Breaking and making genes: the genesis of novel traits in plants

Understanding the mechanisms by which plants adapt, evolve, and acquire new traits is crucial for enhancing agricultural resilience and productivity in the face of global challenges. Among the various mechanisms that drive new gene evolution, gene fusion has emerged as a significant yet relatively understudied contributor. It can arise through chromosomal rearrangements or RNA processing mechanisms, merging segments from different genes to produce novel fusion transcripts. In plants, these fusion events have been associated with key biological functions, including the regulation of specialized metabolism, stress responses, and developmental changes. While fusion genes have been extensively studied in humans, mainly due to their oncogenic potential, their prevalence and functional relevance in plants remain relatively underexplored. This review offers a detailed overview of the molecular mechanisms underlying gene fusion formation, highlighting their participation in gene evolution, functional diversification, and plant adaptation. In addition, we discuss current methodologies for detecting and validating fusion events, including high-throughput sequencing technologies and emerging single-cell sequencing platforms, and outline promising directions for future research aimed at elucidating their biological significance. Collectively, these insights emphasize the expanding importance of gene fusions in plant biology and underscore the need for further investigation into their regulatory and evolutionary roles.