Metabolic characteristics of the annual ephemeral plant Tetracme quadricornis in heterogeneous habitats

Background and Aims The complex metabolic regulation mechanisms of plants enable them to maintain an orderly metabolic process despite varying external conditions, thereby supporting normal growth and development. Yet, the response of metabolites in annual ephemeral plants to changing desert environments is still poorly understood. Methods We utilized plant metabolomics in tandem with multivariate statistical analysis to delve into the metabolic adaptation strategies exhibited by Tetracme quadricornis, a quintessential annual ephemeral plant, within three distinct desert habitats: sandy desert, gravel desert, and saline-alkali desert. Results Analysis of metabolic profiles revealed distinct habitat-specific patterns in Tetracme quadricornis, with terpenoids demonstrating the highest relative abundance in sandy desert habitats, while fatty acids predominated in both gravel desert and saline-alkali desert environments. The diversity of metabolites in both roots and flowers varied significantly across different habitats. Moreover, even within the same habitat, metabolite profiles exhibited notable organ-specific variability. The highest metabolite diversity was observed in stems in sandy desert habitats, roots in gravel desert, and flowers in saline-alkali desert. Metabolite diversity in Tetracme quadricornis was significantly positively correlated with several key ecological factors, including soil electrical conductivity, altitude, and longitude. Conclusions The annual ephemeral plant Tetracme quadricornis employs organ-specific metabolic plasticity to adapt to heterogeneous desert environments. This adaptive strategy is driven by environmental factors and manifested through dynamic nutrient reallocation and a growth–defense trade-off, ultimately enhancing its ecological fitness in arid ecosystems.