Journal of Medicinal Plants Biotechnology

Abstract An experiment was conducted to investigate the effects of water deficit stress (field capacity (FC), 50%, and 30% of FC) and foliar application of gamma-aminobutyric acid (GABA) and spermidine (control and 3 mg L⁻¹), as well as their combined application, on growth and selected physiological traits of basil. The highest plant biomass was observed under irrigation at FC + simultaneous foliar application of spermidine and GABA. The main effects of water deficit and foliar treatments significantly influenced chlorophyll, H2O2, malondialdehyde, proline, elemental content, and essential oil content of the plant. The highest chlorophyll a, calcium, magnesium, phosphorus, and potassium content were observed under irrigation at FC. Irrigation at FC and 50% FC significantly increased chlorophyll b and nitrogen contents. Irrigation at 30% FC resulted in elevated levels of H2O2, malondialdehyde, and proline accumulation. All three foliar treatments led to increased chlorophyll b, nitrogen and potassium contents. Simultaneous foliar application of both compounds contributed to a reduction in H2O2 and malondialdehyde levels, while enhancing chlorophyll a, proline, phenolic compounds, calcium, magnesium, phosphorus, and essential oil contents. Essential oil content was notably increased under irrigation at 50% FC. Sixteen constituents were identified in the basil essential oil, with methyl chavicol (38.42–42.38%) being the predominant compound, particularly prominent in the treatment combining irrigation at 30% FC with foliar application of both compounds. The results of the present study demonstrate the positive effect of concurrent application of both compounds on the evaluated physiological and biochemical traits of basil under water deficit conditions.

Abstract In order to evaluate the physiological and biochemical responses of different ecotypes of caper (Capparis spinosa L.) seedlings to drought stress, an experiment was conducted under laboratory conditions in 2023 at the Seed Quality Analysis Laboratory of the Seed and Plant Certification and Registration Research Institute, Karaj, Iran, using a completely randomized design with three replications. In this study, seeds of nine native caper ecotypes collected from Ardabil Province (Moghan), Alborz (Karaj), Ilam Province (Mehran), North Khorasan Province (Bojnord), Kermanshah Province (Dalahoo), and Khuzestan Province (Ramhormoz, Hendijan, Mahshahr, and Ahvaz) were evaluated. Drought stress was imposed using polyethylene glycol (PEG 6000) at an osmotic potential of −6 bar. The results indicated that drought stress significantly increased malondialdehyde content from approximately 6.5 to 11.3 nmol g⁻¹ FW and hydrogen peroxide from 3.1 to 6.0 µmol g⁻¹ FW, while total chlorophyll content decreased from 0.35 to 0.21 mg g⁻¹ FW. In contrast, proline content (12.7–45.8 µg g⁻¹ FW), total phenolic content (2.6–3.6 mg gallic acid g⁻¹ FW), and antioxidant capacity (38–47% DPPH inhibition) showed significant increases under drought conditions. Comparison among ecotypes revealed that under non-stress conditions, the Karaj and Moghan ecotypes exhibited greater physiological stability, whereas under drought stress, the Mahshahr and Hendijan ecotypes showed the lowest oxidative damage indices and the highest accumulation of protective compounds, and were therefore identified as drought-tolerant ecotypes. Overall, the results highlight the key role of antioxidant defense mechanisms and osmotic adjustment in the adaptation of caper plants to drought stress conditions.

Abstract In the most regions of the world, salinity stress is the most important stress that limits the growth of plants and its performance by decreasing the osmotic potential and disrupting the absorption of water and some nutrients. Salicornia Persica, is a halophyte and annual plant and resistant to the salinity. Ascorbic acid can increase resistance of plant than stress through stimulating the activity of antioxidant enzymes. An experiment was carried out in2019 in the research greenhouse of Malayer University in a factorial format in a completely randomized design, in order to evaluate the effect of different concentrations of ascorbic acid (0, 0. 2mm) on the morphological characteristics of Salicornia Persica, under the conditions of salinity stress (0,300, and 600ppm). The results showed that salinity stress caused a significant increase in the dry weight of aerial parts. On the other hand, spraying with ascorbic acid caused an increase in the dry weight of aerial parts. Salinity caused a reduction in the amount of photosynthetic pigments. The amount of Proline increased at 300ppm salinity and decreased at 600ppm salinity. Generally, It can be concluded that spraying of Salicornia Persica with ascorbic acid improved the growth and the tolerance of this plant against the effects of salinity