Gene Details:

• MSU gene ID: LOC_Os06g12210
• RAPdb gene ID: Os06g0226500
• Gene Symbol: BU1 OsbHLH174
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• These results indicate that BU1 protein is a positive regulator of BR response: it controls bending of the lamina joint in rice and it is a novel primary response gene that participates in two BR signaling pathways through OsBRI1 and RGA1.
• Rice plants overexpressing BU1 (BU1:OX) showed enhanced bending of the lamina joint, increased grain size, and resistance to brassinazole, an inhibitor of BR biosynthesis.
• Consistently, transcriptome analyses revealed that SDG725 depletion results in down-regulation by more than two-fold of over 1000 genes, including D11, BRI1 and BU1, which are known to be involved in brassinosteroid biosynthesis or signaling pathways.
• In addition, compared to the wild type, the induction of BU1 by exogenous brassinolide did not require de novo protein synthesis and it was weaker in a BR receptor mutant OsbriI (Oryza sativa brassinosteroid insensitive1, d61) and a rice G protein alpha subunit (RGA1) mutant d1.
• These results indicate that BU1 may participate in some other unknown processes modulated by BR in rice.
• Furthermore, expression analyses showed that BU1 is expressed in several organs including lamina joint, phloem, and epithelial cells in embryos.
• In contrast to BU1:OX, RNAi plants designed to repress both BU1 and its homologs displayed erect leaves.
• Here, we describe a novel BR-induced rice gene BRASSINOSTEROID UPREGULATED1 (BU1), encoding a helix-loop-helix protein.

Function-related keywords:

• BR-signaling ,  grain ,  brassinosteroid ,  grain-size ,  BR ,  lamina ,  erect

Literature:

• H3K36 methylation is critical for brassinosteroid-regulated plant growth and development in rice .  DOI:  10.1111/j.1365-313X.2011.04873.x ;  PMID:  22136623
• BRASSINOSTEROID UPREGULATED1, encoding a helix-loop-helix protein, is a novel gene involved in brassinosteroid signaling and controls bending of the lamina joint in rice .  DOI:  10.1104/pp.109.140806 ;  PMID:  19648232
• Genome-wide association studies reveal that members of bHLH subfamily 16 share a conserved function in regulating flag leaf angle in rice (Oryza sativa) .  DOI:  10.1371/journal.pgen.1007323 ;  PMID:  29617374
• OrMKK3 Influences Morphology and Grain Size in Rice .  DOI:  10.1007/s12374-020-09290-2 ;  PMID:  33424241

Related News:

Gene Resources:

• NCBI ID: NM_001063738
• UniProt accessions:

Sequences: