Abstract:
The aim of this work is to highlight a resistant endophytic mycoflora in the roots of two
metallophylic species Hedysarum pallidum Desf. and Lygeum spartum L. growing on soil
contaminated with antimony (Sb) and arsenic (As) in Djebel Hamimat (Algeria) region, to
study the toxicity of mycoendophytes with respect to toxicity of Sb and As, to evaluate the
level of oxidative stress and the antioxidant defense systems of Aspergillus tubingensis and
Fusarium oxyporum induced by metalloid toxicity.
Our work demonstrates, the presence of mycoendophytes associated with the roots of the
two plant species studied for the first time in Algeria; H. pallidum, and L. spartum. This
latter have a colonization frequencies of 64.58% and 96.87% respectively. among the
isolated mycoendophytes, only Aspergillus tubingensis was resistant to 500 mM Sb, and
Fusarium oxysporum tolerated 30 mM As.
The toxicity tests in vitro on A. tubingensis and F. oxysporum revealed that these strains
accumulated a significant amounts of Sb in their biomass, in contrast to As. As regards the
indicators of the oxidative stress level and the antioxidant responses of the two endophytic
species, MDA, H2O2 and intracellular proline content increase significantly with increasing
doses of Sb and As in the culture medium. Antioxidant responses vary quantitatively and
qualitatively from a fungal species to another, and from a metalloid to another. This suggests
that these endophytic strains may be potential agents for the bioremediation of soil and
aquatic environments contaminated with antimony and arsenic.
