Work

Ascorbate peroxidase gene family regulates seed germination by modulating ascorbic acid and H2O2 metabolism in kiwifruit (Actinidia chinensis)

Year: 2026

Type: article

Abstract: Kiwifruit ( Actinidia chinensis ) exhibits extremely low seed germination efficiency. This issue severely limits cross-breeding and germplasm innovation of kiwifruit, acting as a major bottleneck. Core regulatory genes governing seed dormancy and germination have been well-studied in model plant species. However, the function of the APX -dependent redox pathway during kiwifruit seed germination is still poorly understood. Here, we identified and characterized the APX gene family ( AchAPX1 - AchAPX7 ) in the A. chinensis genome. Through an integrated approach combining bioinformatics analysis, heterologous overexpression in Arabidopsis thaliana , and transient transformation of A. chinensis seeds via Agrobacterium-mediated infection, we systematically characterized the temporal expression patterns, conserved structural features and functional differentiation of AchAPX genes during seed germination. Under salt stress, overexpression of AchAPX1 and AchAPX4 in A. thaliana significantly enhanced seed germination rate and cotyledon greening rate, increased APX enzymatic activity by approximately 2-fold compared with the wild type, accelerated ascorbic acid (AsA) oxidative catabolism, and efficiently scavenged excess intracellular H₂O₂. Transient overexpression of AchAPX1 and AchAPX4 in A. chinensis seeds further confirmed their germination-promoting function in the native genetic background under normal conditions. Collectively, we provide promising candidate genes for molecular breeding of rapid-germinating kiwifruit varieties.

Source: Scientia Horticulturae

DOI: 10.1016/j.scienta.2026.115109