Algal extract role in alleviating the deleterious effects of lead stress on wheat growth via regulating the antioxidant and mineral contents
摘要
Lead (Pb) is one of the most prevalent heavy metal pollutants in our environment. Although plants do not need lead, they do absorb it from their environment when it is available. So, this investigation examined how lead stress affected the morpho-physiological of wheat plants, also, the possibility for amelioration of lead stress by the use of algal extract (Spirulina platensis algal extract SPAE). A pot trial in a completely randomized design was conducted using foliar application of SPAE of wheat under various lead acetate (Pb (C2H3O2)2) levels. Growth criteria, photosynthetic pigments, and some element contents were severely reduced by Pb. On the other hand, Pb increased the activity of peroxidase, superoxide dismutase, catalase and nitrate reductase, as well as carotenoids and non-enzymatic antioxidants, like phenols, ascorbic acid, glutathione and α-tocopherol. Also, Pb content, lipoxygenase activity and malondialdehyde, hydrogen peroxide and superoxide radicals were also significantly elevated. On the contrary, SPAE significantly improved growth criteria, photosynthetic pigments, and the activities of POX, SOD, CAT, and NR and non-enzymatic antioxidants. The most advantageous effect was observed with 1000 mg L−1 SPAE, it improved growth parameters, photosynthetic pigments, antioxidant enzymes, and compounds via reducing membrane permeability, lipid peroxidation, and reactive oxygen species under different Pb levels. Conclusions: Applying an SPAE to wheat plants has the potential to mitigate the documented negative consequences of Pb on morphological parameters and biochemical analysis restricted to photosynthetic pigments, minerals, oxidative stress indicators and antioxidant enzymes and compounds after 75 days of sowing.