title: Dwarf Tiller1, a Wuschel-related homeobox transcription factor, is required for tiller growth in rice.
abstract: Unlike many wild grasses, domesticated rice cultivars have uniform culm height and panicle size among tillers and the main shoot, which is an important trait for grain yield. However, the genetic basis of this trait remains unknown. Here, we report that Dwarf Tiller1 (DWT1) controls the developmental uniformity of the main shoot and tillers in rice (Oryza sativa). Most dwt1 mutant plants develop main shoots with normal height and larger panicles, but dwarf tillers bearing smaller panicles compared with those of the wild type. In addition, dwt1 tillers have shorter internodes with fewer and un-elongated cells compared with the wild type, indicating that DWT1 affects cell division and cell elongation. Map-based cloning revealed that DWT1 encodes a Wuschel-related homeobox (WOX) transcription factor homologous to the Arabidopsis WOX8 and WOX9. The DWT1 gene is highly expressed in young panicles, but undetectable in the internodes, suggesting that DWT1 expression is spatially or temporally separated from its effect on the internode growth. Transcriptomic analysis revealed altered expression of genes involved in cell division and cell elongation, cytokinin/gibberellin homeostasis and signaling in dwt1 shorter internodes. Moreover, the non-elongating internodes of dwt1 are insensitive to exogenous gibberellin (GA) treatment, and some of the slender rice1 (slr1) dwt1 double mutant exhibits defective internodes similar to the dwt1 single mutant, suggesting that the DWT1 activity in the internode elongation is directly or indirectly associated with GA signaling. This study reveals a genetic pathway synchronizing the development of tillers and the main shoot, and a new function of WOX genes in balancing branch growth in rice.
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; Graduate University of the Chinese Academy of Sciences, Beijing, China.
authors.forename: Wenfei
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; Graduate University of the Chinese Academy of Sciences, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Huangwei
authors.initials: H
authors.lastname: Chu
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, California, United States of America.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Wanqi
authors.initials: W
authors.lastname: Liang
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005801:Genes, Homeobox; D005875:Gibberellins / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D018520:Plant Shoots / Q000235:genetics* / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D005875:Gibberellins; D018398:Homeodomain Proteins; D010940:Plant Proteins; D014157:Transcription Factors; C116421:WUSCHEL protein, Arabidopsis