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

Abstract

Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle were experimentally exposed to increasing levels of iron (0, 10, 20 and 100 mg L(-1) added Fe(II) in Hoagland's nutritive medium). The uptake and translocation of iron from roots to stems and leaves, Fe-secretion through salt glands (Avicennia schaueriana and Laguncularia racemosa) as well as anatomical and histochemical changes in plant tissues were evaluated. The main goal of this work was to assess the diverse capacity of these plants to detect mangroves at risk in an area affected by iron pollution (Vitoria, Espírito Santo, Brazil). Results show that plants have differential patterns with respect to bioaccumulation, translocation and secretion of iron through salt glands. L. racemosa showed the best environmental sensing capacity since the bioaccumulation of iron in both Fe-plaque and roots was higher and increased as the amount of added-iron rose. Fewer changes in translocation factors throughout increasing added-iron were observed in this species. Furthermore, the amount of iron secreted through salt glands of L. racemosa was strongly inhibited when exposed to added-iron. Among three studied species, A. schaueriana showed the highest levels of iron in stems and leaves. On the other hand, Rhizophora mangle presented low values of iron in these compartments. Even so, there was a significant drop in the translocation factor between aerial parts with respect to roots, since the bioaccumulation in plaque and roots of R. mangle increased as iron concentration rose. Moreover, rhizophores of R. mangle did not show changes in bioaccumulation throughout the studied concentrations. So far, we propose L. racemosa as the best species for monitoring iron pollution in affected mangroves areas. To our knowledge, this is the first detailed report on the response of these plants to increasing iron concentration under controlled conditions, complementing existing data on the behavior of the same plants under field exposure.

The role of iron on the growth and development of the seedlings of Rhizophora mangle L.

“…Despite the increase in the concentration of iron in the solution, the formation of iron plaque was not observed in this experiment, corroborating the results found by Arrivabene et al (2016) where seedlings of R. mangle were also cultivated in hydroponical solution with excess of Fe.…”

“…The main source of absorption of trace metals by plants is through the roots, although other tissues may also contribute to this process. A higher concentration of toxic elements in the roots of R. mangle is described in the literature (Mejías et al, 2013;Arrivabene et al, 2016) for mangroves in areas polluted by domestic, agricultural, and industrial effluents. Our results corroborate those of Machado et al (2005), which report the preferential accumulation of Fe and Zn in the tissues of the roots of R. mangle suppressing the translocation of metals to the leaves.…”

“…The effects of heavy metal compounds on mangrove seedlings have been evaluated based on ecological responses such as biomass production (Mejías et al, 2013), leaf loss, bioaccumulation, and translocation (Mejías et al, 2013;Arrivabene et al, 2016;Ray et al, 2021), survival (MacFarlane andBurchett, 2002), functional mechanisms, such as photosynthesis and concentration of photosynthetic pigments (Huang and Wang, 2010), key enzymatic activities in photochemical processes, as well as an increase in the mutation frequency (Caregnato et al, 2008;Zhou et al, 2021) effect on the anatomical structures (Arrivabene et al, 2016;Raju and Ramakrishna, 2021). Despite being a target of interest to the scientific community, there are no studies that evaluate all sides of both the ecological and physiological responses caused by the excess of metals in mangrove species.…”

Chiral Coordination Polymers from a New 2-Deoxy-d-ribose Derivative Linker: Syntheses, Structures, and Fe3+ Fluorescent Probe Functions

“…Among all of the transition-metal elements, iron is the most abundant in the human body and performs some vital roles in the formation of hemoglobin and muscle and the transfer of electrons and oxygen. − On the other hand, the lack or excess of Fe 3+ has various effects on life, such as iron deficiency anemia, liver damage, and even cancer. − At the same time, the steel industry and manufacturing industry have discharged a large quantity of Fe 3+ ions into the environment, which may be absorbed, transferred, and participate in the biomagnification of metals in the entire food chain and cause toxicity to the ecosystem. − The detection of ferric ion is thus significant for not only human health but also the ecological environment.…”

Environmental risk of trace elements in mangrove ecosystems: An assessment of natural vs oil and urban inputs

“…Many of these pollutants are harmful to mangrove associate organisms and humans when transferred through the trophic chain Chai et al, 2019). Trace elements are common pollutants found in mangroves and are considered as a serious threat to human health and other living organisms due to their persistence, potential for bioaccumulation, and toxicity (Arrivabene et al, 2016;Celis et al, 2017;. However, it is important to note that trace elements can be derived from anthropogenic and natural sources that complicate analysis concerning their environmental impact (Anaya-Gregorio et al, 2018;Armstrong-Altrin et al, 2019).…”