Difference between revisions of "Os01g0972900"
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==Annotated Information== | ==Annotated Information== | ||
===Function=== | ===Function=== | ||
| − | During the whole plant life cycle, cell division and expansion work alternately to build and control the precise size of specific organs (Dupuy et al. 2010). In addition, during cell differentiation of post-embryonic tissue, either cell expansion or endoreduplication control the final size. CCS52 protein has been reported to be involved in cell expansion and endoreduplication, the functional characterization of B-type CCS52 (CCS52B) in plants is relatively limited. Previous studies of model plants (Medicago and Arabidopsis) have proposed that MtCCS52B and AtCCS52B play a crucial role in plant cell division. Yeast overexpressing AtCCS52B had smaller cells compared to the wild type, indicating an early start of the mitotic cell division cycle. Moreover, yeast cells harboring OsCCS52B grow slower than the wild type during the cycle, as determined by the proliferation assay (Fig. 4). Another distinct phenotype is yeast cell elongation prior to division. These results indicate that OsCCS52B may function in cell expansion rather than cell division | + | During the whole plant life cycle, cell division and expansion work alternately to build and control the precise size of specific organs (Dupuy et al. 2010). In addition, during cell differentiation of post-embryonic tissue, either cell expansion or endoreduplication control the final size. CCS52 protein has been reported to be involved in cell expansion and endoreduplication, the functional characterization of B-type CCS52 (CCS52B) in plants is relatively limited. Previous studies of model plants (Medicago and Arabidopsis) have proposed that MtCCS52B and AtCCS52B play a crucial role in plant cell division. Yeast overexpressing AtCCS52B had smaller cells compared to the wild type, indicating an early start of the mitotic cell division cycle. Moreover, yeast cells harboring OsCCS52B grow slower than the wild type during the cycle, as determined by the proliferation assay (Fig. 4). Another distinct phenotype is yeast cell elongation prior to division. These results indicate that OsCCS52B may function in cell expansion rather than cell division. Although the yeast cell is elongated, the nuclei size remains similar to the wild type, indicating that no additional endoreduplication cycle occurs in OsCCS52B overexpressing cells (Fig. 3). In Arabidopsis, when AtCCS52B is overexpressed in fission yeast, the cells loose polarity control. Therefore, the nuclei location is not always in the center of the cells. In contrast to this phenomenon, the data presented here show that OsCCS52B overexpressing cells maintain the nuclei within the center of the cell. This indicates that the mode of action of AtCCS52B and OsCCS52B is different when overexpressed in yeast. |
| − | Although the yeast cell is elongated, the nuclei size remains similar to the wild type, indicating that no additional endoreduplication cycle occurs in OsCCS52B overexpressing cells (Fig. 3). In Arabidopsis, when AtCCS52B is overexpressed in fission yeast, the cells loose polarity control. Therefore, the nuclei location is not always in the center of the cells. In contrast to this phenomenon, the data presented here show that OsCCS52B overexpressing cells maintain the nuclei within the center of the cell. | + | To further confirm the functional role of OsCCS52B in plants, a T-DNA insertion mutant line 1B-10423 was characterized. This line exhibited a smaller seedling phenotype and semi-dwarf appearance at the mature stage. This phenotype was caused by a reduction in internode length. In addition, line 1B-10423 contains a narrower kernel than the corresponding wild type. These results indicate that OsCCS52B plays an essential role in the growth and development of rice, not only during the early developmental stage, but also during the grain filling stage. Grain filling is a critical stage, during which cereal plants modulate endosperm (seed) size due to the accumulation of photosynthates, such as starch and protein. Two main processes, endoreduplication and cell expansion, are reported to occur concomitantly with grain filling. Furthermore, endoreduplication and cell expansion might work concurrently or independently. In most cereals, successive rounds of endoreduplication start at 10 DAP and peak at 15–18 DAP. To determine whether the mutation in line 1B-10423 interferes with cellular development during endosperm formation, 15 DAP endosperm was sectioned and stained with DAPI to compare with the corresponding wild-type endosperm. Interestingly, microscopic analysis of the endosperm cells in line 1B-10423 revealed a smaller cell size without altering the nuclei size. Hence, cell size regulation in mutant seed could be separate and independent from the cell cycle progression associated with DNA endoreduplication. Therefore, OsCCS52B is more likely to be involved in the regulation of cell growth during endosperm development. Taken together with the yeast overexpression data, this result supports the hypothesis for the involvement of OsCCS52B in cell expansion rather than endoreduplication. |
| − | To further confirm the functional role of OsCCS52B in plants, a T-DNA insertion mutant line 1B-10423 was characterized. | + | To clarify this phenomenon, cell cycle progression in mutant endosperm was determined using flow cytometry. The results showed that mutant endosperm underwent a normal endoreduplication cycle, showing four peaks in the nuclei proportion corresponding to ploidy levels of 2C, 3C, 6C, and 12C (Fig. 6e). One possibility is that the endoreduplication cycle in the mutant line, 1B-10423, might be mediated by A-type CCS52 (OsCCS52A), which still binds properly to APC and regulates mitotic cyclin to maintain the normal DNA content in nuclei. Another possibility is the presence of other genes, such as Kip-related proteins (KRPs), which functionally regulate the cell cycle by inhibiting cyclin-dependent kinase (CDK) activity. In particular, KRP1 and KRP3 in rice are reported to be involved in maintaining endoreduplication and in determining final seed size, respectively. |
| + | In accordance with our result, previous studies have reported that the level of endoreduplication in maize endosperm does not always affect the cell size, thus providing evidence of another mechanism for seed size regulation. Thus, cell expansion and endoreduplication may be independent events and not necessarily related under certain conditions. Kowles et al. and Fujikura et al. also reported that cell size regulation through cell expansion and DNA contents mediated by endoreduplication might not be tightly coupled. Cell expansion during endosperm development is also regulated by the surrounding phenomena, such as embryo development. In studies using a RNAi approach, the down-regulation of Orysa;CycB1;1 increases embryo size and inhibits endosperm development. This demonstrates the effect of a physical interaction in bordering cells between the embryo and endosperm. | ||
| + | Previous studies report that compensatory systems could maintain normal plant organ size, in which an increase in cell size is triggered by a decrease in cell number and vice versa. This compensation mechanism is thought to occur in the vegetative organs of either dicot or monocot plants. Our data reveal that the cell numbers in mutant endosperm are relatively higher than those in the wild-type. This may be due to a decrease in cell size, which can stimulate a compensatory increase in cell proliferation. However, this condition was not sufficient to restore the kernel phenotype, indicating that compensation mechanisms in endosperm, and their correlation with cell proliferation and cell expansion, are not as simple as those in vegetative organs. Further study is required to address this phenomenon. | ||
| + | In conclusion, these results provide a genetic basis for the involvement of OsCCS52B in maintaining growth and development. In addition, OsCCS52B is responsible for the normal shape and size of rice seeds via cell expansion regulation. Further study will be required to confirm whether transgenic rice overexpressing OsCCS52B alter plant morphology, especially in seed size. | ||
===Expression=== | ===Expression=== | ||
Revision as of 06:55, 9 June 2014
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Contents
Annotated Information
Function
During the whole plant life cycle, cell division and expansion work alternately to build and control the precise size of specific organs (Dupuy et al. 2010). In addition, during cell differentiation of post-embryonic tissue, either cell expansion or endoreduplication control the final size. CCS52 protein has been reported to be involved in cell expansion and endoreduplication, the functional characterization of B-type CCS52 (CCS52B) in plants is relatively limited. Previous studies of model plants (Medicago and Arabidopsis) have proposed that MtCCS52B and AtCCS52B play a crucial role in plant cell division. Yeast overexpressing AtCCS52B had smaller cells compared to the wild type, indicating an early start of the mitotic cell division cycle. Moreover, yeast cells harboring OsCCS52B grow slower than the wild type during the cycle, as determined by the proliferation assay (Fig. 4). Another distinct phenotype is yeast cell elongation prior to division. These results indicate that OsCCS52B may function in cell expansion rather than cell division. Although the yeast cell is elongated, the nuclei size remains similar to the wild type, indicating that no additional endoreduplication cycle occurs in OsCCS52B overexpressing cells (Fig. 3). In Arabidopsis, when AtCCS52B is overexpressed in fission yeast, the cells loose polarity control. Therefore, the nuclei location is not always in the center of the cells. In contrast to this phenomenon, the data presented here show that OsCCS52B overexpressing cells maintain the nuclei within the center of the cell. This indicates that the mode of action of AtCCS52B and OsCCS52B is different when overexpressed in yeast. To further confirm the functional role of OsCCS52B in plants, a T-DNA insertion mutant line 1B-10423 was characterized. This line exhibited a smaller seedling phenotype and semi-dwarf appearance at the mature stage. This phenotype was caused by a reduction in internode length. In addition, line 1B-10423 contains a narrower kernel than the corresponding wild type. These results indicate that OsCCS52B plays an essential role in the growth and development of rice, not only during the early developmental stage, but also during the grain filling stage. Grain filling is a critical stage, during which cereal plants modulate endosperm (seed) size due to the accumulation of photosynthates, such as starch and protein. Two main processes, endoreduplication and cell expansion, are reported to occur concomitantly with grain filling. Furthermore, endoreduplication and cell expansion might work concurrently or independently. In most cereals, successive rounds of endoreduplication start at 10 DAP and peak at 15–18 DAP. To determine whether the mutation in line 1B-10423 interferes with cellular development during endosperm formation, 15 DAP endosperm was sectioned and stained with DAPI to compare with the corresponding wild-type endosperm. Interestingly, microscopic analysis of the endosperm cells in line 1B-10423 revealed a smaller cell size without altering the nuclei size. Hence, cell size regulation in mutant seed could be separate and independent from the cell cycle progression associated with DNA endoreduplication. Therefore, OsCCS52B is more likely to be involved in the regulation of cell growth during endosperm development. Taken together with the yeast overexpression data, this result supports the hypothesis for the involvement of OsCCS52B in cell expansion rather than endoreduplication. To clarify this phenomenon, cell cycle progression in mutant endosperm was determined using flow cytometry. The results showed that mutant endosperm underwent a normal endoreduplication cycle, showing four peaks in the nuclei proportion corresponding to ploidy levels of 2C, 3C, 6C, and 12C (Fig. 6e). One possibility is that the endoreduplication cycle in the mutant line, 1B-10423, might be mediated by A-type CCS52 (OsCCS52A), which still binds properly to APC and regulates mitotic cyclin to maintain the normal DNA content in nuclei. Another possibility is the presence of other genes, such as Kip-related proteins (KRPs), which functionally regulate the cell cycle by inhibiting cyclin-dependent kinase (CDK) activity. In particular, KRP1 and KRP3 in rice are reported to be involved in maintaining endoreduplication and in determining final seed size, respectively. In accordance with our result, previous studies have reported that the level of endoreduplication in maize endosperm does not always affect the cell size, thus providing evidence of another mechanism for seed size regulation. Thus, cell expansion and endoreduplication may be independent events and not necessarily related under certain conditions. Kowles et al. and Fujikura et al. also reported that cell size regulation through cell expansion and DNA contents mediated by endoreduplication might not be tightly coupled. Cell expansion during endosperm development is also regulated by the surrounding phenomena, such as embryo development. In studies using a RNAi approach, the down-regulation of Orysa;CycB1;1 increases embryo size and inhibits endosperm development. This demonstrates the effect of a physical interaction in bordering cells between the embryo and endosperm. Previous studies report that compensatory systems could maintain normal plant organ size, in which an increase in cell size is triggered by a decrease in cell number and vice versa. This compensation mechanism is thought to occur in the vegetative organs of either dicot or monocot plants. Our data reveal that the cell numbers in mutant endosperm are relatively higher than those in the wild-type. This may be due to a decrease in cell size, which can stimulate a compensatory increase in cell proliferation. However, this condition was not sufficient to restore the kernel phenotype, indicating that compensation mechanisms in endosperm, and their correlation with cell proliferation and cell expansion, are not as simple as those in vegetative organs. Further study is required to address this phenomenon. In conclusion, these results provide a genetic basis for the involvement of OsCCS52B in maintaining growth and development. In addition, OsCCS52B is responsible for the normal shape and size of rice seeds via cell expansion regulation. Further study will be required to confirm whether transgenic rice overexpressing OsCCS52B alter plant morphology, especially in seed size.
Expression
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Evolution
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Labs working on this gene
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References
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Structured Information
| Gene Name |
Os01g0972900 |
|---|---|
| Description |
Similar to Clone ZZD405 mRNA sequence. (Fragment) |
| Version |
NM_001052078.1 GI:115442526 GeneID:4326397 |
| Length |
3262 bp |
| Definition |
Oryza sativa Japonica Group Os01g0972900, complete gene. |
| Source |
Oryza sativa Japonica Group ORGANISM Oryza sativa Japonica Group
Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
Spermatophyta; Magnoliophyta; Liliopsida; Poales; Poaceae; BEP
clade; Ehrhartoideae; Oryzeae; Oryza.
|
| Chromosome | |
| Location |
Chromosome 1:44744264..44747525 |
| Sequence Coding Region |
44744407..44744889,44744998..44745225,44745689..44745868,44746003..44746257,44746339..44746443 |
| Expression | |
| Genome Context |
<gbrowseImage1> name=NC_008394:44744264..44747525 source=RiceChromosome01 preset=GeneLocation </gbrowseImage1> |
| Gene Structure |
<gbrowseImage2> name=NC_008394:44744264..44747525 source=RiceChromosome01 preset=GeneLocation </gbrowseImage2> |
| Coding Sequence |
<cdnaseq>atggcgacggacgcgtcccccaagccggcgccgccgcgcctcaacgtgccgccggcgatggcgggggggctccgcctcgatcccgccgtcgcctccccggcccgcctcctcctcgacgtccccaagacgccatccccttccaagaccacgtacagcgaccgcttcatcccctgccgctcctcctcccgcctccacaacttcgccctcctcgaccgcgaccgcgcctccccctcctccaccaccgacgacgccccctactcccgcctcctccgcgccgagatcttcggcccggactccccctccccggctccctcctcccccaacaccaacctcttccgcttcaagaccgaccacccctcgcccaaatcgcccttcgccgcctccgccgccgccaccgccggccactacgactgcaccgccggctccgctgaatcctccacgccgcgcaagccgcccaggaaggtccccaagaccccgcacaaggtcctggacgcgccgtcgctgcaggacgacttctacctcaatcttgtcgactggtcgtcgcagaacacgctcgccgtcggcctcgggaattgcgtctacctctggtcggcttccaattgcaaggtcaccaagctctgcgatttggggcccagggacagcgtctgcgctgtgcactggacccgagaaggctcctatcttgccatcggcaccagccttggcgatgtccagatttgggatagctctcgctgtaaacggattaggaacatgggaggacaccaaacacggactggtgtattagcatggagctcccgaatcttgtcctccggtagcagggacaagaacatattgcagcatgacatccgtgtcccaagtgactatatcagcaagttctcagggcacagatcagaggtctgtggactgaaatggtcgcacgacgaccgtgagcttgcatccggtggaaatgataatcagctgctagtatggaaccaacgttcgcagcagccgatattgaggctgacagaacacacagctgcagttaaagcaatagcatggtcaccacatcagcaaggcctcctggcatcaggtggtggaaccgctgataggtgtatcaggttctggaacacggttaatggaaacatgctgaattcagtggacacaggcagccaggtttgtaatcttgcctggtgtaaaaatgtaaatgagcttgtgagcactcatgggtattcccaaaaccaaatcatggtgtggaagtacccatctatgtcaaaggttgctactctaactggacacacgctgcgagtgctttaccttgcaatgtcacctgatggacagacaatagtaacaggagccggggatgaaaccctcagattttggaatatttttccttcaatgaagacacaggctcctgttcgtgatattgggctctggtcattctcgagaagccacatacggtga</cdnaseq> |
| Protein Sequence |
<aaseq>MATDASPKPAPPRLNVPPAMAGGLRLDPAVASPARLLLDVPKTP SPSKTTYSDRFIPCRSSSRLHNFALLDRDRASPSSTTDDAPYSRLLRAEIFGPDSPSP APSSPNTNLFRFKTDHPSPKSPFAASAAATAGHYDCTAGSAESSTPRKPPRKVPKTPH KVLDAPSLQDDFYLNLVDWSSQNTLAVGLGNCVYLWSASNCKVTKLCDLGPRDSVCAV HWTREGSYLAIGTSLGDVQIWDSSRCKRIRNMGGHQTRTGVLAWSSRILSSGSRDKNI LQHDIRVPSDYISKFSGHRSEVCGLKWSHDDRELASGGNDNQLLVWNQRSQQPILRLT EHTAAVKAIAWSPHQQGLLASGGGTADRCIRFWNTVNGNMLNSVDTGSQVCNLAWCKN VNELVSTHGYSQNQIMVWKYPSMSKVATLTGHTLRVLYLAMSPDGQTIVTGAGDETLR FWNIFPSMKTQAPVRDIGLWSFSRSHIR</aaseq> |
| Gene Sequence |
<dnaseqindica>144..626#735..962#1426..1605#1740..1994#2076..2180#2602..2664#2751..2819#2896..2949#tgaccgttgcaacctcatctccgctcctcttcctcctcctcgtcgtcgttgtcgtcgtcggcggcgcatccagcctcgacgtgccggcggcggtgggtggcggggcagcagacgagcaagaaagagatccctagtctctctcgatggcgacggacgcgtcccccaagccggcgccgccgcgcctcaacgtgccgccggcgatggcgggggggctccgcctcgatcccgccgtcgcctccccggcccgcctcctcctcgacgtccccaagacgccatccccttccaagaccacgtacagcgaccgcttcatcccctgccgctcctcctcccgcctccacaacttcgccctcctcgaccgcgaccgcgcctccccctcctccaccaccgacgacgccccctactcccgcctcctccgcgccgagatcttcggcccggactccccctccccggctccctcctcccccaacaccaacctcttccgcttcaagaccgaccacccctcgcccaaatcgcccttcgccgcctccgccgccgccaccgccggccactacgactgcaccgccggctccgctgaatcctccacgccgcgcaagccgcccaggaaggtccccaagaccccgcacaaggtgggttcccaacgttccttcttccctcttcttgggcatttccacaaacacccactgcgcaactaaaacaatcttttggtttccgatccgtgtgcgtgcgcaactcaggtcctggacgcgccgtcgctgcaggacgacttctacctcaatcttgtcgactggtcgtcgcagaacacgctcgccgtcggcctcgggaattgcgtctacctctggtcggcttccaattgcaaggtcaccaagctctgcgatttggggcccagggacagcgtctgcgctgtgcactggacccgagaaggctcctatcttgccatcggcaccagccttggcgatgtccaggtttccccctctcatctcctctcctctactctctactgaataaattgcctgcagcatatgattgtcttcagtttatctatctagtacttagtagtaattgttttctacactctttagatttcatcacaacaattacacaaactatatacatcaattgttccaaatatcctgaatcctgggctgatgcaattcgcttcgttcaccatctcgtatgatagatgtacactagtaaagatttgaaacataagccctattgctgaaactctaaacttttattcgattctagtactaactatcactatcacaacacgtacatacttctttcaatgtgtccaggatgtgtgcgacagttttgtctgcaaatctcaaactacctatacttgaattagcctattgtttttgttcaactctgtgaatttgttcatggctatcgagaatttgatgcatacataaattccaacagatttgggatagctctcgctgtaaacggattaggaacatgggaggacaccaaacacggactggtgtattagcatggagctcccgaatcttgtcctccggtagcagggacaagaacatattgcagcatgacatccgtgtcccaagtgactatatcagcaagttctcagggcacagatcagaggtgagacttctaactacttccaagccataggtttttggaaaatagctcactaactatgcaagttaaaatcatcccatctcacagtaagatttcagaaccatgtatgtgcatcaagtgacagtttttttggtcaggtctgtggactgaaatggtcgcacgacgaccgtgagcttgcatccggtggaaatgataatcagctgctagtatggaaccaacgttcgcagcagccgatattgaggctgacagaacacacagctgcagttaaagcaatagcatggtcaccacatcagcaaggcctcctggcatcaggtggtggaaccgctgataggtgtatcaggttctggaacacggttaatggaaacatgctgaattcagtggacacaggcagccaggcgagtagttctgaacaagcctctaaaaagtagttcagtgaatttttactgtcatcctcaccagctgctttctgttttcaggtttgtaatcttgcctggtgtaaaaatgtaaatgagcttgtgagcactcatgggtattcccaaaaccaaatcatggtgtggaagtacccatctatgtcaaaggtaagcttaaattcccgtgggctgtcaagcctactaattcaccagttagacaattgtgcatcaagtaatcactcattcggataaaaacgtgaaaaaaagcagaggaagttatgtgtctgatttctcctagggttgtttccaaagaactcattcctttctgtgggccgagacattgactcatggattgcttaaacgcttaaaaggaatttagtatcaacatagttgacgagcatgtaatgcttaaaaagaacaatatcagtatggctgcaaatccaagtgaagtatttcacagggggctattttcatttgtatttgcagataaggataagagtagaataattcctttgaatttttaatatctgttcaagaaagatttccactagtgcagtaccactaagtattttatgttttcgataaacaggttgctactctaactggacacacgctgcgagtgctttaccttgcaatgtcacctgatggacaggtaaatctttttccaaactgcaaatcatgtatccggaaaaatattcctgggaatcgtcctaaatgatgcatattactcatttgcagacaatagtaacaggagccggggatgaaaccctcagattttggaatatttttccttcaatgaagacacaggtaggcatctattgttgaacacagattttatttattttgtggcttgtagcttgaactgccatattgtttgcaccaggctcctgttcgtgatattgggctctggtcattctcgagaagccacatacggtgaccataataggaggcaaagaaaatgcatatgtttgtatgaaacataattttctgaacttgtgcagttcttcagcgatttgtaaattgtgaggcctaattattcatttattgtttgtgtgcgcgtgtgtgtctgtgagatcgagagaaagggagaagaactcatattaacataaccaattctttgtattagaagctcataagtcggctagtttcttgtttggaatttcattgcagagaaacaagggccttgtaatttatcacaaacttatatgcttgtattattctcacacactttgtggccatttcatgacttc</dnaseqindica> |
| External Link(s) |
