Brassinosteroids and lead as stimulators of phytochelatins synthesis in Chlorella vulgaris

The effect of brassinosteroids 10−8 mol/L (BR) (brassinolide, BL; 24-epiBL; homoBL; castasterone, CS; 24-epiCS; homoCS) together with two levels of lead (10−6 and 10−4 mol/L) on the phytochelatins (PC) content of Chlorella vulgaris was studied. The BR and lead (10−4 mol/L) showed a stronger stimulation of the synthesis of PC by the algal cell than the culture treated with lead alone. The effect of BR and lead on Chlorella vulgaris growth was very quick. The stimulatory activity of BR on PC synthesis was arranged in the following order: BL ≫ 24-epiBL ≫ homoBL ≫ CS ≫ 24-epiCS ≫ homoCS.