The transcription factor MhZAT10 enhances antioxidant capacity by directly activating the antioxidant genes MhMSD1, MhAPX3a and MhCAT1 in apple rootstock SH6 (Malus honanensis × M. domestica).

This article focuses on the role of the transcription factor MhZAT10 in enhancing stress tolerance in apple (Malus domestica) rootstock 'SH6' by regulating antioxidant enzyme genes. MhZAT10 directly activates the transcription of three antioxidant-related genes—MhMSD1 (Manganese Superoxide Dismutase 1), MhAPX3a (Ascorbate Peroxidase 3A), and MhCAT1 (Catalase 1)—which localize to multiple subcellular compartments and contribute to reactive oxygen species (ROS) detoxification. Overexpression of MhZAT10 in apple SH6 roots increases antioxidant enzyme activities, reduces ROS accumulation, and improves tolerance to osmotic stress, demonstrating a synergistic regulation of ROS-scavenging pathways. This study provides molecular insights into how MhZAT10-mediated transcriptional activation of multiple antioxidant enzymes supports enhanced abiotic stress tolerance in apple rootstocks.