Gene Details:

• MSU gene ID: LOC_Os07g13170
• RAPdb gene ID: Os07g0235800
• Gene Symbol: SNB SSH1
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• Here, we report the identification of the SUPERNUMERARY BRACT (SNB) gene controlling the transition from spikelet meristem to floral meristem and the floral organ development.
• SNB is expressed in all the examined tissues, but most strongly in the newly emerging spikelet meristems.
• In SNB knockout plants, the transition from spikelet meristems to floral meristems is delayed, resulting in the production of multiple rudimentary glumes in an alternative phyllotaxy.
• These phenotypes suggest that SNB is a heterochronic mutant, affecting the phase transition of spikelet meristems, the pattern formation of floral organs and spikelet meristem determinancy.
• Here we demonstrated that SNB and Oryza sativa INDETERMINATE SPIKELET 1 (OsIDS1) together play important roles in inflorescence architecture and the establishment of floral meristems.
• Two AP2 family genes, supernumerary bract (SNB) and Osindeterminate spikelet 1 (OsIDS1), synergistically control inflorescence architecture and floral meristem establishment in rice.
• We previously reported that SUPERNUMERARY BRACT (SNB) regulates the transition of spikelet meristems into floral meristems in rice (Oryza sativa).
• In SNB osids1 double mutants, the numbers of branches and spikelets within a panicle are significantly decreased, and the transition to a floral meristem is further delayed compared with the SNB single mutant.
• Expression analyses showed that SNB and OsIDS1 are required for spatio-temporal expression of B- and E-function floral organ identity genes in the lodicules.
• A C-to-A point mutation in the 9th intron of SNB altered the splicing of its mRNA, causing the reduced shattering of the SSH1 mutant by altering the development of the abscission layer and vascular bundle at the junction between the seed and the pedicel.
• In addition, the SSH1 mutant had larger seeds and a higher grain weight, resulting from its increased elongation of the glume longitudinal cells.

Function-related keywords:

• meristem ,  inflorescence-architecture ,  spikelet-meristem ,  inflorescence ,  panicle ,  floral-meristem ,  architecture ,  floral ,  spikelet ,  vascular-bundle ,  grain ,  development ,  seed ,  grain-weight ,  shattering

Literature:

• The rice heterochronic gene SUPERNUMERARY BRACT regulates the transition from spikelet meristem to floral meristem .  DOI:  10.1111/j.1365-313X.2006.02941.x ;  PMID:  17144896
• Two AP2 family genes, supernumerary bract (SNB) and Osindeterminate spikelet 1 (OsIDS1), synergistically control inflorescence architecture and floral meristem establishment in rice .  DOI:  10.1111/j.1365-313X.2011.04804.x ;  PMID:  22003982
• Rice miR172 induces flowering by suppressing OsIDS1 and SNB, two AP2 genes that negatively regulate expression of Ehd1 and florigens .  DOI:  10.1186/s12284-014-0031-4 ;  PMID:  26224560
• The APETALA2-Like Transcription Factor SUPERNUMERARY BRACT Controls Rice Seed Shattering and Seed Size .  DOI:  10.1105/tpc.18.00304 ;  PMID:  30626621

Related News:

Gene Resources:

• NCBI ID: DQ374663
• UniProt accessions:

Sequences: