Biomarkers for alumotolerance of winter-hardy forms of Triticum aestivum L. from the VIR collection

All cultivated land in the world is approximately 50 % acidic soil, in Russia it is approximately 30 %. This limits the production of economically significant crops. The area of highly acidic farmland increases annually. The main stressor of acidic soils are aluminum ions (Al3+). One of the most economically significant crops for the Russian Federation is wheat. Therefore, the search for alumotolerant wheat forms remains relevant. The largest number of Al3+ resistant genotypes is found among hexaploid wheat species with genome D, which include Triticum aestivum L. A distinctive feature of this culture is the combination of low temperatures resistance with good baking quality of the flour, therefore, the search for aluminum-tolerant forms among T. aestivum genotypes is economically justified. Hexaploid wheats are well represented in the collection of the Vavilov All-Russian Institute of Plant Genetic Resources (VIR), the main part of which (44 thousand samples) is T. aestivum . In this paper, we for the first time compared the metabolomic profiles (MP) of T. aestivum accessions of different eco-geographical origins adapted to the conditions of the North-West of the Russian Federation, and identified the MP features in aluminum tolerant forms to detect putative metabolic markers for resistance to aluminum ions. Nonspecific metabolomic profiling of 7-day seedling rootlets of 20 T. aestivum accessions varying in degree of sensitivity to Al3+ was performed using gas chromatography coupled with mass spectrometry. Polyols, nucleosides, lactone forms of organic acids, free fatty acids and their derivatives, trioses, pentoses, hexoses, oligosaccharides, phenol-containing substances, terpenes, phytosterols were better represented in MP genotypes with low sensitivity to Al3+. Dispersion analysis revealed significant differences of the MP of the accessions with a more expressed resistance to Al3+. Exposure to a stressor presumably causes changes in the Krebs cycle, the synthesis of carbohydrates, plant hormones, other protective factors, glycerolipids and triglycerides of the membrane complex. Classical discriminant analysis followed by canonical analysis allowed us to identify eleven components with 100 % confidence separating T. aestivum samples with varying degrees of aluminum tolerance. Phosphoric, malic, succinic acids, tetra (RI = 1537) and pentaatomic (RI = 1735) alcohols, and linoleic acid methyl ester, which are statistically confirmed as aluminum tolerance markers, were the most informatively significant factors characterizing resistant forms of T. aestivum . The established biomarkers can be used to search for forms of T. aestivum resistant to Al3+. These forms will be involved in breeding for highly productive T. aestivum varieties with complex resistance to stress factors and adapted to production in the conditions of the North-West of the Russian Federation.