Phytochemical Analysis of Maerua oblongifolia, and Assessment of the Genetic Stability of M. oblongifolia under In Vitro Nanoparticles Exposure

Maerua oblongifolia (Forssk.) is a rare medicinal plant in Saudi Arabia that is threatened with extinction owing to overexploitation, climate change, and poor seed germination. This study aimed to identify, for the first time, the phytochemical compounds existing in M. oblongifolia leaves' extract using gas chromatography and mass spectroscopy (GC-MS). In addition, it aimed to determine the plant growth and genetic uniformity of the plant under the exposure of in vitro biogenic silver and zinc oxide nanoparticles. The GC-MS analysis detected 28 phytochemical compounds. The main compounds obtained from the leaf extracts were triphenylphosphine oxide and 4,5-Dihydrooxazole-5-one, 2-methyl-4-[2,3,4-methozxybenzylidnen]-. The supplementation of AgNPs and ZnO NPs to the culture media significantly enhanced the plant biomass, shoot length, and shoot regeneration of M. oblongifolia. The genetic stability of the plant material was evaluated using inter-simple sequence repeat (ISSR) markers. The application of Ag and ZnO NPs showed genetic stability among treated plants. However, the higher concentration of both nanoparticles induced minor genetic variations recorded as 4.4 and 2.2% in Ag and ZnO NPs, respectively. This work focused on the detection of phytochemical active constituents from M. oblongifolia shoot cultures, and it will be useful for the large-scale manufacturing of these compounds for pharmaceutical and commercial purposes. In addition, it confirmed that the exposure of silver and zinc oxide nanoparticles to the in vitro culture media of plant tissues might be a secure technique with which to produce true-to-type plants.