Integrative Effects of Stress- and Stress Tolerance-Inducing Elicitors on In Vitro Bioactive Compounds of Ajowan (Trachyspermum Ammi (L.) Sprague) Medicinal Plant

Abstract

Bioactive compounds of medicinal plants have a wide range of applications in pharmaceutical, food and other industries. In vitro culture systems have great potential for sustainable production of bioactive compounds of medicinal plants. In the present study, the individual and combined effects of a stress tolerance-inducing (salicylic acid) and a stress-inducing elicitor (polyethylene glycol) were evaluated on regeneration efficiency, antioxidants activity and phytochemical profile of in vitro shoot cultures of ajowan. Different concentrations of salicylic acid (SA) (0, 10, 20, 40, 80 µM) and polyethylene glycol (PEG 6000) (0, 1, 2, 5%) were added to the shoot regeneration Murashige and Skoog medium containing Kin (1.5 mg/L) and NAA (0.25 mg/L) plant growth regulators. Salicylic acid reduced the adverse effect of PEG treatment on number of regenerated shoots and in vitro rooting. The activities of catalase, superoxide dismutase, and peroxidase enzymatic antioxidants were significantly increased in SA + PEG treated plants. The gas chromatography-mass spectrometry (GC-MS)-profiling revealed quantitative and qualitative phytochemical differences between control and SA + PEG treated plants. The greatest means of p-cymene and thymol bioactive compounds were obtained from in vitro shoots treated with 5% PEG + 40 µM SA. The inter-simple sequence repeats (ISSR) markers proved the genetic stability of in vitro regenerated plants. The presented protocol is useful for large-scale sustainable production of secondary metabolites (SMs) of medicinal plants. The same strategy (stress tolerance-inducing elicitor + stress-inducing elicitor) is applicable to increase valuable SMs in other production systems such as hydroponic, greenhouse and field conditions.

Eliciators increase gas exchanges and induce the Zea mays antioxidant system

“…The use of resistance elicitors promotes increases in the secondary metabolites accumulation, which are important in the defense plants system (Niazian et al, 2021). However, the plant metabolism response depends on the concentration and time of the stimulus, as well as the commercial product nature (Caicedo-López et al, 2021).…”