The present study provides new insights into the roles and interactions
of IAA and NO in their regulation of root development
and stress tolerance under sodic alkaline stress. It also can be
concluded that the better protection of antioxidative enzymes'
activities by IAA or NO treatment under sodic alkaline conditions
may alleviate the negative effects of sodic alkaline on chlorophyll
content, fluorescence parameters and carbon and growth levels. In
conclusion, NO, as a downstream signal, is involved in stress
tolerance regulated by IAA under sodic alkaline stress