Cell-type-specific alkaloid and terpenoid biosynthesis in glandular trichomes: single-cell and spatial transcriptomic perspectives.

Glandular trichomes serve as critical cellular factories for plant secondary metabolism, playing a central role in the biosynthesis, transport, and storage of diverse secondary metabolites. However, traditional macro-scale omics approaches often overlook the cellular heterogeneity within tissues, making it difficult to resolve the specific dynamics of different cell types in glandular trichomes. This limitation has hindered a deeper understanding of secondary metabolic pathways and their regulatory mechanisms. Recent advances in single-cell and spatial omics technologies are now helping to address this challenge. Single-cell omics enables researchers to elucidate the complex mechanisms of metabolic biosynthesis and intercellular transport at higher resolution. Meanwhile, spatial omics reveals their precise three-dimensional organization within intact glandular trichomes. By integrating these complementary approaches, researchers can identify candidate genes, spatial distribution of metabolic enzymes and transporters across distinct cell types, thereby constructing more refined and predictive metabolic network models. This review systematically summarizes the latest applications of single-cell and spatial omics technologies in research on glandular trichomes. Particularly focusing on the biosynthetic pathways of alkaloids and terpenoids in key model plants, including