Systematic Analysis and Expression Profiling of the Ginger FWL Gene Family Reveal Its Potential Functions in Rhizome Development and Response to Abiotic Stress

Ginger (Zingiber officinale Roscoe) is a significant medicinal and culinary plant, with its growth influenced by various biotic and abiotic factors. The FWL gene, containing the PLAC8 motif, is prevalent in fungi, algae, higher plants, and animals. In plants, FWL primarily regulates fruit weight, cell division, and participates in heavy metal transport. However, the FWL family members in ginger have not been previously identified. This study identified 21 FWL members within the ginger genome, distributed across nine chromosomes. These 21 FWL genes were categorized into five subfamilies based on the phylogenetic analysis. Gene-structure and motif analyses revealed that ZoFWL has been conserved throughout evolution. Concurrently, the ZoFWL gene exhibits a homologous evolutionary relationship only with Musa acuminata. We identified three pairs of fragment-repeat events encompassing five genes, which likely represent the primary mechanism for amplification within the ZoFWL gene family. The promoter regions of the ZoFWL genes are enriched with numerous cis-acting elements implicated in plant growth, development, and responses to abiotic stress. These include elements responsive to low temperatures, anaerobic induction, MYB binding sites integral to defense and stress responses, and drought inducibility. Expression profiling revealed that the ZoFWL genes are responsive to a quartet of abiotic stressors, with ZoFWL18, in particular, demonstrating a pronounced response to osmotic, low-temperature, heat, and salinity stresses. This underscores the pivotal role of ZoFWLs in abiotic-stress responses. Our findings offer valuable insights into the potential of the ZoFWL gene family in modulating ginger rhizome development and the genes’ response to abiotic stressors, laying a foundational framework for future research into ginger’s resistance breeding.