Structural and Chemical Adaptations of Artemisia monosperma Delile and Limbarda crithmoides (L.) Dumort. in Response to Arid Coastal Environments along the Mediterranean Coast of Egypt

Abstract

Arid coastal habitats are stressful regions subjected to the effects of biotic and abiotic factors. Vascular plants in these habitats display different responses to cope with these environmental fluctuations. This work addressed the morpho-anatomical features and chemical responses of two medicinal vascular plant species Artemisia monosperma Delile and Limbarda crithmoides (L.) Dumort., growing naturally along the Mediterranean coast of Egypt. Soil properties (physical and chemical), morpho-anatomical features and chemical constituents (secondary metabolites, antioxidant activity and essential oils) for the two species were performed. Our results displayed that both species are surviving where soils are alkaline, high saline with low moisture and organic carbon. The morphology of both species appeared woody low shrub with fleshy leaves. The most marked anatomical attributes were the thick cuticle of the epidermal layer in leaves and stems, compact palisade cells and abundant idioblasts (secretory ducts, phenolic compounds and calcium oxalate). Also, sclerenchymatous pericycle fibers in stem and glandular trichomes on the leaf had appeared in A. monosperma. Both plants exhibited a considerable content of phenolics, flavonoids, tannins, alkaloids and antioxidant activity with a higher level in A. monosperma than L. crithmoides. The leaf extracts of both plants showed higher values than the stem extracts. The sesquiterpenes group were the major identified compounds of the essential oils (EOs) in A. monosperma and L. crithmoides, and the majority were oxygenated sesquiterpenes with percentages of 42.63% and 51.49%, respectively. The second major group of EOs was monoterpenes, which were represented in A. monosperma in concentrations (34.04%) much higher than those recorded in L. crithmoides (4.97%). Exploring the local adaptation mechanism used by the target plants helps us to understand how these plants can acclimatize to harsh conditions, and this provides critical insights into the protection and survival strategy of species under extreme conditions.

Habitat preference, phytochemical constituents and biological potency of four Egyptian Mediterranean halophytes

“…In the current study, the coastal soil supporting the studied halophytes was featured by its coarse sandy texture, alkaline range, low water holding capacity, low fertility (low organic matter, TN, TP, K + , Ca 2+, and Mg 2+ ), and high salinity. These findings were in agreement with reports that displayed that, the Mediterranean region hosts different types of soils with low amounts of organic matter, an acidic to alkaline range, and high salinity (Abdelaal et al, 2018;Ciccarelli, 2015;El-Sherbeny et al, 2021). Specifically, such low fertility and deficiency of organic matter along the coastal salt marshes habitat may be attributed to limited nutrient retention capacity and minerals bioavailability, degradation and erosive processes, scarce or irregular rainfall, and long, hot summers (Sardans and Peñuelas, 2013).…”

“…In addition, the total phenols and flavonoids reported for T. nilotica in this study were greater than the previous study estimating total phenols and flavonoids in T. nilotica . Previous literature reported that L. crithmoides contains significant levels of secondary metabolites such as phenolic acids, flavonoids, terpenoids, and essential oils (Adorisio et al, 2020;El-Sherbeny et al, 2021). Concerning soil physicochemical features associated with phytochemical components of the studied halophytes, lower concentrations of soil sulfates, total phosphorous and calcium induce a greater accumulation of total phenols and flavonoids in the studied halophytes.…”

“…The variation in the bioactive metabolites and their bioactivity among the studied halophytes could be attributed to the effects of environmental factors, genetics, age, and nutrients in the soil. Previous research found that the rise in salinity increases the content of polyphenols in plants ( Bartwal et al, 2013;El-Sherbeny et al, 2021). The total phenols of A. macrostachyum from the current study showed greater phenols content than ethanol extract of A. macrostachyum collected from the United Arab Emirates (45.6 mg GAE g -1 dry extract) (Jitan et al, 2018), hexane extract of A. macrostachyum from Portugal (39 mg GAE g -1 dry extract) (Rodrigues et al, 2014), and different solvents of A. macrostachyum collected from Algeria (Chekroun-Bechlaghem et al, 2019), but lower flavonoids than the Portuguese type (Barreira et al, 2017).…”

“…All compounds were prepared or solubilized in dimethyl sulfoxide (DMSO, 10 mM stock). The antitumor potency of each extract was evaluated depending on the IC 50 inhibitory concentration (µg) as follows: 1-10 (very strong), 11-20 (strong), 21-50 (moderate), 51-100 (weak), and greater than 100 (non-cytotoxic) (El-Zayat et al, 2021).…”

Induction of organogenesis and callogenesis in Limbarda crithmoïdes L. (Asteraceae) explants cultured on MS media supplemented with various concentrations of Na+ and K+

“…Limbarda crithmoïdes, well known as Golden samphire, is a succulent perennial coastal plant commonly found in the Mediterranean basin in salt water marsh areas (Zurayk and Baalbaki, 1996). It displays a fascinating capacity to tolerate high sodium concentrations in its aerial parts (Flowers and Colmer, 2008;Vicente and Boscaiu, 2020) allowing it to have salt, water, and metallic stress tolerance (Al Hassan et al, 2016;El-Sherbeny et al, 2021;Dridi et al, 2022a;2022b). L. crithmoïdes has long been collected for its medicinal properties and therapeutic uses.…”