biostudies-literatureLing LGuizhou Science and Technology DepartmentScience and Technology Program of LiupanshuScientific Research (Cultivation) Project of Liupanshui Normal University1169https://www.ebi.ac.uk/biostudies/studies/S-EPMC12467673biostudies-literatureUnknown14(9)<i>Diaporthe eres</i> is a harmful pathogen affecting Hongyang kiwifruit (<i>Actinidia chinensis</i>) after harvest, yet the antioxidant defense strategies are not well understood. This research thoroughly examines the dynamics of the antioxidant response during the infection process. Significant findings indicate an initial 3-day latent period (0-3 dpi) that allowed for pathogen establishment, followed by irreversible tissue breakdown characterized by water-soaked lesions at 4 dpi. The study identified a biphasic activation pattern of superoxide dismutase (SOD) with dual activity peaks (1 dpi and 4 dpi), orchestrated by mitochondrial hub gene <i>CEY00_Acc02790</i> that coordinates peroxidase (POD) networks, while peroxidase (POD) activity exhibited a synchronized but temporary increase, peaking at 4 dpi. Further bioinformatic analysis revealed the possible functional specialization of POD isoforms: α-helix-rich extracellular variants drove cell wall reinforcement through lignification, while random coil-dominant intracellular variants formed to mitigate cytoplasmic reactive oxygen species (ROS) damage, establishing dual physicochemical barriers. Malondialdehyde (MDA) levels rose significantly by 3 dpi, indicating permanent membrane damage. Collectively, these findings elucidate the mechanistic foundation of the <i>Actinidia</i>-<i>Diaporthe</i> pathosystem, identifying the bimodal SOD response and POD specialization as prime targets for developing resistant cultivars and precision postharvest interventions, ultimately reducing losses through biochemical interception of pathogenesis.BiologyAntioxidant Defense Strategies Against &lt;i&gt;Diaporthe eres&lt;/i&gt; Infection in Hongyang Kiwifruit.PMC1246767352020-2023-0-2-18Qi-anKeHeJiChu-ZK[2022]530LPSSY2023KJZDPY06Long XPan SLing LYang TZhang SfalseAntioxidant Defense Strategies Against &lt;i&gt;Diaporthe eres&lt;/i&gt; Infection in Hongyang Kiwifruit.<i>Diaporthe eres</i> is a harmful pathogen affecting Hongyang kiwifruit (<i>Actinidia chinensis</i>) after harvest, yet the antioxidant defense strategies are not well understood. This research thoroughly examines the dynamics of the antioxidant response during the infection process. Significant findings indicate an initial 3-day latent period (0-3 dpi) that allowed for pathogen establishment, followed by irreversible tissue breakdown characterized by water-soaked lesions at 4 dpi. The study identified a biphasic activation pattern of superoxide dismutase (SOD) with dual activity peaks (1 dpi and 4 dpi), orchestrated by mitochondrial hub gene <i>CEY00_Acc02790</i> that coordinates peroxidase (POD) networks, while peroxidase (POD) activity exhibited a synchronized but temporary increase, peaking at 4 dpi. Further bioinformatic analysis revealed the possible functional specialization of POD isoforms: α-helix-rich extracellular variants drove cell wall reinforcement through lignification, while random coil-dominant intracellular variants formed to mitigate cytoplasmic reactive oxygen species (ROS) damage, establishing dual physicochemical barriers. Malondialdehyde (MDA) levels rose significantly by 3 dpi, indicating permanent membrane damage. Collectively, these findings elucidate the mechanistic foundation of the <i>Actinidia</i>-<i>Diaporthe</i> pathosystem, identifying the bimodal SOD response and POD specialization as prime targets for developing resistant cultivars and precision postharvest interventions, ultimately reducing losses through biochemical interception of pathogenesis.2025-01-01T00:00:00Z2025 Sep2026-05-02T03:09:42.539Z2026-05-02T03:07:45.421ZS-EPMC124676734100731410.3390/biology14091169