Uncovering the function of peptides: Bridging hormone signaling, microbial interactions, and root development in plants

Plant root systems are critical for absorbing water and nutrients and anchoring plants in the soil, and their development is regulated by phytohormones and complex signaling pathways. Recent studies have identified small peptides as essential players in governing root development, binding to specific receptors on the cell membrane, and triggering signaling processes. In this study, we summarize recent advances in small peptide regulation of root system architecture and tissue organization, as well as the molecular interaction between peptides and canonical hormone signaling. Additionally, we discuss the functions of small peptides in modulating root development responses to environmental forces like nitrogen and phosphate starvation, osmotic stress, and soil microbes through the activation of local and systemic signaling pathways. This review offers a comprehensive overview of peptide signaling during plant root development and prospects for further crop breeding applications.