Functional Transcriptomic Analysis and Impact of Drought Stress on Phytochemical Content and Expression of Flavonoid-Related Genes in Artemisia ludoviciana Nutt.

Background Artemisia ludoviciana Nutt. is an aromatic perennial and medicinal herb, native to North America. The aerial parts of the plant are widely used in traditional Mexican medicine for the treatment of different diseases, including diabetes. Numerous secondary metabolites related to its medicinal properties have been identified, of which monoterpenoids, sesquiterpenes, and flavonoids are the most significant. Despite the research conducted on A. ludoviciana , there is no transcriptomic data available on the plant to support the synthesis of these compounds in the plant. Results RNA sequencing of A. ludoviciana leaves was conducted to produce 8.4 GB of the plant’s transcriptomic data. After de novo filtering and assembly of the raw data, 52,561 transcripts were generated, of which a total of 29,854 transcripts (56.79%) were annotated against public databases using Blast2GO. Further KEGG pathway analysis led to the mapping of several transcripts associated with the biosynthesis pathways of major plant secondary metabolites. The expression of key flavonoid-related genes ( CHI , F3’MO , FSI , F3’OMT ) was also evaluated in A. ludoviciana after severe water stress conditions. Drought significantly decreased the relative water content (32.78%), total chlorophyll, and carotenoids, while increasing hydrogen peroxide accumulation, showing stress in the plant. The phenol and flavonoid content of the plant also decreased under these conditions. However, the expression of all flavonoid-related genes was upregulated, suggesting an active response of the plant’s flavonoid pathway to water stress and potentially contributing to the plant’s drought tolerance. Conclusions This work provides valuable insights into the functional gene annotation, the biosynthetic pathways of secondary metabolites, and the molecular response of A. ludoviciana to drought stress. This provides the basis for further research into the molecular mechanisms behind the synthesis and accumulation of bioactive compounds in A. ludoviciana , as well as strategies to maintain or enhance the plant’s medicinal properties.