Attenuation of mercury phytotoxicity with a high nutritional level of nitrate in alfalfa plants grown hydroponically

Mercury (Hg) is one of the most dangerous pollutant heavy metals to environment, which causes several toxic effects in plants upon accumulation, such as induction oxidative stress. Nitrate (NO3) prevalent form incorporate nitrogen (N) higher plants, through its reduction nitrite (NO2) by enzyme nitrate reductase (NR). We studied physiological alterations caused Hg (0, 6 and 30 µM) alfalfa grown at two different levels NO3: low, (2 mM; LN), high (12 HN) for week using a semi-hydroponic culture system. Several parameters stress lipid peroxidation, chlorophyll content, biothiol concentration, ascorbate peroxidase (APX) glutathione (GR) activities showed that HN were less affected Hg. activity NO3 concentration also altered under stress, with lower impact nourished NO3. Our results highlight importance nutritional status improve tolerance like