A Study on variations in photosynthetic pigments, soluble sugars, flavonoid, and anthocyanin contents in two halophyte species (Salsola dendroides Pall. and Limonium reniforme (Girard) Linczin in different seasons

Numerous biochemical and molecular mechanisms have been developed in plants to fight against salt stress namely, change in the content of osmolytes, enhancement of phenolic compounds, and supporting photosynthetic activity. These mechanisms lead to products and processes which improve the tolerance to salinity. Since there is no significant research on the resistance mechanisms of the species Salsola dendroides pall and Limonium reniforme (Girard) Lincz., some of these physiological changes in the aforementioned plants were investigated under natural stresses during different seasons to study their tolerance mechanism. To this end, plants were randomly collected from Incheboron area, north of Gorgan with four replicates during spring, summer, and autumn. Results showed that with increased temperature and salinity in summer, chlorophyll pigment contents significantly decreased in both Salsola dendroides and Limonium reniforme species. Soluble sugars content significantly increased in shoots and roots of Salsola dendroides in spring compared with other seasons while soluble sugars content in Limonium reniforme was higher in summer in comparison with spring. In summer, flavonoid contents significantly increased in shoots and roots of both species compared with other seasons. Anthocyanin content significantly changed with the change in seasons, while the highest anthocyanin contents were observed in shoots and roots of Salsola dendroides and Limonium reniforme in summer and autumn, respectively. Most of these changes were associated with activation of physiological and biochemical processes which allow the plants to adapt to saline conditions.