Differential bioaccumulation and translocation patterns in three mangrove plants experimentally exposed to iron. Consequences for environmental sensing.

ARRIVABENE H.; CAMPOS C.Q.; SOUZA, I.C.; WUNDERLIN D.A.; MILANEZ C.R.D; RODRIGUEZ MACHADO, S.

ENVIRONMENTAL POLLUTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 215 p. 302 - 313

0269-7491

Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle were experimentally exposed toincreasing levels of iron (0, 10, 20 and 100 mg L1 added Fe(II) in Hoagland?s nutritive medium). Theuptake and translocation of iron from roots to stems and leaves, Fe-secretion through salt glands (Avicenniaschaueriana and Laguncularia racemosa) as well as anatomical and histochemical changes in planttissues were evaluated. The main goal of this work was to assess the diverse capacity of these plants todetect mangroves at risk in an area affected by iron pollution (Vitoria, Espírito Santo, Brazil). Resultsshow that plants have differential patterns with respect to bioaccumulation, translocation and secretionof iron through salt glands. L. racemosa showed the best environmental sensing capacity since the bioaccumulationof iron in both Fe-plaque and roots was higher and increased as the amount of added-ironrose. Fewer changes in translocation factors throughout increasing added-iron were observed in thisspecies. Furthermore, the amount of iron secreted through salt glands of L. racemosa was stronglyinhibited when exposed to added-iron. Among three studied species, A. schaueriana showed the highestlevels of iron in stems and leaves. On the other hand, Rhizophora mangle presented low values of iron inthese compartments. Even so, there was a significant drop in the translocation factor between aerialparts with respect to roots, since the bioaccumulation in plaque and roots of R. mangle increased as ironconcentration rose. Moreover, rhizophores of R. mangle did not show changes in bioaccumulationthroughout the studied concentrations. So far, we propose L. racemosa as the best species for monitoringiron pollution in affected mangroves areas. To our knowledge, this is the first detailed report on theresponse of these plants to increasing iron concentration under controlled conditions, complementingexisting data on the behavior of the same plants under field exposure.