Gene Details:

• MSU gene ID: LOC_Os05g32270
• RAPdb gene ID: Os05g0389000
• Gene Symbol: SMOS1 SHB RLA1 NGR5
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• SMOS1 expression was induced by exogenous auxin treatment, and the auxin response element (AuxRE) of the SMOS1 promoter acts as a cis-motif through interaction with auxin response factor (ARF).
• We propose that SMOS1 acts as an auxin-dependent regulator for cell expansion during organ size control, and that its function is conserved among land plants.
• In this study, we identified a new rice loss-of-function mutant, small organ size1 (SMOS1), that decreases the final size of various organs due to decreased cell size and abnormal microtubule orientation.
• Furthermore, a functional fluorophore-tagged SMOS1 was localized to the nucleus, supporting the role of SMOS1 as a transcriptional regulator for organ size control.
• SMOS1 encodes an unusual APETALA2 (AP2)-type transcription factor with an imperfect AP2 domain, and its product belongs to the basal AINTEGUMENTA (ANT) lineage, including WRINKLED1 (WRI1) and ADAP.
• Quantitative analysis of cortical cell length and number indicates that SHB has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced.
• SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1.
• These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of SHB mutant phenotypes.
• Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner.
• SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation.
• RLA1 was identical to the previously reported SMALL ORGAN SIZE 1 (SMOS1) which was cloned from another allele.
• Increased NGR5 activity consequently uncouples tillering from nitrogen regulation, boosting rice yield at low nitrogen fertilization levels.
• NGR5 thus enables enhanced nitrogen use efficiency for improved future agricultural sustainability and food security.
• We found that genome-wide promotion of histone H3 lysine 27 trimethylation (H3K27me3) enables nitrogen-induced stimulation of rice tillering: APETALA2-domain transcription factor NGR5 (NITROGEN-MEDIATED TILLER GROWTH RESPONSE 5) facilitates nitrogen-dependent recruitment of polycomb repressive complex 2 to repress branching-inhibitory genes via H3K27me3 modification.
• NGR5 is a target of gibberellin receptor GIBBERELLIN INSENSITIVE DWARF1 (GID1)-promoted proteasomal destruction.

Function-related keywords:

• auxin ,  organ-size ,  transcription-factor ,  root ,  meristem ,  ga ,  GA ,  GA-deficiency ,  GA-biosynthesis ,  root-meristem ,  root-meristem-size ,  Gibberellin ,  nitrogen ,  tillering ,  growth ,  tiller ,  gibberellin ,  yield

Literature:

• A novel AP2-type transcription factor, SMALL ORGAN SIZE1, controls organ size downstream of an auxin signaling pathway .  DOI:  10.1093/pcp/pcu023 ;  PMID:  24486766
• SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation .  DOI:  10.1371/journal.pgen.1005464 ;  PMID:  26275148
• The RLA1/SMOS1 Transcription Factor Functions with OsBZR1 to Regulate Brassinosteroid Signaling and Rice Architecture .  DOI:  10.1105/tpc.16.00611 ;  PMID:  28100707
• Enhanced sustainable green revolution yield via nitrogen-responsive chromatin modulation in rice .  DOI:  10.1126/science.aaz2046 ;  PMID:  32029600

Related News:

Gene Resources:

• NCBI ID:
• UniProt accessions:

Sequences: