Gene Details:
- MSU gene ID: LOC_Os06g45460
- RAPdb gene ID: Os06g0665400
- Gene Symbol: APO1 OsAPO1 SCM2
- Genome: MSU7 , IRGSP-1.0
- Species: Oryza sativa
Functional Descriptions:
- Vegetative development is also affected in the APO1.
- Leaves were formed rapidly throughout the vegetative phase, indicating that APO1 is also involved in temporal regulation of leaf production.
- These phenotypes suggest that the APO1 plays an important role in the temporal regulation of both vegetative and reproductive development.
- We previously reported that the ABERRANT PANICLE ORGANIZATION1 (APO1) gene, encoding an F-box-containing protein orthologous to Arabidopsis (Arabidopsis thaliana) UNUSUAL FLORAL ORGANS, suppresses precocious conversion of rachis branch meristems to spikelets to ensure generation of certain number of spikelets.
- Positional cloning of the gene revealed that SCM2 was identical to ABERRANT PANICLE ORGANIZATION1 (APO1), a gene previously reported to control panicle structure.
- Although SCM2 is a gain-of-function mutant of APO1, it does not have the negative effects reported for APO1 overexpression mutants, such as decreased panicle number and abnormal spikelet morphology.
- In addition, APO1 is associated with the regulation of the plastchron, floral organ identity, and floral determinacy.
- Phenotypic analyses of APO1 and floral homeotic double mutants demonstrate that APO1 positively regulates class-C floral homeotic genes, but not class-B genes.
- Molecular studies revealed that APO1 encodes an F-box protein, an ortholog of Arabidopsis UNUSUAL FLORAL ORGAN (UFO), which is a positive regulator of class-B genes.
- Further analysis indicated that APO2/RFL and APO1, the rice ortholog of Arabidopsis UNUSUAL FLORAL ORGANS, act cooperatively to control inflorescence and flower development.
- ABERRANT PANICLE ORGANIZATION 2/RFL, the rice ortholog of Arabidopsis LEAFY, suppresses the transition from inflorescence meristem to floral meristem through interaction with APO1.
- This alteration in growth rate is opposite to what is observed with the APO1 mutants that have a smaller inflorescence meristem.
- However, in APO1, the main-axis meristem was converted to a spikelet meristem after producing a small number of branch primordia.
- In addition, the branch meristems in APO1 became spikelet meristems earlier than in wild type.
- Therefore, in the inflorescence, the APO1 mutation caused the precocious conversion of the meristem identity.
- In the APO1 flower, lodicules were increased at the expense of stamens, and carpels were formed indeterminately by the loss of meristem determinacy.
- Characterization of rice aberrant panicle organization 1 (APO1) mutants revealed that APO1 positively controls spikelet number by suppressing the precocious conversion of inflorescence meristems to spikelet meristems.
- We report a recessive mutation of rice, aberrant panicle organization 1 (APO1), which severely affects inflorescence architecture, floral organ identity, and leaf production rate.
- In the APO1-D dominant alleles, the inflorescence meristem starts to increase in size more vigorously than the wild type when switching to the reproductive development phase.
- APO1 expression occurred not only in developing panicles but also in the developing vascular bundle systems.
- It suggests that APO1 enhances the formation of vascular bundle systems which, consequently, promote carbohydrate translocation to panicles.
- The HI1 allele is suggested to regulate the amount of APO1 expression, and thereby control the development of vascular bundle systems.
- In this study, using chromosome segment substitution lines, we identified an effective quantitative trait loci (QTL) for culm strength, which was designated STRONG CULM2 (SCM2).
- A near-isogenic line carrying SCM2 showed enhanced culm strength and increased spikelet number because of the pleiotropic effects of the gene.
- Collectively, these results suggest that the level of APO1 activity regulates the inflorescence form through control of cell proliferation in the meristem.
- As the mutant inflorescences and flowers differed considerably between APO1 and ufo, the functions of APO1 and UFO appear to have diverged during evolution.
- Habataki-genotype segregated reciprocal recombinant lines for the APO1 locus increased both the number of PRB (12-13%) and the number of grains per panicle (9-12%), which increased the grain yield per plant (5-7%).
- The PRB1 allele, which includes the APO1 open reading frame (ORF) and the proximal promoter region, controlled only the number of PRB but not the number of grains per panicle.
- Here, we identified four dominant mutants producing an increased number of spikelets and found that they are gain-of-function alleles of APO1.
- The APO1 expression levels are elevated in all four mutants, suggesting that an increase of APO1 activity caused the delay in the program shift to spikelet formation.
- The resultant gene was ABERRANT PANICLE ORGANIZATION 1 (APO1).
- Overexpression of APO1 caused an increase in inflorescence branches and spikelets.
- These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.
- The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss.
- Genetic analyses support that LARGE2 functions with APO1 and APO2 in a common pathway to regulate panicle size and grain number.
Function-related keywords:
- vegetative , floral , panicle , growth , meristem , spikelet-meristem , inflorescence , flower , reproductive , vascular-bundle , culm , grains-per-panicle , spikelet , stamen , leaf , architecture , inflorescence-architecture , spikelet-number , floral-meristem , grain-yield , grain , yield , grain-number , panicle-size
Literature:
- ABERRANT PANICLE ORGANIZATION 1 temporally regulates meristem identity in rice . DOI: 10.1016/j.ydbio.2005.03.016 ; PMID: 15950602
- A gene controlling the number of primary rachis branches also controls the vascular bundle formation and hence is responsible to increase the harvest index and grain yield in rice . DOI: 10.1007/s00122-009-1218-8 ; PMID: 20151298
- Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F-box protein, regulates meristem fate . DOI: 10.1111/j.1365-313X.2007.03200.x ; PMID: 17666027
- ABERRANT PANICLE ORGANIZATION 2/RFL, the rice ortholog of Arabidopsis LEAFY, suppresses the transition from inflorescence meristem to floral meristem through interaction with APO1 . DOI: 10.1111/j.1365-313X.2011.04781.x ; PMID: 21910771
- New approach for rice improvement using a pleiotropic QTL gene for lodging resistance and yield . DOI: 10.1038/ncomms1132 ; PMID: 21119645
- Expression level of ABERRANT PANICLE ORGANIZATION1 determines rice inflorescence form through control of cell proliferation in the meristem . DOI: 10.1104/pp.109.136739 ; PMID: 19386809
- Ozone-Induced Rice Grain Yield Loss Is Triggered via a Change in Panicle Morphology That Is Controlled by ABERRANT PANICLE ORGANIZATION 1 Gene . DOI: 10.1371/journal.pone.0123308 ; PMID: 25923431
- The LARGE2-APO1/APO2 regulatory module controls panicle size and grain number in rice . DOI: 10.1093/plcell/koab041 ; PMID: 33693937
Related News:
Gene Resources:
- NCBI ID: AB292777
- UniProt accessions:
Sequences:
cDNA Sequence
- >LOC_Os06g45460.1
ATGGACCCGCGCGTGTGGCGCCGGCTGCCGCAGCCGCTGGTGGACCGCATCCTGGCGTGCCTCCCGACGCCGTCGTTCCTCCGCCTCCGCGCCGCCTGCCGCCGCTTCTACCACCTCCTCTTCTCCTCCCCGTTCCTCCACTCCCACCTCCTCCTCTCCCCTCACCTCCCCTTCTTCGCCTTCGTCGTCCCCGCCGCCGGCCACCTCCTCCTCCTCGACCCCACCGCCACCGCCTCCTGGTCCCGCCTCCCGCTCCCGCTCCCGCCCGTCGCCGGCGGCCCCGCCGCGTTCTCGCCCGCGGCCGCGTCCGCCGGCCTGCTCGCGTTCCTGTCCGACGCGTCGGGGCACAAGACGCTGCTGCTCGCCAACCCGATCACCCGCCTCCTCGCCGCGCTCCCCATCTCCCCGACCCCGCGCCTCTCCCCCACCGTCGGCCTCGCCGCCGGCCCGACCTCCATCATCGCCGTCGTGGCCGGGGACGACCTCGTGTCCCCCTTCGCCGTCAAGAACATCTCCGCCGACACGTTCGTCGCCGACGCCGCCTCCGTCCCGCCCTCCGGCTTCTGGGCTCCCAGCTCCCTGCTCCCTCGCCTCTCCTCCCTCGATCCCCGCGCCGGCATGGCCTTCGCCTCCGGCAGGTTCTACTGCATGAGCTCGTCGCCGTTTGCGGTTCTGGTGTTCGACGTGGCGGAGAACGTATGGAGCAAGGTGCAGCCGCCGATGAGGCGGTTCCTGAGGTCGCCGGCGCTGGTGGAGCTCGGCGGCGGGAGGGAGGGAGCGGCGAGGGTGGCGCTGGTGTCGGCCGTCGAGAAGAGCCGTCTCAGCGTGCCCCGCAGCGTGCGCCTGTGGACGCTGCGCGGCGGCGGCGGCGGCGGCGGCGGTGGCGCGTGGACGGAGGTGGCGCGGATGCCGCCGGAGGTGCACGCGCAGTTCGCCGCGGCGGAGGGCGGGCGCGGGTTCGAGTGCGCGGCGCACGGCGACTACGTCGTGCTCGCGCCGCGCGGGCCCGTGGCGCAGGCGCCCACGAGCGCGCTCGTGTTCGACTCCCGCCGCGACGAGTGGCGGTGGGCGCCGCCGTGCCCGTACGTCGTCGTCGCGCACCACGGCGGCGCCGGCGCGGCGGGTTTCCGGGTGTTCGCGTACGAGCCCCGGCTGGCGACGCCGGCCATTGGCCTCCTCGACGCCACGGCGCCCGTCGCCTTGCATGGCATGCATGATGGTTAG
CDS Sequence
- >LOC_Os06g45460.1
ATGGACCCGCGCGTGTGGCGCCGGCTGCCGCAGCCGCTGGTGGACCGCATCCTGGCGTGCCTCCCGACGCCGTCGTTCCTCCGCCTCCGCGCCGCCTGCCGCCGCTTCTACCACCTCCTCTTCTCCTCCCCGTTCCTCCACTCCCACCTCCTCCTCTCCCCTCACCTCCCCTTCTTCGCCTTCGTCGTCCCCGCCGCCGGCCACCTCCTCCTCCTCGACCCCACCGCCACCGCCTCCTGGTCCCGCCTCCCGCTCCCGCTCCCGCCCGTCGCCGGCGGCCCCGCCGCGTTCTCGCCCGCGGCCGCGTCCGCCGGCCTGCTCGCGTTCCTGTCCGACGCGTCGGGGCACAAGACGCTGCTGCTCGCCAACCCGATCACCCGCCTCCTCGCCGCGCTCCCCATCTCCCCGACCCCGCGCCTCTCCCCCACCGTCGGCCTCGCCGCCGGCCCGACCTCCATCATCGCCGTCGTGGCCGGGGACGACCTCGTGTCCCCCTTCGCCGTCAAGAACATCTCCGCCGACACGTTCGTCGCCGACGCCGCCTCCGTCCCGCCCTCCGGCTTCTGGGCTCCCAGCTCCCTGCTCCCTCGCCTCTCCTCCCTCGATCCCCGCGCCGGCATGGCCTTCGCCTCCGGCAGGTTCTACTGCATGAGCTCGTCGCCGTTTGCGGTTCTGGTGTTCGACGTGGCGGAGAACGTATGGAGCAAGGTGCAGCCGCCGATGAGGCGGTTCCTGAGGTCGCCGGCGCTGGTGGAGCTCGGCGGCGGGAGGGAGGGAGCGGCGAGGGTGGCGCTGGTGTCGGCCGTCGAGAAGAGCCGTCTCAGCGTGCCCCGCAGCGTGCGCCTGTGGACGCTGCGCGGCGGCGGCGGCGGCGGCGGCGGTGGCGCGTGGACGGAGGTGGCGCGGATGCCGCCGGAGGTGCACGCGCAGTTCGCCGCGGCGGAGGGCGGGCGCGGGTTCGAGTGCGCGGCGCACGGCGACTACGTCGTGCTCGCGCCGCGCGGGCCCGTGGCGCAGGCGCCCACGAGCGCGCTCGTGTTCGACTCCCGCCGCGACGAGTGGCGGTGGGCGCCGCCGTGCCCGTACGTCGTCGTCGCGCACCACGGCGGCGCCGGCGCGGCGGGTTTCCGGGTGTTCGCGTACGAGCCCCGGCTGGCGACGCCGGCCATTGGCCTCCTCGACGCCACGGCGCCCGTCGCCTTGCATGGCATGCATGATGGTTAG
Protein Sequence
- >LOC_Os06g45460.1
MDPRVWRRLPQPLVDRILACLPTPSFLRLRAACRRFYHLLFSSPFLHSHLLLSPHLPFFAFVVPAAGHLLLLDPTATASWSRLPLPLPPVAGGPAAFSPAAASAGLLAFLSDASGHKTLLLANPITRLLAALPISPTPRLSPTVGLAAGPTSIIAVVAGDDLVSPFAVKNISADTFVADAASVPPSGFWAPSSLLPRLSSLDPRAGMAFASGRFYCMSSSPFAVLVFDVAENVWSKVQPPMRRFLRSPALVELGGGREGAARVALVSAVEKSRLSVPRSVRLWTLRGGGGGGGGGAWTEVARMPPEVHAQFAAAEGGRGFECAAHGDYVVLAPRGPVAQAPTSALVFDSRRDEWRWAPPCPYVVVAHHGGAGAAGFRVFAYEPRLATPAIGLLDATAPVALHGMHDG*