Novel epidermal–cortical pattern and root apical silencing of VcCPC promoter activity in Arabidopsis might suggest a joint contribution to hairless roots in blueberry

Blueberry roots exhibit a distinctive type IV epidermal cell patterning, which differs from previously identified epidermis-cortex cell patterns. Although VcCPC maintains its conserved role in promoting root hair differentiation in Arabidopsis, root apical silencing of VcCPC, in conjunction with the novel epidermal-cortical pattern, may contribute to the root hair-deficient phenotype in blueberry. Substituting the native VcCPC promoter with the AtCPC promoter restored root hair development in the Arabidopsis cpc mutant, indicating that regulatory elements present in the AtCPC promoter, but absent in the VcCPC promoter, might mediate the root phenotypic divergence.