Toxicity testing of heavy metals with the Rhizobium-legume symbiosis: High sensitivity to XXXX and @entity3494 compounds.

@entity9491 @entity4250 @entity1568 @entity10222 @entity1372 @entity1507 @entity3409 @entity2556 @entity56778 @entity3494 @entity72394 @entity10278 @entity16258 @entity72393
Legume root nodules are the site of biological @entity1568 fixation in the Rhizobium-legume symbiosis. Nodules are structures unique to this symbiosis and they are morphologically as well as physiologically distinct from other plant organs. Organic substances affecting the macro- or microsymbionts vitality, such as @entity2556 (WETZEL: et al., 1991), reduce nodulation even before visible damage to the plant can be detected. We present data that the formation of nodules (nodulation) may also serve for ecotoxicological evaluation of heavy metals in different binding states. Tests were performed in petri dishes with alfalfa (lucerne) seedlings inoculated with @entity16258 . Cultivation took place in growth cabinets with carefully standardized and documented growth conditions. Data from stressed plants was recorded after 14 days of cultivation on contaminated substrate. A dose responsive decrease in nodulation was found after application of @entity56778 , @entity72393 , @entity10278 , @entity1372 salts of @entity9491 and @entity4250 , @entity72394 , and lead @entity1507 , whereas @entity10222 showed no effect up to a concentration of 3 microM. The dose response curves were used to calculate EC10, EC50 and EC90 values. EC50 values for @entity3409 compounds range from 1.5 to 9.5 pM. Testing different @entity3494 compounds results in EC50 from 2.6 to 20.1 microM. EC50 of lead @entity1507 is 2.2 microM. The sensitivity, reproducibility and reliability of this test system is discussed compared to established biotests.
