Biometric and biochemical attributes of alfalfa seedlings as indicators of stress induced by excessive cadmium

• S Mahmood ^[1] ; S. A Malik ^[2] ; A Tabassum ^[2] ; U Younis ^[2] ; M Athar ^[3]
  1. [1] University of Glasgow

     University of Glasgow

     Reino Unido

     
  2. [2] Bahauddin Zakariya University Institute of Pure and Applied Biology Botany Division
  3. [3] California Department of Food and Agriculture

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• Localización: Journal of soil science and plant nutrition, ISSN-e 0718-9516, ISSN 0718-9508, Vol. 14, Nº. 3, 2014, págs. 546-553
• Idioma: inglés
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  • The biometric and biochemical attributes of alfalfa (Medicago sativa L.) seedlings were studied after their exposure to 0-120 µM cadmium for 28 days using hydroponic culture. The growth, photosynthetic area and pigment contents (chlorophyll a, b and total) declined significantly (p < 0.05) in the presence of high cadmium concentrations (90 and 120 µM). A steady increase in lipid peroxidation assessed via MDA production was observed with increasing levels of cadmium. Cadmium uptake by the plant tissues was concentration dependent. The roots accumulated 1020 µg g-1 of cadmium which was two folds than leaves. An enhanced production up to 600 µg g-1 of proline was observed at higher levels of cadmium. Though, cadmium toxicity was expressed in terms of decline in growth variables, chlorophyll content and oxidative damage but restricted transfer of the metal to the aerial tissue and greater production of proline in response to higher metal content seems to alleviate cadmium toxicity. Thus, ability of alfalfa plants to tolerate high cadmium concentrations can be a manifestation of effective defensive mechanism derived from differential accumulation of metal in plant tissues in addition to enhanced production of proline.