Abstract

The use of irrigation water containing cyanobacterial toxins can cause significant impacts in agricultural and consequently environmental health. The purpose of this study is to evaluate the effects of cyanotoxins (microcystin-LR and saxitoxin) on germination, growth and micronuclei formation in lettuce (Lettuce sativa) and coriander (Coriandrum sativum). Seeds of lettuce and coriander were exposed during 7-9 days to environmentally relevant concentrations of microcystin-LR (MC-LR1= 0.4 µg/L; MC-LR2= 1.0 µg/L; MC-LR3= 5.0 µg/L) and saxitoxin (SX1= 0.02 µg/L; SX2= 0.1 µg/L; SX3= 0.4 µg/L). In germination test, differential responses were observed being lettuce the most affected in the presence of saxitoxin, and coriander to microcystin-LR treatments. Cyanotoxins inhibit seedlings development to both plants species and promote formation of micronuclei in root cells. Cyanotoxins inhibit seed germination, growth and cause DNA damages, but the intensity depends on both the nature of the toxin and plant species. 

Key words: Cyanobacterial toxin, microcystin-LR, saxitoxin, micronuclei, lettuce, coriander.