AcePosF21 interacts with AceMYB102 to alleviate ROS damage from cold stress. A) The variation of fluorescence intensity showed the difference in ROS content among transient expression in kiwifruit calli after 25 °C (control) or 4 °C (cold stress) for 6 h. EV: empty vector; OX: transient overexpression; OX + OX: transient co-overexpression. B–F) The content of O₂^.−B), H₂O₂C), electrolyte leakage D), MDA E) and proline F) of the calli in A). Error bars indicate ± SD in the above experiments, n = 3 to 4. Significant differences were detected by t-test (*P < 0.05; **P < 0.01).