查看文章

Abiotic stresses are the unavoidable great threat for crop production. Crop health can be predicted on the basis of various parameters, which includes the accumulation of photosynthetic pigments, metabolites, reactive oxygen species (ROS) and antioxidants etc. The present study was carried out to compare the tolerance mechanisms operated in V. unguiculata var. KBC-IV subjected to NaCl and PEG stresses and assessed through morphological, physiological and biochemical changes. For this particular study, V. unguiculata was subjected to different concentrations of NaCl and PEG for 8 d. Based on this preliminary study, NaCl (75mM) and PEG (15%) was fixed as the concentration, which had the potential to impart 50% growth retardation. PEG treated plants had decreased photosynthetic pigments, protein, proline, total soluble sugar, and membrane stability index relative to control, whereas carotenoid, MDA, superoxide and total free amino acids content increased significantly, indicating that cell homeostasis was severely hampered under PEG stress. When compared to PEG (15mM) stress, exposure of NaCl (75mM) led to increased accumulation of plant osmolytes, chlorophyll contents and antioxidative enzymes activities. This coordinated response ensured the maintenance of steady state level of ROS in seedlings so as to cope up with NaCl stress in a better way than PEG stress.