Gene Details:

• MSU gene ID: LOC_Os03g29614
• RAPdb gene ID: Os03g0410000
• Gene Symbol: Osmyb3 SG3 SMG3
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• The genetic effect of SG3 on grain length was dependent on GS3 status.
• SG3 overexpression and knockdown plants showed shortened and elongated grains, respectively, which demonstrated that SG3 acts as a negative regulator of grain length.
• The isolation of the SG3 MYB gene provides new gene resource and contributes to the regulatory network of grain length in rice.
• SG3 and GS3 were frequently in coupling phase in indica rice, making them good targets for the breeding of cultivars with short or long grains.
• A gene encoding an R2R3 MYB domain transcriptional regulator was identified as the candidate gene for SG3.
• SG3 was preferentially expressed in panicles after flowering, and SG3 acted as a transcription activator.
• The SMG3 allele from M494 causes an increase in the number of grains per panicle but produces smaller grain size and thousand grain weight.
• Microscopy analysis shows that SMG3 mainly produces long grains by increasing in both cell length and cell number in the length direction, which thus enhances grain weight by promoting cell expansion and cell proliferation.
• Overexpression of SMG3 in rice produces a phenotype with more grains but reduces grain length and weight.
• Our results reveal that SMG3 plays an important role in the coordinated regulation of grain size, grain number per panicle, and grain weight, providing a new insight into synergistical modification on the grain appearance quality, grain number per panicle, and grain weight in rice.
• The SMG3 is constitutively expressed in various organs in rice, and the SMG3 protein is located in the nucleus.
• SMG3 interacts with another grain size regulator, DGS1.
• SMG3 and DGS1 are involved in BR signaling.
• SMG3 encodes a homolog of Arabidopsis (Arabidopsis thaliana) UBIQUITIN CONJUGATING ENZYME 32, which is a conserved ERAD-associated E2 ubiquitin conjugating enzyme.
• Further analyses showed that DGS1 is an active E3 ubiquitin ligase and colocates with SMG3 in the ER.

Function-related keywords:

• grain ,  grain-length ,  breeding ,  transcriptional-regulator ,  transcription-activator ,  grain-size ,  panicle ,  grains-per-panicle ,  grain-number ,  nucleus ,  cell-proliferation ,  grain-weight ,  cell-expansion ,  BR ,  BR-signaling ,  Ubiquitin

Literature:

• Cloning and expression of five myb-related genes from rice seed .  DOI:  10.1016/s0378-1119(97)00344-2 ;  PMID:  9370307
• A minor QTL, SG3, encoding an R2R3-MYB protein, negatively controls grain length in rice .  DOI:  10.1007/s00122-020-03606-z ;  PMID:  32472264
• Bin-based genome-wide association studies reveal superior alleles for improvement of appearance quality using a 4-way MAGIC population in rice .  DOI:  10.1016/j.jare.2020.08.001 ;  PMID:  33364055
• Identification of SMG3, a QTL Coordinately Controls Grain Size, Grain Number per Panicle, and Grain Weight in Rice .  DOI:  10.3389/fpls.2022.880919 ;  PMID:  35548297
• An endoplasmic reticulum-associated degradation-related E2-E3 enzyme pair controls grain size and weight through the brassinosteroid signaling pathway in rice .  DOI:  10.1093/plcell/koac364 ;  PMID:  36519262

Related News:

Gene Resources:

• NCBI ID: D88619
• UniProt accessions:

Sequences: