Identification and characterization of TIFY family genes in Brachypodium distachyon

The TIFY family is a plant-specific gene family encoding proteins characterized by a conserved TIFY domain. This family encodes four subfamilies of proteins, including ZIM-like (ZML), TIFY, PPD and JASMONATE ZIM-Domain (JAZ) proteins. TIFY proteins play important roles in plant development and stress responses. In this study, 21 BdTIFYs were identified in Brachypodium distachyon through genome-wide analysis, including 15 JAZ and 6 ZML genes. Analysis of the distribution of conserved domains showed that there are three additional domains (CCT domain, GATA domain and Jas domain) in the BdTIFY proteins besides the TIFY domain. Phylogenetic analysis indicated that these 21 proteins were classified into two major groups. Expression profile of BdTIFY genes in response to abiotic stresses and phytohormones was analyzed using quantitative real-time RT-PCR. Among 21 BdTIFY genes, 12 of them were induced by JA treatment, and 4 of them were induced by ABA treatment. Most of BdTIFY genes were responsive to one or more abiotic stresses including drought, salinity, low temperature and heat. Especially, BdTIFY5, 9a, 9b, 10c and 11a were significantly up-regulated by multiple abiotic stresses. These results provided important clues for functional analysis of TIFY family genes in B. distachyon.