A WUSCHEL-related homeobox 3B gene, depilous (dep), confers glabrousness of rice leaves and glumes
1 Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
2 Honda Research Institute Japan, Kazusa-Kamatari, Kisarazu-shi, Chiba 292-0818, Japan
3 Present address: Plant Breeding, Genetics and Biotechnology Division, International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
4 Present address: Upland Farming Research Division, NARO Hokkaido Agricultural Research Center, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan
Rice 2012, 5:28 doi:10.1186/1939-8433-5-28Published: 2 October 2012
Glabrousness is an important agricultural trait for the practical breeding of rice. In this study, depilous (dep), the gene responsible for glabrous leaves and glumes of rice was identified by map-based cloning.
The dep gene encodes a WUSCHEL-related homeobox 3B that was fine-mapped to a 22-kb region on the short arm of chromosome 5 using progenies derived from crosses between Koshihikari (pubescent) and GLSL15, an Oryza glaberrima chromosome segment substitution line (glabrous). Complementation tests confirmed the conditioning of the glabrous phenotype by the dep gene. Phylogenetic analysis showed that dep groups with the WOX3 family of plant-specific homeobox transcription factors that are involved in regulating lateral organ development. Localization of dep in the nucleus indicates the function of the gene as a transcription factor. Spatial expression of the gene was observed in the base of young shoots, the leaf sheath, midrib, young roots and nodal structures.
The identification and cloning of dep will not only provide basis for future research on the elucidation of the molecular mechanisms underlying trichome formation in rice but will also aid in breeding programs for the development of glabrous varieties.