NaCl pretreatment alleviates salt stress by enhancement of antioxidant defense system and osmolyte accumulation in mungbean (<i style="">Vigna radiata</i> L. Wilczek)
593-600Enhancement of
salt (NaCl) tolerance by pretreatment with sublethal dose (50 mM) of
NaCl was investigated in
V. radiata seedlings. NaCl stress caused drastic effects on roots
compared to shoots. Accompanying reductions in length, number of root hairs and
branches, roots became stout, brittle and brown in color. Salt stress caused
gradual reduction in chlorophyll, carotenoid pigment contents and chlorophyll
fluorescence intensity also. Superoxide dismutase and catechol peroxidase
activities increased under stress in both roots and leaves. But catalase
activity showed an increase in roots and decrease in leaves. In these
seedlings, the oxidative stress has been observed under salinity stress and the
level of proline, H2O2 and malondialdehyde content were
increased. But pretreatment with sublethal dose of NaCl was able to overcome
the adverse effects of stress imposed by NaCl to variable extents by increasing
growth and photosynthetic pigments of the seedlings, modifying the activities
of antioxidant enzymes, reducing malondialdehyde and H2O2 content
and increasing accumulation of osmolytes like proline. Thus, mungbean plants
can acclimate to lethal level of salinity by pretreatment with sublethal level
of NaCl, improving their health and production under saline condition