Involved in the synthesis of alkyl hydroxycinnamates in root waxes. Functions as a fatty alcohol:hydroxy cinnamoyl-CoA acyltransferase with apparent preference for caffeoyl-CoA. Expressed in the outermost circumference of mature roots, the endodermis of young roots and in the seed coat of developing seeds. Expressed in outer integument layer 1 of the seed coat. Belongs to the plant acyltransferase family.