Plantagos are important economical and medicinal plants that possess several bioactive secondary metabolites, such as phenolics, iridoids, triterpenes, and alkaloids. Triterpenoids are the ubiquitous and dynamic secondary metabolites that are deployed by plants for chemical interactions and protection under biotic/abiotic stress. Plantago ovata, a cultivated species, is the source of psyllium, while Plantago major, a wild species, has significant therapeutic potential. Wild species are considered more tolerant to stressful conditions in comparison to their cultivated allies. In view of this, the present study aimed to decipher the terpenoid biosynthetic pathway operative in P. ovata and P. major using a comparative transcriptomics approach. Majority of terpenoid biosynthetic genes were observed as upregulated in P. major including rate limiting genes of MVA (HMGR) and MEP (DXR) pathways and genes (α-AS, BAS, SM, and CYP716) involved in ursolic acid biosynthesis, an important triterpenoid prevalent in Plantago species. The HPLC output further confirmed the higher concentration of ursolic acid in P. major as compared to P. ovata leaf samples, respectively. In addition to terpenoid biosynthesis, KEGG annotation revealed the involvement of differentially expressed unigenes in several metabolic pathways, aminoacyl-tRNA biosynthesis, biosynthesis of antibiotics, and biosynthesis of secondary metabolites. MYB was found as the most abundant transcription factor family in Plantago transcriptome. We have been able to generate valuable information which can help in improving terpenoid production in Plantago. Additionally, the present study has laid a strong foundation for deciphering other important metabolic pathways in Plantago.

车前草是重要的经济和药用植物，具有多种生物活性次生代谢产物，如酚类、环烯醚萜类、三萜类和生物碱类。三萜类化合物是植物在生物/非生物胁迫下用于化学相互作用和保护的普遍存在和动态的次生代谢物。栽培种车前草是洋车前子的来源，而野生种车前草则具有显着的治疗潜力。与其栽培的盟友相比，野生物种被认为更能耐受压力条件。有鉴于此，本研究旨在破译在P. ovata和P. major中起作用的萜类生物合成途径。使用比较转录组学方法。观察到大多数萜类生物合成基因在P. major中上调，包括 MVA ( HMGR ) 和 MEP ( DXR ) 途径的限速基因和参与熊果酸生物合成的基因（ α-AS、BAS、SM和CYP716 ），这是一种重要的生物合成途径。车前属植物中普遍存在的三萜类化合物。HPLC 输出进一步证实了与P. ovata相比， P . major中熊果酸的浓度更高叶样本，分别。除了萜类生物合成外，KEGG 注释还揭示了差异表达的 unigenes 参与了几种代谢途径、氨酰-tRNA 生物合成、抗生素生物合成和次生代谢物的生物合成。发现 MYB 是车前子转录组中最丰富的转录因子家族。我们已经能够生成有价值的信息，这些信息有助于提高车前草的萜类化合物产量。此外，本研究为破译车前其他重要代谢途径奠定了坚实的基础。