Enhanced Carnosic Acid Levels in Two Rosemary Accessions Exposed to Cold Stress Conditions

Abstract

Two rosemary accessions were subjected to chilling temperatures in control environmental cabins analyzing their variations in rosmarinic and carnosic acids together with their adaptability to these stress conditions. Cold stressed plants of both accessions showed increases in caffeic acid and carnosic acid concentration levels, while other secondary metabolites such as rosmarinic acid, naringin, cirsimaritin, hispidulin, and carnosol showed different responses in both accessions. In addition, cold stressed plants exhibited significant reductions in chlorophylls, beta-carotene, and violaxanthin levels as well as the maximum quantum yield of PSII in both accessions. Hydrogen peroxide and lipid peroxidation levels showed similar responses in both accessions, which were positively and negatively correlated with rosmarinic and carnosic acids. From these results it is therefore suggested that carnosic acid biosynthesis in rosemary plants is induced by chilling periods. On the other hand, we demonstrate that not all rosemary accessions are equally well adapted to chilling temperatures. In fact, for (one) accession cold treated plants severe losses in chlorophyll, beta-carotene, and even xanthophylls (including zeaxanthin and antheraxanthin) were observed, despite no visual symptoms of leaf injury. More research is needed to understand rosmarinic acid variations in rosemary plants under stress conditions.

Total Phenolic Content and Polyphenolic Profile of Tunisian Rosemary (Rosmarinus officinalis L.) Residues

“…Contrary to this, studies accomplished by Yeddes et al (2019) about the effect of bioclimatic area and season on phenolics and antioxidant activities of rosemary growing wild in Tunisia showed that there was a strong correlation between antioxidant activity and phenolic content depending on bioclimatic and season effects [18]. However, our results are in agreement with those published (2007), since as occurs at the present study, for these researchers, variation in the chemical composition of polyphenolic extracts have been attributed to many factors, including abiotic stress,, genetic heritance and the phenological stages of the plants [16,50]. Several phenolic compounds of rosemary determined in this study were similar in content and concentration to those in previous reports [1,24,51].…”

Medicinal importance, pharmacological activities, and analytical aspects of hispidulin: A concise report

“…Phytochemical study of leaves of Leuzea carthamoides was performed and the result showed the presence of seven natural compounds including hispidulin 60 . Cold stressed plants of both accessions showed different responses in both rosemary accessions accessions 61 . Three anti-inflammatory compounds nepetin, jaceosidin and hispidulin have been isolated and identified from dichloromethane extract of Eupatorium arnottianum Griseb 38 .…”

Environmental Factors Affecting the Accumulation of Rosmarinic Acid in Spearmint (Mentha spicata L.) and Peppermint (Mentha piperita L.)

“…For example, spearmint plants enriched for RA exhibit a direct, negative correlation between the accumulation of RA and the antioxidant capacity spearmint extracts from plants grown at high temperatures [11]. Other researchers have found that cold temperatures can enhance the accumulation of RA in rosemary but is dependent on the chemotype [12]. This study examines the changes in RA accumulation in different chemotypes of mint leaf tissue due to environmental effects *Address correspondence to this author at the Department of Plant Agriculture, University of Guelph, Guelph, ON, N1G 2W1, Canada; Tel: (519) 824-4120; Fax: (519) 763-8933; E-mail: lkott@uoguelph.ca (photoperiod, cold stress, soil type, year to year differences) and the effect of physiological status of the plant in indoor tests or field trials.…”