Fig. 3: AcGATA1 promotes AcEGY3 expression and HY0809 thermotolerance.

Luciferase fluorescence (a) and LUC activities (b) in transgenic kiwifruit lines of proEGY3^HY0809 (proEGY3^HY)::LUC and proEGY3^MHZ11(proEGY3^MH)::LUC under control conditions (24 °C) or exposed to high temperature (37 °C) for 1 h. Data represent mean ± SD (n = 3 biological replicates). Different lowercase letters indicate statistical significance at p < 0.05 by one-way ANOVA with Duncan’s multiple-range test. c Diagram of proEGY3^HY and proEGY3^MH showing the natural variation (red bar) and binding sites of GATA1 (green bar) and HSFA2-2 (orange bar). d qRT-PCR analysis of GATA1 expression in HY0809 and MH-Z11 plants exposed to 40 °C for 0, 1, 3, and 8 h, respectively. e The interaction of AcGATA1 and proEGY3^HY was confirmed by dual-luciferase reporter assays in tobacco leaves and quantitative measurements of LUC/REN ratio. EV empty vector. Data represent mean ± SD (n = 3 biological replicates). Asterisks indicate significant differences by two-tailed Student’s t-test (**p < 0.01, ***p < 0.001). “ns” indicates no statistically significant difference. f EMSA of AcGATA1 binding to the GATA-Box from proEGY3^HY (HY-G-Box) but not to the mutant version (HY-G-Box-mut). “+” indicates presence; and “−“ indicates absence. Shoot phenotypes (g) and leaf survival rates (h) of HY0809 and AcGATA1-overexpression lines (OE-1, -2, and -3) after heat stress treatment (42 °C for 8 h). Data represent mean ± SD (n = 9 biological replicates). Asterisks indicate significant differences by two-tailed Student’s t-test (**p < 0.01, ***p < 0.001). i qRT-PCR analysis of AcGATA1 and AcEGY3 expression in HY0809 and AcGATA1-overexpression lines treated with 42 °C for 0 and 1 h. Data represent mean ± SD (n = 9 biological replicates). Different lowercase letters indicate statistical significance at p < 0.05 by one-way ANOVA with Duncan’s multiple-range test. Source data are provided as a Source Data file.