Effect of in vitro drought stress on phenolic acids, flavonols, saponins, and antioxidant activity in Agave salmiana

This work evaluated the effect of in vitro drought stress on morphological characteristics, phenolic compounds, flavonols, saponin content, and antioxidant activity in plantlets of Agave salmiana. Drought stress was induced with polyethylene glycol (PEG) at 0, 10, 20 and 30% w/v in Murashige and Skoog solid medium. The determination of specific flavonols and saponins was achieved via HPLC-DAD and HPLC-ELSD, respectively. Compared with the control, plants grown in 30% PEG showed a change in the width of the leaves and a different color, showing less clarity and more darkening (L = 21.18, b = 14.27) and also had the lowest flavonol content, but the highest total saponin content (tigogenin glycoside, 163 mg of protodioscin equivalents/g dw) and the highest antioxidant activity. Total phenolic compounds did not significantly differ between treatments. Agave salmiana plants cultured in vitro increased their saponin content and antioxidant activity in response to drought stress induced via PEG. •Plants grown under drought stress with 30% PEG were thinner and darker.•Total phenolic compounds did not significantly differ between treatments.•Plants in 30% PEG had the highest total saponin content and antioxidant activity.•The PEG content was positively correlated with saponins and antioxidant activity.•In vitro drought stress increased saponin content and antioxidant activity in A. salmiana.