title: Functional characterization of the poplar R2R3-MYB transcription factor PtoMYB216 involved in the regulation of lignin biosynthesis during wood formation.
abstract: Because of the importance of wood in many industrial applications, tremendous studies have been performed on wood formation, especially in lignin biosynthesis. MYB transcription factors (TFs), which consist of a large family of plant TFs, have been reported to directly regulate lignin biosynthetic genes in a number of plants. In this study, we describe the cloning and functional characterization of PtoMYB216, a cDNA isolated from Chinese white poplar (Populus tomentosa Carr.). PtoMYB216 encodes a protein belonging to the R2R3-MYB family and displays significant similarity with other MYB factors shown to regulate lignin synthesis in Arabidopsis. Gene expression profiling studies showed that PtoMYB216 mRNA is specifically expressed during secondary wall formation in wood. The 1.8-kb promoter sequence of PtoMYB216 was fused to the GUS coding sequence and introduced into wild-type A. thaliana. GUS expression was shown to be restricted to tissues undergoing secondary cell wall formation. Overexpression of PtoMYB216 specifically activated the expression of the upstream genes in the lignin biosynthetic pathway and resulted in ectopic deposition of lignin in cells that are normally unligninified. These results suggest that PtoMYB216 is specific transcriptional activators of lignin biosynthesis and involved in the regulation of wood formation in poplar.
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China.
authors.forename: Qiaoyan
authors.initials: Q
authors.lastname: Tian
authors.forename: Xianqiang
authors.initials: X
authors.lastname: Wang
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Li
authors.forename: Wanxiang
authors.initials: W
authors.lastname: Lu
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Yuanzhong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Keming
authors.initials: K
authors.lastname: Luo
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D003001:Cloning, Molecular; D015870:Gene Expression; D023061:Gene Order; D042541:Intracellular Space; D008031:Lignin / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D032107:Populus / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D021381:Protein Transport; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D014934:Wood / Q000254:growth & development*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D008031:Lignin