Os07g0605200

Please input one-sentence summary here.

Annotated Information

Function

Please input function information here.

OsMADS18 from rice (Oryza sativa) belongs to the phylogenetically defined AP1/SQUA group. The MADS box genes of this group have functions in plant development, like controlling the transition from vegetative to reproductive growth, determination of floral organ identity, and regulation of fruit maturation.

RNAi-Mediated Silencing of OsMADS18

We used an RNAi-based approach to silence OsMADS18 in rice. A specific portion of the OsMADS18 cDNA, lacking the highly conserved MADS box and part of the I region, was cloned in antisense and sense orientation in an RNAi expression cassette, under the control of the cauliflower mosaic virus (CaMV) 35S promoter. The construct was transformed into rice by Agrobacterium-mediated transformation. A total of 31 independent hygromycin-resistant calli were obtained. For each of these calli one regenerated plant was analyzed in detail. The RNAi approach proved to be very efficient in silencing OsMADS18 since 60% of the lines showed reduction of transcript levels to various degrees (Fig. 4). For more than 80% of these lines OsMADS18 mRNAs could not be detected by northern-blot analysis while the remaining 20% still expressed OsMADS18, although very weakly. Both the 31 T0 plants and the T1 progeny of 10 selected transformants were normal in development. No visible alterations were observed in panicleand flower morphology. Furthermore, we analyzed these plants for differences in flowering time under inductive short day (12 h light/12 h dark) and non-inductive long day (16 h light/8 h dark) conditions.This analysis showed that the flowering time of the RNAi plants is comparable to wild-type plants (data not shown). These observations suggest that other genes are possibly redundant with OsMADS18. Possible candidates for such a role, as inferred from phylogenetic analysis, are OsMADS14, OsMADS15,and/or OsMADS20 (Lee et al., 2003).

Overexpression of OsMADS18 in Rice

To address the function of OsMADS18 in rice，we constructed an overexpression cassette, fusing the OsMADS18 coding sequence with the strong CaMV35S promoter. Twenty-seven independent transgenic lines that overexpressed the transgene at different levels were identified (data not shown). Four of these plants that showed the highest levels of OsMADS18 expression remained very small in size and flowered at 105 d after germination compared to wild-type plants which flower at 140 d after germination(Fig. 5A). Two of them (501S and 1102S) were selected for further studies. Expression analysis of progeny plants of line 501S and 1102S demonstrated that OsMADS18 overexpression segregated with the early flowering phenotype (data not shown).In order to test whether OsMADS18 overexpression affected only the transition to flowering or had a broader effect on rice development, we carried out a detailed morphological analysis on plants,ranging from 0 to 30 d after germination (Fig. 5D). The first effects can already be observed 5 d after germination (Fig. 5, B and C). At this time leaves of transgenic plants are still enclosed by the coleoptile, while wild-type leaves are already emerging from it. After 7 d from germination wild-type plants are about 12 mm long while the transgenic 501S and 1102S plants are 5.5 mm on average (Fig. 5D). Lines 501S and 1102S stay smaller than wild-type plants and this effect is due to a lower rate of internode elongation (Fig. 6, D–G) and a reduction in the length of the leaf sheath. Despite this difference, leaf number is comparable between wild-type and transgenic lines. Regardless of this deficiency in elongation ability, mutant lines form axillary meristems earlier than wild-type plants. These axillary buds are visible in lines overexpressing OsMADS18 after 7 d from germination (Fig. 6, A and B), whereas in wild-type plants these buds develop only after 15d, from germination (Fig. 6C and Supplemental Fig. 1, available at www.plantphysiol.org). Furthermore, in the leaves of the transgenic plants the aerenchyma differentiates earlier than in wild-type plants and the aerenchyma cavities are larger (Fig. 6, A and B). We also monitored the effects on root development in the transgenic lines 501S and 1102S. Microscopic analysis revealed that the adventitious root primordia develop at the same time as in wild-type plants although their number was reduced in these transgenic lines. Furthermore, at early stages the adventitious root elongation in lines 501S and 1102S is slower compared to wild-type plants (Fig. 5D; Supplemental Table I). The differences between wild-type and transgenic lines are more evident shortly after germination but, as the plants proceed in development, the developmental gap between wild-type and transgenic lines is progressively reduced (Fig. 5D; Supplemental Table I). After 30 d from germination the number and length of adventitious roots in wild-type and transgenic lines are comparable although in the transgenic lines the aerenchyma is still at a more advanced stage of development (Fig. 6, H and I).

Expression

Please input expression information here.

OsMADS18 is widely expressed in rice with its transcripts accumulated to higher levels in meristems.Expression of OsMADS18 in Arabidopsis Causes an ap1 Mutant Phenotype AP1/SQUA-like genes, when overexpressed, generally cause an early flowering phenotype. To investigate whether OsMADS18 also induces early flowering in Arabidopsis we ectopically expressed OsMADS18 in this heterologous system. No significant effect on flowering time was observed, however, surprisingly, 10% of the plants (of a total of 100 transformants) showed floral phenotypes that were very similar to the ap1 mutant (Fig. 7H; Irish and Sussex, 1990; Bowmanet al., 1993). The mildest phenotypes show only a reduction in sepal and petal size (Fig. 7B). The result is that the pistil is not enclosed by the perianth organs and protrudes from the flower. Plants having an intermediate phenotype have flowers that in the first whorl develop leaf-like organs bearing stellate trichomes, which is typical for cauline leaves (Fig. 7C), while wild-type sepals have simple trichomes(Fig. 7A).Around 5% of the plants showed more severe phenotypes. Some of the first-whorl organs were homeotically converted to carpelloid organs on which ovules developed (Fig. 7F). In these severely affected flowers the petals were, in general, completely absent (Fig. 7, E and F). Frequently the most affected plants had flowers from which extra flowers arose from the axils of the first whorl organs (Fig. 7) and this pattern was reiterated producing tertiary and even quaternary flowers (Fig. 7G).

Evolution

Please input evolution information here.

In CaMV35S:OsMADS18 Arabidopsis Plants AP1 Expression Is Not Affected

One of the possible explanations for the ap1 phenotypes that we observed in the Arabidopsis plants that expressed OsMADS18 could be that in these transgenic plants the expression of the endogenous AP1 gene is repressed. To verify this possibility we per-check for the expression of AP1 in these transgenic plants. Figure 8 shows the RT-PCR products obtained using RNA extracted from transgenic and control wild-type flowers. These analyses show that AP1 expression is not affected in these transgenic plants.

You can also add sub-section(s) at will.

Labs working on this gene

Please input related labs here.

References

Please input cited references here.

Bowman JL, Alvarez J, Weigel D, Meyerowitz EM, Smyth DR (1993) Control of flower development in Arabidopsis thaliana by APETALA1 and interacting genes. Development 119: 721–743

Lee S, Kim J, Son JS, Nam J, Jeong DH, Lee K, Jang S, Yoo J, Lee J, Lee DY, et al (2003) Systematic reverse genetic screening of T-DNA tagged genes in rice for functional genomic analyses: MADS box genes as a test case.Plant Cell Physiol 44: 1403–1411

Irish VF, Sussex IM (1990) Function of the apetala-1 gene during Arabi-dopsis floral development. Plant Cell 2: 741–753

Structured Information

Gene Name	Os07g0605200
Description	MADS box transcription factor 18 (OsMADS18) (MADS box protein 2) (MADS box protein 28) (FDRMADS7)
Version	NM_001066760.1 GI:115473252 GeneID:4343851
Length	5204 bp
Definition	Oryza sativa Japonica Group Os07g0605200, 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	Chromosome 7
Location	Chromosome 7:25448633..25453836
Sequence Coding Region	25448722..25448906,25451634..25451712,25451807..25451871,25451951..25452050,25452166..25452207 ,25452799..25452837,25452934..25453067,25453482..25453587
Expression	GEO Profiles:Os07g0605200
Genome Context	<gbrowseImage1> name=NC_008400:25448633..25453836 source=RiceChromosome07 preset=GeneLocation </gbrowseImage1>
Gene Structure	<gbrowseImage2> name=NC_008400:25448633..25453836 source=RiceChromosome07 preset=GeneLocation </gbrowseImage2>
Coding Sequence	<cdnaseq>atggggagagggccggtgcagctgcggcggatcgagaacaagataaacaggcaggtgaccttctccaagcggaggaacgggctgctgaagaaggcgcacgagatctccgtgctctgtgacgccgacgtcgcgctcatcgtcttctccaccaagggcaagctctacgagttctccagccactccagtatggaagggatccttgaacgctaccagcgttactcgtttgatgaaagagccgtactggagccaaatactgaggaccaggaaaactggggtgatgaatatggaattttgaagtccaaactggatgcacttcagaagagccaaaggcaactcttaggtgaacaattggacacactaacaataaaagaactccagcaattggaacatcaactggaatattctctgaagcatataagatcaaaaaagaatcagcttctgtttgaatcaatttctgagcttcagaagaaggaaaagtcacttaaaaaccagaataatgttctgcaaaagctcatggagacagaaaaggagaaaaacaatgctataataaacactaaccgggaggagcaaaatggagcaacaccaagcacatcatcaccaacaccagtgacggctccagatcccatcccgacaacaaataacagtcaaagccaaccaagaggatcaggggagtcagaagctcaaccgtctccggcacaagcaggcaacagcaagcttccgccatggatgctccggacaagtcacacatga</cdnaseq>
Protein Sequence	<aaseq>MGRGPVQLRRIENKINRQVTFSKRRNGLLKKAHEISVLCDADVA LIVFSTKGKLYEFSSHSSMEGILERYQRYSFDERAVLEPNTEDQENWGDEYGILKSKL DALQKSQRQLLGEQLDTLTIKELQQLEHQLEYSLKHIRSKKNQLLFESISELQKKEKS LKNQNNVLQKLMETEKEKNNAIINTNREEQNGATPSTSSPTPVTAPDPIPTTNNSQSQ PRGSGESEAQPSPAQAGNSKLPPWMLRTSHT</aaseq>
Gene Sequence	<dnaseqindica>90..274#3002..3080#3175..3239#3319..3418#3534..3575#4167..4205#4302..4435#4850..4955#ctccccccatttccatcttccccgagctctccaccctccacccgccaccgccaccgccgccttcgccgccgccgccgccgccgacgacgatggggagagggccggtgcagctgcggcggatcgagaacaagataaacaggcaggtgaccttctccaagcggaggaacgggctgctgaagaaggcgcacgagatctccgtgctctgtgacgccgacgtcgcgctcatcgtcttctccaccaagggcaagctctacgagttctccagccactccaggtacgcacgcgcttagctcctcctcctcctcctcctcctctccgcgacctcccgcctacctacgtagtacggcccatgcccgtcgcctttcctcgccgcgcgcgcgccatgggcgagctcgcggagctccccgttcctgggcggcttgttgatgcgttcgatttcgtttcgtacgggttcctgccttgtgttcgatcgtttccgctgcggaatgcgagggggctggtggtgttggtgcgtgtacgattgctattatttcgtgctgattgatttctctcatgtgctctctgattgcacatacggttcatggctttgtacgtgttcgttcgtgcgattgctgcttagctcgggatggagttgctcgcgaagtctagctagttgtaggttgcttgtgtcccctggattacagctctctatgtgatgctggcatgctgctgctgctgctgccatgcatatcagaagctagtaatatacagtggtggtacatgcactgttgctgatttagctttatatgctgctcagttttgttcttggggactcatcaatcatcgtagcattggtgaacacgttcacttccatttttttttgtataaaaaggaatggaataataggtgaaaaaaaattcatgtgcttcatcagtacgggcggaaagaaagatatgtttaaattttaattagtgtgcttatctaggtttatcatatgcttatactcttgtgtactgtagcatatacaagtgatgcttattaccaaagcctagctaggccggtaaacttgtattatttgtctcgttatttctggaaatcattagagcagcacttcagttgaaatatgcacggacgccttgctaattaagcggctcctctaaccaggccagtaaggtcttaagttactgacaactcctggactggtataaatggcgcggccagctttacatgacatatggtttgatacttttgtttagttaatttcgaggtggaatataaggtgaccagcttacttaacttgttcatttgatgcattcggtttcatttccctttttttttttaagataatgggaagtaaattaatacccggccttgctttaactgaaactacaactttcttttgtccctttagtgtgtactgtcaccaagttagctatacatggtgcaagttgccattgcccattgctattaacttgctctcacaaattggggtgtttatttcttgaaatggattttttaggacaacaataaactgattgacatagctatactgttcaagtataaccatgtttatggttttcaattaagcaaactgcttatgtttatgctaatatcttttgtttaatgggaggaatttaaatatttcattattggtattcctatactctattatttcataatatttggcaattttgaccggtgattgcttcagtttaaccattaatatcttttaaaatttatgattatgatggatgggatttatatctctatatttaccattaccatgtaacatactttaataatatgttacataatctaatactaaaagtttatttataaaattggaatggccaaactaaaacaatgcgaacttaaaatcaccaagtattatgaaatggagggagcataatatcagtagctcgtaagggaaaaaagggacctaaatgatgccttttgtgataaatataatttcaaatttgcaaaatttttggataggcaacaatactctctcattattgtgttagtattaaggtcaagctacttctatgctaccaaatactccttctgttcctttttttatttcttgtctaggatattgacattatccctaacacacatctttctttgtatgatcatctactcataaaatagttaaaatataactacattattcaattatgaatctatgaatgttatttttatacaccgagttgggaactattctaaactctcgaggggacatcccctcattatctgcatgttatccaaacggttgtgaaaaaaattgaaaaaaaataaacaagatagattaatatgtgataaatcactccacaaacatgcaaggacaaattcaaattctacaagttgcaatgaaaaaattaaatttgaccgtgaatatacattaactagccatagtttaatttttttttgttgtaacttgtagaagttgaatttgaacttgcatgtttgtgaagtaatctatcacatattaatctatcttgtcgatttttttttaaaaaaatcataaccatttagatgacatgcaaaaaacgaggggatgttcccttgagagtttagaatccattctccagtgagttgatgttgagatttgattacacatttcaaaacgacttttatttgttaacgaagggagtaatgtggattcaccatatgtactaatgttattaaggccagataatcctttttttaatcattctaattagatataaacttacgacgaagaacatgaatggataaagtttcagccaacaaatacaaatgtttttcaaagtgctatttctgatgcataatttttgtagcagttatgatttaaatttatacatggataatttgaataatggatcctacttttgtagttgtcacctgacaagccttaagaattattgagggtacaaaaattataactgtgcatttgtttgatattgctctaagactatgcttggcatcatcttttgatgcattggtcaaaccaaagcataatcatgtgatacttcttctgtagtatggaagggatccttgaacgctaccagcgttactcgtttgatgaaagagccgtactggagccaaatactgaggaccaggtaaaaaaacatccctgactgttggagaactatctccggctgtttatttaactagctggttagttatctgatcttgatattcattttctcctaggaaaactggggtgatgaatatggaattttgaagtccaaactggatgcacttcagaagagccaaaggtactgcaaactttcttaagaaattttcactttggtaacaagattatgctaacttgagttggtctatctactgctcaaggcaactcttaggtgaacaattggacacactaacaataaaagaactccagcaattggaacatcaactggaatattctctgaagcatataagatcaaaaaaggtgaaatttgtgtccattatgcactgttgactgagggatcaaatttgcttgatttaattatttccaactaatctttgaaaacatcattactttcctttttgtttttcttttgcagaatcagcttctgtttgaatcaatttctgagcttcagaagaaggtaggttaccctcaatgtggctccttaaatagcaatgtagcagtctgtttataccatattgttttggagtattaaagttgcattcaaacaattttcagacaactaactcttcttgccttctaccagaatatattcatgtaaaacatgtcttttggcaattctagaaattccattataagaagaaatcattagtcaatttgaatcacctaaggaactaacgagaagccacttgtcttggtcatattgtgggaaatgcacaatgttgtcaaatgggtataacaggaaagtcgccatcaatgtatatattctaggggagagagaacagactaagtcagactacgttgtaaaattgaacattctacgggaaaataaatcttcgatgcatatggcaaggacttgaccgttagccttttacgcaataatgtatgcataaacatagggaaaaaaaaggacctgcactactgattgttactgtatctgatctggcaagtggcaacagagccatgttaatattgtgctgagaaatggacgaagttgatataggttcgtgctgatgaatattcttacaatctgctatcttcctgtctgcaggaaaagtcacttaaaaaccagaataatgttctgcaaaaggtaaatttcattcttgtttacaacaatgttttatatcagatcactacaaaagctgtattggaggtcaaacccttttgtctacattcttcggagcagctcatggagacagaaaaggagaaaaacaatgctataataaacactaaccgggaggagcaaaatggagcaacaccaagcacatcatcaccaacaccagtgacggctccagatcccatcccgacaacaaataacaggtaccgcttttacttccatatattttgcccctgcactcaccataaataaaacaaaactctgttttgttcttcagcaaatttttattctatattttttcttttatcagacttccattatctatcacagttcagtagtttttgatggtctatgcctaggaaacttaatccggtgaaatttgttcaatcaaatgctgccggtctatttcatatggctattggaagtttggaacaaataagcccaggcctgaaagcgcctgaaccaaacagtgaaaaagcctccaaatggtttggtctcagcttgatatatcatgtctgaacaataacttgacgttaggaatgatctagcatgttactactatttcatcaactccattgtctgttttagttatgctgtttttcctcatcttaattcagtcaaagccaaccaagaggatcaggggagtcagaagctcaaccgtctccggcacaagcaggcaacagcaagcttccgccatggatgctccggacaagtcacacatgaaggcatctgttgatctcaaacgtcactccactcaatggccaacatcaacatgtttcttccaactaaggcagccactgttgtgcaatccatcttccagcgatattgatatatcggcattcggcatagccaatatatattaatgtaatgtatcttgtcaaagcttcatagggttaatgacgccttgagcttctctgttctatatctgtcttgtaacgatctttgcatatctgctgcatttttttttctctc</dnaseqindica>
External Link(s)	NCBI Gene:Os07g0605200, RefSeq:Os07g0605200