Growth regulator mediated changes in leaf area and metabolic activity in mungbean under salt stress condition

Efficacy of treatment as foliar spray of indole-3-acetic acid, gibberellic acid and kinetin (6-furfuryl aminopurine) at 0.1 to 10 μM in ameliorating the harmful effect of NaCI salinity (E.C value 4 ds/m) on metabolic activity was investigated in Vigna radiata (L.) Wilczek. Application of NaCl resulted in decrease in total leaf area in mungbean. Stomatal openings on leaf surface were less prominent and trichomes were shorter in length under salinity stress in comparison with the control. Sodium and chloride contents increased in leaf, root and nodules under salinity whereas, potassium and calcium contents decreased under NaCl stress in various plant parts studied. Proline content increased under salt stress by 76, 217 and 119% in leaf, root and nodule respectively over the control set. Salt stress increased acid phosphatase enzyme activity both in leaf and root of mung bean by about 61 and 48% respectively over the control set. All the three growth regulators used in the present study were able to overcome to variable extents the adverse effects of stress imposed by NaCl solution.