Systematic analysis of the G-box Factor 14-3-3 gene family and functional characterization of GF14a in Brachypodium distachyon.

The 14-3-3 proteins are highly conserved and ubiquitously found in eukaryotes. Plant 14-3-3 proteins are involved in many signaling pathways to regulate plant growth and development. Here we identified seven Brachypodium distachyon 14-3-3 genes and analyzed the evolution, gene structure and expression profiles of these genes. Several cis-elements involved in stress response and hormone pathway were found in the promoter region of 14-3-3 genes. Results of gene expression analysis showed that these genes were induced by abiotic stresses or hormone treatments. Transgenic Arabidopsis overexpressing BdGF14a exhibited increased leaf water content (LWC) and decreased electrolyte leakage (EL) and showed improved drought stress tolerance. BdGF14a transgene significantly up-regulated expression levels of DREB1A and DREB1B, but slightly elevated ABI1 expression. These results indicated that BdGF14a functioned as a positive regulator in plant response to drought stress mainly via ABA independent pathway.