Bioscience Evidence 2025, Vol.15, No.6, 280-290 http://bioscipublisher.com/index.php/be 283 3 The Physiological Regulatory Mechanism of Active Ingredient Accumulation in Leonurus japonicus 3.1 Photosynthesis, carbon and nitrogen allocation and precursor supply The synthesis and accumulation of the active components of motherwort cannot do without the substances and energy provided by photosynthesis, nor can it do without the balance of carbon and nitrogen metabolism. Photosynthesis provides a carbon framework and energy for secondary metabolites such as alkaloids and diterpenoids, and nitrogen is an important source of nitrogen-containing components like alkaloids. Studies have found that under different pH conditions, if the contents of photosynthetic pigments and soluble proteins in leaves increase, the growth and yield of plants will improve, and there will also be more "raw materials" for the synthesis of active components. Especially the synthesis of alkaloids, such as tribulus terrestris, which is closely related to the assimilation and transport of nitrogen. Under high pH conditions, the substrates and products related to the nitrogen addition reaction increase, thereby promoting the formation of alkaloids. 3.2 Hormone regulation Plant hormones have a significant impact on the accumulation of active ingredients in motherwort. Guo et al. (2025) discovered in transcriptome research that under drought conditions, the expression of genes related to hormone signals undergoes significant changes, especially the ABA (abscisic acid) pathway is significantly activated. Among them, ABA can affect the WRKY transcription factor and MAPK signaling pathway, indirectly regulating the synthesis and accumulation of active components in Leonurus japonicus. During this period, hormone signals will also interact with environmental stress to increase the activity of the biosynthetic pathway of active ingredients and help plants cope with adverse conditions more smoothly. 3.3 Enzyme activity and rate-limiting steps In the process of synthesizing active ingredients fromLeonurus japonicus, various enzymes are required, some of which are rate-limiting steps and have a significant impact on the accumulation of components in Leonurus japonicus. Li et al. (2023) conducted a series of studies taking leonurine as the research object. They found that the synthesis process of leonurine mainly requires several enzymes, namely ADC, UGT and SCPL. Through genomic and multi-omics studies, they also found that the massive accumulation of leonurine was mainly attributed to the amplification of the UGT-SCPL gene cluster and the emergence of new functions. 3.4 Stress physiology and induction Environmental changes often cause motherwort to produce more active ingredients. In a dry environment, the contents of malondialdehyde, proline and hydrogen peroxide in Leonurus japonicus plants will all increase. The expression levels of transcription factors such as WRKY will also increase. These changes will enhance the antioxidant response of plants and increase the synthesis of some secondary metabolites. Guo et al. (2025) KEGG analysis also indicated that under drought conditions, the MAPK signaling pathway, hormone signaling pathways, and some genes related to secondary metabolism would significantly increase, thereby promoting the generation of diterpenoids and other components. Zhang et al. (2022) pointed out that changes in pH can affect nitrogen metabolism and the levels of some substrates, and also increase alkaloids such as tribulus terrestris. These physiological responses together enhance the stress tolerance of Leonurus japonicus and also increase the content of its medicinal components. 4 Ecological and Environmental Driving Factors of the Metabolic Profile of Active Ingredients inLeonurus japonicus 4.1 Soil characteristics The texture of the soil, the content of organic matter, water retention capacity and other multiple factors jointly affect the growth of motherwort and the accumulation of nutrients. Chen et al. (2024) concluded that the Available Water Capacity (AWC) of the soil, the portion of water that plants can actually utilize in the soil, is a key factor influencing the distribution and adaptability of motherwort. The efficiency of plants in absorbing water and nutrients varies with AWC, and the synthesis of its active components also changes accordingly. Other properties of the soil, such as pH value, fertility level, and the structure of microbial communities, can also indirectly change the types and contents of secondary metabolites by influencing root metabolism and signal regulation.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==