Integrated transcriptomic and metabolomic analyses uncover the key pathways of Tamarix ramosissima in adaptation to coppice dune development

Background: Tamarix ramosissima is a crucial windbreak and sand-fixing shrub species in the arid deserts of northwest China, where it helps stabilize the ecosystem by trapping dust and enriching soil nutrients. In this study, we systematically investigated the molecular mechanisms underlying T. ramosissima ’s transition through the four developmental stages (initial, growth, stable, and decline) of coppice dunes through integrated physiological, transcriptomic, and metabolomic analyses. Results: From the initial to the growth stage of coppice dunes, soil water content (SWC) gradually decreased, whereas the malondialdehyde (MDA) content in T. ramosissima increased. T. ramosissima could resist drought stress by enhancing soluble protein (SP) and proline (Pro) contents and catalase (CAT) activity. In addition, the decrease in SWC can promote the accumulation of zeatin, dihydrozeatin, and indole-3-acetate in T. ramosissima , thereby accelerating starch consumption to meet plant growth demands. Transcriptome and metabolome analyses revealed that T. ramosissima primarily coordinates gene expression and metabolite accumulation through the ABC transporters, glycerophospholipid metabolism, and glutathione metabolism pathways to adapt to coppice dune development; meanwhile, four hub genes identified by weighted gene co-expression network analysis (WGCNA) are promising candidates for improving drought tolerance in this species. Conclusion: This study reveals that T. ramosissima can adapt to coppice dune development by coordinating gene expression, metabolite accumulation, and physiological regulations. The results provide an important theoretical basis for ecological restoration in arid regions.