β-Estradiol Protects Embryo Growth from Heavy-Metal Toxicity in Germinating Lentil Seeds.

Mammalian sex hormones spread in the environment from both natural and anthropogenic origin. In the present study, we found that treatment with β-estradiol (E) could improve embryo growth and alleviate unsuitable availability of nutrients imposed by cadmium and copper toxicity during germination of lentil ( Lens culinaris Medik.) seeds. The length of embryonic axes decreased in the presence of 100 μM CdCl or 200 μM CuCl. Addition of 10 M E in the germination media could greatly reverse the inhibitory effect of heavy-metal (HM) stress on post-germination events. The cotyledons of E-treated seeds also tended to (1) retain higher protease and amylase activities, (2) breakdown more storage compounds (albumin, globulin, and starch), and (3) have higher contents of free amino acids and glucose than controls without added E (Cd or Cu applied individually). Further investigations showed that exposure to HM dramatically provoked the solute leakage in imbibition medium, whereas the combination of HM with E significantly reduced the loss of nutrients. Moreover, the seed Cd and Cu contents were not significantly different between the cotreatment of Cd or Cu with E and no treatment, meaning that E was not responsible for preventing HM accumulation in seed tissues. [ABSTRACT FROM AUTHOR]