Enhancing antioxidant availability in wheat grains from plants grown under seawater stress in response to microalgae extract treatments.

BACKGROUND The present study was designed to investigate the enhanced antioxidant capacity of whole grains from wheat plants grown under seawater stress in response to microalgae extract treatment. RESULTS The total carotenoid (TCAR), tocopherol (TOC), phenolic (TPC), and protein (PC) contents in whole grains of wheat plants irrigated with 10% and 20% (v/v) seawater (SW) in response to water extracts of microalgae Spirulina maxima (SME) and Chlorella ellipsoida (CEE) as well as exogenous plant growth enhancers of ascorbic acid and benzyladenine treatments were measured. The results showed that the levels of enhanced TCAR (range 0.08-0.14 g kg(-1)), TOC (range 0.05-0.12 g kg(-1)), TPC (range 0.80-2.96 g kg(-1)) and PC (range 93.4-137.9 g kg(-1)) in wheat grains of plants irrigated with 10% and 20% SW were significantly increased in response to SME and CEE treatments. Evaluation of antioxidant activity of ethanolic extracts of grains of SW-stressed plants indicated that DPPH and TBAS radical scavenging activity was significantly increased in response to SME and CEE treatments and coincided with the increase in levels of antioxidant compounds present in each extract. The electrophoretic profiles of the grains of proteins of treated samples exhibited quite different patterns from those in control samples. CONCLUSION The results suggest that the application of algal extracts to wheat plants irrigated with SW is useful for improvement of salinity tolerance. This effect can be triggered by the stimulation of antioxidant components and protein content.