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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.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2767-2774, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418202

RESUMO

To reveal the physiological effects of rice alleviated by cadmium-tolerant Pseudomonas aeruginosa under cadmium stress condition, the influences of bacterial strian on the root vigor and leaf physiological characteristics were analyzed under a set of hydroponic experiments involving adding bacteria suspension, empty carrier, microbial inoculum with 20 µmol·L-1 Cd. Cadmium-free treatment as control. The results showed that the root vigor was significantly inhibited, leaf photosynthetic rate decreased, and the contents of soluble protein, flavonoid and total phenols in rice leaves were reduced, while the contents of malondialdehyde (MDA) and superoxide anion(O2-·) increased significantly under cadmium stress condition. Compared with cadmium treatment, root vigors of rice were increased by 36.1%-42.5% and 49.4%-53.0% respectively in bacteria suspension and microbial inoculum additions, net photosynthetic rates in leaves were increased by 118.5%-147.1% and 137.6%-156.9%, and the contents of soluble protein were increased by 37.0%-49.3% and 37.7%-72.6%, respectively. For the bacteria suspension treatment, the activities of SOD, POD and CAT in leaves were increased by 25.8%-36.6%, 40.9%-55.9%, 24.0%-29.2%, and the activities of SOD, POD and CAT in leaves under microbial inoculum treatment were increased by 36.9%-42.6%, 82.7%-92.6% and 43.3%-52.2%, respectively, with the stimulative effects on antioxidation enzymes in rice leaves being higher than those of bacteria suspension. Compared with cadmium treatment, the contents of MDA and O2-· in rice leaves were reduced by 44.8%-54.7%, 29.4%-41.9% and 9.9%-10.2%, 3.0%-7.1% in microbial inoculum and bacteria suspension treatments, respectively. In contrast, the contents of flavonoids and total phenols were increased by 125.4%-135.7%, 100.8%-119.4% and 139.4%-146.7%, 115.0%-134.7%, respectively. In summary, P. aeruginosa and the microbial inoculum could promote rice seedling growth by improving root vigor and photosynthetic rate, as well as the contents of flavonoids and total phenols, which led to the fact that P. aeruginosa could significantly alleviate the stress of cadmium on rice.


Assuntos
Cádmio/toxicidade , Oryza/fisiologia , Folhas de Planta/fisiologia , Raízes de Plantas/fisiologia , Pseudomonas aeruginosa/fisiologia , Poluentes do Solo/toxicidade , Oryza/microbiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Plântula , Estresse Fisiológico
3.
Yi Chuan ; 41(8): 703-715, 2019 Aug 20.
Artigo em Chinês | MEDLINE | ID: mdl-31447421

RESUMO

Hybrid rice has contributed greatly to global food security. Cytoplasmic male sterility (CMS) and photo/ thermo sensitive genic male sterility (P/TGMS) are genetic bases for three-line and two-line hybrid rice production, respectively. In contrast, (sub-) specific hybrid sterility (HS) is a major barrier for utilization of hybrid vigor of distant hybrid rice. Therefore, understanding the molecular regulatory mechanism of rice fertility is a key technical issue for hybrid rice industry, and a long-standing basic scientific issue for nuclear-cytoplasmic interaction and reproductive isolation. Chinese geneticists of plant sciences have made tremendous contributions on the molecular genetic basis of rice fertility related to hybrid rice production. Here, we review the development of hybrid rice production systems in China and summarize current advance on genetic basis and molecular mechanism of CMS, P/TGMS, and HS involved in hybrid rice. We also discuss problems of hybrid rice production in China and point out new direction for future utilization of heterosis in rice.


Assuntos
Hibridização Genética , Oryza/genética , Oryza/fisiologia , Infertilidade das Plantas/genética , China , Fertilidade/genética , Vigor Híbrido
4.
BMC Plant Biol ; 19(1): 352, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412781

RESUMO

BACKGROUND: Rice plants show yellowing, stunting, withering, reduced tillering and utimately low productivity in susceptible varieties under low temperature stress. Comparative transcriptome analysis was performed to identify novel transcripts, gain new insights into different gene expression and pathways involved in cold tolerance in rice. RESULTS: Comparative transcriptome analyses of 5 treatments based on chilling stress exposure revealed more down regulated genes in susceptible and higher up regulated genes in tolerant genotypes. A total of 13930 and 10599 differentially expressed genes (DEGs) were detected in cold susceptible variety (CSV) and cold tolerant variety (CTV), respectively. A continuous increase in DEGs at 6, 12, 24 and 48 h exposure of cold stress was detected in both the genotypes. Gene ontology (GO) analysis revealed 18 CSV and 28 CTV term significantly involved in molecular function, cellular component and biological process. GO classification showed a significant role of transcription regulation, oxygen, lipid binding, catalytic and hydrolase activity for tolerance response. Absence of photosynthesis related genes, storage products like starch and synthesis of other classes of molecules like fatty acids and terpenes during the stress were noticed in susceptible genotype. However, biological regulations, generation of precursor metabolites, signal transduction, photosynthesis, regulation of cellular process, energy and carbohydrate metabolism were seen in tolerant genotype during the stress. KEGG pathway annotation revealed more number of genes regulating different pathways resulting in more tolerant. During early response phase, 24 and 11 DEGs were enriched in CTV and CSV, respectively in energy metabolism pathways. Among the 1583 DEG transcription factors (TF) genes, 69 WRKY, 46 bZIP, 41 NAC, 40 ERF, 31/14 MYB/MYB-related, 22 bHLH, 17 Nin-like 7 HSF and 4C3H were involved during early response phase. Late response phase showed 30 bHLH, 65 NAC, 30 ERF, 26/20 MYB/MYB-related, 11 C3H, 12 HSF, 86 Nin-like, 41 AP2/ERF, 55 bZIP and 98 WRKY members TF genes. The recovery phase included 18 bHLH, 50 NAC, 31 ERF, 24/13 MYB/MYB-related, 4 C3H, 4 HSF, 14 Nin-like, 31 bZIP and 114 WRKY TF genes. CONCLUSIONS: Transcriptome analysis of contrasting genotypes for cold tolerance detected the genes, pathways and transcription factors involved in the stress tolerance.


Assuntos
Resposta ao Choque Frio/genética , Oryza/genética , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Metabolismo Energético , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genótipo , Oryza/metabolismo , Oryza/fisiologia , Fotossíntese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Sequência de RNA , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
BMC Plant Biol ; 19(1): 351, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412785

RESUMO

BACKGROUND: Rubisco activase (RCA) regulates the activity of Rubisco and is a key enzyme of photosynthesis. RCA expression was widely reported to affect plant photosynthesis and crop yield, but the molecular basis of natural variation in RCA expression in a wide range of maize materials has not been fully elucidated. RESULTS: In this study, correlation analysis in approximately 200 maize inbred lines revealed a significantly positive correlation between the expression of maize RCA gene ZmRCAß and grain yield. A genome-wide association study revealed both cis-expression quantitative trait loci (cis-eQTLs) and trans-eQTLs underlying the expression of ZmRCAß, with the latter playing a more important role. Further allele mining and genetic transformation analysis showed that a 2-bp insertion and a 14-bp insertion in the promoter of ZmRCAß conferred increased gene expression. Because rice is reported to have higher RCA gene expression than does maize, we subsequently compared the genetic factors underlying RCA gene expression between maize and rice. The promoter activity of the rice RCA gene was shown to be stronger than that of the maize RCA gene, suggesting that replacing the maize RCA gene promoter with that of the rice RCA gene would improve the expression of RCA in maize. CONCLUSION: Our results revealed two DNA polymorphisms regulating maize RCA gene ZmRCAß expression, and the RCA gene promoter activity of rice was stronger than that of maize. This work increased understanding of the genetic mechanism that underlies RCA gene expression and identify new targets for both genetic engineering and selection for maize yield improvement.


Assuntos
Oryza/genética , Fotossíntese/genética , Proteínas de Plantas/genética , Zea mays/genética , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Oryza/metabolismo , Oryza/fisiologia , Folhas de Planta , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Regiões Promotoras Genéticas , Locos de Características Quantitativas , Ribulose-Bifosfato Carboxilase , Zea mays/metabolismo , Zea mays/fisiologia
6.
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
7.
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
8.
Sci Total Environ ; 691: 827-834, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326806

RESUMO

Selenium (Se) is an essential element in animals and humans, and its deficiency may cause conditions such as cardiac disease. The production of Se-enriched rice is one of the most important ways to supply Se in the human body, and thus, understanding of the mechanisms of Se-enriched rice is of great significance. A pot experiment was conducted to study the effects of Se addition on the growth, antioxidation, Se uptake and distribution, and Se speciation in three different stages of panicle initiation stage (i.e., pistil and stamen formation stage, pollen mother cell formation stage, pollen mother cell meiosis stage) and the maturity stage. The results showed that soil Se application significantly increased Se uptake in rice. Low rates of Se (<5 mg kg-1) application enhanced the plant growth and rice yield. Se speciation assays showed that SeCys and SeMet were the two main forms found in rice, of which SeMet accounted for 65.5%-100% in the ears and leaves, while SeCys accounted for 61.4%-75.6% in brown rice. SeMet was also the main Se-species found in different subcellular parts at the panicle initiation stage. However, inorganic Se was present in brown rice, mainly as Se(VI), when the soil Se addition exceeded 5 mg kg-1. Lower rates of Se (<5 mg kg-1) promoted the antioxidant capacity, while high levels of Se (≥5 mg kg-1) reduced the antioxidant capacity of rice. The results indicate that Se effects are dose dependent, and the suitable amount of soil Se application for Se-enriched rice production would be <5 mg kg-1.


Assuntos
Antioxidantes/metabolismo , Oryza/fisiologia , Selênio/metabolismo , Poluentes do Solo/metabolismo
9.
Ecotoxicol Environ Saf ; 180: 770-779, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154202

RESUMO

The study implements a periodical intermittent water cycle during rice cultivation providing insight potential in minimizing soil bio-available arsenic. Soil As concentrations were 34 ±â€¯0.49 and 72.03 ±â€¯0.54 mg kg-1 As respectively in two selected fields with rice cultivars gosai and satabdi, in comparison to 42.26 ±â€¯0.37 and 83.69 ±â€¯0.48 mg kg-1 in continuously flooded field soil, determined through ICP-MS. The study found higher translocation of silicon from soil to rice plant parts under intermittent irrigation having pH range of 7.6-9.4 and greater availability of soil organic content that in turn release more labile silicon from soil to aqueous phase for plant accumulation. This increased uptake of silicon strengthens rice shoots, nodes and leaf xylem-phloem integrity compared to conventional continuously flooded rice cultivation approach, suppressing the arsenic translocation, as observed under FE-SEM real-time imaging. Fresh plants were analysed for bioaccumulation and translocation factors of arsenic and silicon to justify the enhanced silicon uptake under proposed practice. Plant stress regulator enzymes viz. malondialdehyde (MDA), total protein, superoxide dismutase (SOD), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) from both conditions and found to be better in intermittent method over conventional practice with higher productivity.


Assuntos
Irrigação Agrícola/métodos , Arsênico/farmacocinética , Oryza/fisiologia , Silício/metabolismo , Poluentes do Solo/farmacocinética , Antioxidantes/metabolismo , Arsênico/análise , Arsênico/toxicidade , Disponibilidade Biológica , Índia , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Estresse Fisiológico/efeitos dos fármacos
10.
Ecotoxicol Environ Saf ; 180: 780-788, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154203

RESUMO

Cadmium (Cd) is one of the most toxic heavy metals, and its accumulation in plants will seriously affect growth and yield. In this study, Cd-sensitive line D69 and Cd-tolerant line D28 were selected, which the Cd content of D28 was higher than D69 in both above and underground parts after Cd treatment. Using a combination of two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-TOF MS/MS, the differential expression changes of phosphorylated proteins between D69 and D28 in leaves were classified and analyzed after Cd treatment. A total of 53 differentially expressed phosphoproteins were identified, which mainly involved in metabolism, signal transduction, gene expression regulation, material transport, and membrane fusion. The phosphorylated proteins of Cd-tolerant and Cd-sensitive lines were all analyzed, and found that some proteins associated with carbon metabolism, proteolytic enzymes, F-box containing transcription factors, RNA helicases, DNA replication/transcription/repair enzymes and ankyrins were detected in Cd-tolerant line D28, which might alleviate the abiotic stress caused by Cd treatment. These results will clarify the phosphorylated pathways in response and resistance to Cd stress in rice.


Assuntos
Cádmio/toxicidade , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Oryza/genética , Oryza/fisiologia , Fosforilação , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Poluentes do Solo/toxicidade
11.
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 Ambiente
12.
Nat Commun ; 10(1): 2738, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227696

RESUMO

The breeding of cereals with altered gibberellin (GA) signaling propelled the 'Green Revolution' by generating semidwarf plants with increased tiller number. The mechanism by which GAs promote shoot height has been studied extensively, but it is not known what causes the inverse relationship between plant height and tiller number. Here we show that rice tiller number regulator MONOCULM 1 (MOC1) is protected from degradation by binding to the DELLA protein SLENDER RICE 1 (SLR1). GAs trigger the degradation of SLR1, leading to stem elongation and also to the degradation of MOC1, and hence a decrease in tiller number. This discovery provides a molecular explanation for the coordinated control of plant height and tiller number in rice by GAs, SLR1 and MOC1.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Giberelinas/metabolismo , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Brotos de Planta/fisiologia , Grão Comestível , Giberelinas/genética , Mutação , Melhoramento Vegetal/métodos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Proteólise , Transdução de Sinais/fisiologia
13.
Plant Sci ; 285: 230-238, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203888

RESUMO

In higher plants, Fibrillins (FBNs) constitute a conserved plastid-lipid-associated (PAPs) protein family and modulate the metabolite transport and lipid metabolism in plastids of dicot species. However, FBNs have not functionally characterized in monocot species. In this study, the function of rice fibrillin 1 (OsFBN1) was investigated. The subcellular localization assay showed that the N-terminal chloroplast transport peptide (CTP) could facilitate the import of OsFBN1 into chloroplast. OsFBN1 specifically bound C18- and C20- fatty acids in vitro. Overexpressing OsFBN1 increased the tiller number but decreased the panicle length, grain-filling percent and JA levels compared to the wild type and RNAi silencing lines under heat stress. In addition, the overexpressing lines had more plastoglobules (PGs) than the wild type and RNAi silencing lines under both normal and heat stress conditions. Moreover, overexpressing OsFBN1 affected the transcription levels of OsAOS2 in JA synthesis, OsTHF1, OsABC1K7 and OsPsaE in thylakoid stability and photosynthesis, OsABC1-4 and OsSPS2 in ubiquinone-metabolism, OsHDR, OsDXR, and OsFPPS in isoprenoid metabolism. Collectively, these findings suggest the essential role of rice OsFBN1 in PG formation and lipid metabolism in chloroplasts, which coordinately regulate the growth and grain filling of the overexpressing lines under heat stress.


Assuntos
Cloroplastos/metabolismo , Ciclopentanos/metabolismo , Grão Comestível/metabolismo , Oryza/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Cloroplastos/ultraestrutura , Grão Comestível/crescimento & desenvolvimento , Resposta ao Choque Térmico , Metabolismo dos Lipídeos , Lipoproteínas/metabolismo , Microscopia Eletrônica de Transmissão , Oryza/genética , Oryza/fisiologia , Oryza/ultraestrutura , Fotossíntese , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Tilacoides/metabolismo
14.
Plant Sci ; 285: 248-257, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203890

RESUMO

Halophytic Oryza coarctata is a good model system to examine mechanisms of salinity tolerance in rice. O. coarctata leaves show the presence of microhairs in adaxial leaf surface furrows that secrete salt under salinity. However, detailed molecular and physiological studies of O. coarctata microhairs are limited due to their relative inaccessibility. This work presents a detailed characterization of O. coarctata leaf features. O. coarctata has two types of microhairs on the adaxial leaf surface: longer microhairs (three morphotypes) lining epidermal furrow walls and shorter microhairs (reported first time) arising from bulliform cells. Microhair morphotypes include (i) finger-like, tubular structures, (ii) tubular hairs with bilobed and flattened heads and (iii) bi-or trifurcated hairs. The unicellular nature of microhairs was confirmed by propidium iodide (PI) staining. An efficient method for the isolation and enrichment of O. coarctata microhairs is presented (yield averaging ˜2 × 105/g leaf tissue). The robustness of the microhair isolation procedure was confirmed by subsequent viability staining (PI), total RNA isolation and RT-PCR amplification of O. coarctata trichome-specific WUSCHEL-related homeobox 3B (OcWox3B) and transporter gene-specific cDNA sequences. The present microhair isolation work from O. coarctata paves the way for examining genes involved in ion secretion in this halophytic wild rice model.


Assuntos
Oryza/anatomia & histologia , Folhas de Planta/anatomia & histologia , Plantas Tolerantes a Sal/anatomia & histologia , Microscopia Confocal , Oryza/fisiologia , Folhas de Planta/citologia , Folhas de Planta/fisiologia , Folhas de Planta/ultraestrutura , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plantas Tolerantes a Sal/fisiologia , Tricomas/anatomia & histologia , Tricomas/fisiologia , Tricomas/ultraestrutura
15.
Plant Physiol Biochem ; 141: 122-132, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31151078

RESUMO

Most of the hot spots about rice research are related to roots; increasing rice yield is mainly associated with improving root traits. Understanding phenotype-gene regulation relationship in different rice cultivars can contribute to the genetic improvement of root system. The expression pattern of root genes in moroberekan (deep and thick roots and high root/shoot ratio "R/S") was compared to that in Giza178 and PM12 (numerous but shallow roots) and IR64 (fewer but deeper roots than the latter ones). In contrast to the other genotypes, moroberekan did not cease developing deep and thick roots even after 60 days from sowing, perhaps because of not only the consistent upregulation but also the interaction of root genes. Xylem sap flow was significantly higher even under drought (low water content) in moroberekan. Auxin signaling-related ARF12 and PIN1 genes could play key roles in improving root traits in response to low water or nitrogen content. Their concurrent upregulation was coincided with developing 1) deeper roots in moroberekan under drought, 2) thicker and deeper roots in PM12 under low nitrogen content (LN) and 3) new roots with thicker and deeper characteristics in the four genotypes after root trimming. The upregulation of PIN1 or ARF12 in Giza178 at LN, PM12 at drought or in IR64 under drought or LN did not greatly change the root traits. Hierarchical analysis showed that ARF12 and PIN1 were distantly related, but overlapped with other genes controlling root traits. Overexpression of ARF12 and PIN1 could improve root traits in rice cultivars.


Assuntos
Regulação da Expressão Gênica de Plantas , Nitrogênio/química , Oryza/genética , Oryza/fisiologia , Raízes de Plantas/fisiologia , Água/química , Análise por Conglomerados , Secas , Perfilação da Expressão Gênica , Genes de Plantas , Genótipo , Fenótipo , Locos de Características Quantitativas
16.
Sci Total Environ ; 686: 546-554, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31185402

RESUMO

Rice is an essential food crop that nourishes >50% of the world population. In many regions of Bangladesh rice production is constrained by high soil salinity and heavy metal contamination due to irrigation practices. Plants may naturally overcome such stress through mutualistic interactions with arbuscular mycorrhizal fungi (AMF). Yet, little is known regarding the diversity and composition of AMF communities in rice fields with high saline and arsenic concentration. Here we used high throughput Illumina sequencing to characterize AMF communities in rice roots from 45 Bangladeshi rice fields, along a large geographical gradient of soil salinity and arsenic contamination. We obtained 77 operational taxonomic units (OTUs, based on a sequence similarity threshold of 97%) from eight AMF families, and showed that high soil salinity and arsenic concentration are significantly associated with low AMF diversity in rice roots. Soil salinity and arsenic concentration also explained a large part of the variation in AMF community composition, but also soil pH, moisture, organic matter content and plant available soil phosphorus played an important role. Overall, our study showed that even at very high salinity and arsenic levels, some AMF OTUs are present in rice roots. Their potential role in mediating a reduction of rice stress and arsenic uptake remains to be investigated.


Assuntos
Arsênico/análise , Micorrizas/crescimento & desenvolvimento , Oryza/microbiologia , Poluentes do Solo/análise , Bangladesh , Monitoramento Ambiental , Micobioma , Oryza/fisiologia , Solo/química , Microbiologia do Solo , Simbiose
17.
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
18.
BMC Plant Biol ; 19(1): 174, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046677

RESUMO

BACKGROUND: Senescence affects the quality and yield of plants by regulating different traits of plants. A few members of S40 gene family, the barley HvS40 and the Arabidopsis AtS40-3, have been shown to play a role in leaf senescence in Barley and Arabidopsis. Although we previously reported that S40 family exist in most of plants, up to now, no more function of S40 members in plant has been demonstrated. The aim of this study was to provide the senescence related information of S40 gene family in rice as rice is a major crop that feeds about half of the human population in the world. RESULTS: A total of 16 OsS40 genes were identified from the genome database of Oryza sativa L. japonica by bioinformatics analysis. Phylogenetic analysis reveals that the 16 OsS40 proteins are classified into five groups, and 4 of the 16 members belong to group I to which also the HvS40 and AtS40-3 is assigned. S40 genes of rice show high structural similarities, as 13 out of the 16 genes have no intron and the other 3 genes have only 1 or 2 introns. The expression patterns of OsS40 genes were analyzed during natural as well as stress-induced leaf senescence in correspondence with senescence marker genes. We found that 6 of them displayed differential but clearly up-regulated transcript profiles under diverse situations of senescence, including darkness, nitrogen deficiency, hormone treatments as well as pathogen infection. Furthermore, three OsS40 proteins were identified as nuclear located proteins by transient protoplast transformation assay. CONCLUSIONS: Taking all findings together, we concluded that OsS40-1, OsS40-2, OsS40-12 and OsS40-14 genes have potential regulatory function of crosstalk among abiotic, biotic and developmental senescence in rice. Our results provide valuable baseline for functional validation studies of the rice S40 genes in rice leaf senescence.


Assuntos
Oryza/fisiologia , Folhas de Planta/fisiologia , Proteínas de Plantas/fisiologia , Envelhecimento , Interação Gene-Ambiente , Genes de Plantas , Oryza/genética , Folhas de Planta/genética , Proteínas Ribossômicas
19.
BMC Genomics ; 20(1): 355, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072298

RESUMO

BACKGROUND: Anaerobic germination tolerance is an important trait for direct-seeded rice varieties. Understanding the genetic basis of anaerobic germination is a key for breeding direct-seeded rice varieties. RESULTS: In this study, a recombinant inbred line (RIL) population derived from a cross between YZX and 02428 exhibited obvious coleoptile phenotypic differences. Mapping analysis using a high-density bin map indicated that a total of 25 loci were detected across two cropping seasons, including 10 previously detected loci and a total of 13 stable loci. Analysis of the 13 stable loci demonstrated that the more elite alleles that were pyramided in an individual, the higher the values of these traits were in the two cropping seasons. Furthermore, some anaerobic germination-tolerant recombinant inbred lines, namely G9, G10, G16, and G151, were identified. A total of 84 differentially expressed genes were obtained from the 13 stable loci via genome-wide expression analysis of the two parents at three key periods. Among them, Os06g0110200, Os07g0638300, Os07g0638400, Os09g0532900, Os09g0531701 and Os12g0539751 constitute the best candidates associated with anaerobic germination. CONCLUSIONS: Both the anaerobic germination-tolerant recombinant inbred lines and the loci identified in this study will provide new genetic resources for improving the anaerobic germination tolerance of rice using molecular breeding strategies, as well as will broaden our understanding of the genetic control of germination tolerance under anaerobic conditions.


Assuntos
Mapeamento Cromossômico/métodos , Cromossomos de Plantas , Germinação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Oryza/genética , Proteínas de Plantas/genética , Locos de Características Quantitativas , Anaerobiose , Oryza/crescimento & desenvolvimento , Oryza/fisiologia
20.
Plant Cell Physiol ; 60(8): 1656-1665, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31076767

RESUMO

Karyogamy is a prerequisite event for plant embryogenesis, in which dynamic changes in nuclear architecture and the establishment of appropriate gene expression patterns must occur. However, the precise role of the male and female gametes in the progression of karyogamy still remains elusive. Here, we show that the sperm cell possesses the unique property to drive steady and swift nuclear fusion. When we fertilized egg cells with sperm cells in vitro, the immediate fusion of the male and female nuclei in the zygote progressed. This rapid nuclear fusion did not occur when two egg cells were artificially fused. However, the nuclear fusion of two egg nuclei could be accelerated by additional sperm entry or the exogenous application of calcium, suggesting that possible increase of cytosolic Ca2+ level via sperm entry into the egg cell efficiently can facilitate karyogamy. In contrast to zygotes, the egg-egg fusion cells failed to proliferate beyond an early developmental stage. Our transcriptional analyses also revealed the rapid activation of zygotic genes in zygotes, whereas there was no expression in fused cells without the male contribution. Thus, the male sperm cell has the ability to cause immediate karyogamy and to establish appropriate gene expression patterns in the zygote.


Assuntos
Oryza/fisiologia , Sementes/fisiologia , Zigoto/fisiologia , Fertilização/fisiologia
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