Nitrate reductase activity of wetland plants

Plant nitrate reductase activity is precisely regulated according to actual conditions and pland demands. It allows considering this activity as a marker of rhizosphere nitrate occurrence and plant preferences for individual N forms. The nitrate presencein wetlands is usually limited by low oxygen availability, moreover high nutrient load results in changes of inorganic N forms occurrence in favour of ammonium. Ammonium assimilation is advantageous from the energy point of view, but nitrate reduction can enhance the cell ability to survive under oxygen limitation. Nitrate may also acts as an osmotic agent in cells. These facts intensify the necessity of better understanding of mineral nutrition of wetland plants, especially nitrogen metabolism and importance of individual nitrogen form as a nitrogen source. The understanding of interactions between wetland plants and their environment is need not only for wetland protection, but also becouse of plant use in wastewater treatment.