Os07g0261200
Ghd7 is a gene controlling rice grain number per panicle,plant height,heading stage,and the main effect of QTL.
Grain Number, Plant Height, and Heading Date7（Ghd7） Is a Central Regulator of Growth, Development, and Stress Response in rice
Contents
Function
In long sunshine condition, the enhanced expression of Ghd7 could delay the earing, increase the plant height and grain number per panicle, and the natural mutant with weaken function can grow to temperate and even colder regions. Ghd7, therefore, has a very important role for an potential increase and adaptability in global rice yield . PhyA alone or phyB and phyC work together can induce Ghd7 mRNA accumulation, and phyB alone can reduce the Ghd7 mRNA level to some degree. In addition phyB and phyA can influence the actiity of the Ghd7 and Hd1 respectively. Hd2 and Hd16, Hd2 and genetic interactions between Ghd7. Hd2 and its genetic interactions has a very important role for heading stage by controlling the condition of long sunshine.
Grain number, plant height, and heading date7 (Ghd7) has been regarded as an important regulator of heading date and yield potential in rice;As a long-day dependent negative regulator of heading date, the degree of phenotypic effect of Ghd7 on heading date and yield traits is quantitatively related to the transcript level and is also influenced by both environmental conditions and genetic backgrounds. Ghd7 regulates yield traits through modulating panicle branching independent of heading date. Ghd7 also regulates plasticity of tiller branching by mediating the PHYTOCHROME B-TEOSINTE BRANCHED1 pathway;so,Ghd7 functions to integrate the dynamic environmental inputs with phase transition, architecture regulation, and stress response to maximize the reproductive success of the rice plant[1].
Grain number, plant height, andheading date7 (Ghd7) encoding a CCT (CONSTANS,CONSTANS-LIKE, and TIMING OF CHLOROPHYLL A/B BINDING1) domain protein is considered to be a key regulator of the rice-specific flowering pathway and also contributes to rice yield potential[2];Ghd7 controls the critical daylength response of Early heading date1 (Ehd1) and florigen expression through circadian gating and phytochrome action[3][4].Ghd7 showed pleiotropic effects on heading date,plant height, and yield traits, and its expression was regulated by light signal and photoperiod[2][3].
The effect of Ghd7 on tillering in different density conditions: Researchers designated NIL(zs7) and NIL(mh7), with almost all of the genetic background of Zhenshan 97 except the introgressed segment, which contained the Ghd7; NIL(mh7) plants had significantly more tillers than NIL(zs7) plants at low-density conditions (Fig. 1), demonstrating that Ghd7 regulates tiller number in a density-dependent manner. Interestingly, there was also a significant increase in secondary branches of the panicles in NIL(mh7) relative to NIL(zs7) at low density, leading to an increased grain number without compromising the number of primary branches;These results suggest that Ghd7 regulates the plasticity of branch development of the plant to adapt to the neighborhood environment[1].
Ghd7 has pleiotropic effects on three agronomic traits---plant height(PH), Heading date (HD) and spikelets per panicle(SPP). Ghd7 delays HD, increases PH and panicle size, and results in enhanced gene expression of Ehd1 and Hd3a under long-day conditions. Expression pattern analysis suggested that Ghd7 may function upstream of Ehd1 and Hd3a in the rice flowering pathway. Association analysis of 19 rice cultivars identified five allelic variants of Ghd7. The Ghd7 alleles with strong genetic effects were shown to increase grain yield by adapting to the long growing season of tropical regions and the Ghd7 alleles with no or reduced effect found in temperate regions shortened the rice life cycle to ensure seed setting[2].
Expression
Ghd7 cDNA of Minghui 63 is 1013 bp, encoding a nucleoprotein composed of 257 amino acid , the product is protein structure,ie,a CCT (CO, CO - LIKE the and TIMING OF CAB1) , and the CCTS OF arabidopsis CO protein domain has a lot OF similarities, but differently. it has no obvious zinc finger protein structure, and these two protein homologous relationship is not too big.
Stresses that regulate the expression of Ghd7:
Drought, abscisic acid, jasmonic acid, and high-temperature stress strongly repressed Ghd7 expression, whereas low temperature enhanced Ghd7 expression. Overexpression of Ghd7 increased drought sensitivity, whereas knock-down of Ghd7 enhanced drought tolerance. Gene chip analysis of expression profiles revealed that Ghd7 was involved in the regulation of multiple processes, including flowering time, hormone metabolism, and biotic and abiotic stresses[1].
Genes regulate the expression of Ghd7 are as follows:
Two orthologs of EARLY FLOWERING3 genes, which mediate the circadian and photoperiodic regulation, act as negative regulators of Ghd7[5][6] ;Rice Indeterminate1 acts as a master switch for the transition from vegetative to reproductive phase and regulates the expression of Ghd7 independent of the photoperiod[7];Ehd3, which contains two plant homeodomain finger motifs and is possibly involved in chromatin state modulation, negatively regulates the transcription of Ghd7[8];Heading date16 (Hd16), a flowering time quantitative trait locus gene, was recently shown to encode a casein kinase I protein that mediates the phosphorylation of GHD7 and enhances the photoperiod response[9].
By using single and double phytochrome mutant lines of rice, results show that either phyA alone or a genetic combination of phyB and phyC can induce Ghd7 mRNA, whereas phyB alone causes some reduction in levels of Ghd7 mRNA. Moreover, phyB and phyA can affect Ghd7 activity and Early heading date1 (a floral inducer) activity in the network, respectively. Therefore, each phytochrome gene of rice has distinct roles, and all of the phytochrome actions coordinately control the critical daylength response of florigen expression in rice;some time-keeping molecular mechanisms exist beside the phytochrome signaling in rice, possibly independent of the circadian clock (Fig. 1). The possible action of phyB to enhance Ghd7 activity and thus to control Ehd1 expression, and the possible action of phyA to reduce Ehd1 activity and thus control Hd3a/RFT1 expression, are likely to be both daylength sensitive. In addition to elucidating how light conditions contribute to the formation of the Ghd7 and Ehd1 gates, these results raise new questions as to the molecular mechanisms by which rice phytochromes measure daylength.[10]
Ghd7 and Protein diversity of Ghd7:
Ghd7 is encoded by Ghd7 .
SNPs in exons, Ghd7 protein diversity was analyzed in the present study.Ghd7 has a partial-dominant effecton flowering time, plant height, and yield traits;The phenotypic effect of Ghd7 is quantitatively related to the abundance of its transcript, and the enhanced transcript level of Ghd7 caused delayed flowering, increased plant height, and yield traits[1].
Localization and Evolution
Ghd7 is located in rice chromosome 7 between markers R1440 and C1023; Further,percisely it is located between RM5436 and RM2256 range ,the length of which is 79 KB. Ghd7, a CCT domain-containing gene located on the short arm of rice chromosome 7, controls the number of grains per panicle, plant height and heading date[2].Ghd7 is thought to be an evolutionarily new gene, because it does not have homologs in Arabidopsis thaliana, and the protein sequence lacks a B-box domain, and the non-CCT portion differs from other CCT domain-containing proteins[2][12].
Ghd7 is a pleiotropic gene that controls the traits of Plant height, heading date, and yield.In this study[11], a rice germplasm collection of 104 accessions (Oryza sativa) and 3 wild rice varieties (O.rufipogon) was used to analyze the evolution and association of Ghd7 with plant height, heading date, and yield. Among the 104 accessions, 76 single nucleotide polymorphisms (SNPs) and six insertions and deletions were found within a 3932-bp DNA fragment of Ghd7. A higher pairwise p and h in the promoter indicated a highly diversified promoter of Ghd7. Sixteen haplotypes and 8 types of Ghd7 protein were detected. SNP changes between haplotypes indicated that Ghd7 evolved from two distinct ancestral gene pools, and independent domestication processes were detected in indica and japonica varietals respectively. In addition to the previously reported premature stop mutation in the first exon of Ghd7, which caused phenotypic changes of multiple traits, we found another functional C/T mutation (SNP S_555) by structure-based association analysis. SNP S_555 is located in the promoter and was related to plant height probably by altering gene expression. Moreover, another seven SNP mutations in complete linkage were found to be associated with the number of spikelets per panicle, regardless of the photoperiod. These associations provide the potential for flexibility of Ghd7 application in rice breeding programs.
Large regions of non-conservation were observed between the sorghum and rice Ghd7 orthologous regions.Sequence analysis demonstrated high gene collinearity across the genus Oryza and a disruption of collinearity among non-Oryza species. In particular, Ghd7 was not present in orthologous positions except in Oryza species. The Ghd7 regions were found to have low gene densities and high contents of repetitive elements, and that the sizes of orthologous regions varied tremendously. The large transposable element contents resulted in a high frequency of pseudogenization and gene movement events surrounding the Ghd7 loci. Annotation information and cytological experiments have indicated that Ghd7 is a heterochromatic gene. Ghd7 orthologs were identified in B. distachyon, sorghum and maize by phylogenetic analysis; however, the positions of orthologous genes differed dramatically as a consequence of gene movements in grasses. Rather, we identified sequence remnants of gene movement of Ghd7 mediated by illegitimate recombination in the B. distachyon genome[13].
Labs working on this gene
1.National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
2.Graduate School of Frontier Sciences, University of Tokyo,and Functional Plant Research Unit, National Institute of Agrobiological Sciences
3.QTL Genomics Research Center, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan
4.Institute of the Society for Techno-innovation of Agriculture, Forestry and Fisheries, Tsukuba, Ibaraki, 305-8518, Japan
References
<references> [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
Structured Information
| Gene Name |
Os07g0261200 |
|---|---|
| Description |
XXX |
| Version |
XXX |
| Length |
XXX bp |
| Definition |
Oryza sativa Japonica Group Os07g0261200, 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 7:XXX..XXX |
| Sequence Coding Region |
start1...end1, start2..end2 |
| Expression | |
| Genome Context |
<gbrowseImage1> name=NC_008400:start..end source=RiceChromosome07 preset=GeneLocation </gbrowseImage1> |
| Gene Structure |
<gbrowseImage2> name=NC_008400:start..end source=RiceChromosome07 preset=GeneLocation </gbrowseImage2> |
| Coding Sequence |
<cdnaseq>XXX</cdnaseq> |
| Protein Sequence |
<aaseq>XXX</aaseq> |
| Gene Sequence |
<dnaseqindica>XXX</dnaseqindica> |
| External Link(s) |
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Weng XY,Wang L,Wang J,et al.(2014) Grain Number, Plant Height, and Heading Date7 Is a Central Regulator of Growth, Development, and Stress Response Plant Physiology 164(2): 735-747
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Xue W, Xing Y, Weng X,et al.(2008)Natural variation in Ghd7 is an important regulator of heading date and yield potential in rice. Nat Genet 40: 761–767
- ↑ 3.0 3.1 3.2 Itoh H, Nonoue Y, Yano M, etal.(2010) A pair of floral regulators sets critical day length for Hd3a florigen expression in rice. Nat Genet 42: 635–638
- ↑ 4.0 4.1 Osugi A, Itoh H, Ikeda-Kawakatsu K, etal.(2011) Molecular dissection of the roles of phytochrome in photoperiodic flowering in rice. Plant Physiol 157: 1128–1137
- ↑ 5.0 5.1 Zhao J, Huang X, Ouyang X, etal.(2012) OsELF3-1, an ortholog of Arabidopsis early flowering 3, regulates rice circadian rhythm and photoperiodic flowering. PLoS ONE 7:e43705
- ↑ 6.0 6.1 Yang Y, Peng Q, Chen GX, etal.(2013) OsELF3 is involved in circadian clock regulation for promoting flowering under long-day conditions in rice. Mol Plant 6: 202–215
- ↑ 7.0 7.1 Wu C, You C, Li C, Long T,et al.(2008) RID1,encoding a Cys2/His2-type zinc finger transcription factor, acts as a master switch from vegetative to floral development in rice. Proc Natl Acad Sci USA 105: 12915–12920
- ↑ 8.0 8.1 Matsubara K, Yamanouchi U, Nonoue Y,et al.(2011) Ehd3, encoding a plant homeodomain finger-containing protein, is a critical promoter of rice flowering. Plant J 66: 603–612
- ↑ 9.0 9.1 Hori K, Ogiso-Tanaka E, Matsubara K, et al.(2013) Hd16, a gene for casein kinase I, is involved in the control of rice flowering time by modulating the day-length response. Plant J 76: 36–46
- ↑ 10.0 10.1 10.2 Osugi A, Itoh H,Ikeda-Kawakatsu K, et al.(2011)Molecular dissection of the roles of phytochrome in photoperiodic flowering in rice. Plant Physiology 157(3): 1128-1137
- ↑ 11.0 11.1 11.2 Lu L, Yan WH, Xue WY; et al.(2012)Evolution and Association Analysis of Ghd7 in Rice. PLoS ONE, 2012, 7(5): e34021
- ↑ 12.0 12.1 Griffiths S, Dunford RP, Coupland G,etal.(2003) The evolution of CONSTANS-like gene families in barley, rice, and Arabidopsis. Plant Physiol 131:1855–1867.
- ↑ 13.0 13.1 13.2 Yang L, Liu T, Li B,et al. (2012) Comparative Sequence Analysis of the Ghd7 Orthologous Regions Revealed Movement of Ghd7 in the Grass Genomes. PLoS ONE 7(11): e50236. doi:10.1371/journal.pone.0050236.
