title: Changes of metal-induced toxicity by H2O 2/NO modulators in Scenedesmus quadricauda (Chlorophyceae).
abstract: Effect of nitric oxide donor (sodium nitroprusside, SNP, 500 μM) or hydrogen peroxide scavenger (dithiothreitol, DTT, 500 μM) on cadmium (Cd) or copper (Cu) uptake (150 μM solutions) and toxicity using Scenedesmus quadricauda was studied. Combined treatments (Cd or Cu + DTT or SNP) usually ameliorated metal-induced toxicity at the level of pigments, proteins, and mineral nutrients in comparison with respective metal alone. Viability tests (MTT and TTC) showed the lowest values preferentially in Cu treatments, indicating higher toxicity in comparison with Cd. Cd showed low impact on amino acids while strong Cu-induced depletion was mitigated by DTT and SNP. Amount of ROS and NO showed the most pronounced responses in SNP variants being rather reciprocal than parallel and regulated ascorbate peroxidase activity. Blot gel analyses of hsp70 protein did not reveal extensive changes after given exposure period. Phenols were elevated by DTT alone while all Cu treatments revealed depletion. Total Cu content decreased while total Cd content increased in metal + SNP or metal + DTT. Subsequent experiment using lower Cd, SNP or DTT doses (10 and 100 μM) revealed concentration-dependent impact on Cd uptake. Overall, DTT was found to be more suitable for the amelioration of metal-induced toxicity.
authors: Department of Botany, Institute of Biology and Ecology, Faculty of Science, P. J. Šafárik University, Mánesova 23, 041 67, Košice, Slovak Republic.
authors: František
authors: F
authors: Štork
authors: Martin
authors: M
authors: Bačkor
authors: Bořivoj
authors: B
authors: Klejdus
authors: Josef
authors: J
authors: Hedbavny
authors: Jozef
authors: J
authors: Kováčik
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D003300:Copper / Q000633:toxicity*; D004229:Dithiothreitol / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D044444:Scenedesmus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D016166:Free Radical Scavengers; D020030:Nitric Oxide Donors; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D002104:Cadmium; D002734:Chlorophyll; D009599:Nitroprusside; D009569:Nitric Oxide; D002338:Carotenoids; C037184:chlorophyll b; D003300:Copper; D009195:Peroxidase; D004229:Dithiothreitol; D000077194:Chlorophyll A