GRF gene family in apricot (Prunus armeniaca L.): genome-wide identification, characterization, and expression patterns during different developmental stages

Growth regulatory factors (GRF) are plant-specific transcription factors involved in growth, development, phytohormone signaling, and responding to stress factors. Although reported in many different plant species, the GRF family in apricot has not been comprehensively analyzed at the genome level. In this study, 10 GRF genes were identified in apricot using integrated bioinformatics tools, and their genome-wide characterization was performed. Phylogenetic tree analysis revealed that PaGRFs are in the same subfamilies with taxonomically related species. Gene structure and motif analysis showed that PaGRFs have variable structures even in the same groups. Cis-acting elements were identified in the promoter region of PaGRFs, which are involved in plant growth and development, and response to abiotic stresses and hormones. Synteny and evolutionary selection analysis revealed that PaGRFs are closely related to Rosaceae species and are under evolutionarily positive selection. Gene ontology and protein–protein interaction analyses revealed that the predicted PaGRF proteins are linked to several different biological and molecular functions. RT-qPCR expression analysis revealed that PaGRFs showed a variable expression pattern in 12 different developmental stages of leaves, flower, and fruit organs of apricot. The information obtained from this study may be helpful to better understand the molecular evolution model of GRF genes in the apricot genome and to highlight their functions in regulating growth and development.