Physiological and biochemical responses of thyme plants to some antioxidants

Abstract

Abstract. Orabi SA, Talaat IM, Balbaa LK. 2014. Physiological and biochemical responses of thyme plants to some antioxidants. Nusantara Bioscience 6: 118-125. Two pot experiments were conducted to investigate the effect of tryptophan, nicotinamide and α-tocopherol (each at 50 and 100 mg/L) on plant growth, essential oil yield, and its main constituents. All treatments significantly promoted plant height, and increased fresh and dry mass (g/plant) of thyme (Thymus vulgaris L.). The treatment with 100 mg/L nicotinamide showed increases in total potassium mainly in the first cut. Total soluble sugars, oil percentage, and oil yield and protein recorded increments with tryptophan treatments. Treatment of Thymus plants with 100 mg/L nicotinamide observed the highest percentage of thymol (67.61%). Oxygenated compounds recorded the highest value with 50 mg/L α-tocopherol treatment, while the maximum non-oxygenated ones resulted from the application of 100 mg/L nicotinamide. All treatments under study significantly affected the activity of oxidoreductase enzymes (POX and PPO). Nicotinamide at the concentration of 100 mg/L recorded the highest increments in APX and GR and the lowest values in oxidoreductase enzyme activities added to the lowest values of lipid peroxidation to enhance the best protection of thyme plants.

Improving growth and productivity of faba bean (Vicia faba L.) using chitosan, tryptophan, and potassium silicate anti-transpirants under different irrigation regimes

“…L-tryptophan is a valuable amino acid. It may act as an osmolyte, an ion transport regulator that modulates stomatal opening and detoxifies harmful effects of heavy metals ( Orabi et al, 2014 ). Furthermore, the tryptophan pathway plays a defensive role in plants ( Hussein et al, 2014 ).…”

Changes in Bitter Fennel Essential Oils Exposed to Foliar Spray with L-Phenylalanine

“…Previous studies reported that amino acids positively affect the production and components of EOs of aromatic plants. For example, geranium, thyme, philodendron, navel orange, hyssop, and lemon plants treated with amino acids have higher EO compositions than the untreated control (Talaat, 2005;Orabi et al, 2014;Abd El-wahed et al, 2016;Aghaei et al, 2019;Khalid et al, 2019Khalid et al, , 2020. However, limited studies have been conducted on the aromatic amino acid L-phenylalanine (L-Phe), which is a key player in plant growth, development, and EO production (Pascual et al, 2016;Aghaei et al, 2019;Poorghadir, 2020).…”