Comprehensive evolutionary analysis of growth-regulating factor gene family revealing the potential molecular basis under multiple hormonal stress in crops.

() are plant-specific transcription factors that contain two highly conserved QLQ and WRC domains, which control a range of biological functions, including leaf growth, floral organ development, and phytohormone signaling. However, knowledge of the evolutionary patterns and driving forces of in crops is limited and poorly characterized. In this study, a total of 96 were identified from eight crops of , , L. ssp. , , L. ssp. , , and . Based on their protein sequences, the were classified into three groups. Evolutionary analysis indicated that the whole-genome or segmental duplication plays an essential role in the expansion, and the s were negatively selected during the evolution of crops. The GRFs protein function as transcriptional activators with distinctive structural motifs in different groups. In addition, the expression of was induced under multiple hormonal stress, including IAA, BR, GA3, 6BA, ABA, and MeJ treatments. Specifically, was significantly induced by IAA at 6 h after phytohormone treatment. Transgenic experiments showed that roots overexpressing were more sensitive to IAA and affect root elongation. This study will broaden our insights into the origin and evolution of the GRF family in crops and will facilitate further research on function.