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1.
New Phytol ; 2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35643887

RESUMO

Salt stress is one of the major environmental factors limiting plant growth and development. Although microtubule (MT) organization is known to be involved in response to salt stress, few tubulin genes have been identified that confer salt insensitivity in plants. In this study, we identified a MT encoding gene, OsTUB1, that increased the survival rate of rice plants under salt stress by stabilizing MT organization and ion transporters. We found that OsTUB1 interacted with Kinesin13A protein, which was essential for OsTUB1-regulated MT organization under salt stress. Further molecular evidence revealed that a OsTUB1-Kinesin13A complex protected rice from salt stress by sustaining membrane-localized Na+ transporter OsHKT1;5, a key regulator of ionic homeostasis. Our results shed light on the function of tubulin and kinesin in regulating MT organization and stabilizing Na+ transporters and Na+ flux at the plasma membrane in rice. The identification of the OsTUB1-Kinesin13A complex provides novel genes for salt insensitivity rice breeding in areas with high soil salinity.

2.
Plant J ; 110(6): 1751-1762, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35404523

RESUMO

Excessive nitrogen fertilizer application is harmful to the environment and reduces the quality of cereal crops. Maintaining crop yields under low nitrogen (LN) conditions and improving quality are important goals for cereal crop breeding. Although the effects of nitrogen assimilation on crop nitrogen-use efficiency (NUE) have been intensively studied, natural variations of the key assimilation genes underlying grain development and quality are largely unclear. Here, we identified an NUE-associated gene, OsGS1;1, encoding glutamine synthase, through genome-wide association analysis, followed by validation experiments and functional analysis. Fifteen single-nucleotide polymorphisms in the OsGS1;1 region led to alternative splicing that generated two functional transcripts: OsGS1;1a and OsGS1;1b. The elite haplotype of OsGS1;1 showed high OsGS1;1b activity, which improved NUE, affected grain development, and reduced amylose content. The results show that OsGS1;1, which is induced under LN conditions, affects grain formation by regulating sugar metabolism and may provide a new avenue for the breeding of high-yield and high-quality rice (Oryza sativa).


Assuntos
Oryza , Processamento Alternativo/genética , Amilose/metabolismo , Grão Comestível/metabolismo , Estudo de Associação Genômica Ampla , Nitrogênio/metabolismo , Oryza/metabolismo , Melhoramento Vegetal
3.
Plant Biotechnol J ; 20(3): 437-453, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34655511

RESUMO

Starch accounts for over 80% of the total dry weight in cereal endosperm and determines the kernel texture and nutritional quality. Amyloplasts, terminally differentiated plastids, are responsible for starch biosynthesis and storage. We screened a series of rice mutants with floury endosperm to clarify the mechanism underlying amyloplast development and starch synthesis. We identified the floury endosperm19 (flo19) mutant which shows opaque of the interior endosperm. Abnormal compound starch grains (SGs) were present in the endosperm cells of the mutant. Molecular cloning revealed that the FLO19 allele encodes a plastid-localized pyruvate dehydrogenase complex E1 component subunit α1 (ptPDC-E1-α1) that is expressed in all rice tissues. In vivo enzyme assays demonstrated that the flo19 mutant showed decreased activity of the plastidic pyruvate dehydrogenase complex. In addition, the amounts of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) were much lower in the developing flo19 mutant endosperm, suggesting that FLO19 participates in fatty acid supply for galactolipid biosynthesis in amyloplasts. FLO19 overexpression significantly increased seed size and weight, but did not affect other important agronomic traits, such as panicle length, tiller number and seed setting rate. An analysis of single nucleotide polymorphism data from a panel of rice accessions identified that the pFLO19L haplotype was positively associated with grain length, implying a potential application in rice breeding. In summary, our study demonstrates that FLO19 is involved in galactolipid biosynthesis which is essential for amyloplast development and starch biosynthesis in rice.


Assuntos
Oryza , Grão Comestível , Endosperma/metabolismo , Galactolipídeos , Regulação da Expressão Gênica de Plantas , Mutação/genética , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/metabolismo , Complexo Piruvato Desidrogenase , Amido/metabolismo
5.
Theor Appl Genet ; 134(5): 1531-1543, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33688983

RESUMO

KEY MESSAGE: we identified a functional chromogen gene C from wild rice, providing a new insight of anthocyanin biosynthesis pathway in indica and japonica. Accumulation of anthocyanin is a desirable trait to be selected in rice domestication, but the molecular mechanism of anthocyanin biosynthesis in rice remains largely unknown. In this study, a novel allele of chromogen gene C, OrC1, from Oryza rufipongon was cloned and identified as a determinant regulator of anthocyanin biosynthesis. Although OrC1 functions in purple apiculus, leaf sheath and stigma in indica background, it only promotes purple apiculus in japonica. Transcriptome analysis revealed that OrC1 regulates flavonoid biosynthesis pathway and activates a few bHLH and WD40 genes of ternary MYB-bHLH-WD40 complex in indica. Differentially expressed genes and metabolites were found in the indica and japonica backgrounds, indicating that OrC1 activated the anthocyanin biosynthetic genes OsCHI, OsF3H and OsANS and produced six metabolites independently. Artificial selection and domestication of C1 gene in rice occurred on the coding region in the two subspecies independently. Our results reveal the regulatory system and domestication of C1, provide new insights into MYB transcript factor involved in anthocyanin biosynthesis, and show the potential of engineering anthocyanin biosynthesis in rice.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Metaboloma , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Compostos Cromogênicos/metabolismo , Perfilação da Expressão Gênica , Oryza/classificação , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo
6.
Rice (N Y) ; 14(1): 29, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33689034

RESUMO

BACKGROUND: The sequences of several important mitochondrion-encoded genes involved in respiration in higher plants are interrupted by introns. Many nuclear-encoded factors are involved in splicing these introns, but the mechanisms underlying this splicing remain unknown. RESULTS: We isolated and characterized a rice mutant named floury shrunken endosperm 5 (fse5). In addition to having floury shrunken endosperm, the fse5 seeds either failed to germinate or produced seedlings which grew slowly and died ultimately. Fse5 encodes a putative plant organelle RNA recognition (PORR) protein targeted to mitochondria. Mutation of Fse5 hindered the splicing of the first intron of nad4, which encodes an essential subunit of mitochondrial NADH dehydrogenase complex I. The assembly and NADH dehydrogenase activity of complex I were subsequently disrupted by this mutation, and the structure of the mitochondria was abnormal in the fse5 mutant. The FSE5 protein was shown to interact with mitochondrial intron splicing factor 68 (MISF68), which is also a splicing factor for nad4 intron 1 identified previously via yeast two-hybrid (Y2H) assays. CONCLUSION: Fse5 which encodes a PORR domain-containing protein, is essential for the splicing of nad4 intron 1, and loss of Fse5 function affects seed development and seedling growth.

7.
J Integr Plant Biol ; 63(5): 865-877, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33615714

RESUMO

A series of nucleotide sugar interconversion enzymes (NSEs) generate the activated sugar donors required for biosynthesis of cell wall matrix polysaccharides and glycoproteins. UDP-glucose 4-epimerases (UGEs) are NSEs that function in the interconversion of UDP-glucose (UDP-Glc) and UDP-galactose (UDP-Gal). The roles of UDP-glucose 4-epimerases in monocots remain unclear due to redundancy in the pathways. Here, we report a brittle plant (bp1) rice mutant that exhibits brittle leaves and culms at all growth stages. The mutant culms had reduced levels of rhamnogalacturonan I, homogalacturonan, and arabinogalactan proteins. Moreover, the mutant had altered contents of uronic acids, neutral noncellulosic monosaccharides, and cellulose. Map-based cloning demonstrated that OsBP1 encodes a UDP-glucose 4-epimerase (OsUGE2), a cytosolic protein. We also show that BP1 can form homo- and hetero-protein complexes with other UGE family members and with UDP-galactose transporters 2 (OsUGT2) and 3 (OsUGT3), which may facilitate the channeling of Gal to polysaccharides and proteoglycans. Our results demonstrate that BP1 participates in regulating the sugar composition and structure of rice cell walls.


Assuntos
Parede Celular/metabolismo , Mucoproteínas/metabolismo , Oryza/metabolismo , UDPglucose 4-Epimerase/metabolismo , Regulação da Expressão Gênica de Plantas , Mucoproteínas/genética , Oryza/genética , Pectinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , UDPglucose 4-Epimerase/genética
8.
New Phytol ; 229(5): 2693-2706, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33119889

RESUMO

Thioredoxins (TRXs) occur in plant chloroplasts as complex disulphide oxidoreductases. Although many biological processes are regulated by thioredoxins, the regulatory mechanism of chloroplast TRXs are largely unknown. Here we report a rice white panicle2 mutant caused by a mutation in the thioredoxin z gene, an orthologue of AtTRX z in Arabidopsis. white panicle2 (wp2) seedlings exhibited a high-temperature-sensitive albinic phenotype. We found that plastid multiple organellar RNA editing factors (MORFs) were the regulatory targets of thioredoxin z. We showed that OsTRX z protein physically interacts with OsMORFs in a redox-dependent manner and that the redox state of a conserved cysteine in the MORF box is essential for MORF-MORF interactions. wp2 and OsTRX z knockout lines show reduced editing efficiencies in many plastidial-encoded genes especially under high-temperature conditions. An Arabidopsis trx z mutant also exhibited significantly reduced chloroplast RNA editing. Our combined results suggest that thioredoxin z regulates chloroplast RNA editing in plants by controlling the redox state of MORFs.


Assuntos
Oryza , Proteínas de Plantas , Plastídeos , Edição de RNA , Tiorredoxinas , Cloroplastos/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/genética , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
9.
Plant Biotechnol J ; 19(1): 167-176, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32710800

RESUMO

Increased use of nitrogen fertilizers has deleterious impact on the environment. Increase in yield potential at low nitrogen supply is regarded as a cereal breeding goal for future agricultural sustainability. Although natural variations of nitrogen transporters have been investigated, key genes associated with assimilation remain largely unexplored for nitrogen use efficiency (NUE) enhancement. Here, we identified a NIN-like protein NLP4 associated with NUE through a GWAS in rice. We found that OsNLP4 transactivated OsNiR encoding nitrite reductase that was critical in nitrogen assimilation in rice. We further constructed quadrupling NREs (Nitrate-responsive cis-elements) in the promoter of OsNiR (p4xNRE:OsNiR) and enhanced nitrogen assimilation significantly. We demonstrated that OsNLP4-OsNiR increased tiller number and yield through enhancing nitrogen assimilation and NUE. Our discovery highlights the genetic modulation of OsNLP4-OsNiR signalling cascade as a strategy for high NUE and yield breeding in rice.


Assuntos
Oryza , Fertilizantes , Nitrogênio , Oryza/genética , Melhoramento Vegetal , Proteínas de Plantas/genética
10.
Theor Appl Genet ; 133(12): 3287-3297, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32852584

RESUMO

KEY MESSAGE: Heterosis QTLs, including qSS7 and qHD8, with dominance effects were identified through GBS and large-scale phenotyping of CSSLs and hybrid F1 populations in a paddy field. Heterosis has contributed immensely to agricultural production, but its genetic basis is unclear. We evaluated dominance effects by creating two hybrid populations: a B-homo set with a homozygous background and heterozygous chromosomal segments and a B-heter set with a heterozygous background and homozygous segments. This was achieved by crossing a set of 156 backcrossed-derived chromosome segment substitution lines (CSSLs) with their recurrent parent (9311), the male parent of the first super-high-yield hybrid Liangyoupei9 (LYP9), and with the female parent (PA64s) of the hybrid. The CSSLs were subjected to a genotyping-by-sequencing analysis to develop a genetic map of segments introduced from the PA64s. We evaluated the heterotic effects on eight yield-related traits in the hybrid variety and F1 populations in large-scale field experiments over 2 years. Using a linkage map consisting of high-density SNPs, we identified heterosis-associated genes in LYP9. Five candidate genes contributed to the high yield of LYP9, with qSS7 and qHD8 repeatedly detected in both B-hybrid populations. The heterozygous segments harboring qSS7 and qHD8 showed dominance effects that contributed to the heterosis of yield components in the hybrid rice variety Liangyoupei9.


Assuntos
Cromossomos de Plantas/genética , Epistasia Genética , Vigor Híbrido , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Mapeamento Cromossômico , Oryza/genética
11.
Front Plant Sci ; 11: 518, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32499797

RESUMO

Meiosis plays an essential role in the production of gametes and genetic diversity of posterities. The normal double-strand break (DSB) repair is vital to homologous recombination (HR) and occurrence of DNA fragment exchange, but the underlying molecular mechanism remain elusive. Here, we characterized a completely sterile Osmfs1 (male and female sterility 1) mutant which has its pollen and embryo sacs both aborted at the reproductive stage due to severe chromosome defection. Map-based cloning revealed that the OsMFS1 encodes a meiotic coiled-coil protein, and it is responsible for DSB repairing that acts as an important cofactor to stimulate the single strand invasion. Expression pattern analyses showed the OsMFS1 was preferentially expressed in meiosis stage. Subcellular localization analysis of OsMFS1 revealed its association with the nucleus exclusively. In addition, a yeast two-hybrid (Y2H) and pull-down assay showed that OsMFS1 could physically interact with OsHOP2 protein to form a stable complex to ensure faithful homologous recombination. Taken together, our results indicated that OsMFS1 is indispensable to the normal development of anther and embryo sacs in rice.

12.
BMC Genet ; 21(1): 62, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32527215

RESUMO

BACKGROUND: The exploitation of novel alleles from wild rice that were lost during rice cultivation could be very important for rice breeding and evolutionary studies. Plant height (PH) was a target of artificial selection during rice domestication and is still a target of modern breeding. The "green revolution" gene semi-dwarf 1 (SD1) were well documented and used in the past decades, allele from wild rice could provide new insights into the functions and evolution of this gene. RESULTS: We identified a PH-related quantitative trait locus, qCL1.2,from wild riceusing a set of chromosome segment substitution lines. qCL1.2encodesa novel allele of SD1 gene. The wild allele of SD1 is a dominant locus that can significantly promote rice internode length by regulating the expression levels of genes involved in gibberellin biosynthesis and signal transduction. Nucleotide diversity and haplotype network analyses of the SD1 gene were performed using 2822 rice landraces. Two previously reported functional nucleotide polymorphisms clearly differentiated japonica and indica rice; however, they were not associated with PH selection. Other new functional nucleotide polymorphisms in the coding, but not promoter, regions were involved in PH selection during rice domestication. Our study increasesunderstanding of the rice SD1 gene and provides additional evidence of this gene's selection during rice domestication. CONCLUSIONS: Our findings provide evidence thatSD1 gene from wild rice enhances plant height and new functional nucleotide polymorphisms of this gene were artificially selected during cultivated rice differentiation.


Assuntos
Oryza/crescimento & desenvolvimento , Oryza/genética , Proteínas de Plantas/genética , Locos de Características Quantitativas , Alelos , Haplótipos
13.
Plant Physiol Biochem ; 151: 469-476, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32289640

RESUMO

Seed dormancy and germination in rice (Oryza sativa L.) are complex and important agronomic traits that involve a number of physiological processes and energy. A mutant named h470 selected from a60Co-radiated indica cultivar N22 population had weakened dormancy that was insensitive to Gibberellin (GA) and Abscisic acid (ABA). The levels of GA4 and ABA were higher in h470 than in wild-type (WT) plants. The gene controlling seed dormancy in h470 was cloned by mut-map and transgenesis and confirmed to encode an ADP-glucose transporter protein. A 1 bp deletion in Os02g0202400 (OsBT1) caused the weaker seed dormancy in h470. Metabolomics analyses showed that most sugar components were higher in h470 seeds than the wild type. The mutation in h470 affected glycometabolism.


Assuntos
Oryza , Dormência de Plantas , Proteínas de Plantas , Sementes , Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas , Germinação , Giberelinas/farmacologia , Oryza/fisiologia , Dormência de Plantas/efeitos dos fármacos , Dormência de Plantas/genética , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Sementes/genética
14.
Nat Commun ; 10(1): 5279, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31754193

RESUMO

Over-application of nitrogen fertilizer in fields has had a negative impact on both environment and human health. Domesticated rice varieties with high nitrogen use efficiency (NUE) reduce fertilizer for sustainable agriculture. Here, we perform genome-wide association analysis of a diverse rice population displaying extreme nitrogen-related phenotypes over three successive years in the field, and identify an elite haplotype of nitrate transporter OsNPF6.1HapB that enhances nitrate uptake and confers high NUE by increasing yield under low nitrogen supply. OsNPF6.1HapB differs in both the protein and promoter element with natural variations, which are differentially trans-activated by OsNAC42, a NUE-related transcription factor. The rare natural allele OsNPF6.1HapB, derived from variation in wild rice and selected for enhancing both NUE and yield, has been lost in 90.3% of rice varieties due to the increased application of fertilizer. Our discovery highlights this NAC42-NPF6.1 signaling cascade as a strategy for high NUE and yield breeding in rice.


Assuntos
Proteínas de Transporte de Ânions/genética , Fertilizantes , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Estudo de Associação Genômica Ampla/métodos , Nitrogênio/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Agricultura/métodos , Proteínas de Transporte de Ânions/metabolismo , Haplótipos , Mutação , Nitratos/metabolismo , Oryza/metabolismo , Melhoramento Vegetal/métodos , Proteínas de Plantas/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Plant Physiol ; 181(3): 1223-1238, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31515447

RESUMO

In flowering plants, the tapetum cells in anthers undergo programmed cell death (PCD) at the late meiotic stage, providing nutrients for further development of microspores, including the formation of the pollen wall. However, the molecular basis of tapetum PCD remains elusive. Here we report a tapetum PCD-related mutant in rice (Oryza sativa), earlier degraded tapetum 1 (edt1), that shows complete pollen abortion associated with earlier-than-programmed tapetum cell death. EDT1 encodes a subunit of ATP-citrate lyase (ACL), and is specifically expressed in the tapetum of anthers. EDT1 localized in both the nucleus and the cytoplasm as observed in rice protoplast transient assays. We demonstrated that the A and B subunits of ACL interacted with each other and might function as a heteromultimer in the cytoplasm. EDT1 catalyzes the critical steps in cytosolic acetyl-CoA synthesis. Our data indicated a decrease in ATP level, energy charge, and fatty acid content in mutant edt1 anthers. In addition, the genes encoding secretory proteases or lipid transporters, and the transcription factors known to regulate PCD, were downregulated. Our results demonstrate that the timing of tapetum PCD must be tightly regulated for successful pollen development, and that EDT1 is involved in the tapetum PCD process. This study furthers our understanding of the molecular basis of pollen fertility and fecundity in rice and may also be relevant to other flowering plants.


Assuntos
ATP Citrato (pro-S)-Liase/metabolismo , Oryza/citologia , Oryza/enzimologia , Proteínas de Plantas/metabolismo , ATP Citrato (pro-S)-Liase/genética , Apoptose/genética , Apoptose/fisiologia , Flores/citologia , Flores/enzimologia , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/metabolismo , Proteínas de Plantas/genética , Pólen/citologia , Pólen/enzimologia , Pólen/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Cell Res ; 29(10): 820-831, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31444468

RESUMO

The transient elevation of cytoplasmic calcium is essential for pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). However, the calcium channels responsible for this process have remained unknown. Here, we show that rice CDS1 (CELL DEATH and SUSCEPTIBLE to BLAST 1) encoding OsCNGC9, a cyclic nucleotide-gated channel protein, positively regulates the resistance to rice blast disease. We show that OsCNGC9 mediates PAMP-induced Ca2+ influx and that this event is critical for PAMPs-triggered ROS burst and induction of PTI-related defense gene expression. We further show that a PTI-related receptor-like cytoplasmic kinase OsRLCK185 physically interacts with and phosphorylates OsCNGC9 to activate its channel activity. Our results suggest a signaling cascade linking pattern recognition to calcium channel activation, which is required for initiation of PTI and disease resistance in rice.


Assuntos
Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Citoplasma/metabolismo , Resistência à Doença/genética , Fungos/patogenicidade , Regulação da Expressão Gênica de Plantas , Mutagênese , Padrões Moleculares Associados a Patógenos/metabolismo , Fosforilação , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo
17.
New Phytol ; 224(1): 306-320, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31225911

RESUMO

Rice (Oryza sativa) is a facultative short-day (SD) plant, flowering early under SD and late under long-day (LD) conditions. Ghd7 is a major regulator of flowering time in rice, which strongly delays flowering under LD. Induction of Ghd7 expression by phytochromes has been shown to contribute to photoperiodic regulation of flowering in rice. Here, we show that Ghd7 also is regulated by phytochromes at a post-transcriptional level. We found that constitutive expression of Ghd7 delays flowering in the wild-type (WT) background, but not in the se5 mutant background (deficient in functional phytochromes) under LD and that Ghd7 protein fails to accumulate in the se5 mutant. We also found that co-expressing OsGIGANTEA (OsGI) with Ghd7 causes reduced accumulation of Ghd7 protein and partially suppresses the delayed flowering phenotype in the WT background, suggesting that phytochromes and OsGI play antagonist roles in regulating Ghd7 protein stability and flowering time. We show that OsPHYA, OsPHYB and OsGI could directly interact with Ghd7. Interestingly, OsPHYA and OsPHYB could inhibit the interaction between OsGI and Ghd7, thus helping to stabilize Ghd7 protein. Our results revealed a new level of Ghd7 regulation by phytochromes and OsGI in photoperiodic control of flowering in rice.


Assuntos
Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/fisiologia , Fotoperíodo , Fitocromo/metabolismo , Proteínas de Plantas/genética , Transcrição Genética , Transporte Ativo do Núcleo Celular/efeitos da radiação , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Flores/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Modelos Biológicos , Oryza/anatomia & histologia , Oryza/efeitos da radiação , Proteínas de Plantas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica/efeitos da radiação , Estabilidade Proteica/efeitos da radiação , Proteólise/efeitos da radiação , Protoplastos/metabolismo , Protoplastos/efeitos da radiação , Transcrição Genética/efeitos da radiação
18.
Plant Mol Biol ; 100(6): 635-645, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31147815

RESUMO

KEY MESSAGE: Rice WSL6 is involved in chloroplast ribosome biogenesis and is essential for early chloroplast development. Construction of the genetic translation system is a prerequisite for chloroplast development in plants. However, the molecular mechanism underlying this process is largely unknown. Here, we isolated a white stripe leaf6 (wsl6) mutant in rice. The mutant seedlings displayed white-striped leaves that were more severe under low-temperature conditions. Transmission electron microscopy analysis showed that the wsl6 mutant was defective in early chloroplast development. Map-based cloning revealed that WSL6 encodes an Era-type guanosine-5'-triphosphate (GTP)-binding protein located in chloroplasts. Immunoblotting and quantitative real-time polymerase chain reaction (qRT-PCR) analyses demonstrated an absence of 70S ribosomes in wsl6 chloroplasts. Further research showed that WSL6 binds to the 16S ribosomal RNA (rRNA) subunit of chloroplast ribosome 30S. In summary, these results show that WSL6 is essential for chloroplast ribosome biogenesis during early chloroplast development in rice.


Assuntos
Cloroplastos/fisiologia , Proteínas de Ligação ao GTP/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Clonagem Molecular , Proteínas de Ligação ao GTP/fisiologia , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Microscopia Eletrônica de Transmissão , Mutação , Oryza/fisiologia , Fenótipo , Pigmentação , Proteínas de Plantas/fisiologia , Biossíntese de Proteínas , RNA Ribossômico 16S/genética , Temperatura
19.
Plant Physiol Biochem ; 139: 495-503, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31015088

RESUMO

The chloroplast is an important organelle that performs photosynthesis as well as biosynthesis and storage of many metabolites. Aminoacyl-tRNA synthetases (aaRSs) are key enzymes in protein synthesis. However, the relationship between chloroplast development and aaRSs still remains unclear. In this study, we isolated a rice albino 1 (ra1) mutant through methane sulfonate (EMS) mutagenesis of rice japonica cultivar Ningjing 4 (Oryza sativa L.), which displayed albinic leaves in seedling stage due to abnormal chloroplast development. Compared with wild type (WT), ra1 showed significantly decreased levels of chlorophylls (Chl) and carotenoids (Car) in 2-week-old seedlings, which also showed obvious plastidic structural defects including abnormal thylakoid membrane structures and more osmiophilic particles. These defects caused albino phenotypes in seedlings. Map-based cloning revealed that RA1 gene encodes a glycyl-tRNA synthetase (GlyRS), which was confirmed by genetic complementation and knockout by Crispr/Cas9 technology. Sequence analysis showed that a single base mutation (T to A) occurred in the sixth exon of RA1 and resulted in a change from Isoleucine (Ile) to Lysine (Lys). Real-time PCR analyses showed that RA1 expression levels were constitutive in most tissues, but most abundant in the leaves and stems. By transient expression in Nicotiana benthamiana, we found that RA1 protein was localized in the chloroplast. Expression levels of chlorophyll biosynthesis and plastid development related genes were disordered in the ra1 mutant. RNA analysis revealed biogenesis of chloroplast rRNAs was abnormal in ra1. Meanwhile, western blotting showed that synthesis of proteins associated with plastid development was significantly repressed. These results suggest that RA1 is involved in early chloroplast development and establishment of the plastidic ribosome system in rice.


Assuntos
Glicina-tRNA Ligase/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plastídeos/metabolismo , Ribossomos/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Glicina-tRNA Ligase/genética , Oryza/genética , Proteínas de Plantas/genética , Plântula/genética , Plântula/metabolismo
20.
Plant Cell Rep ; 37(12): 1667-1679, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30151559

RESUMO

KEY MESSAGE: Loss of function of a mitochondrial complex I subunit (OsNDUFA9) causes abnormal embryo development and affects starch synthesis by altering the expression of starch synthesis-related genes and proteins. Proton-pumping NADH: ubiquinone oxidoreductase (also called complex I) is thought to be the largest and most complicated enzyme of the mitochondrial respiratory chain. Mutations of complex I subunits have been revealed to link with a number of growth inhibitions in plants. However, the function of complex I subunits in rice remains unclear. Here, we isolated a rice floury endosperm mutant (named flo13) that was embryonic lethal and failed to germinate. Semi-thin sectioning analysis showed that compound starch grain development in the mutant was greatly impaired, leading to significantly compromised starch biosynthesis and decreased 1000-grain weight relative to the wild type. Map-based cloning revealed that FLO13 encodes an accessory subunit of complex I protein (designated as OsNDUFA9). A single nucleotide substitution (G18A) occurred in the first exon of OsNDUFA9, introducing a premature stop codon in the flo13 mutant gene. OsNDUFA9 was ubiquitously expressed in various tissues and the OsNDUFA9 protein was localized to the mitochondria. Quantitative RT-PCR and protein blotting indicated loss of function of OsNDUFA9 altered gene expression and protein accumulation associated with respiratory electron chain complex in the mitochondria. Moreover, transmission electron microscopic analysis showed that the mutant lacked obvious mitochondrial cristae structure in the mitochondria of endosperm cell. Our results demonstrate that the OsNDUFA9 subunit of complex I is essential for embryo development and starch synthesis in rice endosperm.


Assuntos
Complexo I de Transporte de Elétrons/metabolismo , Oryza/embriologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Subunidades Proteicas/metabolismo , Sementes/embriologia , Sementes/metabolismo , Amido/biossíntese , Sequência de Bases , Clonagem Molecular , Endosperma/citologia , Endosperma/metabolismo , Endosperma/ultraestrutura , Regulação da Expressão Gênica de Plantas , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Mutação/genética , Oryza/ultraestrutura , Fenótipo , Proteínas de Plantas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Frações Subcelulares/metabolismo
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