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1.
BMC Plant Biol ; 19(1): 340, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382873

RESUMO

BACKGROUND: Circular RNAs (circRNAs) are known to play an important role in the regulation of gene expression in eukaryotes. Photo-thermosensitive genic male sterile (PTGMS) is a very important germplasm resource in two-line hybrid rice breeding. Although many circRNAs have been identified in rice (Oryza sativa L.), little is known about the biological roles of circRNAs in the fertility transition of the PTGMS rice line. RESULTS: In the present study, RNA-sequencing libraries were constructed from the young panicles of the Wuxiang S sterile line rice (WXS (S)) and its fertile line rice (WXS (F)) at three development stages with three biological replicates. A total of 9994 circRNAs were obtained in WXS rice based on high-throughput strand-specific RNA sequencing and bioinformatic approaches, of which 5305 were known circRNAs and 4689 were novel in rice. And 14 of 16 randomly selected circRNAs were experimentally validated with divergent primers. Our results showed that 186 circRNAs were significantly differentially expressed in WXS (F) compared with WXS (S), of which 97, 87 and 60 circRNAs were differentially expressed at the pollen mother cell (PMC) formation stage (P2), the meiosis stage (P3) and the microspore formation stage (P4), respectively. Fertility specific expression patterns of eight circRNAs were analysis by qRT-PCR. Gene ontology (GO) and KEGG pathway analysis of the parental genes of differentially expressed circRNAs (DECs) revealed that they mainly participated in various biological processes such as development, response to stimulation, hormonal regulation, and reproduction. Furthermore, 15 DECs were found to act as putative miRNA sponges to involved in fertility transition in PTGMS rice line. CONCLUSION: In the present study, the abundance and characteristics of circRNAs were investigated in the PTGMS rice line using bioinformatic approaches. Moreover, the expression patterns of circRNAs were different between WXS (F) and WXS (S). Our findings primarily revealed that circRNAs might be endogenous noncoding regulators of flower and pollen development, and were involved in the fertility transition in the PTGMS rice line, and guide the production and application of two-line hybrid rice.


Assuntos
Oryza/genética , RNA/genética , Fertilidade/genética , Fertilidade/fisiologia , Flores/crescimento & desenvolvimento , Genes de Plantas/genética , Genes de Plantas/fisiologia , Resposta ao Choque Térmico , Sequenciamento de Nucleotídeos em Larga Escala , Oryza/fisiologia , Pólen/crescimento & desenvolvimento , RNA/fisiologia
2.
Pestic Biochem Physiol ; 159: 1-8, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400771

RESUMO

We examined the molecular regulation of porphyrin biosynthesis and protective responses in transgenic rice (Oryza sativa) expressing Bradyrhizobium japonicum Fe-chelatase (BjFeCh) after treatment with acifluorfen (AF). During the photodynamic stress imposed by AF, transcript levels of BjFeCh in transgenic plants increased greatly; moreover, transcript levels of OsFeCh2 remained almost constant, whereas in wild type (WT) plants they were considerably down-regulated. In the heme branch, transgenic plants exhibited greater levels of OsFC and HO transcripts than WT plants in the untreated stems as well as in the AF-treated leaves and stems. Both WT and transgenic plants treated with AF substantially decreased transcript levels for all the genes in the chlorophyll branch, with less decline in transgenic plants. After AF treatment, ascorbate (Asc) content and the redox Asc state greatly decreased in leaves of WT plants; however, in transgenic plants both parameters remained constant in leaves and the Asc redox state increased by 20% in stems. In response to AF, the leaves of WT plants greatly up-regulated CatA, CatB, and GST compared to those of transgenic plants, whereas, in the stems, transgenic plants showed higher levels of CatA, CatC, APXb, BCH, and VDE. Photochemical quenching, qP, was considerably dropped by 31% and 18% in WT and transgenic plants, respectively in response to AF, whereas non-radiative energy dissipation through non-photochemical quenching increased by 77% and 38% in WT and transgenic plants, respectively. Transgenic plants treated with AF exhibited higher transcript levels of nucleus-encoded photosynthetic genes, Lhcb1 and Lhcb6, as well as levels of Lhcb6 protein compared to those of WT plants. Our study demonstrates that expression of BjFeCh in transgenic plants influences not only the regulation of porphyrin biosynthesis through maintaining higher levels of gene expression in the heme branch, but also the Asc redox function during photodynamic stress caused by AF.


Assuntos
Proteínas de Bactérias/metabolismo , Bradyrhizobium/enzimologia , Ferroquelatase/metabolismo , Nitrobenzoatos/farmacologia , Oryza/metabolismo , Porfirinas/biossíntese , Proteínas de Bactérias/genética , Ferroquelatase/genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Plantas Geneticamente Modificadas
3.
BMC Plant Biol ; 19(1): 302, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291890

RESUMO

BACKGROUND: Nitrogen (N) and potassium (K) are two important mineral nutrients in regulating leaf photosynthesis. Studying the interactive effects of N and K on regulating N allocation and photosynthesis (Pn) of rice leaves will be of great significance for further increasing leaf Pn, photosynthetic N use efficiency (PNUE) and grain yield. We measured the gas exchange of rice leaves in a field experiment and tested different kinds of leaf N based on N morphology and function, and calculated the interactive effects of N and K on N allocation and the PNUE. RESULTS: Compared with N0 (0 kg N ha- 1) and K0 (0 kg K2O ha- 1) treatments, the Pn was increased by 17.1 and 12.2% with the supply of N and K. Compared with N0K0 (0 kg N and 0 kg K2O ha- 1), N0K120 (0 kg N and 120 kg K2O ha- 1) and N0K180 (0 kg N and 180 kg K2O ha- 1), N supply increased the absolute content of photosynthetic N (Npsn) by 15.1, 15.5 and 10.5% on average, and the storage N (Nstore) was increased by 32.7, 64.9 and 72.7% on average. The relative content of Npsn was decreased by 5.6, 12.1 and 14.5%, while that of Nstore was increased by 8.7, 27.8 and 33.8%. Supply of K promoted the transformation of Nstore to Npsn despite the leaf N content (Na) was indeed decreased. Compared with N0K0, N180K0 (180 kg N and 0 kg K2O ha- 1) and N270K0 (270 kg N and 0 kg K2O ha- 1), K supply increased the relative content of Npsn by 17.7, 8.8 and 7.3%, and decreased the relative content of Nstore by 24.2, 11.4 and 8.7% respectively. CONCLUSIONS: This study indicated the mechanism that K supply decreased the Na but increased the Npsn content and then increased leaf Pn and PNUE from a new viewpoint of leaf N allocation. The supply of K promoted the transformation of Nstore to Npsn and increased the PNUE. The decreased Nstore mainly resulted from the decrease of non-protein N. Combined use of N and K could optimize leaf N allocation and maintain a high leaf Npsn content and PNUE.


Assuntos
Nitrogênio/metabolismo , Oryza/fisiologia , Potássio/metabolismo , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Fotossíntese , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia
4.
BMC Plant Biol ; 19(1): 308, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299895

RESUMO

BACKGROUND: Land preparation is an important component of fragrant rice production. However, the effect of tillage on fragrant rice production is unclear, especially regarding the biosynthesis of 2-acetyl-1-pyrroline (2-AP), which is the main compound of the unique aroma of fragrant rice. This study aimed to explore 2-AP biosynthesis in fragrant rice under different tillage regimes. Three tillage methods were applied in the present study: conventional rotary tillage (CK) as the control, plough tillage (PT), and no-tillage (NT). RESULT: Compared with CK, the PT treatment increased 2-AP content in grain, upregulated the activity of ornithine aminotransferase (OAT) and increased contents of 1-pyrroline and pyrroline-5-carboxylic acid (P5C). Furthermore, the PT treatment increased the grain yield and nitrogen accumulation of fragrant rice. Meanwhile, the 2-AP content in the grain produced under the NT treatment was significantly higher than that in the grain produced under both the PT and CK treatments due to the enhancement of proline content and the activities of proline dehydrogenase (PDH) and △1-pyrroline-5-carboxylic acid synthetase (P5CS). However, the present study observed that the overall production of fragrant rice under NT conditions was inferior due to lower yield, nitrogen accumulation, and anti-oxidative enzymatic activities. Moreover, the organic matter content and soil microorganism quantity increased due to PT and NT treatments. CONCLUSIONS: Compared to CK, PT improved fragrant rice grain yield and nitrogen accumulation and induced an increase in OAT activity and led to an increase in 2-AP concentration. No-tillage also produced increased 2-AP content in grain by enhancing PDH and P5CS activities but limited yields and nitrogen accumulation in fragrant rice.


Assuntos
Oryza/fisiologia , Prolina Oxidase/metabolismo , Pirróis/metabolismo , Odorantes , Oryza/enzimologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prolina/análise , Prolina Oxidase/genética , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia
5.
BMC Plant Biol ; 19(1): 298, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286900

RESUMO

BACKGROUND: Homeodomain-leucine zipper (HD-ZIP) transcription factors play important roles in the growth, development and stress responses of plants, including (presumably) physic nut (Jatropha curcas), which has high drought and salinity tolerance. However, although physic nut's genome has been released, there is little knowledge of the functions, expression profiles and evolutionary histories of the species' HD-ZIP genes. RESULTS: In this study, 32 HD-ZIP genes were identified in the physic nut genome (JcHDZs) and divided into four groups (I-IV) based on phylogenetic analysis with homologs from rice, maize and Arabidopsis. The analysis also showed that most of the JcHDZ genes were closer to members from Arabidopsis than to members from rice and maize. Of the 32 JcHDZ genes, most showed differential expression patterns among four tissues (root, stem cortex, leaf, and seed). Expression profile analysis based on RNA-seq data indicated that 15 of the JcHDZ genes respond to at least one abiotic stressor (drought and/or salinity) in leaves at least at one time point. Transient expression of a JcHDZ16-YFP fusion protein in Arabidopsis protoplasts cells showed that JcHDZ16 is localized in the nucleus. In addition, rice seedlings transgenically expressing JcHDZ16 had lower proline contents and activities of antioxidant enzymes (catalase and superoxide dismutase) together with higher relative electrolyte leakage and malondialdehyde contents under salt stress conditions (indicating higher sensitivity) than wild-type plants. The transgenic seedlings also showed increased sensitivity to exogenous ABA, and increases in the transcriptional abundance of several salt stress-responsive genes were impaired in their responses to salt stress. Further data on JcHDZ16-overexpressing plants subjected to salt stress treatment verified the putative role of JcHDZ genes in salt stress responses. CONCLUSION: Our results may provide foundations for further investigation of functions of JcHDZ genes in responses to abiotic stress, and promote application of JcHDZ genes in physic nut breeding.


Assuntos
Jatropha/genética , Oryza/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Estudo de Associação Genômica Ampla , Jatropha/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/metabolismo , Transcriptoma
6.
Gene ; 714: 143984, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31330237

RESUMO

Intrinsically disordered proteins (IDPs) are highly abundant in eukaryotic proteomes and involved in key biological and cellular processes. Although some resources of disordered protein predictions are available from animal and plant proteomes, those related to cereals are largely unknown. Here, we present an overview of IDPomes from Oryza sativa, Zea mays, Sorghum bicolor and Brachypodium distachyon. The work includes a comparative analysis with the model plant Arabidopsis thaliana. The data show that the intrinsic disorder content increases with the proteome size. Gene Ontology analysis reveals that IDPs in the studied species are involved mainly in regulation of cellular and metabolic processes and responses to stimulus. Our findings strongly suggest that higher plants may use common cellular and regulatory mechanisms for adaptation to various environmental constraints.


Assuntos
Grão Comestível/genética , Proteínas Intrinsicamente Desordenadas/genética , Adaptação Biológica/genética , Arabidopsis/genética , Brachypodium/genética , Ontologia Genética , Genômica/métodos , Oryza/genética , Proteínas de Plantas/genética , Proteoma/genética , Sorghum/genética , Zea mays/genética
7.
Plant Sci ; 286: 17-27, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300138

RESUMO

The plant-specific gibberellic acid (GA)-stimulated transcript gene family is critical for plant growth and development. There are 10 family members in rice (Oryza sativa), known as OsGASRs. However, few have been functionally characterized. Here, we investigated the function of OsGASR9 in rice. OsGASR9 transcripts were detected in various tissues, with the lowest and highest levels in leaves and panicles, respectively. Greater mRNA levels accumulated in young, compared with in old, panicles and spikelets. OsGASR9 localized to the plasma membrane, cytoplasm and nucleus. Transgenic RNA interference-derived lines in the Zhonghua 11 background exhibited reduced plant height, grain size and yield compared with the wild-type. The two osgasr9 mutants in the Nipponbare background showed similar phenotypes. Conversely, the overexpression of OsGASR9 in the two backgrounds increased plant height and grain size. A significantly increased grain yield per plant was also observed in the overexpression lines having a Nipponbare background. Furthermore, by measuring the GA-induced lengths of the second leaf sheaths and α-amylase activity levels of seeds, we concluded that OsGASR9 is a positive regulator of responses to GA in rice. Thus, OsGASR9 may regulate plant height, grain size and yield through the GA pathway and could have an application value in breeding.


Assuntos
Giberelinas/metabolismo , Oryza/genética , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Família Multigênica , Oryza/crescimento & desenvolvimento , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Interferência de RNA
8.
J Agric Food Chem ; 67(28): 7986-7994, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282158

RESUMO

Compositional analyses were performed on samples of rice grain, straw, and derived bran obtained from golden rice event GR2E and near-isogenic control PSBRc82 rice grown at four locations in the Philippines during 2015 and 2016. Grain samples were analyzed for key nutritional components, including proximates, fiber, polysaccharides, fatty acids, amino acids, minerals, vitamins, and antinutrients. Samples of straw and bran were analyzed for proximates and minerals. The only biologically meaningful difference between GR2E and control rice was in levels of ß-carotene and other provitamin A carotenoids in the grain. Except for ß-carotene and related carotenoids, the compositional parameters of GR2E rice were within the range of natural variability of those components in conventional rice varieties with a history of safe consumption. Mean provitamin A concentrations in milled rice of GR2E can contribute up to 89-113% and 57-99% of the estimated average requirement for vitamin A for preschool children in Bangladesh and the Philippines, respectively.


Assuntos
Oryza/genética , Plantas Geneticamente Modificadas/química , Sementes/química , Aminoácidos/análise , Aminoácidos/metabolismo , Bangladesh , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Alimentos Geneticamente Modificados , Engenharia Genética , Valor Nutritivo , Oryza/química , Oryza/metabolismo , Filipinas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Provitaminas/análise , Provitaminas/metabolismo , Sementes/genética , Sementes/metabolismo , Vitamina A/análise , Vitamina A/metabolismo , beta Caroteno/análise , beta Caroteno/metabolismo
9.
Gene ; 713: 143976, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306715

RESUMO

Naturally evolved saline tolerant rice landraces found along the coastline of India are a valuable genomic resource to explore the complex, polygenic nature of salinity tolerance. In the present study, a set of 28 genome wide SSR markers, 11 salt responsive genic SSR markers and 8 Saltol QTL linked SSR markers were used to estimate genetic relatedness and population structure within a collection of 47 rice landraces (including a tolerant and 2 sensitive checks) originating from geographically divergent coastal regions of India. All three marker types identified substantial genetic variation among the landraces, as evident from their higher PIC values (0.53 for genomic SSRs, 0.43 for Genic SSRs and 0.59 for Saltol SSRs). The markers RM431, RM484 (Genomic SSRs), OsCAX (D), OsCAX (T) (Genic SSRs) and RM562 (Saltol SSR) were identified as good candidates to be used in breeding programs for improving salinity tolerance in rice. STRUCTURE analysis divided the landraces into five distinct populations, with classification correlating with their geographical locations. Principal coordinate and hierarchical cluster analyses (UPGMA and neighbor joining) are in close agreement with STRUCTURE results. AMOVA analysis indicated a higher magnitude of genetic differentiation within individuals of groups (58%), than among groups (42%). We also report the development and validation of a new Cleavage Amplified Polymorphic Sequence (CAPS) marker (OsHKT1;5V395) that targets a codon in the sodium transporter gene OsHKT1;5 (Saltol/SKC1 locus) that is associated with sodium transport rates in the above rice landraces. The CAPS marker was found to be present in all landraces except in IR29, Kamini, Gheus, Matla 1 and Matla 2. Significant molecular genetic diversity established among the analyzed salt tolerant rice landraces will aid in future association mapping; the CAPS marker, OsHKT1;5V395 can be used to map rice landraces for the presence of the SNP (Single Nucleotide Polymorphism) associated with increased sodium transport rates and concomitant salinity tolerance in rice.


Assuntos
Marcadores Genéticos , Variação Genética , Repetições de Microssatélites , Oryza/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Sódio/metabolismo , Genótipo , Filogenia
10.
J Agric Food Chem ; 67(32): 8766-8772, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31313921

RESUMO

In decades of hybrid rice breeding, the combining ability has been successfully used to evaluate excellent parental lines and predict heterosis. However, previous studies for the combining ability mainly focused on cultivated rice and rarely involved wild rice. In this study, for the first time, we identified 20 new quantitative trait loci (QTLs) for the combining ability in wild rice using a North Carolina II mating design. Among them, qGCA1, one of the major QTLs that can significantly improve the general combining ability of the plant height, spikelet number, and yield per plant, was delimited to an interval of about 72 kb on chromosome 1. qSCA8, another major QTL, which can significantly improve the specific combining ability of the seed-setting rate and yield per plant, was located in an interval of about 90 kb on chromosome 8. These QTLs discovered from wild rice will provide new ideas to explain the genetic mechanism of the combining ability and establish the basis for breeding of high-combining-ability rice.


Assuntos
Cromossomos de Plantas/genética , Oryza/genética , Locos de Características Quantitativas , Mapeamento Cromossômico , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fenótipo , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
11.
BMC Plant Biol ; 19(1): 249, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185908

RESUMO

BACKGROUND: As an elite japonica rice variety, Kongyu-131 has been cultivated for over 20 years in the third accumulated temperature zone of Heilongjiang Province, China. However, the cultivated area of Kongyu-131 has decreased each year due to extensive outbreaks of rice blast. To achieve the goals of improving blast resistance and preserving other desirable traits in Kongyu-131, a genome-updating method similar to repairing a bug in a computer program was adopted in this study. A new allele of the broad-spectrum blast resistance gene pi21 in the upland rice variety GKGH was mined by genetic analysis and introgressed into the genome of Kongyu-131 to upgrade its blast resistance. RESULT: QTL analysis was performed with an F2 population derived from a cross between Kongyu-131 and GKGH, and a blast resistance QTL was detected near the pi21 locus. Parental Pi21 sequence alignment showed that the pi21 of the donor (GKGH) was a new allele. By 5 InDel or SNP markers designed based on the sequence within and around pi21, the introgressed chromosome segment was shortened to less than 634 kb to minimize linkage drag by screening recombinants in the target region. The RRPG was 99.92%, calculated according to 201 SNP markers evenly distributed on 12 chromosomes. Artificial inoculation at the seedling stage showed that the blast resistance of the new Kongyu-131 was improved significantly. Field experiments also indicated that the improved Kongyu-131 had enhanced field resistance to rice blast and grain-quality traits similar to those of the original Kongyu-131. CONCLUSIONS: It is feasible to improve resistance to rice blast and preserve other desirable traits by precisely improving the Pi21 locus of Kongyu-131. Linkage drag can be eliminated effectively via recombinant selection on both sides of the target gene.


Assuntos
Resistência à Doença/genética , Genes de Plantas , Oryza/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Ligação Genética , Magnaporthe/fisiologia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo
12.
BMC Plant Biol ; 19(1): 250, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185911

RESUMO

BACKGROUND: Cadmium (Cd) is a widespread toxic heavy metal pollutant in agricultural soil, and Cd accumulation in rice grains is a major intake source of Cd for Asian populations that adversely affect human health. However, the molecular mechanism underlying Cd uptake, translocation and accumulation has not been fully understood in rice plants. RESULTS: In this study, a mutant displaying extremely low Cd accumulation (lcd1) in rice plant and grain was generated by EMS mutagenesis from indica rice cultivar 9311 seeds. The candidate SNPs associated with low Cd accumulation phenotype in the lcd1 mutant were identified by MutMap and the transcriptome changes between lcd1 and WT under Cd exposure were analyzed by RNA-seq. The lcd1 mutant had lower Cd uptake and accumulation in rice root and shoot, as well as less growth inhibition compared with WT in the presence of 5 µM Cd. Genetic analysis showed that lcd1 was a single locus recessive mutation. The SNP responsible for low Cd accumulation in the lcd1 mutant located at position 8,887,787 on chromosome 7, corresponding to the seventh exon of OsNRAMP5. This SNP led to a Pro236Leu amino acid substitution in the highly conserved region of OsNRAMP5 in the lcd1 mutant. A total of 1208 genes were differentially expressed between lcd1 and WT roots under Cd exposure, and DEGs were enriched in transmembrane transport process GO term. Increased OsHMA3 expression probably adds to the effect of OsNRAMP5 mutation to account for the significant decreases in Cd accumulation in rice plant and grain of the lcd1 mutant. CONCLUSIONS: An extremely low Cd mutant lcd1 was isolated and identified using MutMap and RNA-seq. A Pro236Leu amino acid substitution in the highly conserved region of OsNRAMP5 is likely responsible for low Cd accumulation in the lcd1 mutant. This work provides more insight into the mechanism of Cd uptake and accumulation in rice, and will be helpful for developing low Cd accumulation rice by marker-assisted breeding.


Assuntos
Cádmio/metabolismo , Proteínas de Transporte de Cátions/genética , Oryza/genética , Proteínas de Plantas/genética , Poluentes do Solo/metabolismo , Sequência de Aminoácidos , Transporte Biológico , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Perfilação da Expressão Gênica , Oryza/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência
13.
Nat Commun ; 10(1): 2501, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175302

RESUMO

Hybrid sterility (HS) between Oryza sativa (Asian rice) and O. glaberrima (African rice) is mainly controlled by the S1 locus. However, our limited understanding of the HS mechanism hampers utilization of the strong interspecific heterosis. Here, we show that three closely linked genes (S1A4, S1TPR, and S1A6) in the African S1 allele (S1-g) constitute a killer-protector system that eliminates gametes carrying the Asian allele (S1-s). In Asian-African rice hybrids (S1-gS1-s), the S1TPR-S1A4-S1A6 interaction in sporophytic tissues generates an abortion signal to male and female gametes. However, S1TPR can rescue S1-g gametes, while the S1-s gametes selectively abort for lacking S1TPR. Knockout of any of the S1-g genes eliminates the HS. Evolutionary analysis suggests that S1 may have arisen from newly evolved genes, multi-step recombination, and nucleotide variations. Our findings will help to overcome the interspecific reproductive barrier and use Asian-African hybrids for increasing rice production.


Assuntos
Quimera/genética , Oryza/genética , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Alelos , Técnicas de Inativação de Genes , Células Germinativas Vegetais
14.
BMC Plant Biol ; 19(1): 257, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31200645

RESUMO

BACKGROUND: Proliferating cell nuclear antigen (PCNA), a conserved trimeric ring complex, is loaded onto replication fork through a hetero-pentameric AAA+ ATPase complex termed replication factor C (RFC) to maintain genome stability. Although architectures of PCNA-RFC complex in yeast have been revealed, the functions of PCNA and protein-protein interactions of PCNA-RFC complex in higher plants are not very clear. Here, essential regions mediating interactions between PCNA and RFC subunits in Arabidopsis and rice were investigated via yeast-two-hybrid method and bimolecular fluorescence complementation techniques. RESULTS: We observed that OsPCNA could interact with all OsRFC subunits, while protein-protein interactions only exist between Arabidopsis RFC2/3/4/5 and AtPCNA1/2. The truncated analyses indicated that the C-terminal of Arabidopsis RFC2/3/4/5 and rice RFC1/2 is essential for binding PCNA while the region of rice RFC3/4/5 mediating interaction with PCNA distributed both at the N- and C-terminal. On the other hand, we found that the C- and N-terminal of Arabidopsis and rice PCNA contribute equally to PCNA-PCNA interaction, and the interdomain connecting loop (IDCL) domain and C-terminal of PCNAs are indispensable for interacting RFC subunits. CONCLUSIONS: These results indicated that Arabidopsis and rice PCNAs are highly conserved in sequence, structure and pattern of interacting with other PCNA monomer. Nevertheless, there are also significant differences between the Arabidopsis and rice RFC subunits in binding PCNA. Taken together, our results could be helpful for revealing the biological functions of plant RFC-PCNA complex.


Assuntos
Arabidopsis/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteína de Replicação C/metabolismo , Arabidopsis/genética , Sequência Conservada , Oryza/genética , Proteínas de Plantas/genética , Antígeno Nuclear de Célula em Proliferação/genética
15.
BMC Plant Biol ; 19(1): 259, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208337

RESUMO

BACKGROUND: Cultivated rice (Oryza sativa L.) is one of the staple food for over half of the world's population. Thus, improvement of cultivated rice is important for the development of the world. It has been shown that abundant elite genes exist in rice landraces in previous studies. RESULTS: A genome-wide association study (GWAS) performed with EMMAX for 12 agronomic traits measured in both Guangzhou and Hangzhou was carried out using 150 accessions of Ting's core collection selected based on 48 phenotypic traits from 2262 accessions of Ting's collection, the GWAS included more than 3.8 million SNPs. Within Ting's core collection, which has a simple population structure, low relatedness, and rapid linkage disequilibrium (LD) decay, we found 32 peaks located closely to previously cloned genes such as Hd1, SD1, Ghd7, GW8, and GL7 or mapped QTL, and these loci might be natural variations in the cloned genes or QTL which influence potentially agronomic traits. Furthermore, we also detected 32 regions where new genes might be located, and some peaks of these new candidate genes such as the signal on chromosome 11 for heading days were even higher than that of Hd1. Detailed annotation of these significant loci were shown in this study. Moreover, according to the estimated LD decay distance of 100 to 350 kb on the 12 chromosomes in this study, we found 13 identical significant regions in the two locations. CONCLUSIONS: This research provided important information for further mining these elite genes within Ting's core collection and using them for rice breeding.


Assuntos
Oryza/genética , Característica Quantitativa Herdável , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/genética , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Desequilíbrio de Ligação/genética , Locos de Características Quantitativas/genética
16.
BMC Plant Biol ; 19(1): 260, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208338

RESUMO

BACKGROUND: Drought is a major abiotic stress factor that influences the yield of crops. Basic leucine zipper motif (bZIP) transcription factors play an important regulatory role in plant drought stress responses. However, the functions of a number of bZIP transcription factors in rice are still unknown. RESULTS: In this study, a novel drought stress-related bZIP transcription factor, OsbZIP62, was identified in rice. This gene was selected from a transcriptome analysis of several typical rice varieties with different drought tolerances. OsbZIP62 expression was induced by drought, hydrogen peroxide, and abscisic acid (ABA) treatment. Overexpression of OsbZIP62-VP64 (OsbZIP62V) enhanced the drought tolerance and oxidative stress tolerance of transgenic rice, while osbzip62 mutants exhibited the opposite phenotype. OsbZIP62-GFP was localized to the nucleus, and the N-terminal sequence (amino acids 1-68) was necessary for the transcriptional activation activity of OsbZIP62. RNA-seq analysis showed that the expression of many stress-related genes (e.g., OsGL1, OsNAC10, and DSM2) was upregulated in OsbZIP62V plants. Moreover, OsbZIP62 could bind to the promoters of several putative target genes and could interact with stress/ABA-activated protein kinases (SAPKs). CONCLUSIONS: OsbZIP62 is involved in ABA signalling pathways and positively regulates rice drought tolerance by regulating the expression of genes associated with stress, and this gene could be used for the genetic modification of crops with improved drought tolerance.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Oryza/genética , Proteínas de Plantas/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Desidratação , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Oryza/fisiologia , Estresse Oxidativo , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas
17.
Gene ; 710: 279-290, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31200083

RESUMO

Plants are frequently exposed to variable environmental stresses that adversely affect plant growth, development and agricultural production. In this study, a trypanothione synthetase gene from Trypanosoma cruzi, TcTryS, was chemically synthesized and its roles in tolerance to multiple abiotic stresses were functionally characterized by generating transgenic rice overexpressing TcTryS. Overexpression of TcTryS in rice endows transgenic plants with hypersensitivity to ABA, hyposensitivity to NaCl- and mannitol-induced osmotic stress at the seed germination stage. TcTryS overexpression results in enhanced tolerance to drought, salt, cadmium, and 2,4,6-trichlorophenol stresses in transgenic rice, simultaneously supported by improved physiological traits. The TcTryS-overexpression plants also accumulated greater amounts of proline, less malondialdehyde and more transcripts of stress-related genes than wild-type plants under drought and salt stress conditions. In addition, TcTryS might play a positive role in maintaining chlorophyll content under 2,4,6-trichlorophenol stress. Histochemical staining assay showed that TcTryS renders transgenic plants better ROS-scavenging capability. All of these results suggest that TcTryS could function as a key regulator in modulation of abiotic stress tolerance in plant, and may have applications in the engineering of economically important crops.


Assuntos
Amida Sintases/genética , Amida Sintases/metabolismo , Oryza/genética , Estresse Fisiológico , Trypanosoma cruzi/enzimologia , Ácido Abscísico/farmacologia , Cádmio/toxicidade , Secas , Regulação da Expressão Gênica de Plantas , Oryza/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Tolerância ao Sal , Trypanosoma cruzi/genética , Regulação para Cima
18.
Nat Commun ; 10(1): 2562, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189898

RESUMO

Cadmium (Cd) accumulation in rice grain poses a serious threat to human health. While several transport systems have been reported, the complicity of rice Cd transport and accumulation indicates the necessity of identifying additional genes, especially those that are responsible for Cd accumulation divergence between indica and japonica rice subspecies. Here, we show that a gene, OsCd1, belonging to the major facilitator superfamily is involved in root Cd uptake and contributes to grain accumulation in rice. Natural variation in OsCd1 with a missense mutation Val449Asp is responsible for the divergence of rice grain Cd accumulation between indica and japonica. Near-isogenic line tests confirm that the indica variety carrying the japonica allele OsCd1V449 can reduce the grain Cd accumulation. Thus, the japonica allele OsCd1V449 may be useful for reducing grain Cd accumulation of indica rice cultivars through breeding.


Assuntos
Cádmio/metabolismo , Grão Comestível/metabolismo , Proteínas de Membrana/metabolismo , Oryza/metabolismo , Poluentes do Solo/metabolismo , Alelos , Asparagina/genética , Cádmio/análise , Membrana Celular/metabolismo , Grão Comestível/química , Humanos , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Oryza/química , Oryza/genética , Filogenia , Melhoramento Vegetal/métodos , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único , Poluentes do Solo/análise , Valina/genética
19.
J Agric Food Chem ; 67(26): 7249-7257, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244201

RESUMO

The duration of the rice growth phase has always been an important target trait. The identification of mutations in rice that alter these processes and result in a shorter growth phase could have potential benefits for crop production. In this study, we isolated an early aging rice mutant, pe-1, with light green leaves, using γ-mutated indica rice cultivar and subsequent screening methods, which is known as the phytochrome synthesis factor Se5 that controls rice flowering. The pe-1 plant is accompanied by a decreased chlorophyll content, an enhanced photosynthesis, and a decreased pollen fertility. PE-1, a close homologue of HY1, is localized in the chloroplast. Expression pattern analysis indicated that PE-1 was mainly expressed in roots, stems, leaves, leaf sheaths, and young panicles. The knockout of PE-1 using the CRISPR/Cas9 system decreased the chlorophyll content and downregulated the expression of PE-1-related genes. Furthermore, the chloroplasts of pe-1 were filled with many large-sized starch grains, and the number of osmiophilic granules (a chloroplast lipid reservoir) was significantly decreased. Altogether, our findings suggest that PE-1 functions as a master regulator to mediate in chlorophyll biosynthesis and photosynthetic pathways.


Assuntos
Cloroplastos/metabolismo , Heme Oxigenase-1/metabolismo , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Clorofila/metabolismo , Cloroplastos/genética , Regulação da Expressão Gênica de Plantas , Heme Oxigenase-1/genética , Mutação , Oryza/genética , Oryza/metabolismo , Fotossíntese , Proteínas de Plantas/genética
20.
J Agric Food Chem ; 67(26): 7399-7409, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244203

RESUMO

Flavonol synthase (FLS) belongs to the 2-oxoglutarate-dependent dioxygenase (2-ODD) superfamily. We isolated OsFLS from the rice ( Oryza sativa) cultivar "Ilmi" OsFLS includes highly conserved 2-ODD-specific motifs and FLS-specific regions. Recombinant OsFLS exhibited both FLS and flavanone 3ß-hydroxylase (F3H) activities, converting dihydroflavonols into flavonols and flavanones into dihydroflavonols, respectively, and more efficiently used dihydrokaempferol than dihydroquercetin as a substrate. OsFLS was expressed in both nonpigmented and pigmented rice seeds and was developmentally regulated during seed maturation. Transgenic tobacco ( Nicotiana tabacum) plants expressing OsFLS produced pale pink or white flowers with significantly increased levels of kaempferol-3- O-rutinoside and dramatically reduced levels of anthocyanin in their petals. Additionally, pod size and weight were reduced compared to the wild type. Several early and late biosynthetic genes of flavonoid were downregulated in the transgenic flowers. We demonstrated that OsFLS is a bifunctional 2-ODD enzyme and functions in flavonol production in planta.


Assuntos
Dioxigenases/genética , Dioxigenases/metabolismo , Oryza/enzimologia , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Antocianinas/biossíntese , Cor , Flavonóis/biossíntese , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Cetoglutáricos/metabolismo , Oryza/genética , Tabaco/genética , Tabaco/metabolismo
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