Identification and expression analysis of TIFY gene family members in barley

【Objective】The identification and expression analysis of barley TIFY gene family members could lay a foundation for the further exploration and understanding of the mechanism of TIFY gene family in barley growth and development and response to stress.【Method】TIFY gene family members were identified from barley by HMMER based on their conserved domain characteristics. Their physicochemical properties,conserved motifs, characteristic domains,cisacting elements, gene structure, phylogeny and expression patterns were predicted using bioinformatics software.【Result】In this study, 15 TIFY genes(HvTIFY1-HvTIFY15) were identified in barley, which were distributed on 5 chromosomes, some of them in clusters. The 15 HvTIFY proteins had the characteristic domain(TIFY) of the TIFY family. According to their different contents of conserved domains,they could be divided into ZML(4) and JAZ(11) subgroups. Most of them were hydrophilic(14) and lightly basic(11) proteins, but all of them were located in the nucleus. With the exception of HvTIFY7,the similarity of secondary structure was high,which was proportionally composed of random coil>α-helix>β- angle. There were,however,obvious differences in the structure of HvTIFYs genes. The number of introns ranged from 0 to 6 for the 11 genes in the Jaz subfamily and from 6 to 7 for the 4 genes in the ZML subfamily. The promoter regions of HvTIFY genes were rich in cis-acting elements such as light,hormone and stress,and its species and distribution were diverse. The 79 TIFY proteins of 5 species were divided into 4 subfamilies. The ZML, TIFY and JAZ subfamilies contain TIFY proteins of monocotyledons and dicotyledons,while the PPD subfamily only contains TIFY proteins of dicotyledons. There were significant differences in the expression of the 15 HvTIFY genes in different tissues and organs, in which HvTIFY1,HvTIFY2 and HvTIFY8 genes were highly expressed in 8 tissues, HvTIFY10 and HvTIFY15 genes were moderately expressed,HvTIFY6 expression was low and HvTIFY11 expression was not detected. Different HvTIFY genes displayed different sensitivities to salt stress in different root tissues.【Conclusion】There is some functional differentiation in the 15 HvTIFY genes identified from barley with obvious tissue and spatiotemporal specificity,which are speculated to have important regulatory roles in hormone regulation and the barley response to adverse conditions.