Ascorbic Acid (Asa) improves Salinity Tolerance in Wheat (Triticum Aestivum L.) by Modulating Growth and Physiological Attributes.

Wheat (Triticum aestivum L.) is one of the most important staple foods. High concentration of sodium chloride severely affects plants in general and wheat in specific. In this study the ameliorative effects of ascorbic acid (AsA) against sodium chloride stress were investigated in two commercial wheat cultivars (Galaxy 2013 and Akbar 2019). Experiments were conducted in three replicates. Two levels of salt (0, 150 mM) along with exogenous application of ascorbic acid (0, 30 mM, 60 mM) were applied at three leaves seedling stage. At the establishment of treatments, data regarding physiological, biochemical and yield attributes were recorded and subjected to statistical analysis. The application of AsA significantly (p≤0.05) improved growth, yield and key physiological attributes in tested wheat varieties under salinity stress. Overall wheat genotype Akbar 2019 showed better growth under salt stress. It is concluded from this study that AsA may be used to mitigate salinity effects in wheat.

Oxidative stress and low molecular weight antioxidants in triticale shoots under chloride salinization

We studied the alterations in oxidative stress indicators (hydrogen peroxide, superoxide radical, lipid peroxidation – LPO) and the alterations in the content of low molecular weight metabolites (ascorbic acid, glutathione, proline, chlorophyll and carotenoids) in the shoots of triticale (Triticosecale) under short-term (0-96 h) sodium chloride stress (120 mM) with statistical methods: principal component analysis (PCA) and cluster analysis. An analysis of the alterations in oxidative stress indicators allowed us to calculate the correlation coefficients for the pairs: peroxide – superoxide (0.52), peroxide – LPO (0.62), superoxide – LPO (0.23). The inclusion in the analysis of data on alterations in the content of low molecular weight antioxidants showed that the PCA method forms three main groups for all the studied characteristics: (1) LPO and hydrogen peroxide, (2) chlorophyll and carotenoids, (3) glutathione and ascorbate. The correlation coefficients were calculated for pairs: ascorbate – glutathione (0.71), ascorbate – proline (0.81), glutathione – proline (0.28). Such a value of the coefficient of the first pair suggests that ascorbic acid also performs numerous other functions, in addition to participating in the ascorbate-glutathione cycle. The high correlation between ascorbate and proline can be explained by the similar nature of alterations in their content in triticale shoots under conditions of short-term sodium chloride stress. Negative correlation coefficients in pairs of hydrogen peroxide – chlorophyll (-0.73), peroxide – carotenoids (-0.75), ascorbic acid – LPO (-0.70), LPO – proline (-0.69) give reason to talk about the possible protective role of photosynthesis pigments from accumulating hydrogen peroxide, as well as the potential role of ascorbic acid and proline in protecting membranes from lipid peroxidation. The application of the cluster analysis method showed that first and second order clusters between ascorbate, proline and glutathione reflect their known antioxidant role. The results obtained may also indicate that pigments have a much lower protective function.