Editing of SlMYB60 Reveals a Role in Cuticle Formation in Tomato

RNA-seq analyses confirmed the strong downregulation of SlMYB60 in the edited lines and identified 186 differentially expressed genes (DEGs), many of which involved in cell wall or cuticle biosynthesis. Chlorophyll leaching assays indicated increased permeability in mutant lines, while electron microscopy revealed defects in epidermal cell surface structure and patterning. Notably, slmyb60 mutants exhibited thinner stomatal ledges compared to wild type, suggesting defects in stomatal architecture.

Although modulating stomatal activity remains a promising strategy to improve drought resilience in tomato, our findings reveal that SlMYB60, unlike its Arabidopsis homolog, is not confined to guard cells and plays broader roles in epidermal development, indicating divergences in the MYB60 regulatory network between Arabidopsis and tomato.