On the basis of previous studies, an antioxidant enriched high yield potential genotype (Accession VA13) was selected for this investigation. This genotype was grown in pots of a rain shelter open field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh (AEZ-28, 24° 23′ north latitude, 90° 08′ east longitude, 8.4 m.s.l.). The seeds were sown in plastic pots (15 cm in height and 40 cm length and 30 cm width) in a randomized complete block design (RCBD) with three replications. N: P₂O₅:K₂O were applied @92:48:60 kg/ha as a split dose. First, in pot soil, @46:48:60 kg ha 1 N: P₂O₅:K₂O and second, at 7 days after sowing (DAS) @46:0:0 kg/ha N: P₂O₅:K₂O. The genotype was grouped into three sets and subjected to four salinity stress treatments that are, 100 mM NaCl, 50 mM NaCl, 25 mM NaCl, and control or no saline water (NS). Pots were well irrigated with fresh water every day up to 10 days after sowing (DAS) of seeds for proper establishment and vigorous growth of seedlings. Imposition of salinity stress treatment was started at 11 DAS and continued up to 40 DAS (edible stage). Saline water (100 mM NaCl, 50 mM NaCl and 25 mM NaCl) and fresh water were applied to respective pots once a day. At 40 DAS the leaves of Amaranthus tricolor were harvested. All the parameters were measured in six samples.

At Moderate salinity stress (MSS) and Severe salinity stress (SSS) conditions, leaf color parameters and pigments, vitamins, phenolic acids, flavonoids and antioxidant capacity of A. tricolor leaves were very high compared to control condition. Hence, salt-stressed A. tricolor leaves had a good source of natural antioxidants compared to plant grown in normal cultivation practices.

Plant material: Coriander (Coriandrum sativum L.) fruits were collected from cultivated plants in the region of Korba (northeastern Tunisia) in April 2006. Seeds were set to germinate at 25 ℃. Ten-day-old coriander seedlings were grown in quarter-strength Hoagland's solution laced with 0 mM, 25 mM, 50 mM and 75 mM of NaCl. The culture was placed in a greenhouse with 25 ℃ day maximum and 18 ℃ night minimum, under artificial light of 141 µmol/m² /s (6000 lux) with 16 h photoperiod and 60-80% air humidity. Nutrient solution was continuously aerated. Growth parameters: Plants were harvested at the seedling stage 3 weeks after treatment.

Essential oil content was 1762.64 µg/g dry weight (DW) (0.18%) and 1255.77 µg/g DW (0.12%) in stems and leaves, respectively. At low and moderate stress, a significant difference in the essential oil content was developed between stems, with a significant decrease, and leaves, with an increase up to 43%. Under high salinity, the oil content of both organs decreased significantly. The major volatile compound of stems and leaves was (E)-2-decenal with 24% and 52%, respectively. Other important components were decanal, (E)-2-dodecenal, dodecanal, (E)-2-undecenal, (E)-2-tridecenal and (E)-2-undecanal. Further, the content of these compounds were affected differently by the treatment level and by the organ type.

To break the seed dormancy, they were soaked in boiling water for 10 min and were then placed in Petri dishes moistened with distilled water and kept in a refrigerator (4 ℃) for 7 days. Seeds were then sown in plastic pots containing sands and powdered leaves (1:2) and were allowed to grow in the greenhouse with the mean day/night temperature and relative humidity of 29 ℃ , 38 % and 17 ℃ , 50 % respectively. Sixty days after seed germination, uniform seedlings with two nodes and four opposite leaves were transplanted into big plastic pots (30 × 50 cm). Each pot was filled with 10 kg of air-dried soil and two seedlings were used per pot for all treatments.Eight weeks after transplanting, plants were subjected to different levels of salinity supplied with irrigation water. In order to prevent osmotic shock, salt solutions were added gradually at several stages and so, lasting for three weeks. To keep the levels of soil salt concentration constant, distilled water was used in subsequent irrigations. At the end of salt treatment, total soil electrical conductivities including control were determined by EC meter (0.40, 2.3, 4.5, 6.8 and 9.1 dS/m). Salt stress symptoms (leaf tip chlorosis and necrosis) in plants treated with high salt concentrations appeared after three weeks. At this time, seedlings were harvested. A total of 10 g of fresh leaf material was harvested per plant, 3.5 g of which was used for HGC-MS analysis and the rest was allowed to dry at room temperature.

Moderate salinity could induce S. mirzayanii to produce high amounts of some valuable volatile oils and total phenolic compounds.

This experiment in a greenhouse of the College of Horticulture, Nanjing Agricultural University, Nanjing, China. Plants were cultivated under a natural light condition with 30 &#8451 day maximum and 15 &#8451 night minimum, and 60-80% air humidity. Schizonepeta tenuifolia Briq. seeds were bought from Xincheng Chinese Herbal Medicine Industry (Anguo, China). In March, 2017, seeds were sown in trays containing a compost of humus, vermiculite, and perlite (1:2:1) and irrigated with distilled water to keep moist. About 8 days later, seeds were germinated and quarter-strength modified Hoagland's solution was used for irrigation. Thirty-seven days later (establishment phase), homogenous plants with a height of nearly 15 cm were transplanted into plastic pots filled with pure quartz sand. Two plants were cultivated in each pot and irrigated with 200 mL half-strength modified Hoagland's solution every second day. Six days later, the plants were divided into five groups and salt treatments were initiated. A total of 300 mL of the above nutrient solution supplemented with 0, 25, 50, 75, or 100 mM NaCl was applied every day. To prevent osmotic shock, salt concentrations increased gradually with 25 mM NaCl every other day until the designated concentration was reached. The experimental design was completely randomized with 70 individuals for each treatment. All plants were harvested after 12 days since salt stress symptoms (leaf chlorosis and necrosis) occurred, especially in those treated with 75 and 100 mM NaCl.

Contents of antioxidants, including phenolics and flavonoids, increased at low (25 mM) or moderate (50 mM) levels, but declined at severe (75 and 100 mM) levels. On leaf surfaces, big peltate and small capitate glandular trichomes (GTs) were found. Salt treatments, especially at moderate and severe concentrations, enhanced the density of total GTs on both leaf sides. The most abundant compound in GT volatile exudates was pulegone. Under salinity, relative contents of this component and other monoterpenes decreased significantly; biosynthesis and accumulation of esters were enhanced, particularly sulfurous acid,2-ethylhexyl hexyl ester, which became the second major compound as salinity increased. In conclusion, salt stress significantly influenced the growth and secondary metabolism of S. tenuifolia, enabling us to study the changes of its pharmacological activities.