Fig. 1 Phylogenetic tree of F-box proteins in pepper，tomato and rice

Fig. 2 Phylogenetic tree of pepper F-box gene family

Fig. 3 Conserved motifs and gene structure of pepper F-box proteins Ⅰ-Ⅶ represent the number and characteristic analysis of family members of pepper F-box based on phylogenetic relationships

Fig. 4 Predicted types and distribution of cis-acting elements in the promoter regions of pepper F-box genes

Fig. 5 Intraspecies collinearity analysis of pepper F-box genes

Fig. 6 Collinearity analysis of F-box genes between pepper and four reference species

Fig. 7 Expression heatmap of pepper F-box genes in different tissues L：Leaves；AL：Adult leaves；AS：Adult stem；AR：Adult root；F：Flowers；P10：Petals；O10：Ovary；STA10：Stamen；FST：Whole fruit；ST：Seed and placenta；G：Peel；S：Seeds；T：Placenta. L1-L9 and F1-F9 correspond to sampling periods ranging from 2 to 50 d after the emergence of new leaves and flower buds，respectively. Sampling was conducted every 3 d for L1-L2 and F1-F2；every 5 d for L3-L7 and F3-F7；every 10 d for L8-L9 and F8-F9. FST0 and FST1 correspond to whole fruits sampled 3 and 7 d after pollination，respectively. G1-G11 correspond to fruit pulp samples collected 10-60 d after pollination，with sampling every 5 d. ST1 and ST2 correspond to seeds and placentas collected 10 and 15 d after pollination. S3-S11 and T3-T11 correspond to seed and placenta sampling periods 20-60 d after pollination，with sampling every 5 d.

Fig. 8 Relative expression of CaSLY1 in different pepper tissues ** P < 0.01

Fig. 9 Subcellular localization of pepper CaSLY1 protein in Nicotiana benthamiana epidermal cells

Fig. 10 Effect of CaSLY1 gene silencing on plant phenotype in pepper A：Comparison of plant phenotypes between TRV2（control）and TRV2::CaSLY1（silenced）plants；B：Relative expression levels of the CaSLY1 gene in the two groups of plants；C：Phenotypic comparison. ** and *** Indicating significant differences between different experimental groups at 0.01 and 0.001 level