Cuticular waxes in alpine grassland plants: Chemical diversity, biosynthesis, and ecological adaptation with biotechnological insights

Cuticular waxes, complex hydrophobic layers coating alpine grassland plants, are critical for survival in extreme environments characterized by freezing temperatures, intense UV-B radiation, and physiological drought. This review synthesizes advances in understanding the chemical diversity, biosynthesis, and ecological roles of these waxes, emphasizing their adaptive significance. This review reveals that alpine species exhibit remarkable plasticity in wax composition, with alkanes, alcohols, and specialized metabolites (β-diketones, alkylresorcinols) dynamically regulated by altitude-driven stressors. Phylogenetic analyses highlight weak taxonomic signals in wax profiles. This suggests that convergent evolution, rather than shared ancestry, is a dominant driver of chemical traits shaped by similar environmental pressures. Notably, alpine plants like Polygonum viviparum L. and Koeleria cristata Pers. employ lineage-specific strategies—such as polyketide synthase-mediated β-diketone synthesis—to balance stress resilience and ecological function. The challenges in resolving the genetic and environmental influences on wax traits are discussed, along with calls for integrated multiomics approaches to decode the molecular mechanisms underlying adaptation. Beyond ecology, we explore the ethnobotanical relevance of wax-rich species in traditional grazing systems and their potential in biotechnological applications, such as UV-protective cosmetics. By bridging fundamental research with agricultural innovation, this study positions alpine cuticular wax studies as an opportunity for addressing climate resilience and biodiversity conservation.