Morpho-Physiological Response of Stevia (Stevia Rebaudiana Bertoni) to Salinity Under Hydroponic Culture Condition (A Case Study in Iran)

Abstract

The results showed that root characteristics (such as root fresh weight (RFW), root dry weight (RDW), root volume (RV), root length (RL), root area (RA), root diameter, root mass density (RMD), and dry root mass density (DRMD)) reduced with the intensification of NaCl. The effect of NaCl was significant on the protein content, activity of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), and DPPH. The increasing of NaCl caused significantly enhancement of protein content, CAT activity, and total antioxidant activity. The POD activity showed a significant decrease by the increasing of sodium chloride rate. The PPO and POD activities by the increasing sodium chloride rate showed a significant decrease. Steviol glycosides (SVglys) compositions: stevioside (Stev), rebaudioside A (Reb A), rebaudioside B (Reb B), rebaudioside C (Reb C) and dulcoside A (Dulc A) and SVglys content showed changes under the influence of salinity. In 30 mM NaCl treatment was obtained the highest value of total SVglys yield and SVglys content. The findings from this study lead to the conclusion that, salinity stress caused reduces root characteristics and changes in physiological traits (protein content, activity of CAT, POD, PPO and total antioxidant activity DPPH). On the other hand, at the lowest salinity level (30 mM), the highest amount SVglys was obtained. It seems that the high level of SVglys at lower salinity levels is one of the reasons for salinity tolerance in Stevia, which requires further investigation.

Integration of Antioxidant Activity Assays Data of Stevia Leaf Extracts: A Systematic Review and Meta-Analysis

“…However, other parameters concerning the drying procedure of the fresh leaves, the particle size of the dried leaves, the extraction method, including maceration time, pH, temperature, pressure, solvent polarity during the preparation of extracts, or even the maintenance conditions of the extracts (influencing the stability of each phenolic compound [131,143]), could have added confusion to our meta-analysis. The antioxidant capacity of a stevia extract is also influenced by the culture conditions of the plant, including salinity, fertilizer dose, H2O2 stress, light, and soil pH [131,144]. Information on these parameters was not given in the included studies.…”

Growth, physiological, and biochemical responses of thyme (Thymus vulgaris L.) to the application of arbuscular mycorrhizal fungi under cadmium stress conditions

“…Peroxidase activity was assayed adopting the method of Polle et al (1994) and Aghighi Shahverdi et al (2018). According to this method, POD activity was determined at 436 nm by its ability to convert guaiacol to tetraguaiacol (€ = 26.6 mM -1 cm -1 ).…”

Morpho-physiological and phytochemical responses of basil (Ocimum basilicum L.) to toxic heavy metal cadmium

“…To extract protein, 0.2 g of fresh tissue plant was pulverized in a mortar using liquid nitrogen and then one mL of buffer Tris-HCl (0.05 M, pH = 7.5) was added. The obtained mixture centrifuged for 21 min at 13,000 rpm, at 4 °C and the supernatant was used for enzyme activity measurements (Aghighi Shahverdi et al, 2017). The peroxidase activity was determined in a reaction of the mixture, which consisted of a suitable amount of 28 mM guaiacol, 5 mM H2O2, 25 mM Na-phosphate buffer (pH 6.8) and enzyme (Ghanati et al, 2002).…”