Defense Responses of Wheat Seedling under Biotic Stress Mimicked by the Linear β-(1,3)-Glucan
Reactive oxygen species (ROS) production causes damage, and to better deal with the toxic effects of ROS, the seeds have developed detoxification mechanisms, among which the enzymes of the antioxidant system (catalase, superoxide dismutase, ascorbate peroxidase ). Another result supports the link between ROS and redox regulation catalyzed by redoxin family in the seed. Among which, thioredoxins (Trxs) and peroxiredoxins (Prxs), particularly 1-Cys-Prx, expressed during maturation and germination steps. This study aim to assess the effect of the laminarin (β-(1,3)-glucan) as an elicitor in the triggering of the natural defenses of the wheat seedling. Also, the fungus Fusarium oxysporum, known to attack wheat during maturation, exhibit a high chitin / glucan ratio. Thus, we have followed the expression of several markers known for their roles in the protection against oxidative stress, including 1-Cys-Prx, a protein-specific of cereals seed, as well as catalase and ascorbate peroxidase enzymes of the antioxidant system. The β-(1,3)-glucan induce the expression of pathogenesis related genes known for their antimicrobial activities. The triggering of defense mechanisms using exogenous elicitors, allowed to developed new strategies of phytosanitary protection more respectful of the environment.
