Genetic determination of drought resistance in common wheat (Triticum aestivum L.)

Abstract

The aim of the work is to analyze the literature data on genetic determinants and molecular mechanisms involved in the regulation of adaptation and resistance to drought in common wheat. Results. Regulation of the response to osmotic stress in common wheat is carried out through several abscisic acid-dependent or independent pathways. ABA inhibits the growth processes of aerial parts of the plant by inhibiting the action of auxins and cytokinins, increases the hydraulic conductivity of roots by modulating the activity of aquaporins - membrane water channels, changes the flow of ions in the closing cells of the stomata, which leads to their closure and a decrease in water consumption for transpiration. ABA activates a number of TFs that regulate the expression of genes, the products of which are necessary to eliminate the negative consequences of water deficit. ABA-dependent is activation of the genes of antioxidant defense enzymes - superoxide dismutase, peroxidase, catalase and enzymes of the ascorbate-glutathione cycle. Activators of their transcription are NAC, MYB, WRKY, NF-Y, ZFHD and TaERF3 TFs. Expression of LEA genes and dehydrins, which prevent protein aggregation due to dehydration, is ensured by both ABA-dependent and -independent signal transduction pathways, with the help of AREB/ABF, NAC, MYB, WRKY, AP2/EREBP and ZFHD TFs. ABA also activates the biosynthesis of proline - one of the main low-molecular osmoprotectants that accumulate in the cell and ensure the stability of its water regime. Osmolyte accumulation is regulated by MYB, WRKY, NF-Y and TaERF3 TFs. Conclusions. Thus, in the article is considered the regulatory role of ABA in the formation of drought resistance through molecular interactions involving aquaporins, dehydrins, SNRK2 protein kinases, LEA proteins and their genes, as well as genes of transcription factors NAC, MYB, WRKY, NF-Y, AP/ EREBP, ZFHD, DREB. However, due to the complexity of the wheat genome and the polygenicity of the drought resistance trait, there is currently no line of molecular genetic markers for certain alleles of drought resistance genes that would allow predicting the drought resistance of Ukrainian breeding varieties. The molecular genetic mechanisms underlying drought resistance and the identification of genes with the greatest phenotypic effect, as well as the modeling of the work of these genes at different stages of ontogenesis and the involvement of drought resistance alleles in breeding programs, currently require further research.