The mechanisms of fiber flax adaptation to high soil acidity (a review)

Excessive soil acidity is one of the main factors causing significant losses in crop production. Using fiber flax, the effect of soil acidity on the yield and fiber quality of various samples representing the world gene pool of this crop is shown. The optimum acidity for fiber flax is within a narrow range – pHKCl 5.3–5.6. On strongly acid soils (pHKCl less than 4.5) with threshold values of the toxic aluminum (Al3+) content, 10–11 mg/100 g, a decrease in the flax yield is over 50%. Currently, along with the mechanisms of detoxification of toxic aluminum in acid soils, genetic aspects of aluminum resistance have also been determined. It is shown that one of the most significant components of the common defense response of plants to various stresses is their antioxidant systems. An important role in the antioxidant defense system belongs to glutathione transferases. Using high-through put sequencing and quantitative PCR, a change in the expression of genes and microRNAs in flax plants was revealed in response to the toxic effect of aluminum ions. Using flax genotypes contrasting in acid resistance, an increase in the expression of genes encoding UDP-glycosyltransferases (UGT) and glutathione-S-transferases (GST) was established under aluminum stress. The increase in expression was more pronounced in aluminum-resistant flax cultivars than in sensitive ones. Also, the differences in the change of miR390 and miR393 expression between resistant and sensitive genotypes were revealed under the toxic effects of aluminum ions. Understanding the resistance mechanisms makes it possible to accelerate the development of flax and other crop cultivars adaptive to edaphic stress, which is important for obtaining high and guaranteed yields of agricultural products