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The basic helix-loop-helix transcription factor OsBLR1 regulates leaf angle in rice via brassinosteroid signalling
- Source :
- Plant Molecular Biology. 102:589-602
- Publication Year :
- 2020
- Publisher :
- Springer Science and Business Media LLC, 2020.
-
Abstract
- Leaf angle is a key factor in plant architecture and crop yield. Brassinosteroids (BRs) regulate many developmental processes, especially the leaf angle in monocots. However, the BR signalling pathway is complex and includes many unknown members. Here, we propose that Oryza sativa BRASSINOSTEROID-RESPONSIVE LEAF ANGLE REGULATOR 1 (OsBLR1) encodes a bHLH transcription factor, and positively regulates BR signalling to increase the leaf angle and grain length in rice (Oryza sativa L.). Lines overexpressing OsBLR1 (blr1-D and BLR1-OE-1/2/3) had similar traits, with increased leaf angle and grain length. Conversely, OsBLR1-knockout mutants (blr1-1/2/3) had erect leaves and shorter grains. Lamina joint inclination, coleoptile elongation, and root elongation assay results indicated that these overexpression lines were more sensitive to BR, while the knockout mutants were less sensitive. There was no significant difference in the endogenous BR contents of blr1-1/2 and wild-type plants. These results suggest that OsBLR1 is involved in BR signal transduction. The blr1-D mutant, with increased cell growth in the lamina joint and smaller leaf midrib, showed significant changes in gene expression related to the cell wall and leaf development compared with wild-type plants; furthermore, the cellulose and protopectin contents in blr1-D were reduced, which resulted in the increased leaf angle and bent leaves. As the potential downstream target gene of OsBLR1, the REGULATOR OF LEAF INCLINATION1 (OsRLI1) gene expression was up-regulated in OsBLR1-overexpression lines and down-regulated in OsBLR1-knockout mutants. Moreover, we screened OsRACK1A as an interaction protein of OsBLR1 using a yeast two-hybrid assay and glutathione-S-transferase pull-down.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Mutant
Plant Science
Biology
Genes, Plant
01 natural sciences
Cell wall
Gene Knockout Techniques
03 medical and health sciences
chemistry.chemical_compound
Plant Growth Regulators
Gene Expression Regulation, Plant
Brassinosteroids
Gene expression
Basic Helix-Loop-Helix Transcription Factors
Genetics
Brassinosteroid
Transcription factor
Plant Proteins
Oryza sativa
fungi
food and beverages
Oryza
General Medicine
Plants, Genetically Modified
Cell biology
Plant Leaves
Phenotype
030104 developmental biology
Coleoptile
chemistry
Elongation
Agronomy and Crop Science
Signal Transduction
Transcription Factors
010606 plant biology & botany
Subjects
Details
- ISSN :
- 15735028 and 01674412
- Volume :
- 102
- Database :
- OpenAIRE
- Journal :
- Plant Molecular Biology
- Accession number :
- edsair.doi.dedup.....7ed6d568de052c2fd3ae230453da41c4