Phylogenetic, structure and expression analysis of growth regulatory factors (GRF) genes in wheat (Triticum aestivum L.) using in silico methods

Growth regulating factors (Growth Regulatory Factors) are plant-specific transcription factors which contain two conserved domains, QLQ and WRC. Members of this family are involved in diverse biological and physiological processes, such as growth, development and stress and hormone responses. In this study, wheat GRF genes were identified and analysis by bioinformatics methods. GRF genes identification was performed by blastP. Then evolutionary relationships, gene structure, promoter, miRNA, gene ontology and expression of identified genes were analyzed. 30 TaGRFs (TaGRF1–30) distributed on 12 chromosomes were identified by searching wheat genome database and were clustered into six subgroups according to their phylogenetic relationships. TaGRFs belonging to the same subgroup shared a similar motif composition and gene structure. They all contain two conserved motifs (QLQ and WRC) and have 2–5 exons. Due to the identification of stresses, hormones and tissue specific cis elements in the TaGRFs promoter, these genes are involved in many biological processes of wheat. MiR396 target analysis indicated that 26 GRFs mRNA contained miRNA396 target position in wheat. RNA-seq data from the expVip database showed that TaGRF1, TaGRF4 and TaGRF7 were strongly expressed in root, shoot, leave, spike and grain in vegetative and reproductive stages. This data also indicated that all TaGRF genes except TaGRF16 were expressed in vegetative stage of spike. The results of this study provide the evolutionary and functional information needed for Design of functional studies of this gene family.