Effect of salicylic acid and salt stress on growth (cell division), photosynthetic pigments and beta-carotene content of unicellular alga Dunaliella salina Teod

Dunaliella salina is unicellular green micro-algae living in lakes and marine habitats containing high salt concentration. This alga produces different cellular compounds such as beta-carotene under environmental stresses. In this research, the effect of both salt stress and salicylic acid on growth rate, photosynthesis pigments and beta-caroten content of the cells were investigated. Results showed in all experiments, the salicylic acid or combination of salicylic acid and salt stress decreased cell division rate. The presence of salicylic acid reduced the effect of salt stress on beta-carotene and chlorophyll content of the cells. The result indicated that salt stress can increase beta-carotene content. Both salt stress and salicylic acid due to decrease in cell division decreased chlorophyll and beta-carotene per volume unit.