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- Analysis of the use of microcystin-contaminated water in the growth and nutritional quality of the root-vegetable, Daucus carotaPublication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Almeida, A.; Vasconcelos, V.; Campos, A.Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation. To this purpose, young carrots were grown in soil during 1 month in natural conditions and exposed to Mycrocystis aeruginosa aqueous extracts containing environmentally realistic concentrations of MC-LR (10 and 50 MC-LR μg/L). The results showed that MC-LR may decrease root growth after 28 days of exposure to 50 μg/L and increase photosynthetic efficiency. We also observed changes in mineral and vitamin content in carrots as a result of the exposure to contaminated water. Moreover, MC-LR was detected in carrot roots by ELISA at very low concentration 5.23 ± 0.47 ng MC eq./g FW. The soil retained 52.7 % of the toxin potentially available for plants. This result could be attributed to MC-LR adsorption by soil particles or due to microbial degradation of the toxin. We conclude that the prolonged use of MC-LR-contaminated water may affect crop growth, alter the nutritional value of vegetable products, and potentiate contamination.
- Determination of glyphosate bioconcentration in lettuce (Lactuca sativa) simultaneously exposed to cylindrospermopsin in a soil systemPublication . Lessa, P.; Sengupta, S.; Pinto, Edgar; Freitas, Marisa; Azevedo, J.; Oliveira, F.; Campos, A.; Vasconcelos, V.Glyphosate has become the most widely used herbicide worldwide. The mode of action of this herbicide is linked to the inhibition of 5-enolpyruvylshikimate-3-phopsphate synthase enzyme, which blocks the plant’s biosynthesis of aromatic amino acids.
- Cylindrospermopsin and glyphosate accumulation in lettuce (Lactuca sativa) simultaneously exposed to both toxicants in hydroponic and soil systemsPublication . Sengupta, S.; Freitas, Marisa; Pinto, Edgar; Ferreira, I.; Oliveira, F.; Azevedo, J.; Prieto, A.; Diez-Quijada, L.; Jos, A.; Cameán, A.M.; Campos, A.; Vasconcelos, V.In nature, the simultaneous occurrence of multiple emergent contaminants such as cyanotoxins (e.g., cylindrospermopsin (CYN)) and herbicides (e.g., glyphosate (GLY)), is highly expectable and it can be anticipated, mainly in the aquatic and terrestrial environments. The use of contaminated water for irrigation can be hazardous to the agricultural sector and some studies have reported that, individually, these contaminants can be accumulated in the edible tissues exerting a negative influence on crop plants safety and ultimately in human health. Furthermore, recent studies have suggested that some cyanotoxins (e.g., microcystins) can change the membrane permeability of roots, resulting in changes in the accumulation rates of other contaminants in plants. Since edible plants are exposed to a wide variety of substances through irrigation water, there is increasing concern in the potential adverse effects of the interactions between those substances when present simultaneously, especially when this can have potential public health consequences. The aim of this study was to determine the accumulation of CYN in Lactuca sativa simultaneously exposed to GLY at environmentally relevant concentrations. Lettuce plants were exposed for 15 days to 50 μg/L or kg of CYN-containing crude extract (Chrysosporum ovalisporum culture - LEGE X001) and 750 μg/L or kg of GLY, in hydroponic and soil systems, respectively. The resins (HP20, SP700, and XAD18) were evaluated for MC-LR uptake kinetics, capacities, and extraction efficiencies and simple procedures were developed for determining MC-LR concentration in binding disc extracts by Adda-ELISA (U.S. EPA Method 546). The XAD18-DGT/Adda-ELISA method had a 7-d deployment time detection limit of ≈0.05 μg/L and capacity of > 250 μg/L of MC-LR in water samples which encompass U.S. EPA and WHO advisory concentrations for drinking and recreational waters. The XAD18DGT/Adda-ELISA method determined timeaveraged MC-LR concentrations in waters with wide ranging pH (4.9–8.3) and ionic strength (0.04–0.8 M) under well-stirred and quiescent conditions with 90–101% accuracy. In addition to high sensitivity and accuracy, the method is simple, inexpensive, and applicable for determining MC-LR and related MCs concentrations in waterbodies with wide ranging chemical characteristics and hydrodynamic conditions. 4.11.07 Cylindrospermopsin and Glyphosate Accumulation in Lettuce (Lactuca sativa) Simultaneously Exposed to Both Toxicants in Hydroponic and Soil Systems S. Sengupta, School of Bio Sciences and Technology Vellore Institute of Technology, Vellore - 632 014, Tamil Nadu, India; M.M. Freitas, School of Health, Polytechnic Institute of Porto; E. Pinto, I. Ferreira, LAQV/REQUIMTE, Departament of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050313 Porto, Portugal; F. Oliveira, J. Azevedo, CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450–208 Porto; A. Prieto, L. Diez-Quijada, A. Jos, A.M. Cameán, Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, Profesor García González n◦2, 41012 Seville, Spain / Toxicology; A. Campos, Interdisciplinary Centre of Marine and Environmental Sciences, CIIMAR; V. Vasconcelos, CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450–208 Porto In nature, the simultaneous occurrence of multiple emergent contaminants such as cyanotoxins (e.g., cylindrospermopsin (CYN)) and herbicides (e.g., glyphosate (GLY)), is highly expectable and it can be anticipated, mainly in the aquatic and terrestrial environments. The use of contaminated water for irrigation can be hazardous to the agricultural sector and some studies have reported that, individually, these contaminants can be accumulated in the edible tissues exerting a negative influence on crop plants safety and ultimately in human health. Furthermore, recent studies have suggested that some cyanotoxins (e.g., microcystins) can change the membrane permeability of roots, resulting in changes in the accumulation rates of other contaminants in plants. Since edible plants are exposed to a wide variety of substances through irrigation water, there is increasing concern in the potential adverse effects of the interactions between those substances when present simultaneously, especially when this can have potential public health consequences. The aim of this study was to determine the concentration of CYN and GLY in lettuce plants (roots and leaves) was determined by LC/MSMS. The results show that, at the described conditions, CYN was accumulated in roots (0.06-7.62 μg CYN/g Dw) and leaves (0.13-1.1 μg CYN/g Dw) of lettuce, especially when plants were exposed in hydroponic system. However, interestingly, when lettuce plants were exposed simultaneously to both toxicants the concentration of CYN assimilated by lettuce plants (roots and leaves) was respectively, 1.5fold and 1-3-2.2-fold lower than in the exposure to isolated CYN. Conversely, the plants exposed to the mixture in soil system, showed that the concentration of GLY incorporated by lettuce (roots and leaves) was higher than in the exposure to the isolated compound (0.04 - 0.21 µg GLY/g and < LOQ - 0.84 µg GLY/g, respectively). This finding highlights the potential for the enhancement of GLY accumulation in lettuce plants due to their cooccurrence with CYN, and it underlines the importance of further research regarding the mechanism involved.
- Effects of the irrigation with Microcystin contaminated water on the quality of carrots (Daucus carota)Publication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Vasconcelos, V.; Campos, A.Cyanobacteria blooms are often found in freshwaters and may reflect the increased eutrophication of these environments. Microcystin-LR (MC-LR), mainly produced by Microcystis aeruginosa, is the most documented and studied cyanotoxin causing serious problems to human health. Contaminated waters are commonly used for agriculture purposes and may represent a risk to food safety and crop’s quality. The plant root system is usually more exposed via soil irrigation, and therefore, rootvegetables are more predisposed to contamination. Is important to evaluate the possible negative effects of the use of water containing MC in the physiology and quality of carrots (Daucus carota) due to its importance for human nourishment and economy.
- Impact of microcystin contaminated water on quality of carrots (Daucuscarota)Publication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Vasconcelos, Vitor; Campos, AlexandreCyanobacteria blooms are often found in freshwaters and may reflect the increased eutrophication of these environments and because of this many water resources worldwide may have a limited utilization. The presence of these microorganisms may pose a serious threat to water quality because many of them produce a large diversity of toxins that can be harmful to human health (Figueiredo et a l., 2004). On the other hand contaminated waters used to agricultural purposes may pose additional concerns to food safety. The absorption of toxins by plants may induce morphological and physiological changes that can lead to a loss of productivity as well as toxin bioaccumulation in edible tissues. However, the impact of cyanotoxins on plants and its ability to enter the food chain via this pathway is not fully understood (Kitleret al ., 2012). Microcystin (MC) is the cyanotoxin most frequently present in eutrophic freshwaters causing serious problems to human health, being the liver the main target. These toxins are potent and specific inhibitors of protein phosphatases PP1 and PP2Ain both animals and higher plants (Figueiredo et al., 2004). It is known that MC affect a number of physiological processes in plants (Corbel et al ., 2013). The plant root system is usually more exposed, via soil irrigation, and therefore root-vegetables more prone to contamination. Carrots (Daucuscarota) are root-vegetables with great importance for human nourishment and economy, with extensive use all over the world (Singh et al ., 2012).
- Effects of cylindrospermopsin and glyphosate at environmentally relevant concentrations on growth and mineral content of beetroot plants (Beta vulgaris)Publication . Priya, V.; Freitas, Marisa; Pinto, Edgar; Almeida, A.; Oliveira, F.; Azevedo, J.; Campos, A.; Sudhakaran, R.; Vasconcelos, V.Natural toxins produced by freshwater cyanobacteria, such as cylindrospermopsin (CYN), have been regarded as an emergent environmental threat. Cyanotoxins can be applied directly to soil by using contaminated water for agricultural irrigation. Despite the risks for food safety, the impact of cyanotoxins in agriculture is not yet fully understood. Furthermore, in soil-plant system the simultaneous occurrence of cyanotoxins and pesticides can be highly expectable. Pesticides, especially residues of glyphosate (GLY), have been frequently detected in soils and have been recognized to contribute to soil toxicity. Beetroot (Beta vulgaris) are root vegetables, extensively consumed worldwide with great importance for human nourishment and economy. It is, therefore, important to evaluate the effects of using water contaminated with CYN and GLY on beetroot cultivation. This study aimed to assess the effects of environmentally relevant concentrations of CYN, GLY and a mixture of both on growth and mineral content of beetroot (roots and leaves) cultivated in soil system. Plants were exposed in controlled conditions to CYN-crude extracts (50μg/kg) (Chrysosporum ovalisporum culture - LEGE X-001), isolated and in mixture with GLY (750 μg/kg) for 4 months. Beetroot growth was assessed by determining its fresh (Fw) and dry weight (Dw). The determination of mineral content was made by inductively coupled plasma-mass spectrometry (ICP-MS), after sample mineralization by microwaveassisted acid digestion. The results denote that Fw and Dw of beetroot (leaves and roots, respectively) were significantly changed (P