Yahia Nourredine , Ali  Naima , Habouche Dalila , Semache Habib , Saad Karim , Fyad-Lamèch Fatima Zohra

Laboratoire Génétique et Amélioration des Plantes. Department of Biology, Faculty of Natural Sciences and Life, University Ahmed Ben Bella (Oran 1), Algeria
Author    Correspondence author
Molecular Plant Breeding, 2015, Vol. 6, No. 5   doi: 10.5376/mpb.2015.06.0005
Received: 26 Dec., 2014    Accepted: 31 Jan., 2015    Published: 25 Feb., 2015

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Nourredine et al., Changes of peroxidase activities under cold stress in annuals populations of Medicago, Molecular Plant Breeding, 2015, Vol.6, No. 5 1-9 (doi: 10.5376/mpb.2015.06.0005)

Up to 15 percent of the world’s agricultural production is lost to frost. Increasing knowledge on antioxidant systems under chilling stress could lead to understanding tolerance to extreme temperatures and at least  lead to possible genetic improvements. To minimize oxidative damage, plants have evolved various enzymatic and non-enzymatic defense mechanisms to detoxify free radicals and reduce oxidative stress. Changes of peroxidase activities are generally related to cold stress responses. The aims of this work was to investigate changes in antioxidant enzyme peroxidase  EC 1.11.1.7 (POD) activities of 8 accessions of Medicago exposed during post germination to low non-freezing temperature. After 3 days of germination, levels of enzyme activity were examined at different durations, 5, 8, and 11 days at a low temperature (4°C) (T₁, T₂,and T₃) and untreated plantlets  (controls), 2, 4, 6, 8, 10, 11, 12, and 14 days at 22°C (T₀₂, T₀₄, T₀₆, T₀₈, T₀₁₀, T₀₁₁, T₀₁₂,and T₀₁₄) respectively. The most noticeable result in this current study, POD activities were higher under low temperature regimes than control. This activities increases in the beginning of the stress in both the tolerant and the sensible accessions. However, POD activities decreases in less tolerant accession with cold under treatment duration, whereas it is relatively maintained in tolerant accession. On the other hand, the data indicated that expression of isozymes in response to cold stress depends on the duration and is higher in tolerant than in sensible one.

Cold stress; Annual accessions;Medicago; Peroxidase (POD) (EC 1.11.1.7); Antioxidant activities