Medicinal Plant Research 2025, Vol.15, No.4, 151-160 http://hortherbpublisher.com/index.php/mpr 152 osmotic regulatory substances, and the changes in gene expression, that promote root adaptation and recovery. By integrating the research results on substrate optimization, light regulation and the interaction of beneficial microorganisms, this study hopes to propose practical strategies to enhance the survival rate of transplanting, and promote the vigorous growth of plants, thereby supporting the sustainable cultivation and industrial application of A. roxburghii. 2 Root Characteristics and Transplantation Effects 2.1 Structural and functional traits of tissue-cultured roots The root systems of A. roxburghii cultured in tissue culture, exhibit distinct morphological characteristics. Compared with wild or conventionally propagated plants, their root volume, length and quantity have all increased. Especially the tetraploid variant, has a thicker root system and larger stomata, which may enhance its water absorption and nutrient absorption capacity (Huang et al., 2022; Zhang et al., 2025b). Under optimized in vitro culture conditions, like the combination of specific plant growth regulators and phoqualities, the vigorous development of root systems can be further promoted. Under the ideal protocol, the rooting rate can exceed 90% (Wang et al., 2022; Zhang et al., 2025b). The root system of A. roxburghii in tissue culture, also had high metabolic activity, manifested as increased contents of amino acids, minerals and various bioactive components (e.g., A. roxburghii glycosides, flavonoids) (Ye et al., 2020; Huang et al., 2022; Wang et al., 2022). These root systems are sensitive to environmental signals, and can support acclimation and growth through metabolic regulation. The presence of beneficial endophytic fungi can further promote root metabolism, and the accumulation of secondary metabolites (Ye et al., 2020). 2.2 Physiological effects of transplantation Transplanting can expose tissue culture seedlings to sudden changes in substrate, humidity and microbial environment, often resulting in decreased water and nutrient absorption capacity (Wang et al., 2022; Zhang et al., 2025b). This is because its root system has not fully developed, or has been damaged during the transplanting process, making it difficult to adapt to non-sterile environments, causing transplanting shock and reducing the survival rate. Transplanting stress can damage the integrity of root cell membranes, increase their sensitivity to oxidative damage, and weaken their physiological functions. For instance, salt and phosphate stress can lead to an increase in reactive oxygen species levels in roots, while treatments, like the application of strigolactone, can alleviate such damage and help maintain the stability of cell membranes (Zhang et al., 2025a; Zhong et al., 2025). 2.3 Necessity of root recovery The powerful root regeneration ability, is an important feature for A. roxburghii, to overcome transplanting shock. Efficient root regeneration, can restore the functions of water and nutrient absorption, maintain metabolic activity, and promote the accumulation of medicinal components (Ye et al., 2020; Wang et al., 2022). So, optimizing the relevant schemes of rooting medium and environmental conditions, is very important for achieving maximum root regeneration (Wang et al., 2022). The successful recovery of root system function, is closely related to the overall growth and survival of the plant. The enhancement of root vitality, can promote biomass accumulation, increase the content of secondary metabolites, and improve the survival rate after transplantation (Huang et al., 2022; Zhang et al., 2025b). At the same time, the utilization of beneficial microorganisms and customized light conditions, also can further promote root recovery and plant development (Wang et al., 2018; Ye et al., 2020). 3 Physiological Mechanisms of Root Adaptation and Recovery 3.1 Role of hormones in root recovery Auxin, especially indole-3-acetic acid (IAA) and its analogues, such as indole-3-butyric acid (IBA) and naphthalene-acetic acid (NAA), are key hormones for the differentiation of roots and the formation of adventative roots in the tissue culture of A. roxburghii. Optimizing auxin concentration in rooting medium, can increase root
RkJQdWJsaXNoZXIy MjQ4ODYzNA==