Common bean (Phaseolus vulgaris L.) seedlings overcome NaCl stress as a result of presoaking in Moringa oleifera leaf extract

- Moringa leaf extract (MLE), a presoaking solution for plant coexistence with salinity.
- Soaking the bean seed in MLE alleviated the adverse effects of NaCl-salinity.
- MLE-presoaked bean seedlings had a strong growth under NaCl-salinity.
- MLE supported the antioxidant system in bean plants to tolerate salinity stress.

Bean seed soaking in Moringa oleifera leaf extract to overcome NaCl stress and its effect on growth, yield, osmoprotectants and antioxidant system of bean plants were investigated. Plants exposed to NaCl exhibited a significant decline in growth, yield, leaf photosynthetic pigments and K+ contents and K+/Na+ ratio, while showed a significant increase in the contents of osmoprotectants and Na+, and the activity of enzymatic and non-enzymatic antioxidants. However, the presoaking treatment improved growth, yield and antioxidant system, and detoxified the stress generated by 100 mM NaCl. The combined treatment of NaCl + presoaking in Moringa oleifera leaf extract overcame the adverse effects of NaCl stress by the increase in the content of osmoprotectants, the activity of enzymatic and non-enzymatic antioxidants and the ratio of K+/Na+. Therefore, we recommend using Moringa oleifera leaf extract as a soaking solution for bean seeds before sowing in a saline soil.