Analyses of abiotic stress and brassinosteroid-related some genes in barley roots grown under salinity stress and HBR treatments: Expression profiles and phylogeny

We aimed to investigate abiotic stress (<i>WAK</i>, <i>HvPIP1.1</i>, <i>HvPIP1.2</i>, <i>HvPIP1.3</i>, <i>HvPIP1.5</i>, <i>CYCD3</i>, <i>DREB2</i>) and brassinosteroid-related gene (<i>DWARF4</i>) expressions in barley (<i>Hordeum vulgare</i> L. cv. “Hilal”) roots grown under different salt (150 and 250 mM), HBR (0.5 and 1 μM), and salt + HBR applications during 48 and 72 h at dark with their controls. Phylogenetic trees were also constructed to observe relationships among genes found in other plants. The expression of <i>HvPIP1.2</i> and <i>WAK</i> reduced after salt treatment while <i>HvPIP1.3</i>, <i>DREB2</i> and <i>DWARF4</i> expressions increased. <i>HvPIP1.1</i>, <i>HvPIP1.2</i>, <i>HvPIP1.3</i>, <i>HvPIP1.5</i> and <i>DWARF4</i> expressions were upregulated under only HBR applications. Salt + HBR treatments increased <i>HvPIP1.1</i>, <i>DREB2</i> and <i>DWARF4</i> but decreased <i>HvPIP1.2.</i> Phylogenetic analyses indicated that <i>Oryza sativa</i> L. shared similar sequences with <i>HvPIP1.5</i>. <i>CYCD3</i> could diverge relatively earlier from cyclin genes during evolution as it segregates in a distinct clade. <i>Sorghum bicolor</i> showed sequence homology with <i>DREB2</i>. <i>Oryza australiensis</i> L. and <i>DWARF4</i> were found in the same clade. To our knowledge, this is the first detailed report related to salt stress and HBR applications in terms of the expression of different genes in barley, providing a valuable information for molecular breeding improvement of stress-related traits.