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Hypothermia, drought, salinity and heavy metals are the most widespread stress factors negatively affecting plant growth and development. Plants respond to these stress factors on molecular, cellular, and physiological levels through the complicated mechanisms of signal perception and transduction, subsequently inducing various defense mechanisms. Transcription factors controlling the expression of numerous defense proteins are the most significant abiotic stress reaction regulators. Mainly, the negative environmental influence activates the AP2/ERF, WRKY, MYB, NAC, bZIP transcription factors. The numerous transcription factors genes can be used in genetic engineering of agricultural crops resistant to abiotic stress. These genes are also of great interest in marker assisted selection of cultivated plants. This review is dedicated to description of transcription factors and their genes, involved in plant response to hypothermia, drought, salinity and heavy metals.

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Endophytic Bacillus subtilis is a non-pathogenic beneficial bacterium which promotes plant growth and tolerance to abiotic stresses, including drought. However, the underlying physiological mechanisms are not well understood. In this study, the potential role that endogenous salicylic acid (SA) plays in regulating endophytic B. subtilis-mediated drought tolerance in wheat (Triticum aestivum L.) was examined. The study was conducted on genotypes with contrasting levels of intrinsic drought tolerance (drought-tolerant (DT) cv. Ekada70; drought-susceptible (DS) cv. Salavat Yulaev). It was revealed that B. subtilis 10-4 promoted endogenous SA accumulation and increased the relative level of transcripts of the PR-1 gene, a marker of the SA-dependent defense pathway, but two wheat cultivars responded differently, with the highest levels exhibited in DT wheat seedlings. These had a positive correlation with the ability of strain 10-4 to effectively protect DT wheat seedlings against drought injury by decreasing osmotic and oxidative damages (i.e., proline, water holding capacity (WHC), and malondialdehyde (MDA)). However, the use of the SA biosynthesis inhibitor 1-aminobenzotriazole prevented endogenous SA accumulation under normal conditions and the maintenance of its increased level under stress as well as abolished the effects of B. subtilis treatment. Particularly, the suppression of strain 10-4-induced effects on proline and WHC, which are both contributing factors to dehydration tolerance, was found. Moreover, the prevention of strain 10-4-induced wheat tolerance to the adverse impacts of drought, as judged by the degree of membrane lipid peroxidation (MDA) and plant growth (length, biomass), was revealed. Thus, these data provide an argument in favor of a key role of endogenous SA as a hormone intermediate in triggering the defense responses by B. subtilis 10-4, which also afford the foundation for the development of the bacterial-induced tolerance of these two different wheat genotypes under dehydration.

The allelic states of waxy genes in genomes A, B and D were studied by genome-specific primers in cultivars and lines of common wheat of the pre-Ural steppe. The studied cultivars and lines revealed differences in genotypes for genome A.

The expression profile of transcription factor genes was studied in varieties of common wheat in the pre-Ural steppe zone in response to drought and hypothermia. Increased transcriptional activity under stress is indicated for the TabZIP1, TabZIP60, TaDREB1, and TaNAC 69 genes.