Changes in secondary metabolites in the halophytic putative crop species Crithmum maritimum L., Triglochin maritima L. and Halimione portulacoides (L.) Aellen as reaction to mild salinity

It is assumed that salinity enhances the concentration of valuable metabolites in halophytes. The objective was to find a salt concentration and a point in time at which the yield for the valuable metabolites was maximal. Therefore, three different halophyte species were grown under different salinities and harvested over a period from shortly after stress induction up to three weeks. Various reaction patterns were found in the metabolite composition of the analyzed plant material. Halimione portulacoides showed a "short term response", indicated by an increase in all metabolites analyzed after a few hours, whereas Crithmum maritimum showed a "long term response" through accumulation of proline starting after days. Triglochin maritima did not change in metabolite concentration, but like the other plant species the biomass was reduced by salinity. Generally, a higher production in secondary metabolites by higher salinity was outbalanced by a reduction in biomass production. Concentrations of analyzed antioxidants showed a similar reaction and correlated with each other.