Gibberellin in Regulating Poplar Growth, Development, and Stress Responses

Gibberellic acid (GA) plays a central role in regulating growth, development, and stress responses. Poplars exhibit woody-specific GA regulatory mechanisms due to their long-life cycle, continuous vascular cambium activity, and seasonal dormancy. While the GA biosynthetic pathway is highly conserved between herbaceous and woody plants, key poplar synthesis genes such as KS1 and KS2 show vascular tissue-specific expression. Centered on the GID1-DELLA signaling pathway, GA modulates downstream genes via ubiquitination and interacts synergistically or antagonistically with hormones like IAA, ABA, and JA to regulate poplar growth and stress responses. Under abiotic stress, poplars downregulate GA levels and accumulate DELLA proteins to enhance resistance. During biotic stress, GA integrates with miRNAs and transcription factors, maintaining growth-defense balance through the DELLA-MYC2 module. Addressing current gaps in holistic GA regulatory network studies and weak understanding of biotic stress mechanisms, this review summarizes poplar GA synthesis, metabolism, and signaling pathways, elucidating their roles in woody-specific traits and stress responses. We aim to provide a theoretical support for GA molecular mechanism research in woody plants and forest tree breeding.