The function of PmAP2L-D in regulating stamens into petals. (a) Subcellular localization of PmAP2L-S/D in tobacco leaves. (b) Phenotypic observation of 35S::Pmu-pre-172a, 35S::PmAP2L-S, and 35S::PmAP2L-D transgenic tobacco plants. Scale bar = 1 cm. (c)35S::PmAP2L-D tobacco (type I) show the formation of two rounds of floral structures within the sepals, forming another corolla within the corolla. Scale bar = 1 cm. (d) Amplification of the type I phenotype. Scale bar = 1 cm. (e)35S::PmAP2L-D tobacco (type II) show the transformation of stamens to petals. Scale bar = 1 cm. (f) The number of stamens in transgenic tobacco with miR172a, PmAP2L-S, and PmAP2L-D genes. Data are represented as the mean ± SD of five biological replicates (n = 5). Different letters above the bars indicate a significant difference (P < 0.05, one-way ANOVA). (g) qRT-PCR of RC5G0530900 in TRV control and silenced plants. The mean ± SD from three biological replicates (n = 3) are shown. Asterisks indicate statistically significant differences (two-sided Student's t test; ^***P < 0.001). (h) The number of petals in TRV and TRV-RC5G0530900. The mean ± SD from 12 biological replicates (n = 12) are shown. Asterisks indicate statistically significant differences (two-sided Student's t test; ^****P < 0.0001). (i) Images of TRV and TRV- RC5G0530900 infected plants were taken 50 d after infiltration. (j) qRT-PCR of PmAP2L and floral development genes (PmAP3–1, PmAP3–2, PmAG, and PmSEP3) in flower buds after PmAP2L-D/S and PmMIR172a overexpression. EV, empty vector; OE, overexpression. The mean ± SD from three biological replicates (n = 3) are shown. Different letters above the bars indicate a significant difference (P < 0.05, one-way ANOVA). (k) qRT-PCR of PmAP2L and floral development genes (PmAP3–1, PmAP3–2, PmAG, and PmSEP3) in flower buds after VIGS treatment. The mean ± SD from three biological replicates (n = 3) are shown. Different letters above the bars indicate a significant difference (P < 0.05, one-way ANOVA).