM CdSO4) alone, and in combination with Zn2+ (900 μM ZnSO4), in modified Hoagland nutrient solution. The results demonstrate that S. sclarea plants exposed to Cd2+ toxicity accumulated a significant amount of Cd2+ in their tissues, with higher concentrations in roots than in leaves. Cadmium exposure enhanced total Zn2+ uptake but also decreased its translocation to leaves. The accumulated Cd2+ led to a substantial decrease in photosystem II (PSII) photochemistry and disrupted the chloroplast ultrastructure, which coincided with an increased lipid peroxidation. Zinc application decreased Cd2+ uptake and translocation to leaves, while it mitigated oxidative stress, restoring chloroplast ultrastructure. Excess Zn2+ ameliorated the adverse effects of Cd2+ on PSII photochemistry, increasing the fraction of energy used for photochemistry (ΦPSII) and restoring PSII redox state and maximum PSII efficiency (Fv/Fm), while decreasing excess excitation energy at PSII (EXC). We conclude that excess Zn2+ application eliminated the adverse effects of Cd2+ toxicity, reducing Cd2+ uptake and translocation and restoring chloroplast ultrastructure and PSII photochemical efficiency. Thus, excess Zn2+ application can be used as an important method for low Cd2+-accumulating crops, limiting Cd2+ entry into the food chain.

Sclareol and linalyl acetate are produced by glandular trichomes through the MEP pathway

Sclareol, an antifungal specialized metabolite produced by clary sage, Salvia sclarea, is the starting plant natural molecule used for the hemisynthesis of the perfume ingredient ambroxide. Sclareol is mainly produced in clary sage flower calyces; however, the cellular localization of the sclareol biosynthesis remains unknown. To elucidate the site of sclareol biosynthesis, we analyzed its spatial distribution in the clary sage calyx epidermis using laser desorption/ionization mass spectrometry imaging (LDI–FTICR-MSI) and investigated the expression profile of sclareol biosynthesis genes in isolated glandular trichomes (GTs). We showed that sclareol specifically accumulates in GTs’ gland cells in which sclareol biosynthesis genes are strongly expressed. We next isolated a glabrous beardless mutant and demonstrate that more than 90% of the sclareol is produced by the large capitate GTs. Feeding experiments, using 1-13C-glucose, and specific enzyme inhibitors further revealed that the methylerythritol-phosphate (MEP) biosynthetic pathway is the main source of isopentenyl diphosphate (IPP) precursor used for the biosynthesis of sclareol. Our findings demonstrate that sclareol is an MEP-derived diterpene produced by large capitate GTs in clary sage emphasing the role of GTs as biofactories dedicated to the production of specialized metabolites.

Parfum perfect soi timpuriu de Salvia sclarea L.

The biological Salvia sclarea L. (sage) is a species with a special economic value, determined by the essential oil that has multiple uses in perfumery, cosmetics, aromatherapy, food, etc. The variety Par-fum Perfect is a triple hybrid with constant heterosis. The content of essential oil was determined three times per season through hydro distillation in Ginsberg apparatus and recalculated for dry matter. The production of essential oil in two years of harvesting constitutes 73,5kg/ha (8,7 kg/ha in first year and 64,8 in second year). The variety's efficiency is 3,2kg essential oil of per ton of inflorescences.

Manifestarea heterozisului la hibrizi F1 de Salvia sclarea L.

22 hybrids F1 of Salvia sclarea L., were evaluated, which show heterosis in a series of quantitative characters, which directly influence productivity, at the same time being a valuable breeding material for the elaboration of few varieties of hybrid origin. They showed a remarkable effect of heterosis on the number of branches of the inflorescence a hybrid in steps: +55.8% in relation to the maternal form and +61.4 % in relation to the paternal form. The essential oil content is high (0.877–1.836%); the highest ef-fect of heterosis being recorded by a stepped hybrid: +25.0% in relation to the maternal form, +87.9% in relation to the paternal form.

Impacts of Extracts From Styrax officinalis L. on Seedling Growth of Salvia sclarea L.

Many plant species synthesize different biochemical substances from their various organs (leaves, flowers, fruits and roots, etc.). While some of these biochemical substances which are known as allelochemicals have a stimulating effect on the growth and development of other plants, some of them have an inhibitory effect. In this study, the effect of extracts obtained from the Styrax officinalis L., which spreads naturally in the Mediterranean and Aegean regions, on the seedling growth of Salvia sclarea L. were investigated. In the study, the extracts prepared with water at 5% concentration from dry fruit peel and seed coat of S. officinalis, and tap water as control were used. According to the results of this study, it was determined that the fruit peel and seed coat extracts obtained from S. officinalis had a significant inhibitory effect on the emergence of S. sclarea seeds and its seedling growth. The inhibitory effect of fruit peel was higher than that of seed coat.

Creation of clary sage cultivar using cell engineering methods. 2. Study of plant-regenerants at the stages of breeding process

Clary sage (Salvia sclarea L.) is a widely demanded essential oil plant. The products of its processing are used in medicine, perfumery and cosmetics, food industry, paint and varnish production. The main breeding tasks are to develop cultivars that combine high yield and quality of essential oil, resistant to abiotic and biotic stresses. All clary sage cultivars registered in the ‘State register of breeding achievements allowed for use’ Russian Federation were obtained on the basis of traditional methods. The initial breeding material of S. sclarea was obtained at the FSBSI “Research Institute of Agriculture of Crimea” using methods of cell engineering (induction of somaclones from callus cultures, obtaining hybrids in embryoculture and cell selection for resistance to osmotic stress). The aim of this work was to study the main economic and morphometric parameters of clary sage samples created using various biotechnological methods at the main stages of the breeding process. As a material for research, we used samples obtained in vitro using three biotechnological methods – regenerants (R2-R3) from calli of ‘C-785’ and ‘Taigan’ cultivars, obtained in isolated embryo culture hybrids (Salvia sclarea L. x S. grandiflora Etling.) and forms selected in embryoculture on a selective medium with an osmotic (mannitol or NaCl). When studying 10 sage samples (seed progeny of regenerants) in the breeding nursery (2012–2014), three that exceeded the control cultivar ‘Taigan’ in terms of basic economic characteristics were identified. The collection of essential oil from them was 1.2-1.4 times higher than in the control. In the nursery of competitive variety trials (2016–2019), when studying three samples (No. R3-1-6, 226-08 and 1-01), No. R3-1-6 was selected for a number of indicators. This sample is seed progeny of regenerant obtained by the induction of morphogenesis from callus. A characteristic feature of this sample was an increase in the number of lateral shoots per inflorescence by 41.1 %, which contributed to an increase in the mass of inflorescences. By the yield of inflorescences (162.0 c/ha) and the collection of essential oil (51.5 kg/ha), No. R3-1-6 exceeded control by 24.9 % and 43.9 %, respectively. The patent on the new clary sage cultivar ‘Selinzh’ (No. R3-1-6), in the creation of which the method of cell engineering was used for the first time, was received.

Assessment of Production and Qualitative Characteristics of Different Populations of Salvia sclarea L. Found in Sicily (Italy)

Salvia sclarea L. is an important industrial crop, valued for its herbal-aromatic properties and high quality essential oils, that is used in food, pharmaceuticals and cosmetics. In this study, carried out from 2009 to 2010, the morphological and production characteristics and essential oil content and composition of three Sicilian populations were studied. In particular, the composition of essential oils extracted from primary and secondary inflorescences using steam distillation was assessed. Morphological, production and qualitative data from the three populations were subjected to analysis of variance and cluster analysis. Regarding the quality of the oils, only the most prevalent compounds were taken into consideration in this study. The three populations were linalyl acetate/linalool chemotypes. Highly significant variations were found for the effective local population and inflorescence type in the composition of the essential oil principal components. In particular, the primary inflorescences were found to be accumulation sites favoured by monoterpenes, and secondary inflorescences were favoured by sesquiterpenes and sclareol. Populations “S. Stefano Quisquina” and “Alcara Li Fusi” performed best on a morphological and production level, whereas populations “Prizzi”and “Alcara Li Fusi” performed best in terms of quality. Population “S. Stefano Quisquina” produced high levels of sclareol. Biotype selection from within the populations should be based on both morphological, production and quality analyses.