Assessment of chromium bio-accumulation potential in sunflowers ; Avaliação do potencial de bioacumulação de cromo em plantas de girassol

Plant-based remediation (phyto-remediation) is a biotechnological tool used for the decontamination of polluted soils and water bodies, even by metals. Bioaccumulation in sunflower (Helianthus annus L.) grown in soil contaminated by metallic chromium (Cr) is studied. The sunflower is one of the best hyperaccumulators for phyto-remediation sites polluted by metals. The accumulation of Cr in shoot biomass content and oil extracted from seeds of plants grown in soil contaminated by the metal were analyzed. The sunflower plants were grown in pots and treatments comprised potassium dichromate solutions (K2Cr2O7) at concentrations 0, 18, 36 and 72 mg kg-1, whilst analyses were performed by atomic absorption spectrometry. Results showed that there was a significant reduction in plant biomass of plants in proportion to Cr dose, accumulating high percentages of metal in shoot plant tissues. It was toxic at the highest concentration (72 mg kg-1), whereas metal rates were the same at different concentrations of Cr in the soil, in oil. Sunflower plants have a Cr phytoextractor potential when cultivated in soil contaminated by the metal. Oil extracted from the seeds grown under these conditions is not suitable for human consumption due to its high metal content rates. ; A remediação baseada em plantas (fitorremediação) é uma ferramenta biotecnológica utilizada para a descontaminação de solos e/ou corpos d’água poluídos, inclusive por metais. O objetivo do presente estudo foi estudar a bioacumulação em plantas de girassol (Helianthus annus L.) cultivadas em solo contaminado por cromo (Cr) metálico utilizando a planta girassol, que é um dos melhores “hiperacumuladores” para a fitorremediação de locais poluídos por metais. Foram analisados o acúmulo de Cr no conteúdo de biomassa da parte aérea e no óleo extraído das sementes das plantas cultivadas em solo contaminado por esse metal. Os girassóis foram cultivados em vasos e os tratamentos foram com soluções de dicromato de potássio (K2Cr2O7) nas concentrações zero, 18, 36 e 72 ...