Evolutionary diversity of cell-type-specific expression and stress response in Brassicaceae roots

To explore these stress adaptations at the cellular level, we built root single-cell transcriptome atlases for five biodiverse Brassicaceae species, including two stress-sensitive models (Arabidopsis thaliana and Sisymbrium irio), two extremophytes (Eutrema salsugineum and Schrenkiella parvula), and a polyploid oil crop (Camelina sativa), under control, salt, and ABA treatments.

Although these species share similar root anatomy, most Arabidopsis cell type markers were not conserved across species. Cortex cell populations with distinct transcriptomes were spatially segregated among species. Lineage-specific gains in stress responses were more common than losses among cell-type responses across species.