Genome-wide investigation of the PtaGRF and PtaGIF families reveals potential targets for cone development and gibberellin signaling in Chinese pine

Key messageWe identified 7 PtaGRF and 3 PtaGIF genes and analyzed the potential functions of PtaGRF02-PtaGIF02 that may mediate cone development and gibberellin signaling in Chinese pine.AbstractGrowth-regulating factors (GRFs) and GRF-interacting factors (GIFs) act as transcription cofactors that influence plant growth and development. While these genes have been extensively studied in various plant species, a comprehensive genome-wide analysis of GRFs and GIFs in conifers has been lacking. In this study, we identified 7 PtaGRFs and 3 PtaGIFs in Chinese pine (Pinus tabuliformis) and conducted a detailed analysis of their motifs, domains, structures, and regulatory elements. Phylogenetic analysis revealed that GRF proteins grouped into five clades, with PtaGRFs forming a single clade. We further investigated chromosome mapping and collinearity. Through expression profiling and correlation analysis, PtaGRF02 and PtaGIF02 were excavated, which may play a role in cone development. Protein-protein interaction analysis indicated that these two factors could interact with proteins involved in flower development. Moreover, PtaGRF02 and PtaGIF02 were shown to interact with each other through yeast two-hybrid and BiFC assays, and they were found to interact with PtaDELLAs to modulate gibberellin (GA) signaling. Overall, our findings offer valuable genetic insights into reproductive development in conifers.