title: Identification and characterization of cotton genes involved in fuzz-fiber development.
abstract: Cotton fuzz fibers, like Arabidopsis trichomes, are elongated unicells. It is postulated that a transcriptional complex of GLABRA1 (GL1), GLABRA3 (GL3), and TRANSPARENT TESTAGLABRA1 (TTG1) might be in existence in Arabidopsis as evidenced by their physical interaction in yeast, and the complex regulates expression of GLABRA2 (GL2) controlling trichome cell differentiation; it is also assumed that TRIPTYCHON (TRY) and CAPRICE (CPC) counteract the complex formation in neighboring cells. Here, the homologs GaMYB23 (a homolog of GL1), GaDEL65 (a homolog of GL3), GaTTG1, GaCPC and GaTRY were identified in Gossypium arboreum. We show that GaMYB23 can bind to and activate the promoters of GaCPC, GaGL2 and GaTRY, and that GaMYB23, GaTRY and GaTTG1 could interact with GaDEL65 in yeast and in planta. In situ analysis showed that GaMYB23, GaGL2, GaDEL65, and GaTRY were predominantly expressed in fuzz fiber, but GaTRY proteins were primarily found in undeveloped epidermal cells. A G. arboreum fuzzless mutant with consistently high level GaMYB23 transcript has lost the detectable GaMYB23-promoter of GaGL2 complex, corresponding to sharply reduced transcription of GaGL2. Our results support that cotton homologs to the genetic molecules regulating Arabidopsis trichome differentiation interacted in the epidermis of ovules and the redundant GaMYB23 serves as a negative regulator in fuzz-fiber patterning.
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang 455000, China.
authors.forename: Gaskin
authors.initials: G
authors.lastname: Wang
authors.forename: Guo-Hong
authors.initials: GH
authors.lastname: Zhao
authors.forename: Yin-Hua
authors.initials: YH
authors.lastname: Jia
authors.forename: Xiong-Ming
authors.initials: XM
authors.lastname: Du
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D019070:Cell Lineage; D003001:Cloning, Molecular; D032561:Cotton Fiber; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D003368:Gossypium / Q000235:genetics*; D008969:Molecular Sequence Data; D019441:Plant Epidermis / Q000166:cytology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D021381:Protein Transport; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D010940:Plant Proteins
keywords: Convergent evolution; Gossypium arboreum; fuzz, fuzzless mutant; lateral inhibitor; trichome