# Halophyte _Artemisia caerulescens_ L.: Metabolites from In Vitro Shoots and Wild Plants
###### Abstract  
Halophyte plants are potential resources to deal with the increasing soil salinity determined by climatic change. In this context, the present study aimed to investigate the germplasm conservation of _Artemisia caerulescens_ collected in the San Rossore Estate (Pisa, Italy) through in vitro culture, biochemical properties, and the phytochemical composition of the volatile fraction of both in vitro shoots and different organs of wild plants (leaves, young and ripe infloresances). The best medium tested for the shoot proliferation was MS, with the addition of 1 \(\upmu\)M BA. Total polyphenol content and antioxidant activity were noticeable in both the infloresances, while leaves and in vitro shoots showed lower amounts. Concerning the phytochemical investigation, the headspaces (HSs) and the essential oils (EOs) were characterized by oxygenated monoterpenes as the main chemical class of compounds in all samples, and with \(\upalpha\)- and \(\upbeta\)-thujone as the major constituents. However, the EOs were characterized by noticeable percentages of phenylpropanoids (23.6-28.8%), with brevifolia as the unique compound, which was not detected in the spontaneous volatile emissions of the same parts of the wild plant. Good amounts of EOs were obtained from different organs of the wild plant, comprising between 0.17% and 0.41% of the young and ripe infloresances, respectively. s 2022  
used for cosmetic and pharmaceutical applications [2]. In recent times, EOs have gained increasing interest due to consumers' preference for natural products [6] and have been used in many fields of applications, from human health to agriculture, thanks to their broad spectrum of bioactivities, which is attributable to their chemical composition [7; 8; 9; 10]. The genus _Artemisia_ comprises a wide range of species that have been subjected to phytochemical attention for their chemical diversity and EO production. These differences are attributable to their ability to colonize areas with different kinds of vegetation and ecological conditions, thus leading to different morphological and biological features [11; 12]. Among the countless species of _Artemisia_, _A. caerulescens_ is a wild aromatic species of great environmental interest due to its ability to grow and reproduce in selected areas of the central and western Mediterranean, which is characterized by highly saline soils [13]. This is a perennial, bushy, more or less tomentose plant, with a strong aromatic odour, very branched erect stems, and bearing both whole and 1-2-pinmate leaves. The flower heads, all with tubular flowers, are not very showy and arranged in a dense panicle (Figure 1a,b). The fruits are oval achenes, smooth and without pappus. The species is in fact considered a true halophyte [14] and is listed as a characterizing and/or diagnostic species of saline EU Habitats [15; 16]. Despite species showed a remarkable interest in the environmental and conservation fields, even with evidence of some particular aspects in its behaviour such as the interaction between propagation by seed and seasonal fluctuations of salinity [17], to date, there were very few studies in literature. This information deficit affects various fields of study, including those related to its phytochemical profile and medicinal properties, which are the subject of the present research. As a part of an ongoing project, which deals with the cultivation and analysis of halophyte species growing in the salt marshes on the coast of Tuscany, the present study aims to investigate preliminary evidence from in vitro cultures of _A. caerulescens_ collected  
Figure 1: (**a**) _Artemisia caerulescens_ in its natural habitat in the San Rossore estate (photo by [PERSON]); (**b**) ripe infloresence (**c**) 4-week-old shoots in MSO medium; (**d**) 4-week-old shoots in 4 mM MS-BA medium. in the San Rossore Estate (Pisa, Italy) in order to verify the possibility of its germplasm conservation, thus avoiding environmental depletion and allowing for the selection of the most promising cultivation lines.