RT Journal Article SR Electronic T1 Control of Plant Trichome Development by a Cotton Fiber MYB Gene JF The Plant Cell JO Plant Cell FD American Society of Plant Biologists SP 2323 OP 2334 DO 10.1105/tpc.104.024844 VO 16 IS 9 A1 Wang, Shui A1 Wang, Jia-Wei A1 Yu, Nan A1 Li, Chun-Hong A1 Luo, Bin A1 Gou, Jin-Ying A1 Wang, Ling-Jian A1 Chen, Xiao-Ya YR 2004 UL http://www.plantcell.org/content/16/9/2323.abstract AB Cotton (Gossypium spp) plants produce seed trichomes (cotton fibers) that are an important commodity worldwide; however, genes controlling cotton fiber development have not been characterized. In Arabidopsis thaliana the MYB gene GLABRA1 (GL1) is a central regulator of trichome development. Here, we show that promoter of a cotton fiber gene, RD22-like1 (RDL1), contains a homeodomain binding L1 box and a MYB binding motif that confer trichome-specific expression in Arabidopsis. A cotton MYB protein GaMYB2/Fiber Factor 1 transactivated the RDL1 promoter both in yeast and in planta. Real-time PCR and in situ analysis showed that GaMYB2 is predominantly expressed early in developing cotton fibers. After transferring into Arabidopsis, GL1::GaMYB2 rescued trichome formation of a gl1 mutant, and interestingly, 35S::GaMYB2 induced seed-trichome production. We further demonstrate that the first intron of both GL1 and GaMYB2 plays a role in patterning trichomes: it acts as an enhancer in trichome and a repressor in nontrichome cells, generating a trichome-specific pattern of MYB gene expression. Disruption of a MYB motif conserved in intron 1 of GL1, WEREWOLF, and GaMYB2 genes affected trichome production. These results suggest that cotton and Arabidopsis use similar transcription factors for regulating trichomes and that GaMYB2 may be a key regulator of cotton fiber development.