Evaluation of morpho-physiological and biochemical indicators of salinity stress in Argemone mexicana L., medicinal plant from Papaveraceae

Abstract Plant growth is significantly impacted by abiotic stress factors including soil salinity and plants do have different mechanism to nullify the effect of these stresses. The current study is to understand the various physio-biochemical characteristics of Mexican prickly poppy ( Argemone mexicana L.), a medicinally valued species belongs to poppy family under different saline conditions (0 mM, 100 mM, 200 mM and 300 mM) to investigate the mechanisms underlying salinity tolerance. The results showed that salinity caused a negative impact on number of leaves, stomatal index and chlorophyll content in plants. Decreased chlorophyll content suggests a decline in photosynthetic rate. The concentrations of stress specific amino acid proline, soluble sugar sucrose, and secondary metabolite phenol were increased in plants treated with increasing concentrations of NaCl solution. Sucrose helps to protect the isolated chloroplast from damage caused by salinity stress. The degree of bleaching seen in the leaf disc assay was an indication of the damage caused by stress. These findings indicated that higher proline, sugar, and phenol content could be the key factors, which offer advantage to Argemone under saline conditions.