River's Ulva intestinalis L. extract protects common bean plants (Phaseolus vulgaris L.) against salt stress

Abstract

• Ulva intestinalis extract contained many substances that are important for plant to tolerate salt stress. • Salt stress reduced growth parameters, water content, indole acetic acid, and photosynthetic pigments of common bean plants. • Ulva intestinalis repair damage cause by salt stress in common bean plants. • Ulva intestinalis increased the ability of common bean plants to tolerate salt stress by increasing the accumulation of secondary metabolites. • Ulva intestinalis increased the ability of common bean plants to tolerate salt stress by increasing the antioxidant enzymes activity. This study investigated the effect of Ulva intestinalis L. extract on common bean ( Phaseolus vulgaris L.) plants grown under salt stress. Two concentrations of Ulva intestinalis extract, 6% and 12% were applied by irrigation and spraying to plants under 51.33 mM of NaCl. The results indicated that the treated plants showed a great ability to tolerate salt stress (51.33 mM) by increasing plant growth and photosynthetic pigment content compared to plants irrigated only with NaCl. Additionally, there was a significant improvement in the expression of antioxidant metabolites, such as flavonoid content and ascorbic acid content. Furthermore, there was a significant improvement in antioxidant enzyme activities, such as superoxide dismutase (EC 1.15.1.1), glutathione peroxidase (EC 1.11.1.9), glutathione-S-transferase (EC 2.5.1.18), and glutathione reductase (EC 1.8.1.7) in stressed plants, especially those sprayed with 6% of Ulva intestinalis extract. Overall, our results suggest that the application of Ulva intestinalis extract could be a promising biostimulant for the growth of common bean plants under salinity stress.