Global Landscape of Alternative Splicing in Tree Peony Floral Organs and the Mechanism Underlying PsuSEP3L‐ and PsuSEP3S‐Mediated Flower Type Diversification

Summary Statement We systematically characterized alternative splicing (AS) events in the tree peony cultivar ‘Zhao Fen’, with a focus on the types, distribution, number, and domains of AS across various floral organs. The AS of MADS‐box genes plays a crucial role in the formation of distinct floral organs in tree peony with different flower types. We further cloned the two AS variants of PsuSEP3 , namely PsuSEP3L and PsuSEP3S , and elucidated that PsuSEP3L and PsuSEP3S have distinct functions and differentially affect the formation of floral organs in the tree peony cultivar ‘Zhao Fen’ through interacting with PsuAP1 and PsuAG .