Gene Details:

• MSU gene ID: LOC_Os10g25780
• RAPdb gene ID: Os10g0397400
• Gene Symbol: BRD2 DIM DWF1 LHDD10 LTBSG1
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• The BRD2 locus contains a single base deletion in the coding region of Dim/dwf1, a homolog of Arabidopsis thaliana DIMINUTO/DWARF1 (DIM/DWF1).
• Overproduction and repression of Dim/dwf1 resulted in contrasting phenotypes, with repressors mimicking the BRD2 phenotype and overproducers having large stature with increased numbers of flowers and seeds.
• The Rice brassinosteroid-deficient dwarf2 mutant, defective in the rice homolog of Arabidopsis DIMINUTO/DWARF1, is rescued by the endogenously accumulated alternative bioactive brassinosteroid, dolichosterone.
• Based on these observations, we discuss an alternative BR biosynthetic pathway that produces DS when Dim/DWF1 is defective.
• LHDD10 was constitutively expressed in various tissues, but more so in shoot apices and panicles.
• We isolated LHDD10 by map-based cloning; it encoded a putative FAD-linked oxidoreductase protein (a brassinosteroid biosynthetic gene) that localized to the nucleus.
• In this study, we characterized a late heading, dwarf mutant known as LHDD10 selected following ethyl methane sulfonate (EMS)-treatment of ssp.
• Brassinosteroid (BR) biosynthetic gene LHDD10 controls late heading and plant height in rice (Oryza sativa L.).
• Our data showed that LHDD10 influences heading date by controlling the expression of heading date regulators, such as OsMADS50 in both LD and SD conditions.
• The LTBSG1 seedlings had a lower endogenous BR level and could be restored to the phenotype of wild type by exogenous BR.
• This study demonstrated that LTBSG1 could play a new role in regulating panicle and grain development by BR biosynthetic pathway.
• In the present study, a mutant named LTBSG1 (longer top branch and shorter grain 1) was isolated from the cultivar “Zhenong 34” (Oryza sativa L.
• The histocytological analysis indicated that the elongated top branch and shorter grain of mutant LTBSG1 were caused from the defects of cell elongation.
• The LTBSG1 knock-out lines showed similar phenotype defects as mutant LTBSG1, which confirmed that LTBSG1 was responsible for top branch elongation and grain size reduction.
• LTBSG1 was constitutively expressed and the protein was widely localized in chloroplast, nucleus and cytomembrane.
• The LTBSG1 gene in mutant revealed a single nucleotide substitution (G-A) in the exon 2 of LOC_Os10g25780, causing an amino acid variation (Glycine-Arginine) in the FAD (Flavin-adenine dinucleotide)-binding domain of delta (24)-sterol reductase, which was involved in the brassinosteroid (BR) biosynthesis.
• In summary, the current study has identified a new BRD2 allele, which facilitated the further research on the molecular mechanism of this gene on regulating growth and development.
• Natural variation of the BRD2 allele affects plant height and grain size in rice.
• The zqdm1 identified from a rice mutant is a novel allele of BRD2 and is responsible for regulating rice plant height, grain size and appearance, which has possibilities on improving rice quality.
• Complementation tests have confirmed that 369-bp insertion in BRD2 was responsible for the plant height and grain size changing in the zqdm1 mutant.
• Over-expression of BRD2 driven by different promoters into indica rice variety Jiafuzhan (JFZ) results in slender grains, suggesting its function on regulating grain shape.

Function-related keywords:

• dwarf ,  seed ,  brassinosteroid ,  flower ,  BR ,  shoot ,  map-based-cloning ,  height ,  heading-date ,  Brassinosteroid ,  plant-height ,  nucleus ,  seedlings ,  panicle ,  grain ,  development ,  grain-size ,  cell-elongation ,  growth ,  quality ,  grain-shape

Literature:

• The Rice brassinosteroid-deficient dwarf2 mutant, defective in the rice homolog of Arabidopsis DIMINUTO/DWARF1, is rescued by the endogenously accumulated alternative bioactive brassinosteroid, dolichosterone .  DOI:  10.1105/tpc.105.030973 ;  PMID:  15994910
• Brassinosteroid (BR) biosynthetic gene lhdd10 controls late heading and plant height in rice (Oryza sativa L.) .  DOI:  10.1007/s00299-015-1889-3 ;  PMID:  26518431
• OsGSR1 is involved in crosstalk between gibberellins and brassinosteroids in rice .  DOI:  10.1111/j.1365-313X.2008.03707.x ;  PMID:  18980660
• LTBSG1, a New Allele of BRD2, Regulates Panicle and Grain Development in Rice by Brassinosteroid Biosynthetic Pathway .  DOI:  10.3390/genes9060292 ;  PMID:  29891831
• Natural variation of the BRD2 allele affects plant height and grain size in rice .  DOI:  10.1007/s00425-022-03939-7 ;  PMID:  35780402

Related News:

Gene Resources:

• NCBI ID:
• UniProt accessions:

Sequences: