Salt stress triggered changes in osmoregulation and antioxidants in herbaceous perennial inula plants (Asteraceae)

Abstract

Global demand to cure ailments is a growing need. Inula genus extensively holds hundreds of species in warmer regions of Europe and Asia. It is being well-known for its phytochemical and pharmacological applications in industry thanks to its anti-inflammatory and antimicrobial interests. However, growth and production of Inula in the cuttingedge industry is commonly influenced by salt stress except for the halophyte species such as the Inula crithmoides. Salt tolerance level by means of changes in osmoregulation and antioxidant systems in an herbaceous perennial Inula plant has been biochemically evaluated here. Both salt stress treatments caused photosynthetic pigments’ degradation, increase in the leaf levels of osmolytes, and induction of oxidative stress indicated by the malondialdehyde (MDA). Higher hydrogen peroxide (H2O2) amount was recorded in high salt concentration than low salt. High salinity caused an increase in ascorbate (ASC) and glutathione (GSH) contents besides target enzymes of Inula leaves. NaCl tolerance of Inula also was found comprehensible through the higher concentrations of proline and to a lesser extent, total soluble sugar. Salt tolerance mechanisms of this rich bioresourse needs to be further studied in detail for herbal medicines in pharma sector.