Light-mediated elicitation of Tessaria absinthioides calli for the production of anthocyanins: correlation with protein expression

This study explores the metabolic responses of undifferentiated cells of Tessaria absinthioides to light elicitation, with a focus on the production and accumulation of anthocyanins. It was observed that anthocyanin concentrations in cell biomass were notably higher compared to those in wild flowers, albeit with slight compositional differences, according to the HPLC-DAD analysis. Proteomic analysis showed that exposure to fluorescent light under a 16-hour photoperiod induced significant changes in protein expression in T. absinthioides calli. Under these conditions, 578 proteins were overexpressed and 486 proteins were uniquely identified. These proteins were predominantly clustered in key functional categories such as protein processing, cellular transport, DNA regulation, as well as those involved in sesquiterpene synthesis and developmental regulation. Furthermore, proteins essential for the phenylpropanoid pathway and anthocyanin biosynthesis were identified in light-exposed calli, with many significantly overexpressed compared to dark-grown cultures. A similar trend was observed in enzymes associated with the de novo synthesis of arginine, a precursor to stress-responsive metabolites like polyamines and nitric oxide. These findings can help elucidate the adaptive capabilities of T. absinthioides in vitro cultures, particularly the metabolic pathways involved in anthocyanin production in response to light elicitation. They also highlight the significance of cell cultures for the sustainable bioproduction of natural pigments.