Roles of Exogenous α-Lipoic Acid and Cysteine in Mitigation of Drought Stress and Restoration of Grain Quality in Wheat
Amr Elkelish,
Mohamed M. El-Mogy,
Gniewko Niedbała,
Magdalena Piekutowska,
Mohamed A. M. Atia,
Maha M. A. Hamada,
Mostafa Shahin,
Soumya Mukherjee,
Ahmed Abou El-Yazied,
Mohamed Shebl,
Mohammad Shah Jahan,
Ali Osman,
Hany G. Abd El-Gawad,
Hatem Ashour,
Reham Farag,
Samy Selim,
Mohamed F. M. Ibrahim
Affiliations
Amr Elkelish
Botany Department, Faculty of Science, Suez Canal University Ismailia, Ismailia 41522, Egypt
Mohamed M. El-Mogy
Vegetable Crops Department, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
Gniewko Niedbała
Department of Biosystems Engineering, Faculty of Environmental and Mechanical Engineering, Poznań University of Life Sciences, Wojska Polskiego 50, 60-627 Poznań, Poland
Magdalena Piekutowska
Department of Geoecology and Geoinformation, Institute of Biology and Earth Sciences, Pomeranian University in Słupsk, Partyzantów 27, 76-200 Słupsk, Poland
Mohamed A. M. Atia
Molecular Genetics and Genome Mapping Laboratory, Genome Mapping Department, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), Giza 12619, Egypt
Maha M. A. Hamada
Department of Agronomy, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Mostafa Shahin
Department of Agronomy, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Soumya Mukherjee
Department of Botany, Jangipur College, University of Kalyani, Kalyani 742213, India
Ahmed Abou El-Yazied
Department of Horticulture, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Mohamed Shebl
Food Science Department, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Mohammad Shah Jahan
College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
Ali Osman
Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt
Hany G. Abd El-Gawad
Department of Horticulture, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Hatem Ashour
Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Reham Farag
Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Samy Selim
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia
Mohamed F. M. Ibrahim
Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Cysteine (Cys) and α-lipoic acid (ALA) are naturally occurring antioxidants (sulfur-containing compounds) that can protect plants against a wide spectrum of environmental stresses. However, up to now, there are no conclusive data on their integrative roles in mitigation of drought stress in wheat plants. Here, we studied the influence of ALA at 0.02 mM (grain dipping pre-cultivation treatment) and Cys (25 and 50 ppm as a foliar application) under well watered and deficit irrigation (100% and 70% of recommended dose). The results showed that deficit irrigation markedly caused obvious cellular oxidative damage as indicated by elevating the malondialdehyde (MDA) and hydrogen peroxide content (H2O2). Moreover, water stressed plants exhibited multiple changes in physiological metabolism, which affected the quantitative and qualitative variables of grain yield. The enzymatic antioxidants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POX) were improved by Cys application. SOD and APX had the same response when treated with ALA, but CAT and POX did not. Moreover, both studied molecules stimulated chlorophyll (Chl) and osmolytes’ biosynthesis. In contrast, the Chl a/b ratio was decreased, while flavonoids were not affected by either of the examined molecules. Interestingly, all above-mentioned changes were associated with an improvement in the scavenging capacity of reactive oxygen species (ROS), leaf relative water content (RWC), grain number, total grain yield, weight of 1000 kernels, gluten index, falling number, and alveographic parameters (P, W, and P/L values). Furthermore, heatmap plot analysis revealed several significant correlations between different studied parameters, which may explore the importance of applied Cys and ALA as effective compounds in wheat cultivation under water deficit conditions.
