Evaluation of Cadmium Bioaccumulation-Related Physiological Effects in Salvinia biloba: An Insight towards Its Use as Pollutant Bioindicator in Water Reservoirs

Abstract

Free-living macrophytes play an important role in the health of aquatic ecosystems. Therefore, the use of aquatic plants as metal biomonitors may be a suitable tool for the management of freshwater reservoirs. Hence, in this study, we assessed the effects of cadmium (Cd) in Salvinia biloba specimens collected from the Middle Paraná River during a 10-day experiment employing artificially contaminated water (100 μM Cd). S. biloba demonstrated a great ability for Cd bioaccumulation in both the root-like modified fronds (named “roots”) and the aerial leaf-like fronds (named “leaves”) of the plants. Additionally, Cd toxicity was determined by the quantification of photosynthetic pigments (chlorophylls a and b, and carotenoids), flavonoids, and soluble carbohydrate contents in S. biloba over time (1, 3, 5, 7, and 10 days). In general, deterioration was more pronounced in leaves than in roots, suggesting a greater implication of the former in long-term Cd sequestration in S. biloba. Deleterious effects in the appraised parameters were well correlated with the total amount of Cd accumulated in the leaves, and with the qualitative changes observed in the plants’ phenotype during the 10-day metal exposure assay. The flavonoids and carotenoids in leaves were highly affected by low Cd levels followed by root carbohydrates. In contrast, chlorophylls and root flavonoids were the least impacted physiological parameters. Therefore, our results demonstrate that S. biloba displays dissimilar organ-linked physiological responses to counteract Cd phytotoxicity and that these responses are also time-dependent. Though further research is needed, our work suggests that easy-handled physiological data obtained from autochthonous free-floating S. biloba specimens may be used as a valuable tool for metal-polluted water biomonitoring.

Metal Detoxification in Land Plants: From Bryophytes to Vascular Plants. STATE of the Art and Opportunities

“…In the genus Salvinia , several species ( S. auriculata , S. biloba , S. herzogii , S. minima , S. molesta , S. natans and S. rotundifolia ) have the capacity to accumulate PTEs in sufficiently high amounts to be used for efficient wastewater depuration (e.g., [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ]), reaching accumulation ranges of 6000–18,000 mg Kg −1 dry weight for Cd, Cr, Cu, Fe, Ni and Pb [ 57 , 64 , 76 , 77 ]. Natural variation in the capacity to accumulate PTEs exists among species, as in the case of Azolla , another aquatic fern genus with good potential for wastewater phytoremediation.…”

Potential of Salvinia biloba Raddi for removing atrazine and carbendazim from aquatic environments

“…1a) from a low-depth lagoon situated at the coordinates 32°52′35″S and 60°40′33″W (Entre Ríos, Argentina). This location corresponds to a natural wetland area at the Middle Paraná River already described by our group in previous works (Tello Zevallos et al 2018;Castillo Loría et al 2019;Emiliani et al 2020Emiliani et al , 2021. During collection, macrophytes were kept at ambient temperature in plastic containers filled with water from the river.…”

Lithium Accumulation in Salvinia natans Free-Floating Aquatic Plant

“…The bioavailability of metals to plants and the changes induced in the plants by different metals as well as their defense mechanisms were previously studied [ 5 ]. Chlorophyll is responsible for collecting solar energy during photosynthesis, while carotenoids eliminate the reactive oxygen species in the damaged tissues [ 7 ]. Changes in the photosynthetic pigments indicate the presence of stress factors, such as toxic elements.…”