Fig. 2: ABA induces the expression of FvALKBH10B through FvABF3 in strawberry.

a The changes in gene expression of FvALKBH10B in response to ABA (50 μM) in strawberry fruits at large green stage as determined by RT-qPCR. ACTIN was used as an internal control. b LC-MS/MS assay revealing the decrease in total m⁶A levels after exogenous application of ABA in strawberry fruits at large green stage. c Expression pattern of FvABF3 in response to ABA in strawberry fruits at large green stage. In a–c, fruit samples were treated with ABA for indicated times before sampling. d Y1H assay showing the binding of FvABF3 to the promoter fragment of FvALKBH10B. The empty pGADT7 was used as the negative control. AbA Aureobasidin. e EMSA reveals that FvABF3 directly binds to the ABRE cis-acing elements in the FvALKBH10B promoter. The probe sequences are shown, with red letters representing the intact or mutated ABRE elements. For d, e, the experiment was repeated independently three times with similar results. f ChIP-qPCR assay shows the direct binding of FvABF3 to the promoter of FvALKBH10B. Pink boxes, ABRE elements; blue lines, regions used for ChIP-qPCR. Negative controls (ACTIN and TUBULIN) are included. g Transcriptional activity assay of FvABF3. The reporter plasmid contains the FvALKBH10B promoter fused with firefly luciferase (LUC), with renilla luciferase (REN) as an internal control. A representative image is shown. h, i Representative images of strawberry fruits silencing (h) or overexpressing (i) FvABF3. Fruits at large green stage were used for agroinfiltration and considered as days 0. EV, empty vector. Scale bar, 0.5 cm. j, k Anthocyanin contents in fruits shown in h (j) and i (k). l, m The mRNA levels of FvABF3 and FvALKBH10B in fruits at days 2 shown in h (l) and i (m), as determined by RT-qPCR. For a–c, f, and j–m, values are means ± SEM (n = 3 biological replicates). For g, values are means ± SEM (n = 5 biological replicates). Asterisks indicate significant differences (unpaired two-sided t-test; **P < 0.01, ***P < 0.001). NS no significant. Source data are provided as a Source Data file.