Algal extracts improve antioxidant defense abilities and salt tolerance of wheat plant irrigated with sea water

Abstract

Effect of irrigation bread wheat plants (Triticum aestivum L., cv. Giza 94) with sea water (10 and 20% v/v), spraying with microalgae extracts obtained from Chlorella ellipoida and Spirulina maxima (5 gL-1 dry weight in 0.1% Tween solution) cultivated under normal and stress conditions were studied. Some plant bioregulators (BRGs, ascorbic acid and benzyl adenine, at 200 ppm) at the vegetative growth stage on photosynthetic pigments, antioxidant components, activity of some antioxidant enzymes, lipid peroxidation products, growth parameters, mineral content and economic yield were estimated. Irrigation of wheat plants with sea water led to an increase in Na+ ion, activities of antioxidant enzymes, superoxide dismutase, ascorbate peroxidase and total peroxidase, and TBARs components. In contrast, the contents of photosynthetic pigments and yield components were reduced. Furthermore, the overall growth of wheat plants was interrupted by irrigation with sea water (10 and 20%) and the effect was pronounced at higher level (20%). Application of BRGs had a slight effect on plant growth, antioxidant behaviour and activity of antioxidant enzymes in plants irrigation with sea water compared with that in stressed wheat plants. Application of algal extracts significantly increased the contents of total chlorophyll and antioxidant phenomenon. In additional, application of algal extracts exhibited strong positive correlation with increase in fresh weight (FW), grain weight and yield components. It is concluded that productive purpose of wheat crop by mean of brackish water (at 20 v/v level) is possible under a level of economical value through its application of algal extracts. Key words: Microalgae, sea water, wheat, salinity stress, antioxidant systems.