PoSERK-PoLEC1-PoABI3 interaction modulates BR/IAA/ABA homeostasis to drive somatic embryogenesis in tree peony: Novel insights into a regulatory network enhancing propagation in multipurpose crops

Tree peony ( Paeonia suffruticosa Andr.) is a multifunctional industrial crop highly valued for its seed oil enriched with α-linolenic acid, bioactive medicinal components, and ornamental floriculture applications, serving as a critical resource in global agricultural and pharmaceutical supply chains. However, its industrial development faces significant bottlenecks, including the lack of dedicated cultivars optimized for industrial-scale production and lengthy breeding cycles that hinder rapid commercialization. Somatic embryogenesis (SE) offers a solution for rapid clonal propagation of elite germplasm, but the low efficiency of tree peony regeneration systems severely restricts commercial applications. In this study, we identified PoSERK as a key regulator of SE. Overexpression of PoSERK increased embryogenic callus formation and activated BR/IAA-ABA crosstalk. Critically, we report the first plant-specific interaction between PoSERK and PoABI3 , and have preliminarily elucidated that PoSERK may drive hormone-mediated embryogenesis by binding to the promoters of PoLEC1 and PoABI3 . This regulatory module supports dynamic hormone balancing during SE, providing a potential research direction and novel strategy for enhancing the propagation of elite tree peony germplasm through biotechnological approaches. • Elucidating PoSERK 's role during tree peony embryogenesis. • First identified PoSERK-PoABI3 as embryogenesis regulator. • Highlighted PoSERK 's hub function in LAFL transcriptional network. • Provided novel biotechnological strategies for elite tree peony cultivar breeding.