Project description:Genome and methylome variation in populations of Plantago lanceolata (narrow-leaved plantain) in an experiment investigating plant response to elevated [CO2]
Project description:Background: The unique vertical climate of Yunnan Province provides diverse resources for livestock development; however, frequent seasonal droughts during winter and spring result in a severe imbalance between forage supply and demand, constituting a major bottleneck for sustainable pastoral agriculture. Plantago lanceolata, a high-quality forage species characterized by exceptional drought and poverty tolerance, offers significant agronomic advantages, including early spring regrowth and suitability for over-sowing in perennial pastures. These traits make it vital for mitigating forage shortages and ensuring a stable supply in Yunnan. Although commercially cultivated in New Zealand and Australia, its adaptability evaluation and the molecular mechanisms underlying its drought resistance in China remain largely unexplored. Results: In this study, pot-based water-restricted experiments were conducted to simulate field drought conditions (Ψs ≈ -0.94 MPa). Systemic physiological and molecular responses were analyzed using biochemical assays, transcriptomics (Illumina NovaSeq 6000), and non-targeted metabolomics (LC-MS). Drought stress reduced the net photosynthetic rate by 93.2% while increasing peroxidase activity by 495.7%. Transcriptomic profiling identified 12,572 DEGs, which were significantly enriched in pathways related to photosynthesis, ROS scavenging, flavonoid biosynthesis, and phytohormone signal transduction. Metabolomic analysis detected 372 DEMs, with flavonoids (flavones and flavonols) and soluble sugars identified as the primary responsive metabolites. Integrated multi-omics analysis further screened key genes involved in drought tolerance regulation, including FNS II, F3H, and LOX. Conclusion: This study elucidates a multi-layered drought resistance mechanism in Plantago lanceolata, characterized by the synergistic coordination of ABA-JA hormonal crosstalk, photosystem remodeling, low-energy carbohydrate-mediated osmotic adjustment, and compartmentalized antioxidant defense, with flavonoid biosynthesis acting as a terminal chemical barrier. Key candidate genes and metabolites associated with these responses were identified. These findings provide multi-omic evidence for elucidating the environmental adaptation mechanisms of Plantago lanceolata and offer valuable candidate gene targets for the molecular breeding of stress-resistant forage crops.