Genome-Wide Analysis of the GRAS Gene Family in Barley ( Hordeum vulgare L.)

The GRAS (named after first three identified proteins within this family, GAI, RGA, and SCR) family contains plant-specific genes encoding transcriptional regulators that play a key role in gibberellin (GA) signaling, which regulates plant growth and development. Even though genes have been characterized in some plant species, little research is known about the genes in barley ( L.). In this study, we observed 62 GRAS members from barley genome, which were grouped into 12 subgroups by using phylogenomic analysis together with the GRAS genes from Arabidopsis ( ), maize ( ), and rice ( . Chromosome localization and gene structure analysis suggested that duplication events and abundant presence of intronless genes might account for the massive expansion of gene family in barley. The analysis of RNA-seq data indicates the expression pattern of genes in various tissues at different stages in barley. Noteworthy, our qRT-PCR analysis showed the expression of 18 candidate genes abundantly in the developing inflorescence, indicating their potential roles in the barley inflorescence development and reproduction. Collectively, our evolutionary and expression analysis of GRAS family are useful for future functional characterization of GA signaling in barley and agricultural improvement.