-- module regulates GA -induced pseudo-embryo development and parthenocarpy in pear ().

Parthenocarpy can ensure fruit setting without fertilization and generate seedless fruits. has been shown to play a role in gibberellin (GA)-induced parthenocarpy in pears. However, the transcriptional response mechanism of to GA remains unclear. In this study, using a yeast one-hybrid assay combined with co-expression analysis, was initially identified as a transcription regulator of , which was further confirmed by electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter assays. The biofunction of was further verified using transient transgene tests, stable transgenic pear callus and tomato. overexpression resulted in reduced cell death and higher fluorescence intensity after fluoresce diacetate (FDA) staining, as well as delayed fruit-drop by increasing expression in unpollinated pear fruitlets and callus. In contrast, silencing caused cell death and early fruit-drop with decreased expression. Moreover, after emasculation, heterologous overexpression of induced parthenocarpy and enlarged seed size in pollinated tomato fruits. Silencing , a homolog of in tomatoes, resulted in smaller fruit and seed size, and these traits were restored by co-overexpression with . Furthermore, we investigated the protein interaction between PbMYB56 and PbDELLA, which is crucial component of the GA signaling pathway. This interaction inhibited PbMYB56-induced transcriptional activation of . Co-overexpression of and contributed to reduced seed development and loss of parthenocarpy potential in tomatoes. Collectively, our study identifies PbDELLA-PbMYB56- as a regulatory module of GA-induced pseudo-embryo and parthenocarpy development, offering insights into the mechanism underlying parthenocarpy formation in pears.