Trihelix transcription factors: versatile regulators in plant growth and development, abiotic, and biotic stress responses.

Transcription factors (TFs) are central regulators of plant life activities. Trihelix transcription factors, a plant-specific family characterized by a conserved trihelix (helix-loop-helix-loop-helix) DNA-binding domain, play essential roles in modulating plant growth, development, and stress responses. This review systematically outlines the structural characteristics and phylogenetic classification of trihelix transcription factors, with a particular emphasis on their multifaceted regulatory functions during the development of seeds, fruits, leaves, flowers, and roots. We also provide a deep analysis of the molecular mechanisms by which trihelix members mediate responses to abiotic stresses (e.g., drought, salinity, temperature extremes, and hypoxia) and biotic stresses (e.g., pathogen infection). Critically, we synthesize emerging evidence into core regulatory pathways, illustrating how key trihelix factors such as GTL1 function as central nodes that coordinate antagonistic processes like growth, stress adaptation, and immunity. Finally, we highlight unresolved key questions in the field and suggest future research directions, aiming to establish a theoretical foundation for further functional exploration and agricultural utilization of trihelix transcription factors.