An environmentally regulated dichotomy in cell lineages of the root.

Most Arabidopsis root cell lineages exhibit a stereotyped bifid topology with an environment-responsive transcriptional state shared across multiple cell types.

• Why it matters: Understanding root cell plasticity is crucial because roots adapt their development to local environmental conditions, but the underlying molecular mechanisms remain unclear.
• What they did: Single-cell RNA sequencing and spatial transcript mapping of Arabidopsis roots revealed that most cell lineages have a bifid developmental trajectory, with one branch enriched for genes linked to environmental responses, including ABA signalling, and this state is conserved across ecotypes and persists despite developmental perturbations.
• The result: This environment-responsive transcriptional state is reduced in ABA-deficient and ABA-insensitive mutants and becomes more prevalent under water-deficit conditions, indicating it is modulated by environmental factors and adds an extra layer of root cell identity.