Exploring two bioreactor systems for micropropagation of Vaccinium membranaceum and the antioxidant enzyme profiling in tissue culture-raised plants

Abstract Vaccinium membranaceum (black huckleberry) is known for its high content of bioactive compounds. This study introduces a novel approach for bioreactor micropropagation using stationary (Growtek) and temporary immersion (RITA) bioreactor systems using a liquid nutrient medium to enhance the in vitro propagation of black huckleberry. Adventitious shoot regeneration from leaf explants reached 80% efficiency in a semi-solid nutrient medium with 10 μM thidiazuron. Shoot proliferation was optimized in liquid culture, where the Growtek system yielded the most robust shoot regeneration at 76% and second highest was observed on RITA at 40.33%. Morphological and histological analyses of different cultured explants revealed various stomatal density, trichome formation and mesophyll tissue organization. Biochemical profiling of antioxidant enzymes showed that greenhouse grown leaves had higher levels of bioactive compounds, such as flavonoids, proanthocyanins, and antioxidant activity. However, Growtek-cultured leaves exhibited elevated phenolic content and catalase activity. Additionally, antioxidant enzymes, including catalase (2.8 U g −1 min −1 flw) and superoxide dismutase (0.80 U g −1 min −1 flw), were higher in Growtek and leaf-cultured shoots, respectively. The greenhouse grown plants demonstrated the highest overall phytochemical activity, with the most abundant proanthocyanins (8.3 mg g −1 flw) and anthocyanins (26 mg g −1 flw). This work presents a highly efficient liquid micropropagation protocol for black huckleberry with insights into its bioactive compounds and antioxidant enzyme profiles, highlighting its potential in commercial production and medicinal applications.