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1.
Proc Natl Acad Sci U S A ; 116(32): 15967-15972, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31341087

RESUMO

The organization of microtubules into a bipolar spindle is essential for chromosome segregation. Both centrosome and chromatin-dependent spindle assembly mechanisms are well studied in mouse, Drosophila melanogaster, and Xenopus oocytes; however, the mechanism of bipolar spindle assembly in plant meiosis remains elusive. According to our observations of microtubule assembly in Oryza sativa, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum, we propose that a key step of plant bipolar spindle assembly is the correction of the multipolar spindle into a bipolar spindle at metaphase I. The multipolar spindles failed to transition into bipolar ones in OsmtopVIB with the defect in double-strand break (DSB) formation. However, bipolar spindles were normally assembled in several other mutants lacking DSB formation, such as Osspo11-1, pair2, and crc1, indicating that bipolar spindle assembly is independent of DSB formation. We further revealed that the mono-orientation of sister kinetochores was prevalent in OsmtopVIB, whereas biorientation of sister kinetochores was frequently observed in Osspo11-1, pair2, and crc1 In addition, mutations of the cohesion subunit OsREC8 resulted in biorientation of sister kinetochores as well as bipolar spindles even in the background of OsmtopVIB Therefore, we propose that biorientation of the kinetochore is required for bipolar spindle assembly in the absence of homologous recombination.

2.
Plant Physiol ; 180(2): 952-965, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30926655

RESUMO

Stigma and ovule initiation is essential for sexual reproduction in flowering plants. However, the mechanism underlying the initiation of stigma and ovule primordia remains elusive. We identified a stigma-less mutant of rice (Oryza sativa) and revealed that it was caused by the mutation in the PINOID (OsPID) gene. Unlike the pid mutant that shows typical pin-like inflorescences in maize (Zea mays) and Arabidopsis (Arabidopsis thaliana), the ospid mutant does not display any defects in inflorescence development and flower initiation, and fails to develop normal ovules in most spikelets. The auxin activity in the young pistil of ospid was lower than that in the wild-type pistil. Furthermore, the expression of most auxin response factor genes was down-regulated, and OsETTIN1, OsETTIN2, and OsMONOPTEROS lost their rearrangements of expression patterns during pistil and stamen primordia development in ospid Moreover, the transcription of the floral meristem marker gene, OSH1, was down-regulated and FLORAL ORGAN NUMBER4, the putative ortholog of Arabidopsis CLAVATA3, was up-regulated in the pistil primordium of ospid These results suggested that the meristem proliferation in the pistil primordium might be arrested prematurely in ospid Based on these results, we propose that the OsPID-mediated auxin signaling pathway plays a crucial role in the regulation of rice stigma and ovule initiation by maintaining the floral meristem.

3.
J Integr Plant Biol ; 61(8): 911-916, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30697955

RESUMO

Apomixis is an asexual reproduction way of plants that can produce clonal offspring through seeds. In this study, we introduced apomixis into rice (Oryza sativa) by mutating OsSPO11-1, OsREC8, OsOSD1, and OsMATL through a CRISPR/Cas9 system. The quadruple mutant showed a transformation from meiosis to mitosis and produced clonal diploid gametes. With mutated Osmatl, which gives rise to haploid induction in plants, the quadruple mutant is expected to be able to be produced apomictic diploid offspring. We named this quadruple mutant as AOP (Apomictic Offspring Producer) for its ability to produce apomictic offspring.

4.
Nat Biotechnol ; 37(3): 283-286, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30610223

RESUMO

Heterosis, or hybrid vigor, is exploited by breeders to produce elite high-yielding crop lines, but beneficial phenotypes are lost in subsequent generations owing to genetic segregation. Clonal propagation through seeds would enable self-propagation of F1 hybrids. Here we report a strategy to enable clonal reproduction of F1 rice hybrids through seeds. We fixed the heterozygosity of F1 hybrid rice by multiplex CRISPR-Cas9 genome editing of the REC8, PAIR1 and OSD1 meiotic genes to produce clonal diploid gametes and tetraploid seeds. Next, we demonstrated that editing the MATRILINEAL (MTL) gene (involved in fertilization) could induce formation of haploid seeds in hybrid rice. Finally, we combined fixation of heterozygosity and haploid induction by simultaneous editing of all four genes (REC8, PAIR1, OSD1 and MTL) in hybrid rice and obtained plants that could propagate clonally through seeds. Application of our method may enable self-propagation of a broad range of elite F1 hybrid crops.


Assuntos
Sistemas CRISPR-Cas/genética , Oryza/genética , Proteínas de Plantas/genética , Sementes/genética , Fertilização/genética , Edição de Genes , Engenharia Genética/métodos , Genoma de Planta/genética , Hibridização Genética , Meiose/genética , Oryza/crescimento & desenvolvimento , Fenótipo , Sementes/crescimento & desenvolvimento
5.
New Phytol ; 222(2): 805-819, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30584664

RESUMO

Meiotic recombination is closely linked with homologous pairing and synapsis. Previous studies have shown that HOMOLOGOUS PAIRING PROTEIN2 (HOP2), plays an essential role in homologous pairing and synapsis. However, the mechanism by which HOP2 regulates crossover (CO) formation has not been elucidated. Here, we show that OsHOP2 mediates the maturation of COs by promoting homologous pairing and synapsis in rice (Oryza sativa) meiosis. We used a combination of genetic analysis, immunolocalization and super-resolution imaging to analyze the function of OsHOP2 in rice meiosis. We showed that full-length pairing, synapsis and CO formation are disturbed in Oshop2 meiocytes. Moreover, structured illumination microscopy showed that OsHOP2 localized to chromatin and displayed considerable co-localization with axial elements (AEs) and central elements (CEs). Importantly, the interaction between OsHOP2 and a transverse filament protein of synaptonemal complex (ZEP1), provided further evidence that OsHOP2 was involved in assembly or stabilization of the structure of the synaptonemal complex (SC). Although the initiation of recombination and CO designation occur normally in Oshop2 mutants, mature COs were severely reduced, and human enhancer of invasion 10 (HEI10)10 foci were only present on the synapsed region. Putting the data together, we speculate that OsHOP2 may serve as a global regulator to coordinate homologous pairing, synapsis and meiotic recombination in rice meiosis.

6.
Plant Cell ; 30(12): 3024-3037, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30538156

RESUMO

Response regulators play significant roles in controlling various biological processes; however, their roles in plant meiosis remain unclear. Here, we report the identification of OsRR24/LEPTOTENE1 (LEPTO1), a rice (Oryza sativa) type-B response regulator that participates in the establishment of key molecular and morphological features of chromosomes in leptotene, an early stage of prophase I in meiosis. Although meiosis initiates normally, as indicated by staining of the centromere-specific histone CENH3, the meiotic chromosomes in lepto1 mutant pollen mother cells fail to form the thin thread-like structures that are typical of leptotene chromosomes in wild-type pollen mother cells. Furthermore, lepto1 mutants fail to form chromosomal double-strand breaks, do not recruit meiosis-specific proteins to the meiotic chromosomes, and show disrupted callose deposition. LEPTO1 also is essential for programmed cell death in tapetal cells. LEPTO1 contains a conserved signal receiver domain (DDK) and a myb-like DNA binding domain at the N terminus. LEPTO1 interacts with two authentic histidine phosphotransfer (AHP) proteins, OsAHP1 and OsAHP2, via the DDK domain, and a phosphomimetic mutation of the DDK domain relieves its repression of LEPTO1 transactivation activity. Collectively, our results show that OsRR24/LEPTO1 plays a significant role in the leptotene phase of meiotic prophase I.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Meiose/genética , Proteínas Nucleares/metabolismo , Oryza/genética , Proteínas de Ciclo Celular/genética , Cromossomos de Plantas/genética , Meiose/fisiologia , Prófase Meiótica I/genética , Prófase Meiótica I/fisiologia , Proteínas Nucleares/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/genética , Pólen/metabolismo
7.
Genomics Proteomics Bioinformatics ; 16(6): 389-392, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30594646

RESUMO

On November 18, 2018, the Future Science Prize Awarding Ceremony was held in Beijing. In the area of life science, Professors Jiayang Li, Longping Yuan, and Qifa Zhang shared the prize for their pioneering contributions in producing high-yield, superior-quality rice through systematic study of molecular mechanisms associated with specific rice features and application of novel approaches in rice breeding. The Future Science Prize is also touted as "China's Nobel Prize", fully affirming their achievements in rice basic research and breeding.


Assuntos
Engenharia Genética/métodos , Oryza/crescimento & desenvolvimento , Oryza/genética , Melhoramento Vegetal/métodos , Distinções e Prêmios , China , Embaralhamento de DNA , Pesquisa
8.
PLoS Genet ; 14(11): e1007769, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30419020

RESUMO

Meiotic cytokinesis influences the fertility and ploidy of gametes. However, limited information is available on the genetic control of meiotic cytokinesis in plants. Here, we identified a rice mutant with low male fertility, defective callose in meiosis 1 (dcm1). The pollen grains of dcm1 are proved to be defective in exine formation. Meiotic cytokinesis is disrupted in dcm1, resulting in disordered spindle orientation during meiosis II and formation of pollen grains with varied size and DNA content. We demonstrated that meiotic cytokinesis defect in dcm1 is caused by prematurely dissolution of callosic plates. Furthermore, peripheral callose surrounding the dcm1 pollen mother cells (PMCs) also disappeared untimely around pachytene. The DCM1 protein contains five tandem CCCH motifs and interacts with nuclear poly (A) binding proteins (PABNs) in nuclear speckles. The expression profiles of genes related to callose synthesis and degradation are significantly modified in dcm1. Together, we propose that DCM1 plays an essential role in male meiotic cytokinesis by preserving callose from prematurely dissolution in rice.

9.
Proc Natl Acad Sci U S A ; 115(42): 10810-10815, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30275327

RESUMO

During meiosis, the number of double-strand breaks (DSBs) far exceeds the final number of crossovers (COs). Therefore, to identify proteins involved in determining which of these DSBs repaired into COs is critical in understanding the mechanism of CO control. Across species, HEI10-related proteins play important roles in CO formation. Here, through screening for HEI10-interacting proteins via a yeast two-hybrid system, we identify a CO protein HEI10 Interaction Protein 1 (HEIP1) in rice. HEIP1 colocalizes with HEI10 in a dynamic fashion along the meiotic chromosomes and specially localizes onto crossover sites from late pachytene to diplotene. Between these two proteins, HEI10 is required for the loading of HEIP1, but not vice versa. Moreover, mutations of the HEIP1 gene cause the severe reduction of chiasma frequency, whereas early homologous recombination processes are not disturbed and synapsis proceeds normally. HEIP1 interacts directly with ZIP4 and MSH5. In addition, the loading of HEIP1 depends on ZIP4, but not on MER3, MSH4, or MSH5. Together, our results suggest that HEIP1 may be a member of the ZMM group and acts as a key element regulating CO formation.

10.
Commun Biol ; 1: 84, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30271965

RESUMO

The wild relatives of rice have adapted to different ecological environments and constitute a useful reservoir of agronomic traits for genetic improvement. Here we present the ~777 Mb de novo assembled genome sequence of Oryza granulata. Recent bursts of long-terminal repeat retrotransposons, especially RIRE2, led to a rapid twofold increase in genome size after O. granulata speciation. Universal centromeric tandem repeats are absent within its centromeres, while gypsy-type LTRs constitute the main centromere-specific repetitive elements. A total of 40,116 protein-coding genes were predicted in O. granulata, which is close to that of Oryza sativa. Both the copy number and function of genes involved in photosynthesis and energy production have undergone positive selection during the evolution of O. granulata, which might have facilitated its adaptation to the low light habitats. Together, our findings reveal the rapid genome expansion, distinctive centromere organization, and adaptive evolution of O. granulata.

11.
Front Plant Sci ; 9: 1236, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30210516

RESUMO

The repair of SPO11-dependent double-strand breaks (DSBs) by homologous recombination (HR) ensures the correct segregation of homologous chromosomes. In yeast and human, RAD17 is involved in DNA damage checkpoint control and DSB repair. However, little is known about its function in plants. In this study, we characterized the RAD17 homolog in rice. In Osrad17 pollen mother cells (PMCs), associations between non-homologous chromosomes and chromosome fragmentation were constantly observed. These aberrant chromosome associations were dependent on the formation of programmed DSBs. OsRAD17 interacts with OsRAD1 and the meiotic phenotype of Osrad1 Osrad17 is indistinguishable from the two single mutants which have similar phenotypes, manifesting they could act in the same pathway. OsZIP4, OsMSH5 and OsMER3 are members of ZMM proteins in rice that are required for crossover formation. We found that homologous pairing and synapsis, which was roughly unaffected in Oszip4 and Osrad17 single mutant, was severely disturbed in the Oszip4 Osrad17 double mutant. Similar phenotypes were observed in the Osmsh5 Osrad17 and Osmer3 Osrad1 double mutants, suggesting the cooperation between the checkpoint proteins and ZMM proteins in assuring accurate HR in rice.

12.
Plant J ; 96(4): 842-854, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30144334

RESUMO

Nitrogen is one of the most important nutrient element that is essential for plant growth and development. Many genes have been reported to contribute to nitrogen absorption and transportation. However, genes involved in nitrogen reutilization are seldom reported. Ornithine δ-aminotransferase (δOAT) is the enzyme connecting arginine cycling and proline cycling. Here, we found that OsOAT, the homologue of δOAT in rice, is essential for nitrogen reutilization through mediating arginase activity. In the Osoat mutant, metabolic abnormality induced by nitrogen deficiency in floret causes malformed glumes, incapable glume opening and anther indehiscence. These defects in the mutant affect the pollination process and lead to a low seed setting rate as well as abnormal seed shape. Intriguingly, urea can rescue the phenotypes of the Osoat mutant. Therefore, OsOAT is crucial for nitrogen reutilization and plays a critical role in floret development and seed setting in rice.

13.
J Exp Bot ; 69(20): 4703-4713, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-29955878

RESUMO

The widespread introduction of semi-dwarf1 (sd1), also known as the 'Green Revolution' gene, has dramatically increased rice yield. However, the extensive use of limited sources of dwarf genes may cause 'bottleneck' effects in breeding new rice varieties. Alternative dwarf germplasms are quite urgent for rice breeding. Here, we characterized a new allele of the rice Slr1-d mutant, Slr1-d6, which reduced plant height by 37%, a much milder allele for dwarfism. Slr-d6 was still responsive to gibberellin (GA) to a reduced extent. The mutation site in Slr1-d6 was less conserved in the TVHYNP domain, leading to the specific semi-dominant dwarf phenotype. Expression of SLR1 and five key GA biosynthetic genes was disturbed in Slr1-d6, and the interaction between Slr1-d6 and GID1 was decreased. In the genetic background of cultivar 9311 with sd1 eliminated, Slr1-d6 homozygous plants were ~70 cm tall. Moreover, Slr1-d6 heterozygous plants were equivalent in height to the standard sd1 semi-dwarf 9311, but with a 25% yield increase, showing its potential application in hybrid rice breeding.

14.
Mol Plant ; 11(3): 359-380, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29409893

RESUMO

Rice (Oryza sativa) is a major staple food crop for more than 3.5 billion people worldwide. Understanding the regulatory mechanisms of complex agronomic traits in rice is critical for global food security. Rice is also a model plant for genomics research of monocotyledons. Thanks to the rapid development of functional genomic technologies, over 2000 genes controlling important agronomic traits have been cloned, and their molecular biological mechanisms have also been partially characterized. Here, we briefly review the advances in rice functional genomics research during the past 10 years, including a summary of functional genomics platforms, genes and molecular regulatory networks that regulate important agronomic traits, and newly developed tools for gene identification. These achievements made in functional genomics research will greatly facilitate the development of green super rice. We also discuss future challenges and prospects of rice functional genomics research.

15.
New Phytol ; 218(2): 789-803, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29479720

RESUMO

In angiosperms, the key step in sexual reproduction is successful acquisition of meiotic fate. However, the molecular mechanism determining meiotic fate remains largely unknown. Here, we report that OsSPOROCYTELESS (OsSPL) is critical for meiotic entry in rice (Oryza sativa). We performed a large-scale genetic screen of rice sterile mutants aimed to identify genes regulating meiotic entry and identified OsSPL using map-based cloning. We showed that meiosis-specific callose deposition, chromatin organization, and centromere-specific histone H3 loading were altered in the cells corresponding to pollen mother cells in Osspl anthers. Global transcriptome analysis showed that the enriched differentially expressed genes in Osspl were mainly related to redox status, meiotic process, and parietal cell development. OsSPL might form homodimers and interact with TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factor OsTCP5 via the SPL dimerization and TCP interaction domain. OsSPL also interacts with TPL (TOPLESS) corepressors, OsTPL2 and OsTPL3, via the EAR motif. Our results suggest that the OsSPL-mediated signaling pathway plays a crucial role in rice meiotic entry, which appears to be a conserved regulatory mechanism for meiotic fate acquisition in angiosperms.

16.
BMC Genomics ; 18(1): 778, 2017 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-29025389

RESUMO

BACKGROUND: The role of histone modifications in the DNA damage response has been extensively studied in non-plant systems, including mammals and yeast. However, there is a lack of detailed evidence showing how chromatin dynamics, either an individual mark or combined chromatin states, participate in regulating differentially expressed genes in the plant DNA damage response. RESULTS: In this study, we used RNA-seq and ChIP-seq to show that differentially expressed genes (DEGs), in response to ionizing radiation (IR), might be involved in different pathways responsible for the DNA damage response. Moreover, chromatin structures associated with promoters, exons and intergenic regions are significantly affected by IR. Most importantly, either an individual mark or a certain chromatin state was found to be highly correlated with the expression of up-regulated genes. In contrast, only the chromatin states, as opposed to any individual marks tested, are related to the expression of the down-regulated genes. CONCLUSIONS: Our findings demonstrate that IR-related DEGs are modulated by distinct epigenetic mechanisms. Either chromatin states or distinct histone dynamics may act sequentially or in combination in regulating up-regulated genes, but the complex chromatin structure is mainly responsible for the expression of down-regulated genes. Thus, this study provides new insights into how up- and down-regulated genes are epigenetically regulated at the chromatin levels, thereby helping us to understand distinct epigenetic mechanisms that function in the plant DNA damage response.


Assuntos
Cromatina/genética , Cromatina/efeitos da radiação , Radioisótopos de Cobalto/farmacologia , Raios gama , Oryza/genética , Oryza/efeitos da radiação , Transcriptoma/efeitos da radiação , Dano ao DNA , Éxons/genética , Histonas/metabolismo , Análise de Sequência de RNA , Transcrição Genética/efeitos da radiação
17.
Plant Cell ; 29(10): 2597-2609, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28939596

RESUMO

Telomere bouquet formation, a highly conserved meiotic event, plays an important role in homologous pairing and therefore progression of meiosis; however, the underlying molecular mechanism remains largely unknown. Here, we identified ZYGOTENE1 (ZYGO1), a novel F-box protein in rice (Oryza sativa), and verified its essential role in bouquet formation during early meiosis. In zygo1 mutants, zygotene chromosome aggregation and telomere clustering failed to occur. The suppressed telomere clustering in homologous pairing aberration in rice meiosis1 (pair1) zygo1 and rice completion of meiotic recombination (Oscom1) zygo1 double mutants, together with the altered localization of OsSAD1 (a SUN protein associated with the nuclear envelope) in zygo1, showed that ZYGO1 has a significant function in bouquet formation. In addition, the interaction between ZYGO1 and rice SKP1-like protein 1 suggested that ZYGO1 might modulate bouquet formation as a component of the SKP1-Cullin1-F-box complex. Although double-strand break formation and early recombination element installation occurred normally, zygo1 mutants showed defects in full-length pairing and synaptonemal complex assembly. Furthermore, crossover (CO) formation was disturbed, and foci of Human enhancer of invasion 10 were restricted to the partially synapsed chromosome regions, indicating that CO reduction might be caused by the failure of full-length chromosome alignment in zygo1 Therefore, we propose that ZYGO1 mediates bouquet formation to efficiently promote homolog pairing, synapsis, and CO formation in rice meiosis.


Assuntos
Meiose/genética , Oryza/genética , Proteínas de Plantas/metabolismo , Pareamento Cromossômico/genética , Pareamento Cromossômico/fisiologia , Meiose/fisiologia , Oryza/citologia , Proteínas de Plantas/genética
18.
Plant Cell ; 29(7): 1697-1708, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28696221

RESUMO

Homologous recombination plays a central role in guaranteeing chromosome segregation during meiosis. The precise regulation of the resolution of recombination intermediates is critical for the success of meiosis. Many proteins, including the RECQ DNA helicases (Sgs1/BLM) and Topoisomerase 3α (TOP3α), have essential functions in managing recombination intermediates. However, many other factors involved in this process remain to be defined. Here, we report the isolation of meiotic chromosome association 1 (MEICA1), a novel protein participating in meiotic recombination in rice (Oryza sativa). Loss of MEICA1 leads to nonhomologous chromosome association, the formation of massive chromosome bridges, and fragmentation. MEICA1 interacts with MSH7, suggesting its role in preventing nonallelic recombination. In addition, MEICA1 has an anticrossover activity revealed by suppressing the defects of crossover formation in msh5 meica1 compared with that in msh5, showing the similar function with its interacted protein TOP3α. Thus, our data establish two pivotal roles for MEICA1 in meiosis: preventing aberrant meiotic recombination and regulating crossover formation.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , Meiose , Oryza/genética , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Cromatina/metabolismo , Segregação de Cromossomos , Sequência Conservada , DNA Topoisomerases Tipo I/genética , Recombinação Homóloga , Mutação , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Domínios Proteicos , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Técnicas do Sistema de Duplo-Híbrido
19.
New Phytol ; 216(2): 373-387, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28295376

RESUMO

Genetic imprinting refers to the unequal expression of paternal and maternal alleles of a gene in sexually reproducing organisms, including mammals and flowering plants. Although many imprinted genes have been identified in plants, the functions of these imprinted genes have remained largely uninvestigated. We report genome-wide analysis of gene expression, DNA methylation and small RNAs in the rice endosperm and functional tests of five imprinted genes during seed development using Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated gene9 (CRISPR/Cas9) gene editing technology. In the rice endosperm, we identified 162 maternally expressed genes (MEGs) and 95 paternally expressed genes (PEGs), which were associated with miniature inverted-repeat transposable elements, imprinted differentially methylated loci and some 21-22 small interfering RNAs (siRNAs) and long noncoding RNAs (lncRNAs). Remarkably, one-third of MEGs and nearly one-half of PEGs were associated with grain yield quantitative trait loci. Most MEGs and some PEGs were expressed specifically in the endosperm. Disruption of two MEGs increased the amount of small starch granules and reduced grain and embryo size, whereas mutation of three PEGs reduced starch content and seed fertility. Our data indicate that both MEGs and PEGs in rice regulate nutrient metabolism and endosperm development, which optimize seed development and offspring fitness to facilitate parental-offspring coadaptation. These imprinted genes and mechanisms could be used to improve the grain yield of rice and other cereal crops.


Assuntos
Genes de Plantas , Impressão Genômica , Oryza/embriologia , Oryza/genética , Sementes/embriologia , Sementes/genética , Alelos , Sistemas CRISPR-Cas/genética , Cruzamentos Genéticos , Metilação de DNA , Elementos de DNA Transponíveis/genética , Endosperma/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Modelos Biológicos , Locos de Características Quantitativas/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Sementes/anatomia & histologia
20.
J Genet Genomics ; 43(12): 694-701, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27965027

RESUMO

An awned rice (Oryza sativa) plant carrying a tiny extra chromosome was discovered among the progeny of a telotrisomic line 2n+4L. Fluorescence in situ hybridization (FISH) using chromosome specific BAC clones revealed that this extra chromosome was a ring chromosome derived from part of the long arm of chromosome 4. So the aneuploidy plant was accordingly named as 2n+4L ring. We did not detect any CentO FISH signals on the ring chromosome, and found only the centromeric probe Centromeric Retrotransposon of Rice (CRR) was co-localized with the centromere-specific histone CENH3 as revealed by sequential FISH after immunodetection. The extra ring chromosome exhibited a unique segregation pattern during meiosis, including no pairing between the ring chromosome and normal chromosome 4 during prophase I and pre-separation of sister chromatids at anaphase I.


Assuntos
Centrômero/genética , Oryza/genética , Cromossomos em Anel , Sequências de Repetição em Tandem , Meiose/genética , Mutação , Oryza/citologia , Oryza/fisiologia , Reprodução
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