Os01g0667400

DWARF TILLER1 (DWT1) controls the developmental uniformity of the main shoot and tillers in rice (Oryza sativa).

Annotated Information

Function

DWARF TILLER1 (DWT1) controls the developmental uniformity of the main shoot and tillers in rice (Oryza sativa). DWT1 mutant has no obvious morphological difference with wild-type plant at the initial vegetative stage. However, DWT1 developes dwarfed tillers with the main shoot having nearly normal height during the reproductive stage. DWT1 tillers have shorter internodes with fewer and un-elongated cells, indicating that DWT1 affects cell division and cell elongation. DWT1 encodes a WUSCHEL-related homeobox (WOX) transcription factor homologous to the Arabidopsis WOX8 and WOX9.

Morphology of the wild type and dwt1 plants after heading Mature main shoots and tillers with leaves removed from the culm Close-up view of the internodes after heading stage Morphology of panicles from the main shoot (MS) and tillers (TS) of wild type (WT) and dwt1 after heading

Expression

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. Altered expression of genes involved in cell division and cell elongation, cytokinin/gibberellin homeostasis and signaling have been revealed in DWT1 shorter internodes. Previous reports indicated no effect of these hormonal pathways on the coordination between the tiller and the main shoot growth, but latest resoults reveals that the DWT1 activity is directly or indirectly associated with GA signaling in the internode elongation.

Molecular characterization of DWT1:

A. Map-based cloning of the DWT1 gene. The chromosomal region containing DWT1 is diagrammed as the top line with molecular markers shown above the line. The number below the corresponding markers indicates the numbers of recombinants between the markers and DWT1. The BAC clones are shown as overlapping lines. B. Structure of the DWT1 gene. The mutant sequence has one nucleotide C763 deletion in the second exon. Black boxes indicate exons, white boxes indicate UTRs and lines indicate introns. The grey box shows the homeobox domain.

C. The plant stature of dwt1, the wild type, and complemented transgenic plants (DWT1-COM). D. The morphology of the second internodes of dwt1, wild type, and complemented transgenic plants (DWT1-COM). E–H. Nuclear localization of DWT1 protein. YFP fluorescence image (E), light view (F), PI stained image (G) and overlay of the three images (H) of Nicotiana benthamiana leaf epidermal cell transformed with the 35S:DWT1-YFP construct.

Expression pattern of DWT1 transcripts and proteins:

A. qRT-PCR analysis of DWT1 gene expression levels in the wild-type tissues including coleoptiles (36 h after seed germination), root tips, mature leaf and sheath, the second internode during elongating (1 cm in length), segments of the upper (U), middle (M), and lower (L) parts of the second internode with 3 cm in length, dormant tiller bud, panicle (less than 1 cm in length), spikelet at stage Sp8 during development of pistil [63], young embryo (10 days after fertilization), and callus with 20–days regeneration. Rice ACTIN1 (OsACTIN1) was used as a control. B. qRT-PCR analysis of DWT1 gene expression levels in young panicle of wild type.

C–L. In situ hybridization of DWT1. Signals were detected in the primary branch meristem (E), secondary branch meristem (C, F), top portion of the panicle (G), shoot apical and radical apical of young embryo (I), and endodermis and exodermis of root tip (K). D, H, J and L were corresponding sections hybridized with the sense probe.I,II,III,IV, the first, second, third and the forth internode, respectively; pb, primary branch meristem; sb, secondary branch meristem; yl, young leave; fm, floral meristem; ifm, inflorescence meristem; exd, exodermis layer; end, endodermis layer.

M–R. YFP fluorescence image of the branch meristem (M–O) and the internode (P–R) in transgenic plants expressing pDWT1:DWT1-YFP. M and P are fluorescence image, N and Q are light view, O and R are overlapping of fluorescence image and light view. S. Western-blot analysis of DWT1 protein levels.

Evolution

Please input evolution information here.

Labs working on this gene

1 State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China

2 Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China

3 Graduate University of the Chinese Academy of Sciences, Beijing, China

4 Department of Plant Biology, Carnegie Institution for Science, Stanford, California, United States of America

References

1. Wenfei Wang;Gang Li;Jun Zhao;Huangwei Chu;Wenhui Lin;Dabing Zhang;Zhiyong Wang;Wanqi Liang

 DWARF TILLER1, a WUSCHEL-Related Homeobox Transcription Factor, Is Required for Tiller Growth in Rice
 PLoS Genetics, 2014, 10(3): e1004154

2. Wenfei Wang;Huangwei Chu;Dabing Zhang;Wanqi Liang

 Fine Mapping and Analysis of DWARF TILLER1 in Controlling Rice Architecture
 Journal of genetics and genomics, 2013, 40(9): 493-495