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1.
Mol Plant ; 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33220510

RESUMO

Under conditions of labor or resource scarcity, direct seeding, rather than transplantation, is a preferred mode of rice (Oryza sativa. L) cultivation. This approach requires varieties that exhibit uniform seedling emergence. Mesocotyl elongation (ME), the main driver of rice seedling rapid emergence from soil, is enhanced by darkness and inhibited by light. Plant polyamine oxidases (PAOs) oxidate polyamines (PAs) and release H2O2. Here, we established that OsPAO5 expression in rice seedlings is increased in the presence of light, and inhibited by darkness. To determine its role in ME, we created OsPAO5 mutants using CRISPR/Cas9. Compared with the wild type, pao5 mutants had longer mesocotyls, released less H2O2, and synthesized more ethylene. The mutant seedlings emerged at a higher and more uniform rate, indicating potential use in direct seeding. Nucleotide polymorphism analysis revealed that an SNP variation (PAO5-578G/A) in the 578 bp upstream of OsPAO5 start codon alters its expression, which is further selected during rice mesocotyl domestication. The PAO5-578G genotype consisting with long mesocotyl mainly exists in wild rice, most Aus and some Geng (Japonica) accessions. Intriguingly, knocking out of OsPAO5 can remarkably increase the grain weight, grain numbers and yield potential. In summary, we developed a novel strategy to obtain elite rice with higher emergence vigor and yield potential, which can be conveniently and widely used to breed varieties of direct-seeding rice.

2.
Plant Biotechnol J ; 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33236499

RESUMO

Foods high in amylose content and resistant starch (RS) offer great potential to improve human health and lower the risk of serious noninfectious diseases. Common wheat (Triticum aestivum L.) is a major staple food crop globally. However, the RS contents in the grains of modern wheat varieties are low. Here, we report the generation of high-amylose wheat through targeted mutagenesis of TaSBEIIa in a modern winter wheat cv Zhengmai 7698 (ZM) and a spring wheat cv Bobwhite by CRISPR/Cas9, respectively. We generated a series of transgene-free mutant lines either with partial or triple null TasbeIIa alleles in ZM and Bobwhite, respectively. Analyses of starch composition, structure and properties revealed that the effects of partial or triple null alleles were dosage dependent with triple null lines demonstrated more profound impacts on starch composition, fine structures of amylopectin, and physiochemical and nutritional properties. The flours of triple null lines possessed significantly increased amylose, RS, protein and soluble pentosan contents which benefit human health. Baking quality analyses indicated that the high-amylose flours may be used as additives or for making cookies. Collectively, we successfully modified the starch composition, structure and properties through targeted mutagenesis of TaSBEIIa by CRISPR/Cas9 in both winter and spring wheat varieties, and generated transgene-free high-amylose wheat. Our finding provides deep insights on the role of TaSBEIIa in determining starch composition, structure, properties and end-use quality in different genetic backgrounds, and improving RS content with multiple breeding and end-use applications in cereal crop species through genome editing for health benefits.

3.
Front Genet ; 11: 13, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32076435

RESUMO

In rice, the contents of protein and amino acids are the major parameters of nutritional quality. Co-localization of quantitative trait loci (QTLs) for heading date and protein content were reported, but pleiotropism of heading-date genes on protein contents has not been investigated. Here, we reported that rice florigen gene RFT1 plays an important role in controlling amino acid contents of rice grain. Firstly, 73 QTLs for the contents of 17 amino acids in unmilled rice were detected using recombinant inbred lines (RILs) of the indica rice cross Zhenshan 97 (ZS97)/Milyang 46 (MY46). Then, the effect of the largest cluster consisting of 14 QTLs, located in proximity to the rice florigen genes RFT1 and Hd3a, was validated using three populations consisting of near isogenic lines (NILs) that only segregated a region covering the target QTL. The first and second NIL populations were derived from a residual heterozygote identified from the ZS97/MY46 RIL population, consisting of homozygous lines that were only segregated in a 29.9-kb region covering the two florigen genes and a 1.7-kb region for RFT1, respectively. The third NIL population was segregated for the RFT1 ZS97 transgene in the background of japonica rice cultivar Zhonghua 11. In all the three NIL populations, RFT1 was shown to have a strong effect on the contents of most amino acids, with the ZS97 allele always having the reducing effects. By comparing QTLs for amino acid contents detected in the ZS97/MY46 RIL population and genes/QTLs previously identified for heading date difference between ZS97 and MY46, possible pleiotropism on amino acid contents was also shown for other key heading-date genes including Hd1, Ghd7, and OsGI.

4.
Sci China Life Sci ; 63(2): 228-238, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31919631

RESUMO

The palea and lemma are floral organ structures unique to grasses; these structures form the hull and directly affect grain size and quality. However, the molecular mechanisms controlling the development of the hull are not well understood. In this study, we characterized the rice (Oryza sativa) abnormal flower and grain1 (afg1) mutant, a new allele of OsMADS6. Similar to previously characterized osmads6 alleles, in the afg1 floret, the palea lost its marginal region and acquired the lemma identity. However, in contrast to other osmads6 alleles, the afg1 mutant showed altered grain size and grain quality, with decreased total starch and amylose contents, and increased protein and soluble sugar contents. The analysis of transcriptional activity suggested that AFG1 is a transcriptional activator and may affect grain size by regulating the expression levels of several genes related to cell expansion and proliferation in the afg1 mutant. These results revealed that AFG1 plays an important role in determining palea identity and affecting grain yield and quality in rice.


Assuntos
Grão Comestível/genética , Flores/genética , Proteínas de Domínio MADS/genética , Oryza/genética , Proteínas de Plantas/genética , Alelos , Sequência de Aminoácidos , Amilose/genética , Mapeamento Cromossômico , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Domínio MADS/metabolismo , Mutação/genética , Oryza/crescimento & desenvolvimento , Fenótipo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Amido/genética , Açúcares/metabolismo , Transcrição Genética
5.
J Integr Plant Biol ; 62(7): 948-966, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31449354

RESUMO

The percentage of amylose in the endosperm of rice (Oryza sativa) largely determines grain cooking and eating qualities. Granule-bound starch synthase I (GBSSI) and GBSSII are responsible for amylose biosynthesis in the endosperm and leaf, respectively. Here, we identified OsGBP, a rice GBSS-binding protein that interacted with GBSSI and GBSSII in vitro and in vivo. The total starch and amylose contents in osgbp mutants were significantly lower than those of wild type in leaves and grains, resulting in reduced grain weight and quality. The carbohydrate-binding module 48 (CBM48) domain present in the C-terminus of OsGBP is crucial for OsGBP binding to starch. In the osgbp mutant, the extent of GBSSI and GBSSII binding to starch in the leaf and endosperm was significantly lower than wild type. Our data suggest that OsGBP plays an important role in leaf and endosperm starch biosynthesis by mediating the binding of GBSS proteins to developing starch granules. This elucidation of the function of OsGBP enhances our understanding of the molecular basis of starch biosynthesis in rice and contributes information that can be potentially used for the genetic improvement of yield and grain quality.

6.
BMC Plant Biol ; 19(1): 109, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894127

RESUMO

BACKGROUND: Two-line hybrid rice with high yield potential is increasingly popular and the photo- and temperature-sensitive male sterile line is one of the basic components for two-line hybrid rice breeding. The development of male sterile lines through conventional breeding is a lengthy and laborious process, whereas developing thermo-sensitive genic male sterile (TGMS) lines for two-line hybrid breeding by editing a temperature-sensitivity gene by CRISPR/Cas9 is efficient and convenient. RESULTS: Here, thermo-sensitive genic male sterility (TGMS) was induced by employing the CRISPR/Cas9 gene editing technology to modify the gene TMS5. Two TGMS mutants, tms5-1 and tms5-2, both lacking any residual T-DNA, were generated in the indica rice cultivar Zhongjiazao17 (cv. YK17) background. When grown at a sub-optimal temperature (22 °C), both mutants produced viable pollen and successfully produced grain through self-fertilization, but at temperatures 24 and 26 °C, their pollen was sterile and no grain was set. F1 hybrids derived from the crosses between YK17S (tms5-1) and three different restorer lines outperformed both parental lines with respect to grain yield and related traits. CONCLUSION: The YK17S generated by CRISPR/Cas9 system was proved to be a new TGMS line with superior yield potential and can be widely utilized in two-line hybrid breeding of indica rice.


Assuntos
Sistemas CRISPR-Cas , Oryza/genética , Melhoramento Vegetal/métodos , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Quimera , Mutagênese , Oryza/fisiologia , Plantas Geneticamente Modificadas , Pólen/genética , Pólen/crescimento & desenvolvimento , Temperatura
7.
Front Plant Sci ; 10: 175, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30838015

RESUMO

Rice yield is closely related to plant leaf shape and chlorophyll content. In this study, we isolated and identified a narrow and rolled leaf mutant, temporarily named nrl3 with darker green leaves. Histological analysis showed that nrl3 has a reduced number of vascular bundles and undergoes abnormal abaxial sclerenchymatous cell differentiation. The NRL3 mutant phenotype was controlled by a single recessive gene, fine-mapped to a 221 kb interval between Indel3 and RM2322 on Chr3. There are 42 ORF in this interval. Sequencing identified an SNP mutant leading to a premature stop in ORF 18, the candidate gene. Bioinformation analysis indicated that NRL3 encodes a novel protein with unknown function. NRL3 is localized in cytoplasm, membrane and nucleus. Expression analysis of nrl3 showed that genes involved in chlorophyll synthesis were significantly up-regulated while those involved in chlorophyll degradation and programmed cell death (PCD) were significantly down-regulated. The expression levels of photosynthesis genes were also affected. Y2H and BIFC assays indicated that NRL3 interacts directly with NAL9/VYL to regulate leaf morphology in rice. Thus, NRL3 plays an important role in leaf morphogenesis and chlorophyll accumulation, and can be used as a new gene resource for constructing improved rice.

8.
Plant Biotechnol J ; 17(7): 1222-1235, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30552799

RESUMO

Identification of seed development regulatory genes is the key for the genetic improvement in rice grain quality. NF-Ys are the important transcription factors, but their roles in rice grain quality control and the underlying molecular mechanism remain largely unknown. Here, we report the functional characterization a rice NF-Y heterotrimer complex NF-YB1-YC12-bHLH144, which is formed by the binding of NF-YB1 to NF-YC12 and then bHLH144 in a sequential order. Knock-out of each of the complex genes resulted in alteration of grain qualities in all the mutants as well as reduced grain size in crnf-yb1 and crnf-yc12. RNA-seq analysis identified 1496 genes that were commonly regulated by NF-YB1 and NF-YC12, including the key granule-bound starch synthase gene Wx. NF-YC12 and bHLH144 maintain NF-YB1 stability from the degradation mediated by ubiquitin/26S proteasome, while NF-YB1 directly binds to the 'G-box' domain of Wx promoter and activates Wx transcription, hence to regulate rice grain quality. Finally, we revealed a novel grain quality regulatory pathway controlled by NF-YB1-YC12-bHLH144 complex, which has great potential for rice genetic improvement.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/enzimologia , Proteínas de Plantas/metabolismo , Sintase do Amido/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Grão Comestível , Oryza/genética , Proteínas de Plantas/genética , Sementes , Sintase do Amido/genética
9.
Plant Biotechnol J ; 16(11): 1878-1891, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29577566

RESUMO

Starch is the main form of energy storage in higher plants. Although several enzymes and regulators of starch biosynthesis have been defined, the complete molecular machinery remains largely unknown. Screening for irregularities in endosperm formation in rice represents valuable prospect for studying starch synthesis pathway. Here, we identified a novel rice white-core endosperm and defective grain filling mutant, ospk2, which displays significantly lower grain weight, decreased starch content and alteration of starch physicochemical properties when compared to wild-type grains. The normal starch compound granules were drastically reduced and more single granules filled the endosperm cells of ospk2. Meanwhile, the germination rate of ospk2 seeds after 1-year storage was observably reduced compared with wild-type. Map-based cloning of OsPK2 indicated that it encodes a pyruvate kinase (PK, ATP: pyruvate 2-O-phosphotransferase, EC 2.7.1.40), which catalyses an irreversible step of glycolysis. OsPK2 has a constitutive expression in rice and its protein localizes in chloroplasts. Enzyme assay showed that the protein product from expressed OsPK2 and the crude protein extracted from tissues of wild-type exhibits strong PK activity; however, the mutant presented reduced protein activity. OsPK2 (PKpα1) and three other putative rice plastidic isozymes, PKpα2, PKpß1 and PKpß2, can interact to form heteromer. Moreover, the mutation leads to multiple metabolic disorders. Altogether, these results denote new insights into the role of OsPK2 in plant seed development, especially in starch synthesis, compound granules formation and grain filling, which would be useful for genetic improvement of high yield and rice grain quality.


Assuntos
Grão Comestível/crescimento & desenvolvimento , Endosperma/crescimento & desenvolvimento , Genes de Plantas/genética , Oryza/genética , Proteínas de Plantas/genética , Piruvato Quinase/genética , Amido/biossíntese , Endosperma/metabolismo , Genes de Plantas/fisiologia , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Piruvato Quinase/metabolismo , Piruvato Quinase/fisiologia
10.
J Exp Bot ; 68(18): 5147-5160, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29045742

RESUMO

The plastid-encoded RNA polymerase (PEP) plays an important role in the transcription machinery of mature chloroplasts, yet details of its function remain elusive in rice. Here, we identified a novel PEP-associated protein (PAP), WLP2, based on its two allelic white leaf and panicle mutants, wlp2s and wlp2w. The two mutants were albino lethal at high temperatures and showed decreased chlorophyll accumulation, abnormal chloroplast ultrastructure, and attenuated photosynthetic activity. Map-based cloning suggested that WLP2 encodes a putative pfkB-type carbohydrate kinase family protein, which is homologous to fructokinase-like 1 (AtFLN1) in Arabidopsis. WLP2 is mainly expressed in green tissues and its protein localizes in chloroplasts. Expression levels of PEP-encoded genes, chloroplast development genes and photosynthesis-related genes were compromised in wlp2 mutants, indicating that WLP2 is essential for normal chloroplast biogenesis. Moreover, WLP2 and its paralog OsFLN2 can physically interact with thioredoxin OsTRXz to form a TRX-FLN regulatory module, which not only regulates transcription of the PEP-encoded genes but also maintains the redox balance in chloroplasts under heat stress. Furthermore, the wlp2w mutant gene represents a potential advantage in enhancing seed purity and high-throughput breeding. Our results strongly indicate that WLP2 protects chloroplast development from heat stress via a TRX-FLN regulatory module in rice.


Assuntos
Proteínas de Arabidopsis/metabolismo , Cloroplastos/enzimologia , Cloroplastos/fisiologia , Oryza/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Mapeamento Cromossômico , RNA Polimerases Dirigidas por DNA/metabolismo , Temperatura Alta , Mutação , Oryza/genética , Oryza/fisiologia , Oxirredução , Fenótipo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Sementes/enzimologia , Sementes/genética , Sementes/fisiologia , Estresse Fisiológico , Tiorredoxinas/metabolismo
11.
PLoS One ; 12(5): e0177989, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28558018

RESUMO

Magnesium-protoporphyrin IX monomethyl ester cyclase (MPEC) catalyzes the conversion of MPME to divinyl protochlorophyllide (DVpchlide). This is an essential enzyme during chlorophyll (Chl) biosynthesis but details of its function in rice are still lacking. Here, we identified a novel rice mutant yellow-leaf 1 (yl-1), which showed decreased Chl accumulation, abnormal chloroplast ultrastructure and attenuated photosynthetic activity. Map-based cloning and over-expression analysis suggested that YL-1 encodes a subunit of MPEC. The YL-1 protein localizes in chloroplasts, and it is mainly expressed in green tissues, with greatest abundance in leaves and young panicles. Results of qRT-PCR showed that Chl biosynthesis upstream genes were highly expressed in the yl-1 mutant, while downstream genes were compromised, indicating that YL-1 plays a pivotal role in the Chl biosynthesis. Furthermore, the expression levels of photosynthesis and chloroplast development genes were also affected. RNA-seq results futher proved that numerous membrane-associated genes, including many plastid membrane-associated genes, have altered expression pattern in the yl-1 mutant, implying that YL-1 is required for plastid membrane stability. Thus, our study confirms a putative MPME cyclase as a novel key enzyme essential for Chl biosynthesis and chloroplast membrane stability in rice.


Assuntos
Clorofila/biossíntese , Enzimas/genética , Oryza/metabolismo , Protoporfirinas/metabolismo , Enzimas/metabolismo , Genes de Plantas , Microscopia Eletrônica de Transmissão , Mutação , Oryza/genética , Oryza/crescimento & desenvolvimento , Fotossíntese
12.
Front Plant Sci ; 8: 298, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28326091

RESUMO

Cereals high in amylose content (AC) and resistant starch (RS) offer potential health benefits. Previous studies using chemical mutagenesis or RNA interference have demonstrated that starch branching enzyme (SBE) plays a major role in determining the fine structure and physical properties of starch. However, it remains a challenge to control starch branching in commercial lines. Here, we use CRISPR/Cas9 technology to generate targeted mutagenesis in SBEI and SBEIIb in rice. The frequencies of obtained homozygous or bi-allelic mutant lines with indels in SBEI and SBEIIb in T0 generation were from 26.7 to 40%. Mutations in the homozygous T0 lines stably transmitted to the T1 generation and those in the bi-allelic lines segregated in a Mendelian fashion. Transgene-free plants carrying only the frame-shifted mutagenesis were recovered in T1 generation following segregation. Whereas no obvious differences were observed between the sbeI mutants and wild type, sbeII mutants showed higher proportion of long chains presented in debranched amylopectin, significantly increased AC and RS content to as higher as 25.0 and 9.8%, respectively, and thus altered fine structure and nutritional properties of starch. Taken together, our results demonstrated for the first time the feasibility to create high-amylose rice through CRISPR/Cas9-mediated editing of SBEIIb.

13.
Sci Rep ; 7: 40124, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28054650

RESUMO

Starch is the main storage carbohydrate in higher plants. Although several enzymes and regulators for starch biosynthesis have been characterized, a complete regulatory network for starch synthesis in cereal seeds remains elusive. Here, we report the identification and characterization of the rice Brittle1 (OsBT1) gene, which is expressed specifically in the developing endosperm. The osbt1 mutant showed a white-core endosperm and a significantly lower grain weight than the wild-type. The formation and development of compound starch granules in osbt1 was obviously defective: the amyloplast was disintegrated at early developmental stages and the starch granules were disperse and not compound in the endosperm cells in the centre region of osbt1 seeds. The total starch content and amylose content was decreased and the physicochemical properties of starch were altered. Moreover, the degree of polymerization (DP) of amylopectin in osbt1 was remarkably different from that of wild-type. Map-based cloning of OsBT1 indicated that it encodes a putatively ADP-glucose transporter. OsBT1 coded protein localizes in the amyloplast envelope membrane. Furthermore, the expression of starch synthesis related genes was also altered in the osbt1 mutant. These findings indicate that OsBT1 plays an important role in starch synthesis and the formation of compound starch granules.


Assuntos
Adenosina Difosfato Glucose/metabolismo , Endosperma/enzimologia , Proteínas de Membrana Transportadoras/metabolismo , Oryza/enzimologia , Plastídeos/enzimologia , Amido/biossíntese , Amilopectina/metabolismo , Deleção de Genes , Proteínas de Membrana Transportadoras/genética , Oryza/genética , Oryza/metabolismo
14.
J Integr Plant Biol ; 59(2): 134-153, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27957808

RESUMO

Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains of gif2 showed a slower filling rate and a significant lower final grain weight and yield compared to wild-type. The starch content in gif2 was noticeably decreased and its physicochemical properties were also altered. Moreover, gif2 endosperm cells showed obvious defects in compound granule formation. Positional cloning identified GIF2 to encode an ADP-glucose pyrophosphorylase (AGP) large subunit, AGPL2; consequently, AGP enzyme activity in gif2 endosperms was remarkably decreased. GIF2 is mainly expressed in developing grains and the coded protein localizes in the cytosol. Yeast two hybrid assay showed that GIF2 interacted with AGP small subunits OsAGPS1, OsAGPS2a and OsAGPS2b. Transcript levels for granule-bound starch synthase, starch synthase, starch branching enzyme and starch debranching enzyme were distinctly elevated in gif2 grains. In addition, the level of nucleotide diversity of the GIF2 locus was extremely low in both cultivated and wild rice. All of these results suggest that GIF2 plays important roles in the regulation of grain filling and starch biosynthesis during caryopsis development, and that it has been preserved during selection throughout domestication of modern rice.


Assuntos
Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Amido/biossíntese , Sequência de Bases , Clonagem Molecular , Ecótipo , Endosperma/metabolismo , Endosperma/ultraestrutura , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Teste de Complementação Genética , Glucose-1-Fosfato Adenililtransferase/metabolismo , Mutação/genética , Oryza/genética , Fenótipo , Proteínas de Plantas/genética , Subunidades Proteicas/metabolismo , Frações Subcelulares/metabolismo
15.
PLoS One ; 11(10): e0164748, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27764161

RESUMO

Polycomb group (PcG) proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2) protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice.


Assuntos
Clonagem Molecular/métodos , Mutação , Oryza/crescimento & desenvolvimento , Proteínas do Grupo Polycomb/genética , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Oryza/genética , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Locos de Características Quantitativas
16.
Plant Mol Biol ; 84(3): 301-14, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24132771

RESUMO

Plastidial ribosome proteins (PRPs) form the major component of the plastidial ribosome. Here we describe a rice mutant named wlp1 (white leaf and panicles 1) selected from a population of tissue culture regenerants. The early seedling leaves of the mutant were albino, as was the immature panicle at heading, and the phenotype was more strongly expressed in plants exposed to low temperature conditions. Changes in the leaf pigmentation of the mutant were due to altered chlorophyll content and chloroplast development. Positional cloning of WLP1, followed by complementation and knock-down experiments, showed that it encodes a 50S ribosome L13 protein. The WLP1 protein localized to the chloroplast. WLP1 was mainly transcribed in green tissues and particularly abundantly in the early seedling leaves. In addition, the expression level of WLP1 was induced by the low temperature. The transcription pattern of a number of genes involved in plastidial transcription/translation and in photosynthesis was altered in the wlp1 mutants. These results reveal that WLP1 is required for normal chloroplast development, especially under low temperature conditions. This is the first report on the function of PRPs in rice.


Assuntos
Cloroplastos/fisiologia , Temperatura Baixa , Genes de Plantas , Proteínas Nucleares/genética , Oryza/genética , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Clorofila/metabolismo , Clonagem Molecular , Perfilação da Expressão Gênica , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Proteínas Nucleares/química , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Fotossíntese , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Ribossômicas/química , Homologia de Sequência de Aminoácidos , Frações Subcelulares/metabolismo , Transcrição Genética
17.
Gene ; 527(1): 201-6, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23769924

RESUMO

A recombinant inbred line (RIL) population bred from a cross between a javanica type (cv. D50) and an indica type (cv. HB277) rice was used to map seven quantitative trait loci (QTLs) for thousand grain weight (TGW). The loci were distributed on chromosomes 2, 3, 5, 6, 8 and 10. The chromosome 3 QTL qTGW3.2 was stably expressed over two years, and contributed 9-10% of the phenotypic variance. A residual heterozygous line (RHL) was selected from the RIL population and its selfed progeny was used to fine map qTGW3.2. In this "F2" population, the QTL explained about 23% of the variance, rising to nearly 33% in the subsequent "F2:3" generation. The physical location of qTGW3.2 was confined to a ~556 kb region flanked by the microsatellite loci RM16162 and RM16194. The region also contains other factors influencing certain yield-related traits, although it is also possible that qTGW3.2 affects these in a pleiotropic fashion.


Assuntos
Genes de Plantas , Oryza/genética , Sementes/genética , Alelos , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Ligação Genética , Endogamia , Oryza/anatomia & histologia , Locos de Características Quantitativas , Sementes/anatomia & histologia
18.
Plant Cell Rep ; 32(9): 1455-63, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23689259

RESUMO

KEY MESSAGE: A new rice floral organ mutant bh1 , had a negative effect on grain yield. BH1 was fine mapped to 87.5 kb on chr2. A 55 kb chromosome segment was deleted in bh1. The cereal spikelet is enclosed by the lemma and palea. The lemma and palea of the floral mutant designated bh1, a selection from a T-DNA library generated from the rice cultivar Asominori, takes on an abnormal curve-shaped appearance only late in floral development, finally forming a beak-shaped hull. The mutation had a negative effect on thousand grain weight, seed set rate and germination rate. Genetic analysis indicated that the mutant phenotype was determined by a single recessive gene. Through map-based approach, BH1 gene was finally located to a ~87.5-kbp region on the long arm of chromosome 2. An analysis of the gene content of this region indicated that the mutation involves the loss of a 55-kbp stretch, harboring four open reading frames. Transcription profiling based on qRT-PCR revealed that the genes OsMADS1, OsMADS14, OsMADS15, OsMADS18, REP1, CFO1, and DL, all of which are also involved in lemma and palea development and identity specification, were down-regulated in the bh1 mutant. BH1 is therefore an important floral organ development gene.


Assuntos
Flores/crescimento & desenvolvimento , Oryza/genética , Proteínas de Plantas/metabolismo , Mapeamento Cromossômico , Cromossomos de Plantas , DNA Bacteriano/genética , DNA de Plantas/genética , Regulação para Baixo , Flores/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes Recessivos , Germinação , Mutação , Fases de Leitura Aberta , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fenótipo , Proteínas de Plantas/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Deleção de Sequência
19.
Genomics ; 101(2): 157-62, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23220350

RESUMO

Fragrance is an important component of end-use quality in rice. A set of 516 fragrant rice accessions were genotyped and over 80% of them carried the badh2.7 allele. A subset of 144 mostly fragrant accessions, including nine of Oryza rufipogon, was then subjected to a detailed diversity and haplotype analysis. The level of linkage disequilibrium in the Badh2 region was higher among the fragrant accessions. Re-sequencing in the Badh2 region showed that badh2.7, badh2.2 and badh2.4-5 all arose in the japonica genepool, and spread later into the indica genepool as a result of deliberate crossing. However, loss-of-function alleles of Badh2 are also found in the indica genepools, and then transferred into japonica. Evidence for three new possible FNPs was obtained from the Badh2 sequence of 62 fragrant accessions. Based on these data, we have elaborated a model for the evolution of Badh2 and its participation in the rice domestication process.


Assuntos
Genes de Plantas , Haplótipos , Odorantes , Oryza/genética , Alelos , Evolução Molecular , Éxons , Pool Gênico , Variação Genética , Desequilíbrio de Ligação , Análise de Sequência de DNA
20.
Theor Appl Genet ; 125(6): 1303-12, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22772587

RESUMO

Grain shape is an important component of end-use quality in rice. The genomic location of the grain shape QTL GS7 was narrowed to lie within a 4.8-kb segment on chromosome 7. The homologous region in cv. Nipponbare contains no annotated genes, while two open reading frames were predicted, one of which (ORF2) represented a likely candidate for GS7 gene on the basis of correlation between sequence variation and phenotype. Semi-quantitative and quantitative RT-PCR analysis of ORF2 transcription showed that the gene was active in both the leaf and panicle when the cv. D50 allele was present, but not in the presence of the cv. HB277 allele. A microsatellite-based phylogeny and a re-sequencing analysis of ORF2 among a set of 52 diverse rice accessions suggested that the cv. D50 GS7 allele may have originated from the tropical japonica genepool. The effect on grain length of the alternative alleles at GS7and GS3 showed that combination type 3/A was associated with longer grains than type 1/A. An Indel marker developed within the ORF2 sequence was informative for predicting grain length.


Assuntos
Alelos , Genes de Plantas , Variação Genética , Oryza/genética , Sementes/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , DNA de Plantas/genética , Genótipo , Repetições de Microssatélites , Fases de Leitura Aberta , Fenótipo , Locos de Características Quantitativas , Análise de Sequência de DNA
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