Gene Details:

• MSU gene ID: LOC_Os01g08700
• RAPdb gene ID: Os01g0182600
• Gene Symbol: OsGI
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• Time-course metabolome analyses of leaves revealed no trends of change in primary metabolites in OsGI plants, and net photosynthetic rates and grain yields were not affected.
• Consistently, OsGI-1 plants showed semi-dwarf phenotype with reduced internode and leaf sheath elongation.
• The S3574 and C60910 genes were expressed to similar extents during the vegetative and reproductive phases, like OsGI.
• Here we found that mRNA levels of a few major genes encoding GA2-oxidase which can inactivate bioactive gibberellins (GAs) were remarkably increased in OsGI-1 plants.
• Overexpression of OsGI, an orthologue of the Arabidopsis GIGANTEA (GI) gene in transgenic rice, caused late flowering under both SD and LD conditions.
• Hd3a expression is induced by Ehd1 (Early heading date 1) expression when blue light coincides with the morning phase set by OsGIGANTEA(OsGI)-dependent circadian clocks.
• In rice, OsGI, Hd1 and Hd3a were identified as orthologs of GI, CO and FT, respectively, and are also important regulators of flowering.
• Further investigations showed that the expression of OsGI and Ghd7 was up-regulated in the oself3 mutant, indicating that OsELF3 acts as a negative regulator upstream of OsGI and Ghd7 in the flowering-time control under long-day conditions.
• Transcript levels of OsGI, phytochrome genes, and Early heading date3 (Ehd3), which function upstream of Ghd7, were unchanged in the mutant.
• Recently, an extensive time-course transcriptome analysis of rice (Oryza sativa) leaves in natural field conditions revealed that OsGIGANTEA, the sole rice ortholog of the Arabidopsis GIGANTEA gene, governs the robust diurnal rhythm of rice leaf transcriptomes even under natural diurnal conditions; rice OsGI mutants exhibited severely defective transcriptome rhythms under strong diurnal changes in environmental cues.
• Flowering genes downstream of OsPRR1 such as OsGI and Hd1 were down regulated in the A654 mutant.
• Together, these results suggest that overexpression of OsLF might repress expression of OsGI and Hd1 by competing with OsPRR1 in interacting with OsPIL13 and OsPIL15 and thus induce late flowering.
• Transcript levels of three flowering regulators-Ehd1, OsMADS14, and Hd3a-were decreased in these mutants, whereas those of OsGI and Hd1 were unchanged.
• To further investigate the relationship with other flowering promoters, we generated transgenic plants in which expression of Ehd1 or OsGI was suppressed.
• In summary, OsMADS51 is a novel flowering promoter that transmits a SD promotion signal from OsGI to Ehd1.
• The expression patterns of the rice homolog of GI, OsGI, were similar to those of the Arabidopsis GI, suggesting the conservation of some mechanisms for the photoperiodic regulation of flowering between these two species.
• Results showed that mutation of OsGI conferred tolerance to osmotic stress generated by polyethylene glycol (PEG), increased proline and sucrose contents, and accelerated stomata movement.
• In addition, qRT-PCR and microarray analysis revealed that the transcript abundance of some osmotic stress response genes, such as OsDREB1E, OsAP37, OsAP59, OsLIP9, OsLEA3, OsRAB16A, and OsSalT, was significantly higher in OsGI than in WT plants, suggesting that OsGI might be a negative regulator in the osmotic stress response in rice.

Function-related keywords:

• grain ,  dwarf ,  reproductive ,  sheath ,  vegetative ,  gibberellin ,  flower ,  heading-date ,  yield ,  leaf ,  grain-yield ,  tolerance ,  stress ,  stomata ,  stress-response ,  sucrose

Literature:

• An atypical HLH protein OsLF in rice regulates flowering time and interacts with OsPIL13 and OsPIL15 .  DOI:  10.1016/j.nbt.2011.04.006 ;  PMID:  21549224
• Functional characterization of rice OsDof12 .  DOI:  10.1007/s00425-009-0893-7 ;  PMID:  19198875
• Os-GIGANTEA confers robust diurnal rhythms on the global transcriptome of rice in the field .  DOI:  10.1105/tpc.111.083238 ;  PMID:  21571948
• Circadian regulation of rice (Oryza sativa L.) CONSTANS-like gene transcripts .  DOI:   ;  PMID:  15055520
• Adaptation of photoperiodic control pathways produces short-day flowering in rice .  DOI:  10.1038/nature01549 ;  PMID:  12700762
• OsMADS50 and OsMADS56 function antagonistically in regulating long day (LD)-dependent flowering in rice .  DOI:  10.1111/j.1365-3040.2009.02008.x ;  PMID:  19558411
• Physiological significance of the plant circadian clock in natural field conditions .  DOI:  10.1111/j.1365-3040.2012.02555.x ;  PMID:  22681566
• Functional analyses of the flowering time gene OsMADS50, the putative SUPPRESSOR OF OVEREXPRESSION OF CO 1/AGAMOUS-LIKE 20 (SOC1/AGL20) ortholog in rice .  DOI:  10.1111/j.1365-313X.2004.02082.x ;  PMID:  15144377
• OsELF3 is involved in circadian clock regulation for promoting flowering under long-day conditions in rice .  DOI:  10.1093/mp/sss062 ;  PMID:  22888152
• A pair of floral regulators sets critical day length for Hd3a florigen expression in rice .  DOI:  10.1038/ng.606 ;  PMID:  20543848
• Isolation of rice genes possibly involved in the photoperiodic control of flowering by a fluorescent differential display method .  DOI:  10.1093/pcp/pcf059 ;  PMID:  12040096
• Identification of dynamin as an interactor of rice GIGANTEA by tandem affinity purification (TAP) .  DOI:  10.1093/pcp/pcn019 ;  PMID:  18296724
• OsMADS51 is a short-day flowering promoter that functions upstream of Ehd1, OsMADS14, and Hd3a .  DOI:  10.1104/pp.107.103291 ;  PMID:  17951465
• Trithorax group protein Oryza sativa Trithorax1 controls flowering time in rice via interaction with early heading date3 .  DOI:  10.1104/pp.113.228049 ;  PMID:  24420930
• A study of phytohormone biosynthetic gene expression using a circadian clock-related mutant in rice .  DOI:  10.4161/psb.6.12.18207 ;  PMID:  22101345
• Mutation of OsGIGANTEA Leads to Enhanced Tolerance to Polyethylene Glycol-Generated Osmotic Stress in Rice .  DOI:  10.3389/fpls.2016.00465 ;  PMID:  27148296
• Nitrogen Mediates Flowering Time and Nitrogen Use Efficiency via Floral Regulators in Rice .  DOI:  10.1016/j.cub.2020.10.095 ;  PMID:  33278354
• Clock component OsPRR73 positively regulates rice salt tolerance by modulating OsHKT2;1-mediated sodium homeostasis .  DOI:  10.15252/embj.2020105086 ;  PMID:  33347628
• Transcriptional and post-transcriptional regulation of heading date in rice .  DOI:  10.1111/nph.17158 ;  PMID:  33341945
• OsRRM, an RNA-Binding Protein, Modulates Sugar Transport in Rice (Oryza sativa L.) .  DOI:  10.3389/fpls.2020.605276 ;  PMID:  33363560
• The transcriptional repressor OsPRR73 links circadian clock and photoperiod pathway to control heading date in rice .  DOI:  10.1111/pce.13987 ;  PMID:  33377200
• OsPRR37 Alternatively Promotes Heading Date Through Suppressing the Expression of Ghd7 in the Japonica Variety Zhonghua 11 under Natural Long-Day Conditions .  DOI:  10.1186/s12284-021-00464-1 ;  PMID:  33630174
• A clock regulatory module is required for salt tolerance and control of heading date in rice .  DOI:  10.1111/pce.14167 ;  PMID:  34402093

Related News:

Gene Resources:

• NCBI ID: AJ133787  , AP003047
• UniProt accessions:

Sequences: