The study functionally characterizes three tomato CNR/FWL proteins (SlFWL2, SlFWL4, SlFWL5) and demonstrates that SlFWL5 localizes to plasmodesmata, where it regulates leaf size and morphology by promoting cell expansion likely through cell‑to‑cell communication. Gain‑ and loss‑of‑function transgenic tomato lines reveal that SlFWL5 is a key regulator of organ growth via modulation of plasmodesmatal signaling.

The study constructs a ~1‑million‑cell single‑nuclei transcriptome atlas of Arabidopsis leaves to reveal that drought stress accelerates transcriptional programs associated with maturation and aging, thereby limiting leaf growth in proportion to stress intensity. Targeted upregulation of FERRIC REDUCTION OXIDASE 6 in mesophyll cells partially rescues leaf growth under drought, demonstrating the functional relevance of these transcriptional changes.

The study develops an updated genome-scale metabolic model of tomato leaf (CBZ_iSL3433) incorporating carbamazepine (CBZ) transformation reactions to simulate the pollutant's stress impact under phototrophic conditions. Constraint-based analysis predicts significant reductions in biomass and altered fluxes in nutrient assimilation and secondary metabolism, which are largely ameliorated by biostimulants such as proline, spermine, glycerol, and ethanol. This framework demonstrates a systems-level approach for screening strategies to mitigate pharmaceutical pollutant stress in crops.