ATP-binding cassette transporter G (ABCG) has been shown to be engaged in export of broad-spectrum compounds with structural differences, but little is known concerning its role in cutin formation of cotton (Gossypium spp.). In this study, we conduct a genome-wide survey and detected 69, 71, 124 and 131 ABCG genes within G. arboretum, G. raimondii, G. hirsutum and G. barbadense, separately. The above ABCGs could be divided into four groups (Ia, Ib, Ic, II). Some ABCG genes such as GhABCG15, whose homologous gene transports cuticular lipid in Arabidopsis, was preferentially expressed in the dev...