Suchergebnisse

The uptake of metals by plants and their partitioning between different organs is an important issue in fields like plant ecology, phytochemistry, phytoremediation and, in the case of plants with edible parts, food quality. In this work a five-month field experiment was carried out to investigate the uptake and partitioning of 20 elements (Mg, K, Ca, Na, Mn, Fe, Co, Cu, Zn, Mo, Sr, Ba, Al, Ti, V, Cr, As, Cd, TI and Pb) by Swiss chards (Beta vulgaris). The effect of the harvesting time on the accumulation of these elements in roots, stalks and leaf blades was studied using plants cultivated in two different but adjacent air-open plots subjected to conventional or organic farming techniques. Plants were collected at six growth stages during their production cycle and samples were analysed by ICP-MS after microwave assisted acid digestion. Toxic elements (except Cd) were mainly immobilised in roots, whereas essential elements were translocated to aboveground organs. In general, the element concentrations in plant organs decreased with time. The use of organic fertilisers promoted the presence of nutrients in blades and stalks. Pb and Cd concentrations in the edible parts were always below the maximum levels set by the European Union.

Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes ( txn1 , gpx1 , txnrd3 , and txnrd2 ) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1 , gpx1 , and txnrd2 . Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system ( txn1 , txnrd3 , and txnrd2 ) but upregulated gpx1 , confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/food when evaluating the toxicity of Hg. ; Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The work was supported by grants from the Spanish MINECO (RTC-2014–2837-2- "SELATUN: Minimización de la problemática del mercurio del atún y valorización del atún como alimento saludable, Programa Retos-Colaboración 2014" and CTM2012-40203-C02-01- "BMW: Biomarcadores estándar de base científica en mejillón para diagnosticar y monitorizar los efectos biológicos de la polución en el Golfo de Bizkaia: implementación de la DEME"), Euskampus Fundazioa-Campus of International Excellence (307615SAA2), and from the Basque Government Elkartek Grant KK-2016/00057- "MAROMEGA: Nuevas alternativas para la producción de omega-3 a partir de recursos marinos."

Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes ( txn1 , gpx1 , txnrd3 , and txnrd2 ) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1 , gpx1 , and txnrd2 . Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system ( txn1 , txnrd3 , and txnrd2 ) but upregulated gpx1 , confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/food when evaluating the toxicity of Hg. ; Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The work was supported by grants from the Spanish MINECO (RTC-2014–2837-2- "SELATUN: Minimización de la problemática del mercurio del atún y valorización del atún como alimento saludable, Programa Retos-Colaboración 2014" and CTM2012-40203-C02-01- "BMW: Biomarcadores estándar de base científica en mejillón para diagnosticar y monitorizar los efectos biológicos de la polución en el Golfo de Bizkaia: implementación de la DEME"), Euskampus Fundazioa-Campus of International Excellence (307615SAA2), and from the Basque Government Elkartek Grant KK-2016/00057- "MAROMEGA: Nuevas alternativas para la producción de omega-3 a partir de recursos marinos."