Hydrogel substrate alleviates salt stress with increase antioxidant enzymes activity of bean (Phaseolus vulgaris L.) under salinity stress

Abstract

The effect of varying hydrogel (0, 0.05 and 0.1% w/w) supply on major antioxidant enzyme (super oxide
dismutase, SOD; catalase, CAT and peroxidase, POD) activity, membrane permeability and salt
tolerance index (STI) of bean plants in different salt source and doses stress were investigated. Plants
were treated with eight salt sources (NaCl, Na2SO4, CaCl2, CaSO4, KCl, K2SO4, MgCl2, and MgSO4) and
four concentrations (0, 30, 60, and 120 mM doses) for 60 days in a growth media. Salt type, doses and
hydrogel (HG) affected soil electrical conductivity. Soil salinity affected the parameters considered and
changed the antioxidant activity of plants. Different salt concentrations negatively affected STI of
plants. High salt concentration caused substantial increase leakage of plant. CAT antioxidant enzyme
activities of plants decreased with increasing salt doses, and the lowest value was obtained for NaCl
application. SOD and POD enzyme activity of plant were increased with increasing salt doses, and the
highest value was obtained for NaCl application. HG added to saline soil significantly improved the
variables affected by high salinity and also reduced soil electricity conductivity, electrolyte leakage of
plant, enhanced STI and caused decrease SOD and POD enzyme activity. The result suggested that HG
have great potential for use in alleviating salinity stress on plant growth and growth parameter, in saline
soils of arid and semi-arid areas. This HG appears to be highly effective for use as soil conditioners in
vegetable growing, to improve crop tolerance and growth saline conditions. It is intended to confirm the
results of these studies by field trials.