Glandular trichomes of tobacco (Nicotiana tabacum) produce blends of acylsucroses that contribute to defence against pathogens and herbivorous insects, but the mechanism of assembly of these acylsugars has not yet been determined. In this study, we isolated and characterized two trichome-specific acylsugar acyltransferases that are localized in the endoplasmic reticulum, NtASAT1 and NtASAT2. They sequentially catalyse two additive steps of acyl donors to sucrose to produce di-acylsucrose. Knocking out of NtASAT1 or NtASAT2 resulted in deficiency of acylsucrose; however, there was no effect on acylsugar accumulation in plants overexpressing NtASAT1 or NtASAT2. Genomic analysis and profiling revealed that NtASATs originated from the T subgenome, which is derived from the acylsugar-producing diploid ancestor N. tomentosiformis. Our identification of NtASAT1 and NtASAT2 as enzymes involved in acylsugar assembly in tobacco potentially provides a new approach and target genes for improving crop resistance against pathogens and insects.

Trichomes are specialized structures derived from epidermal cell differentiation that are are widely distributed in angiosperms, gymnosperms, and bryophytes and exhibit remarkable morphological diversity. Based on structural characteristics, trichomes are classified into secretory (glandular trichomes) and non-secretory (non-glandular trichomes) types, both of which play pivotal roles in adaptation to the environment. The model plant Arabidopsis, with its unicellular non-glandular trichomes, has become a classic system for studying plant cell differentiation and morphogenesis. This review systematically synthesizes advances in Arabidopsis trichome research, delineates conserved and species-specific regulatory mechanisms of trichome development across diverse taxa, and dissects the genetic regulatory networks governing trichome initiation, endoreduplication (nuclear DNA replication), cell division, and branching morphogenesis. These networks precisely coordinate plant morphogenesis, stress resilience, metabolic regulation, and environmental adaptability through hormonal signaling and epigenetic modifications, thereby establishing a theoretical framework for plant developmental biology and molecular breeding.