Gene Details:

• MSU gene ID: LOC_Os09g36200
• RAPdb gene ID: Os09g0532000
• Gene Symbol: SGR OsSGR
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• SGR, like the gene for pheophorbide a oxygenase (PaO), was constitutively expressed, but was upregulated by dark-induced senescence in rice leaves.
• Senescence-induced expression of SGR and PaO was enhanced by ABA, but inhibited by cytokinin.
• This indicates that upregulation of SGR increases Chl breakdown during senescence in rice.
• A small quantity of chlorophyllide a accumulated in SGR leaves, but this also accumulated in wild-type rice leaves during senescence.
• In this study, we found that overexpression of SGR (Ov-SGR) resulted in the generation of singlet oxygen and other reactive oxygen species and produced a chlorophyll-dependent regional cell death phenotype on leaves of rice seedlings.
• Transcriptome analyses using Affymetrix Rice GeneChips revealed that Ov-SGR rice seedlings exhibited a number of signs of singlet oxygen response.
• Overexpression of SGR results in oxidative stress and lesion-mimic cell death in rice seedlings.
• The Stay-Green Rice (SGR) protein is encoded by the SGR gene and has been shown to affect chlorophyll (Chl) degradation during natural and dark-induced leaf senescence.
• We show that SGRL is primarily expressed in green tissues, and is significantly downregulated in rice leaves undergoing natural and dark-induced senescence.
• Overexpression of SGRL reduces the levels of Chl and Chl-binding proteins in leaves, and accelerates their degradation in dark-induced senescence leaves in rice.
• The gene, designated Stay Green Rice (SGR), was cloned by a positional cloning strategy encoding an ancient protein containing a putative chloroplast transit peptide.
• It is thought that the Stay Green Rice (SGR) gene is involved in the disaggregation of the light harvesting complex and in the subsequent breakdown of chlorophyll and apo-protein during senescence.
• Promoter variations in the Stay-Green (OsSGR) gene encoding the chlorophyll-degrading Mg++-dechelatase were found to trigger higher and earlier induction of OsSGR in indica, which accelerated senescence of indica rice cultivars.
• Japonica OsSGR alleles introgressed into indica-type cultivars in Korean rice fields lead to delayed senescence, with increased grain yield and enhanced photosynthetic competence.
• Taken together, these data establish that naturally occurring OsSGR promoter and related lifespan variations can be exploited in breeding programs to augment rice yield.

Function-related keywords:

• senescence ,  seedling ,  oxidative ,  leaf ,  cytokinin ,  chloroplast ,  cell-death ,  grain ,  grain-yield ,  yield ,  breeding

Literature:

• The Stay-Green Rice like (SGRL) gene regulates chlorophyll degradation in rice .  DOI:  10.1016/j.jplph.2013.05.016 ;  PMID:  23816327
• Molecular cloning and function analysis of the stay green gene in rice .  DOI:  10.1111/j.1365-313X.2007.03221.x ;  PMID:  17714430
• Overexpression of SGR results in oxidative stress and lesion-mimic cell death in rice seedlings .  DOI:  10.1111/j.1744-7909.2011.01037.x ;  PMID:  21375689
• Natural variations at the Stay-Green gene promoter control lifespan and yield in rice cultivars .  DOI:  10.1038/s41467-020-16573-2 ;  PMID:  32499482
• Characterization of a novel allele encoding pheophorbide a oxygenase in rice .  DOI:  10.1080/15592324.2020.1864606 ;  PMID:  33369525

Related News:

Gene Resources:

• NCBI ID: AY850134
• UniProt accessions:

Sequences: