title: Intron-mediated alternative splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B regulates cell wall thickening during fiber development in Populus species.
abstract: Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics/Chinese Academy of Sciences Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yunjun
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jiayan
authors.initials: J
authors.lastname: Sun
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Laigeng
authors.initials: L
authors.lastname: Li
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D002473:Cell Wall / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007438:Introns / Q000235:genetics*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D052585:Phloem / Q000166:cytology / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics; D030821:Plants, Genetically Modified; D032107:Populus / Q000166:cytology* / Q000235:genetics* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014934:Wood / Q000166:cytology / Q000235:genetics; D052584:Xylem / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors