Medicinal Plant Research 2025, Vol.15, No.3, 119-128 http://hortherbpublisher.com/index.php/mpr 126 This combined effect mainly stems from the complementary roles of different hormones in cell division, elongation and differentiation. Auxin (like IBA and NAA) mainly stimulate root induction, while cytokinins, such as 6-BA, promote cell division and bud cluster formation. Strigolactone and other novel regulators may further optimize root structure, and reduce oxidative stress by regulating hormone signaling and stress response (Zhang et al., 2025a; Zhong et al., 2025). 7.2 Relationship between root development and antioxidant capacity Existing studies have shown that, robust root development is positively correlated with the increase of antioxidant enzyme activities (SOD, CAT, POD) and the accumulation of secondary metabolites (flavonoids, polysaccharides, etc.) (Ye et al., 2017; Wang et al., 2018). Treatments that can enhance root vitality, such as optimizing light quality or a reasonable combination of hormones, usually can also improve antioxidant capacity, indicating that there is a coordinated mechanism between root development and antioxidant response, jointly promoting plant growth and stress resistance (Ye et al., 2017; Wang et al., 2018; Sun et al., 2023). High-level antioxidant capacity, can help reduce oxidative stress in the transplanting process of A. roxburghii seedlings, thereby increasing the survival rate. The application of exogenous antioxidants or growth regulators has been proven to enhance the stress tolerance of plants, and increase the survival rate after transplantation (Zeng et al., 2016; Sun et al., 2023). 7.3 Implications for A. roxburghii tissue culture production Optimizing the types and concentrations of growth regulators, combined with environmental factors, like light quality, is the key to cultivating high-quality and healthy seedlings. Studies have found that the combined use of auxin and cytokinin, as well as the supplementation of blue or red light treatment, can maximize the promotion of root development and the accumulation of antioxidant substances (Wang et al., 2018; Zhang et al., 2025a). The adoption of environmentally friendly regulators, such as strigolactone and natural polyamines, offers new prospects for the sustainable and large-scale production of A. roxburghii. These methods can enhance the growth and stress resistance of plants, but also comply with environmental protection and health safety standards, which is conducive to the resource protection and industrial utilization of this precious medicinal plant (Sun et al., 2023; Zhong et al., 2025). 8 Concluding Remarks Growth regulators play a unique role in the root development of A. roxburghii and sometimes produce a synergistic effect. Common auxin (like IBA, NAA), cytokinins (6-BA), and novel hormones (strigolactone) perform outstandingly in promoting the number, length and rooting rate of root systems. Combined treatment (1.0 mg/L IBA + 1.0 mg/L NAA), is often more effective than a single hormone, with a rooting rate of up to 92% and vigorous growth of stems and leaves. Strigolactone can also alleviate the inhibition of stress on root growth and promote root elongation in a phosphorus-deficient environment. The effect is more obvious when hormone treatment is combined with environmental factors (light quality). Blue light and red light can not only improve the overall growth of plants, but also enhance the activity of antioxidant enzymes (SOD, CAT, POD), and promote the accumulation of secondary metabolites, like flavonoids and polysaccharides, thereby enhancing stress resistance and medicinal value. But, it should be noted that most studies are still confined to in vitro or greenhouse conditions and may not fully reflect the actual situation in the complex field environment. Under natural conditions, root development and antioxidant responses may yield different results, thereby affecting the universality of research conclusions. Although there have been many achievements at the physiological and biochemical levels, there is still a lack of research at the molecular level that, links hormone treatment with gene expression and metabolic pathways. The latest advancements in transcriptomics suggest that, further exploration of its underlying mechanisms is needed. Future research should integrate genomics, transcriptomics and metabolomics, to reveal the molecular networks induced by regulators, so as to precisely regulate plant growth and stress response. The optimized application of
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