Differential Effects of Some Ascorbates on Phaseolus vulgaris L. In Response to Salinity Stress

THIS study aimed to investigate the differential impact of potassium (K) and calcium (Ca) ascorbate on physiological and biochemical responses of Phaseolus vulgaris to salt stress. To understand these differential responses, Phaseolus vulgaris seeds were soaked in a single or mixture (1:1, 1:2 and 2:1) of K-ascorbate: Ca-ascorbatc and then subjected to salt stress (100 inM). In general, salt stress reduced plant growth, inhibited photosynthesis, respiration and stomatal conductance and induced oxidative stress. The antioxidant defense system (e.g., total phenol, proline and antioxidant enzymes) increased as a consequence of salt stress. Ascorbate pretreatment generally reduced stress, in particular at the level of oxidative stress parameters, where it decreased lipid peroxidation In contrast, the pretreatment of seeds with ascoibate mitigate salinity stress at the growth and oxidative stress levels. Comparing the two ascorbate salts it was found that during stress, Ca-ascorbate increased growth, photosynthesis and antioxidants more than K-ascorbatc. Where 1:2 (K-ascorbate: Ca-ascorbate) ratio showed the highest stress mitigation effect. These specific responses were also identified and supported by Principal Component Analysis (PCA).