Find in Library

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 (<i>Gossypium</i> spp.). In this study, we conduct a genome-wide survey and detected 69, 71, 124 and 131 ABCG genes within <i>G. arboretum</i>, <i>G. raimondii</i>, <i>G. hirsutum</i> and <i>G. barbadense</i>, separately. The above ABCGs could be divided into four groups (Ia, Ib, Ic, II). Some <i>ABCG</i> genes such as <i>GhABCG15</i>, whose homologous gene transports cuticular lipid in <i>Arabidopsis</i>, was preferentially expressed in the development of fiber. A weighted gene co-expression network analysis (WGCNA) demonstrated that <i>GhABCG</i> expression was significantly associated with the amount of 16-Hydroxypalmitate (a main component of cutin precursor) in cotton fibers. Further, silencing of <i>GhABCG15</i> by virus-induced gene silencing (VIGS) in cotton generated brightened and crinkled leaves as well as reduced thickness of cuticle and increased permeability. Chemical composition analysis showed the cutin content in <i>GhABCG15</i>-silenced leaves had decreased while the wax content had increased. Our results provide an insight for better understanding of the role of the <i>Gossypium</i> ABCG family and revealed the essential role of GhABCGs in cotton cutin formation.