Genome Estimation and Phytochemical Compound Identification in the Leaves and Callus of <i>Abrus precatorius</i>: A Locally Endangered Plant from the Flora of Saudi Arabia

Abrus precatorius is considered to be a valuable source of natural products for the development of drugs against various diseases. Herein, the genome size and phytochemical compounds in the leaves and callus of A. precatorius were evaluated. The endangered A. precatorius was collected from the Al-Baha mountains, Saudi Arabia and identified based on the phylogenetic analysis of a DNA sequence amplified by ITS1 and ITS4 primers. The callus was induced by the culture of stem explants onto Murashige and Skoog medium (MS) supplemented with various combinations of 2,4-dichlorophenoxyacetic acid (2,4D) and 6-Benzylaminopurine (BAP). The callus with the highest fresh weight (2.03 g) was obtained in the medium containing 0.5µM BA and 5 µM 2,4-D after 8 weeks of culture; thus, the callus of this combination was selected for the genome estimation and phytochemical compound extraction. The genetic stability of the leaves from the donor as well as in the regenerated callus was analyzed by flow cytometry with optimized tomato (2C = 1.96 pg) as an external reference standard. The 2C DNA content was estimated to 1.810 pg ± 0.008 and 1.813 pg ± 0.004 for the leaves and callus, respectively. Then, the total phenol and total flavonoid contents in the methanol extract of the callus and leaves were measured using a spectrophotometer and the High-performance liquid chromatography (HPLC ) methods. The results showed that the methanolic extract of the leaves was higher in total phenols and total flavonoids than the callus extract. Finally, the extracts of callus and leaves were analyzed for phytochemical compound through the Gas chromatography and Mass spectroscopy (GC-MS). A total of 22 and 28 compounds were detected in the callus and leaves, respectively. The comparative analysis showed that 12 compounds of the secondary metabolites were present in both extracts

Biosynthesis and Characterization of ZnO Nanoparticles Using Ochradenus arabicus and Their Effect on Growth and Antioxidant Systems of Maerua oblongifolia

Zincoxide nanoparticles (ZnO NPs) are among the most produced and used nanomaterials worldwide, and in recent times these nanoparticles have also been incorporate in plant science and agricultural research. The present study was planned to synthesize ZnO NPs biologically using Ochradenus arabicus leaves and examine their effect on the morphology and physiology properties of Maerua oblongifolia cultured in vitro. ZnO NPs were characterized by UV–visible spectroscopy (UV–vis), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy, which demonstrated hexagonal shape nanoparticles of size ranging from 10 to 50 nm. Thus, the study uncovered an efficient, eco-friendly and simple technique for biosynthesis of multifunctional ZnO NPs using Ochradenus arabicus following growth of Maerua oblongifolia shoots in different concentrations of ZnO NPs (0, 1.25, 2.5, 5, 10, or 20 mg L−1) in Murashige and Skoog medium. Remarkable increases in plant biomass, photosynthetic pigments, and total protein were recorded up to a concentration of 5 mg L−1; at the same time, the results demonstrated a significant reduction in lipid peroxidation levels with respect to control. Interestingly, the levels of proline and the antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) activities were increased significantly in response to all ZnO NP treatments. These findings indicate that bioengineered ZnO NPs play a major role in accumulation of biomass and stimulating the activities of antioxidant enzymes in plant tissues. Thus, green-synthesized ZnO NPs might be of agricultural and medicinal benefit owing to their impacts on plants in vitro

Improving the Production of Secondary Metabolites via the Application of Biogenic Zinc Oxide Nanoparticles in the Calli of <i>Delonix elata</i>: A Potential Medicinal Plant

The implementation of nanotechnology in the field of plant tissue culture has demonstrated an interesting impact on in vitro plant growth and development. Furthermore, the plant tissue culture accompanying nanoparticles has been showed to be a reliable alternative for the biosynthesis of secondary metabolites. Herein, the effectiveness of zinc oxide nanoparticles (ZnONPs) on the growth of Delonix elata calli, as well as their phytochemical profiles, were investigated. Delonix elata seeds were collected and germinated, and then the plant species was determined based on the PCR product sequence of ITS1 and ITS4 primers. Afterward, the calli derived from Delonix elata seedlings were subjected to 0, 10, 20, 30, 40, and 50 mg/L of ZnONPs. The ZnONPs were biologically synthesized using the Ricinus communis aqueous leaf extract, which acts as a capping and reducing agent, and zinc nitrate solution. The nanostructures of the biogenic ZnONPs were confirmed using different techniques like UV–visible spectroscopy (UV), zeta potential measurement, Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Adding 30 mg/L of ZnONPs to the MS media (containing 2.5 µM 2,4-D and 1 µM BAP) resulted in the highest callus fresh weight (5.65 g) compared to the control and other ZnONP treatments. Similarly, more phenolic accumulation (358.85 µg/g DW) and flavonoid (112.88 µg/g DW) contents were achieved at 30 mg/L. Furthermore, the high-performance liquid chromatography (HPLC) analysis showed significant increments in gallic acid, quercetin, hesperidin, and rutin in all treated ZnONP calli compared to the control. On the other hand, the gas chromatography and mass spectroscopy (GC-MS) analysis of the calli extracts revealed that nine phytochemical compounds were common among all extracts. Moreover, the most predominant compound found in calli treated with 20, 30, 40, and 50 mg/L of ZnONPs was bis(2-ethylhexyl) phthalate, with percentage areas of 27.33, 38.68, 22.66, and 17.98%, respectively. The predominant compounds in the control and in calli treated with 10 mg/L of ZnONPs were octadecanoic acid, 2-propenyl ester and heptanoic acid. In conclusion, in this study, green ZnONPs exerted beneficial effects on Delonix elata calli and improved their production of bioactive compounds, especially at a dose of 30 mg/L

Zinc Oxide Nanoparticles (ZnO NPs), Biosynthesis, Characterization and Evaluation of Their Impact to Improve Shoot Growth and to Reduce Salt Toxicity on Salvia officinalis In Vitro Cultivated

Green synthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts have recently attracted considerable attention due to their environmental protection benefits and their easy and low cost of fabrication. In the current study, ZnO NPS were synthesized using the aqueous extract of Ochradenus arabicus as a capping and reducing agent. The obtained ZnO NPs were firstly characterized using ultraviolet visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR), transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive X-ray absorption (EDX), zeta potential, and zeta size. All these techniques confirmed the characteristic features of the biogenic synthesized ZnO NPs. Then, ZnO NPs were evaluated for their effects on morphological, biochemical, and physiological parameters of Salvia officinalis cultured in Murashige and Skoog medium containing 0, 75, 100, and 150 mM of NaCl. The results showed that ZnO NPs at a dose of 10 mg/L significantly increased the shoot number, shoot fresh weight, and shoot dry weight of Salvia officinalis subjected or not to the salt stress. For the shoot length, a slight increase of 4.3% was recorded in the plant treated by 150 mM NaCl+10 mg/L ZnO NPs compared to the plant treated only with 150 mM of NaCl. On the other hand, without NaCl, the application of both concentrations 10 mg/L and 30 mg/L of ZnO NPs significantly improved the total chlorophyll content by 30.3% and 21.8%, respectively. Under 150 mM of NaCl, the addition of 10 mg/L of ZnO NPs enhanced the total chlorophyll by 1.5 times, whilst a slight decrease of total chlorophyll was recorded in the plants treated by 150 mM NaCl + 30 mg/L ZnO NPs. Additionally, ZnO NPs significantly enhance the proline accumulation and the antioxidative enzyme activities of catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) in plants under salinity. Our findings revealed that green synthesized ZnO NPs, especially at a dose of 10 mg/L, play a crucial role in growth enhancement and salt stress mitigation. Hence, this biosynthesized ZnO NPs at a concentration of 10 mg/L can be considered as effective nanofertilizers for the plants grown in salty areas