Plant CLE peptides: functions, challenges, and future prospects

Peptide hormones have garnered significant research interest since their initial discovery in higher plants. As crucial components of intercellular communication, CLE peptides have been shown to regulate plant development in response to both developmental and environmental cues. Here, we present a systematic review of recent findings on CLE peptide signaling pathways and their associated mechanisms in plants. We summarize our current understanding of the biological functions and regulatory mechanisms of CLE peptides, highlighting (1) their roles in plant growth, including root, leaf, and reproductive development, with a particular focus on meristem regulation; (2) their involvement in mitigating abiotic stresses such as drought and low light; and (3) their contribution to plant–microbial interactions, such as arbuscular mycorrhizal symbiosis. We also suggest future directions for research on plant CLE peptides to enhance our understanding of their functions and promote their application in crop breeding.