Chemical Variation in Essential Oil Profiles Detected Using Headspace Solid-Phase Microextraction Gas Chromatography Spectrometry in Response to Potassium, Nitrogen, and Water Available to Micropropagated Plants of Salvia stenophylla (Burch. ex Benth.)

Abstract

The effects of nitrogen, potassium, water stress, and phytohormones were studied using a Salvia stenophylla (Burch. ex Benth.) microplant system. In vitro regeneration was monitored and then followed with volatile secondary metabolite profiling through headspace solid-phase microextraction gas chromatography. Plantlet growth was most prolific on half-strength Murashige and Skoog medium without phytohormones. An increase in macronutrients supplied to the microplants enhanced accumulation of the commercially important (−)-α-bisabolol, while no significant changes to the relative abundance of β-bisabolene, α-muurolene, α-patchoulene, and D-limonene (among others) became apparent. Water-stressed plants, treated with sorbitol and polyethylene glycol, had a lowered rooting capacity in vitro. Overall, as a plant production system, micropropagation did not have deleterious effects on the biochemistry of S. stenophylla as no significant differences in metabolic profiles existed between conventional garden plants and in vitro propagules, regardless of phytohormone treatment. We also show that nutrient manipulation can be used efficiently as a strategy for positively altering secondary metabolism. This will ultimately benefit the domestication of this commercially important medicinal herb.