Identification and in Silico Characterization of GT Factors Involved in Phytohormone and Abiotic Stresses Responses in Brachypodium distachyon.

GT factors play critical roles in plant growth and development and in response to various environmental stimuli. Considering the new functions of GT factors on the regulation of plant stress tolerance and seeing as few studies on Brachypodium distachyon were available, we identified GT genes in B. distachyon, and the gene characterizations and phylogenies were systematically analyzed. Thirty-one members of BdGT genes were distributed on all five chromosomes with different densities. All the BdGTs could be divided into five subfamilies, including GT-1, GT-2, GTγ, SH4, and SIP1, based upon their sequence homology. BdGTs exhibited considerably divergent structures among each subfamily according to gene structure and conserved functional domain analysis, but the members within the same subfamily were relatively structure-conserved. Synteny results indicated that a large number of syntenic relationship events existed between rice and B. distachyon. Expression profiles indicated that the expression levels of most of BdGT genes were changed under abiotic stresses and hormone treatments. Moreover, the co-expression network exhibited a complex regulatory network between BdGTs and BdWRKYs as well as that between BdGTs and BdMAPK cascade gene. Results showed that GT factors might play multiple functions in responding to multiple environmental stresses in B. distachyon and participate in both the positive and negative regulation of WRKY- or MAPK-mediated stress response processes. The genome-wide analysis of BdGTs and the co-regulation network under multiple stresses provide valuable information for the further investigation of the functions of BdGTs in response to environment stresses.