Differential physiological responses of two salvinia species to hexavalent chromium at a glance.

PRADO, CAROLINA; CHOCOBAR PONCE, SILVANA; PAGANO, EDUARDO; PRADO, FERNANDO; ROSA, MARIANA

AQUATIC TOXICOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 175 p. 213 - 221

0166-445X

tIn plants of Salvinia rotundifolia and Salvinia minima the effect of two Cr(VI) concentrations (5 and20 mg L−1) applied for 7 days was assessed by measuring changes in biomass, photosynthetic pigments,Cr accumulation, malondialdehyde (MDA), membrane stability index (MSI), thiols (TT, NPT and PBT), andphenolics (SP and IP). Biomass in S. minima was decreased at highest Cr(VI) concentration, but there wereno changes in S. rotundifolia. Metal accumulation was different in both species. S. minima accumulatesmore metal in fronds, but S. rotundifolia accumulates more metal in lacinias. Results also showed thatS. minima translocates more Cr to fronds than S. rotundifolia, but at the whole plant level higher accu-mulation occurred in this last. Tolerance index (Ti) was higher in S. rotundifolia. Chl b and carotenoidswere decreased only upon exposure to high Cr(VI) concentration in both species. Cr(VI) treatment didnot enhance MDA accumulation. Cr exposure had no impact on MSI values when comparing with Cr-untreated values. Thiols in fronds and lacinias showed different distribution patterns between species. IPand NPT were higher in S. rotundifolia lacinias that accumulate more Cr than S. minima lacinias. Whilst SPand NPT were higher in S. minima fronds compared with S. rotundifolia ones. This may indicate that thesespecies can cope with Cr(VI) toxicity, either through metal complexation and/or metal reduction or bythe scavenging of ROS derived from Cr-induced oxidative stress. Based on Cr accumulation and biomassproduction, S. rotundifolia seems more suitable to remove Cr(VI) from polluted waters.