Mitigation of Salinity Stress and Lead Toxicity in Maize by Exogenous Application of the Sorghum Water Extract

The increasedconcentrationof lead(Pb) in soils is a serious
threat tohumanbeings andplants all over theworld. Salinitystress is alsoa
major issue across the globe, which limits crop productivity. The use of
allelochemicalshasbecomeaneffectivestrategytomitigatethetoxiceffectsof
abioticstresses. Sorghumisan important cropgrownacross theglobe, and it
alsopossesses anappreciablyallelopathicpotential.Therefore, this studywas
planned todetermine the impacts of the sorghumwater extract (SWE) on
improvingmaizegrowthunderPbandsalinitystress.Theexperiment included
different treatments;control,SWE(3%), anddifferent levelsofPbandsalinity
stress;T1:control,T2:50mMNaCl,T3:100mMNaCl,T4:250μMPb,andT5:
500μMPb.Leadandsalinitystressreducedthemaizegrowthbythegenesisof
reactive oxygen species (ROS), as evidenced by higher production of
malondialdehyde (MDA: 39.1 and 32.28%) and hydrogen peroxide (H2O2:
20.62and17.81%).SprayingplantswithSWEimprovedthemaizegrowthbyincreasingantioxidantactivities(ascorbateperoxidase:
APX,catalase:CAT,peroxidase:PODandsuperoxidedismutase:SOD),photosyntheticpigments, relativewatercontents(RWC),
osmolyteaccumulation(proline,totalsolubleproteins:TSP, freeaminoacids:FAA),potassiumaccumulation,anddecreasingMDA,
H2O2, sodium, chloride, andPbaccumulation. Inconclusion, theapplicationofSWEmitigatesadverseimpactsofPbandsalinity
stressesbyimprovingchlorophyll synthesisandosmolyteaccumulation, activatingtheantioxidantdefensesystem, andpreventing
theentryof toxic ions