Optimisation of Potassium Chloride Nutrition for Proper Growth, Physiological Development and Bioactive Component Production in Prunella vulgaris L

Abstract

Prunella vulgaris L. is an important medicinal plant with a variety of pharmacological activities, but limited information is available about its response to potassium chloride (KCl) supplementation. P. vulgaris seedlings were cultured in media with four different KCl levels (0, 1.00, 6.00 and 40.00 mM). Characteristics relating to the growth, foliar potassium, water and chlorophyll content, photosynthesis, transpiration, nitrogen metabolism, bioactive constituent concentrations and yield were determined after three months. The appropriate KCl concentration was 6.00 mM to result in the highest values for dry weight, shoot height, spica and root weight, spica length and number in P. vulgaris. The optimum KCl concentration resulted in a maximum net photosynthetic rate (Pn) that could be associated with the highest chlorophyll content and fully open stomata conductance. A supply of surplus KCl resulted in a higher concentration of foliar potassium and negatively correlated with the biomass. Plants that were treated with the appropriate KCl level showed a greater capacity for nitrate assimilation. The Pn was significantly and positively correlated with nitrate reductase (NR) and glutamine synthetase (GS) activities and was positively correlated with leaf-soluble protein and free amino acid (FAA) contents. Both KCl starvation (0 mM) and high KCl (40.00 mM) led to water loss through a high transpiration rate and low water absorption, respectively, and resulted in increased concentrations of ursolic acid (UA), oleanolic acid (OA) and flavonoids, with the exception of rosmarinic acid (RA). Moreover, the optimum concentration of KCl significantly increased the yields of RA, UA, OA and flavonoids. Our findings suggested that significantly higher plant biomass; chlorophyll content; Pn; stronger nitrogen anabolism; lower RA, UA, OA and flavonoid accumulation; and greater RA, UA, OA and flavonoid yields in P. vulgaris could be expected in the presence of the appropriate KCl concentration (6.00 mM).

Deep Eutectic Solvents: An Overview of its Application as a “Green” Extractant

“…About 3.658 mg g -1 and 1.049 mg g -1 of rosmarinic acid and salviaflaside respectively were extracted. The results obtained in this work proved that the amount of rosmarinic acid and salviaflaside extracted were higher compared to the previously reported extraction technique and conventional solvents in the findings of Chen et al, [51][52][53]. Nam et al, [54] have compared the extraction efficiency of DES with conventional solvent (methanol) to extract bioactive compounds from a biomass.…”

Effects of ammonium to nitrate ratio on growth, nitrogen metabolism, photosynthetic efficiency and bioactive phytochemical production ofPrunella vulgaris

“…It is a well-known Chinese medicinal herb used to reduce fever, alleviate sore throat, and accelerate wound healing (Chen et al, 2011;Pinkas et al, 1994;Psotová et al, 2003Psotová et al, , 2006. It is also commonly used as a traditional medicinal herb in some Asian and Europe countries, such as Korea, Japan, Turkey, the Czech Republic, Poland, and Germany (Chen et al, 2013). In addition to its pharmaceutical uses, the spicas of P. vulgaris are manufactured for tea, and the fresh leaves of P. vulgaris are consumed as a vegetable dish in southeastern China (Chen et al, 2011(Chen et al, , 2013.…”

“…Prunella vulgaris is rich in phenolic acids, triterpenes, flavonoids, and the anionic polysaccharide prunelline (Chen et al, 2013;Cheung & Zhang, 2008;Jiang et al, 2008). Rosmarinic acid (RA), one of the phenolic acids found in P. vulgaris, suppresses lipoperoxidation, scavenges superoxide radicals, and exhibits antiinflammatory and antioxidant bioactivities (Psotová et al, 2006).…”

“…Among triterpenes, ursolic acid (UA) and oleanolic acid (OA) are especially known for their bioactivities, including hepatoprotection, antihyperglucemia, antifungal, antitumor, and antiinflammatory activities (Liu, 1995). Total flavonoids exhibit a wide range of biological effects, including antiviral, antiinflammatory, antibacterial, vasodilatory, and antiallergic actions (Chen et al, 2013;Cook & Samman, 1996;Liu et al, 2012).…”

“…It offers several advantages over field cultivation, such as process standardization, faster crop growth, year-round production and the production of high-quality raw material that is clean and easy to process due to minimal contamination from pollutants and micro-organisms (Letchamo et al, 2002). Moreover, secondary metabolism can be regulated in soilless culture systems via appropriate control of the nutrient solution fed to the plants (Chen et al, 2013).…”