المؤلفون: Ilya V. Seregin, Anna D. Kozhevnikova

المصدر: International Journal of Molecular Sciences; Volume 24; Issue 13; Pages: 10822

مصطلحات موضوعية: copper, iron, manganese, metal accumulation in plants, metal detoxification, metal homeostasis, metal remobilization, metal transport, nickel, nicotianamine, stress, zinc

جغرافية الموضوع: agris

الوصف: Nicotianamine (NA) is a low-molecular-weight N-containing metal-binding ligand, whose accumulation in plant organs changes under metal deficiency or excess. Although NA biosynthesis can be induced in vivo by various metals, this non-proteinogenic amino acid is mainly involved in the detoxification and transport of iron, zinc, nickel, copper and manganese. This review summarizes the current knowledge on NA biosynthesis and its regulation, considers the mechanisms of NA secretion by plant roots, as well as the mechanisms of intracellular transport of NA and its complexes with metals, and its role in radial and long-distance metal transport. Its role in metal tolerance is also discussed. The NA contents in excluders, storing metals primarily in roots, and in hyperaccumulators, accumulating metals mainly in shoots, are compared. The available data suggest that NA plays an important role in maintaining metal homeostasis and hyperaccumulation mechanisms. The study of metal-binding compounds is of interdisciplinary significance, not only regarding their effects on metal toxicity in plants, but also in connection with the development of biofortification approaches to increase the metal contents, primarily of iron and zinc, in agricultural plants, since the deficiency of these elements in food crops seriously affects human health.

وصف الملف: application/pdf

العلاقة: Molecular Plant Sciences; https://dx.doi.org/10.3390/ijms241310822Test

الإتاحة: https://doi.org/10.3390/ijms241310822Test

المؤلفون: Thomas Grischek, Sebastian Paufler

المصدر: Water; Volume 9; Issue 5; Pages: 317

مصطلحات موضوعية: riverbank filtration, iron, manganese, remobilization

جغرافية الموضوع: agris

الوصف: At many sites, anoxic conditions and dissolution of iron and manganese are already present, or are likely to develop during riverbank filtration (RBF). A prediction of iron and manganese mobilization during riverbank filtration is required to evaluate the need for further water treatment. Different methods have been tested at RBF sites in Germany: water and sediment analysis, batch and column experiments using river water, sequential extraction, and the mass balance approach. At these sites, a “wash out” effect was observed, resulting in a gradual decrease in iron concentrations between the riverbank and the abstraction well over two decades. Hydrogeochemical exchange processes in the aquifer can cause a long-term release of iron and manganese even if the organics concentration in the river water is low. Contrary to common expectations, high iron concentrations are often dominated by the portion of landside groundwater, whereas iron concentrations in bank filtrate often undergo a long-term decline.

وصف الملف: application/pdf

العلاقة: Water Quality and Contamination; https://dx.doi.org/10.3390/w9050317Test

الإتاحة: https://doi.org/10.3390/w9050317Test