p; Improvingsalttoleranceofcottonseedlingswith-aminolevulinicacidK.Watanabe,T.Tanaka,Y.Hotta,H.Kuramochi&Y.TakeuchiABSTRACTOfdifferentplantgrowthregulators(PGRs)tested,-aminolevulinicacid(ALA)wasfoundtoimprovethesalttoleranceofcottonseedlings.CottonseedlingstreatedwithALAcouldgrowinsoilcontaininglevelsashighas.(wt/wt)NaCl.TheanalysesofmineralcompositionsofplantpartsrevealedthattheNa+concentrationsintherootsoftheplantstreatedwithALAweresuppressedtolowconcentrations.Fromtheseresults,itcanbepresumedthatthepresenceofALAmaycauseareductionofNa+uptake.Abbreviations:PGRs–plantgrowthregulators;ALA–-aminolevulinicacidhydrochloride;GA–gibberellin;BA–benzyladenine;IAA–indoleaceticacid;ABA–abscisicacidKeywords:-aminolevulinicacid,cotton,Na+uptake,plantgrowthregulators,salt-stresstolerance.IntroductionThesalinizationofsoilhasbecomeanincreasinglyimportanttopic.Becausefewcropplantscanbegrownsuccessfull