title: A R2R3-MYB transcription factor that is specifically expressed in cotton (Gossypium hirsutum) fibers affects secondary cell wall biosynthesis and deposition in transgenic Arabidopsis.
abstract: Secondary cell wall (SCW) is an important industrial raw material for pulping, papermaking, construction, lumbering, textiles and potentially for biofuel production. The process of SCW thickening of cotton fibers lays down the cellulose that will constitute the bulk (up to 96%) of the fiber at maturity. In this study, a gene encoding a MYB-domain protein was identified in cotton (Gossypium hirsutum) and designated as GhMYBL1. Quantitative real-time polymerase chain reaction (RT-PCR) analysis revealed that GhMYBL1 was specifically expressed in cotton fibers at the stage of secondary wall deposition. Further analysis indicated that this protein is a R2R3-MYB transcription factor, and is targeted to the cell nucleus. Overexpression of GhMYBL1 in Arabidopsis affected the formation of SCW in the stem xylem of the transgenic plants. The enhanced SCW thickening also occurred in the interfascicular fibers, xylary fibers and vessels of the GhMYBL1-overexpression transgenic plants. The expression of secondary wall-associated genes, such as CesA4, CesA7, CesA8, PAL1, F5H and 4CL1, were upregulated, and consequently, cellulose and lignin biosynthesis were enhanced in the GhMYBL1 transgenic plants. These data suggested that GhMYBL1 may participate in modulating the process of secondary wall biosynthesis and deposition of cotton fibers.
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Sun
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Si-Ying
authors.initials: SY
authors.lastname: Gong
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Nie
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Geng-Qing
authors.initials: GQ
authors.lastname: Huang
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Xue-Bao
authors.initials: XB
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D002482:Cellulose / Q000378:metabolism; D032561:Cotton Fiber; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D003368:Gossypium / Q000235:genetics*; D008031:Lignin / Q000378:metabolism; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D052584:Xylem / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D002482:Cellulose; D008031:Lignin