Foliar application of nano-silicon enhances drought tolerance rate of pot marigold (Calendula officinalis L.) by regulation of abscisic acid signaling.

Pot marigold (Calendula officinalis L.) is an herbaceous ornamental and medicinal plant. Climate models predict a reduction of precipitations and increasing the average temperature.

Exogenous putrescine application imparts salt stress-induced oxidative stress tolerance via regulating antioxidant activity, potassium uptake, and abscisic acid to gibberellin ratio in Zinnia flowers.

This research was conducted to investigate the efficacy of putrescine (PUT) treatment (0, 1, 2, and 4 mM) on improving morphophysiological and biochemical characteristics of Zinnia elegans "State Fair" flowers under salt stress (0, 50, and 100 mM NaCl). The experiment was designed in a factorial setting under completely randomized design with 4 replications. The results showed that by increasing the salt stress intensity, the stress index (SSI) increased while morphological traits such as plant height decreased.