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Sample records for african rice oryza

  1. Rice (Oryza) hemoglobins

    Science.gov (United States)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  2. Fine Mapping of Spr3,a Locus for Spreading Panicle from African Cultivated Rice(Oryza glaberrima Steud.)

    Institute of Scientific and Technical Information of China (English)

    Ji-Jing Luo; Wei Hao; Jian Jin; Ji-Ping Gao; Hong-Xuan Lin

    2008-01-01

    A CSSL(chromosome segment substitution line),SG-64,carrying a segment of chromosome 4 from African cultivated rice(CG-14)in the genetic background of vat.Wuyujing-7(japonica),showed a spreading panicle,which was different significantly from that of Wuyujing-7 with an erect compact panicle.The gene controlling a spreading panicle is referred to as Spr3,and is mapped on chromosome 4.To uncover the genetic basis of Spr3,a large F2 population derived from cross between SG-64 and Wuyujing-7 was constructed for fine mapping of the Spr3 locus.The high-resolution linkage analysis revealed that the Spr3 locus was narrowed down to a 4.6-kb region.The delimited genomic DNA regions of Wuyujing-7 and CG.14 were sequenced and compared.Sequence mutations between Wuyujing-7 and CG-14 were evident and the candidate genes for the locus were predicted.Publicly available databases were searched for homologous cDNA sequences.However,any coding regions or other meaningful sequences for the Spr3 locus were not found within this delimited region.This result suggested that Spr3 is an unknown genetic factor in controlling the outspreading of the primary branches in rice inflorescence.In addition.NIL(Spr3)exhibited seed shattering.The formation of spreading panicle was accompanied by a few undesirable traits and the spreading panicle links with seed shattering suggest that the spreading panicle was likely Iost during the domestication and selection for high seed productivity of cultivated rice.

  3. Phylogeography of Asian wild rice, Oryza rufipogon, reveals multiple independent domestications of cultivated rice, Oryza sativa

    OpenAIRE

    Londo, Jason P.; Chiang, Yu-Chung; Hung, Kuo-Hsiang; Chiang, Tzen-Yuh; Schaal, Barbara A.

    2006-01-01

    Cultivated rice, Oryza sativa L., represents the world’s most important staple food crop, feeding more than half of the human population. Despite this essential role in world agriculture, the history of cultivated rice’s domestication from its wild ancestor, Oryza rufipogon, remains unclear. In this study, DNA sequence variation in three gene regions is examined in a phylogeographic approach to investigate the domestication of cultivated rice. Results indicate that India and Indochina may rep...

  4. Xanthomonas oryzae pv oryzae triggers immediate transcriptomic modulations in rice

    Directory of Open Access Journals (Sweden)

    Grewal Rumdeep K

    2012-01-01

    Full Text Available Abstract Background Xanthomonas oryzae pv oryzae is a devastating pathogen of rice and has been extensively studied as a model pathogen of monocotyledons. Expressional studies in both the contenders have been undertaken in past to understand the molecular mechanism underlying the compatible and incompatible interactions in the pathosystem. Continuous update on database and gene annotations necessitates constant updating on the roles of the new entities as well as reinterpretation of regulations of the previous ones. Moreover the past endeavors have addressed the middle or late defense responses of the rice plant whereas in the present study an attempt has been made to investigate the early defense responses taking place immediately after inoculation. Results Microarray was used to study the transcriptional modulations in eighteen days old rice seedling leaves of both susceptible and resistant genotypes one hour after inoculation. In resistant plants as compared to susceptible ones 274 genes were found to be differentially expressed. Annotations could be assigned to 112 up- and 73 down-regulated transcripts and gene interaction maps were generated for 86 transcripts. Expressional data and interaction maps were used to develop a hypothetical scheme of the molecular events taking place during early defense response. Network analysis with the differential transcripts showed up-regulation of major clusters of cell signaling proteins and transcription factors while growth and basal metabolic components were largely found to be down-regulated. Conclusions This study provides an understanding of the early defense signaling in rice cells. Components of the calcium and lipid signaling as well as MAPK cascade were modulated, by signals from surface receptors and cytosolic R-proteins, to arouse jasmonic acid and ethylene signaling and suppress auxin signaling through various transcription factors. Abscisic acid modulation was also evident through the

  5. Molecular detection of Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola, and Burkholderia glumae in infected rice seeds and leaves

    Science.gov (United States)

    Polymerase chain reaction (PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR green real-time PCR were developed to facilitate simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Bur...

  6. Antimicrobial peptide melittin against Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen in rice

    OpenAIRE

    SHI, Wei; Li, Caiyun; Li, Man; Zong, Xicui; Han, Dongju; Chen, Yuqing

    2016-01-01

    Xanthomonas oryzae pv. oryzae is a destructive bacterial disease of rice, and the development of an environmentally safe bactericide is urgently needed. Antimicrobial peptides, as antibacterial sources, may play important roles in bactericide development. In the present study, we found that the antimicrobial peptide melittin had the desired antibacterial activity against X. oryzae pv. oryzae. The antibacterial mechanism was investigated by examining its effects on cell membranes, energy metab...

  7. REACTION OF RICE (ORYZA SATIVA) CULTIVARS TO PENETRATION AND INFECTION BY CURVULARIA TUBERCULATA AND C. ORYZAE

    Science.gov (United States)

    Isolates of Curvularia species were collected from weedy Cyperaceae species and are being evaluated as possible biocontrol agents of sedge weeds in rice (Oryza sativa). Curvularia species have been reported from rice; thus cultivars of rice were tested to determine rice seedling responses to these ...

  8. In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

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    Verdier Valérie

    2010-06-01

    Full Text Available Abstract Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo, induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc. Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that

  9. Niclosamide inhibits leaf blight caused by Xanthomonas oryzae in rice

    OpenAIRE

    Sung-Il Kim; Jong Tae Song; Jin-Yong Jeong; Hak Soo Seo

    2016-01-01

    Rice leaf blight, which is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), results in huge losses in grain yield. Here, we show that Xoo-induced rice leaf blight is effectively controlled by niclosamide, an oral antihelminthic drug and molluscicide, which also functions as an anti-tumor agent. Niclosamide directly inhibited the growth of the three Xoo strains PXO99, 10208 and K3a. Niclosamide moved long distances from the site of local application to distant rice tissues...

  10. Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein.

    Science.gov (United States)

    2006-01-01

    This report addresses the safety of cosmetic ingredients derived from rice, Oryza sativa. Oils, Fatty Acids, and Waxes: Rice Bran Oil functions in cosmetics as a conditioning agent--occlusive in 39 formulations across a wide range of product types. Rice Germ Oil is a skin-conditioning agent--occlusive in six formulations in only four product categories. Rice Bran Acid is described as a surfactant-cleansing agent, but was not in current use. Rice Bran Wax is a skin-conditioning agent--occlusive in eight formulations in five product categories. Industry did not directly report any use of Rice Bran Wax. Hydrogenated Rice Bran Wax is a binder, skin-conditioning agent--occlusive, and viscosity-increasing agent--nonaqueous in 11 formulations in six product categories. Rice Bran Oil had an oral LD50 of > 5 g/kg in white rats and Rice Wax had an oral LD50 of > 24 g/kg in male mice. A three-generation oral dosing study reported no toxic or teratologic effects in albino rats fed 10% Rice Bran Oil compared to a control group fed Peanut Oil. Undiluted Rice Bran Oil, Rice Germ Oil, and Hydrogenated Rice Bran Wax were not irritants in animal skin tests. Rice Bran Oil was not a sensitizer. Rice Bran Oil, Rice Germ Oil, Rice Wax, and Hydrogenated Rice Bran Wax were negative in ocular toxicity assays. A mixture of Rice Bran Oil and Rice Germ Oil had a ultraviolet (UV) absorption maximum at 315 nm, but was not phototoxic in a dermal exposure assay. Rice Bran Oil was negative in an Ames assay, and a component, gamma-oryzanol, was negative in bacterial and mammalian mutagenicity assays. Rice oils, fatty acids, and waxes were, at most, mildly irritating in clinical studies. Extracts: Rice Bran Extract is used in six formulations in four product categories. Rice Extract is a hair-conditioning agent, but was not in current use. Hydrolyzed Rice Extract is used in four formulations and current concentration of use data were provided for other uses. Hydrolyzed Rice Bran Extract, described

  11. Transcriptional Profiling of Rice Early Response to Magnaporthe oryzae Identified OsWRKYs as Important Regulators in Rice Blast Resistance

    OpenAIRE

    WEI, Tong; Ou, Bin; Li, Jinbin; Zhao, Yang; Guo, Dongshu; Zhu, Youyong; Chen, Zhangliang; Gu, Hongya; Li, Chengyun; Qin, Genji; Qu, Li-Jia

    2013-01-01

    Rice blast disease is a major threat to rice production worldwide, but the mechanisms underlying rice resistance to the causal agent Magnaporthe oryzae remain elusive. Therefore, we carried out a transcriptome study on rice early defense response to M. oryzae. We found that the transcriptional profiles of rice compatible and incompatible interactions with M. oryzae were mostly similar, with genes regulated more prominently in the incompatible interactions. The functional analysis showed that ...

  12. Sensory acceptability evaluation of irradiated rice, oryza sativa indica

    International Nuclear Information System (INIS)

    The non-glutinous and glutinous types of polished rice, Oryza sativa indica were subjected to gamma rays at ambient temperature and stored at 27+-10C for one week. The irradiated rice was cooked and tasted by members of trained panel. Using Hedonic scale and Triangle test, the acceptability of irradiated rice was justified. Gamma irradiation up to 100 krads did not significantly cause off-color, off-odor and off flavor in irradiated non-glutino rice. Glutinous rice irradiated at 60 krads could not be significantly differentiated from non-irradiated sample

  13. Niclosamide inhibits leaf blight caused by Xanthomonas oryzae in rice.

    Science.gov (United States)

    Kim, Sung-Il; Song, Jong Tae; Jeong, Jin-Yong; Seo, Hak Soo

    2016-01-01

    Rice leaf blight, which is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), results in huge losses in grain yield. Here, we show that Xoo-induced rice leaf blight is effectively controlled by niclosamide, an oral antihelminthic drug and molluscicide, which also functions as an anti-tumor agent. Niclosamide directly inhibited the growth of the three Xoo strains PXO99, 10208 and K3a. Niclosamide moved long distances from the site of local application to distant rice tissues. Niclosamide also increased the levels of salicylate and induced the expression of defense-related genes such as OsPR1 and OsWRKY45, which suppressed Xoo-induced leaf wilting. Niclosamide had no detrimental effects on vegetative/reproductive growth and yield. These combined results indicate that niclosamide can be used to block bacterial leaf blight in rice with no negative side effects. PMID:26879887

  14. Photosynthetic activity in rice seedlings infected with Piricularia oryzae Cavara

    International Nuclear Information System (INIS)

    Changes in photosynthetic activity in the rice seedlings infected with piricularia oryzae Cavara (blast disease) were examined comparing with the non-infected seedlings. The assimilated 14C radioactivity was about 50% lower in the infected rice seedlings than in the non-infected seedlings. A little difference in the distribution of 14C radioactivity was observed. The 14C activity in the cationic fraction of ethanol soluble fractions was a little higher in the infected seedling. (auth.)

  15. Fungicide sensitivity in the wild rice pathogen Bipolaris oryzae

    Science.gov (United States)

    In recent years the occurrence of fungal brown spot, caused by Bipolaris oryzae has increased in cultivated wild rice (Zizania palustris) paddies in spite of the use of fungicides. To implement an efficient integrated disease management system, we are exploring whether field isolates have developed ...

  16. Improvement in rice resistance to Pyricularia oryzae through mutagenesis

    International Nuclear Information System (INIS)

    Rice (Oryza sativa L.) is the staple diet of Costa Ricans. Normally, people eat rice at least twice daily. This cereal is very important both for production and consumption. The sowing area in Costa Rica is approximately 70,000 ha/a. The rice area is characterized by high temperature and high humidity, which are also the conditions required for the high inoculation of pathogens. Of the diseases that prevail under such conditions, blast disease, caused by Pyricularia oryzae, is one of the most severe, resulting in yield losses of up to 90% when attacks are severe. Use of induced mutations in cereals has been shown to be an excellent tool, often using gamma rays as the mutagen agent for crop improvement. The main objective of our work was to induce resistance to blast disease in the commercial variety CR-1113, which is the most important cultivar in Costa Rica. 4 refs

  17. Antimicrobial peptide melittin against Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen in rice.

    Science.gov (United States)

    Shi, Wei; Li, Caiyun; Li, Man; Zong, Xicui; Han, Dongju; Chen, Yuqing

    2016-06-01

    Xanthomonas oryzae pv. oryzae is a destructive bacterial disease of rice, and the development of an environmentally safe bactericide is urgently needed. Antimicrobial peptides, as antibacterial sources, may play important roles in bactericide development. In the present study, we found that the antimicrobial peptide melittin had the desired antibacterial activity against X. oryzae pv. oryzae. The antibacterial mechanism was investigated by examining its effects on cell membranes, energy metabolism, and nucleic acid, and protein synthesis. The antibacterial effects arose from its ability to interact with the bacterial cell wall and disrupt the cytoplasmic membrane by making holes and channels, resulting in the leakage of the cytoplasmic content. Additionally, melittin is able to permeabilize bacterial membranes and reach the cytoplasm, indicating that there are multiple mechanisms of antimicrobial action. DNA/RNA binding assay suggests that melittin may inhibit macromolecular biosynthesis by binding intracellular targets, such as DNA or RNA, and that those two modes eventually lead to bacterial cell death. Melittin can inhibit X. oryzae pv. oryzae from spreading, alleviating the disease symptoms, which indicated that melittin may have potential applications in plant protection. PMID:26948237

  18. Relationships of wild and domesticated rices (Oryza AA genome species) based upon whole chloroplast genome sequences.

    Science.gov (United States)

    Wambugu, Peterson W; Brozynska, Marta; Furtado, Agnelo; Waters, Daniel L; Henry, Robert J

    2015-01-01

    Rice is the most important crop in the world, acting as the staple food for over half of the world's population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly supported phylogeny of the AA genome species. The pan tropical distribution of these rice relatives was found to be explained by long distance dispersal within the last million years. The analysis resulted in a clustering pattern that showed strong geographical differentiation. The species were defined in two primary clades with a South American/African clade with two species, O glumaepatula and O longistaminata, distinguished from all other species. The largest clade was comprised of an Australian clade including newly identified taxa and the African and Asian clades. This refined knowledge of the relationships between cultivated rice and the related wild species provides a strong foundation for more targeted use of wild genetic resources in rice improvement and efforts to ensure their conservation. PMID:26355750

  19. Genome sequence and rapid evolution of the rice pathogen Xanthomonas oryzae pv. oryzae PXO99A

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    Szurek Boris

    2008-05-01

    Full Text Available Abstract Background Xanthomonas oryzae pv. oryzae causes bacterial blight of rice (Oryza sativa L., a major disease that constrains production of this staple crop in many parts of the world. We report here on the complete genome sequence of strain PXO99A and its comparison to two previously sequenced strains, KACC10331 and MAFF311018, which are highly similar to one another. Results The PXO99A genome is a single circular chromosome of 5,240,075 bp, considerably longer than the genomes of the other strains (4,941,439 bp and 4,940,217 bp, respectively, and it contains 5083 protein-coding genes, including 87 not found in KACC10331 or MAFF311018. PXO99A contains a greater number of virulence-associated transcription activator-like effector genes and has at least ten major chromosomal rearrangements relative to KACC10331 and MAFF311018. PXO99A contains numerous copies of diverse insertion sequence elements, members of which are associated with 7 out of 10 of the major rearrangements. A rapidly-evolving CRISPR (clustered regularly interspersed short palindromic repeats region contains evidence of dozens of phage infections unique to the PXO99A lineage. PXO99A also contains a unique, near-perfect tandem repeat of 212 kilobases close to the replication terminus. Conclusion Our results provide striking evidence of genome plasticity and rapid evolution within Xanthomonas oryzae pv. oryzae. The comparisons point to sources of genomic variation and candidates for strain-specific adaptations of this pathogen that help to explain the extraordinary diversity of Xanthomonas oryzae pv. oryzae genotypes and races that have been isolated from around the world.

  20. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

  1. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    International Nuclear Information System (INIS)

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M3, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M4 generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo

  2. The structure of the lipooligosaccharide from Xanthomonas oryzae pv. Oryzae: the causal agent of the bacterial leaf blight in rice.

    Science.gov (United States)

    Di Lorenzo, Flaviana; Palmigiano, Angelo; Silipo, Alba; Desaki, Yoshitake; Garozzo, Domenico; Lanzetta, Rosa; Shibuya, Naoto; Molinaro, Antonio

    2016-06-01

    The structure of the lipooligosaccharide (LOS) from the rice pathogen Xanthomonas oryzae pv. oryzae has been elucidated. The characterization of the core oligosaccharide structure was obtained by the employment of two chemical degradation protocols and by analysis of the products via NMR spectroscopy. The structure of the lipid A portion was achieved by MALDI mass spectrometry analysis on purified lipid A. The LOS from Xanthomonas oryzae pv. oryzae revealed to possess the same core structure of Xanthomonas campestris pv. campestris and interesting novel features on its lipid A domain. The evaluation of the biological activity of both LOS and isolated lipid A was also executed. PMID:27085742

  3. Selection of Representative Magnaporthe oryzae Isolates and Rice Resistant Gene Types for Screening of Blast-resistant Rice Cultivars

    OpenAIRE

    Jaeduk Goh; Dong-Bum Shin; Seong-Sook Han; Byung-Ryun Kim; Se-Won Lee; Jae-Hwan Roh; Ji-Ung Jeung; Young-Chan Cho

    2013-01-01

    Rice blast is one of the most serious disease threatening stable production of rice. Breeding of resistant cultivars has been used as the most effective and useful method to controll rice blast caused by Magnaporthe oryzae. To collect rice blast isolates in fields and test their pathogenicity on new cultivars are important for establishment of new resistant cultivars breeding program of rice. Pathotypes of Korean rice blast isolates have been categorized to Korean differential rac...

  4. Toward understanding of rice innate immunity against Magnaporthe oryzae.

    Science.gov (United States)

    Azizi, P; Rafii, M Y; Abdullah, S N A; Nejat, N; Maziah, M; Hanafi, M M; Latif, M A; Sahebi, M

    2016-01-01

    The blast fungus, Magnaporthe oryzae, causes serious disease on a wide variety of grasses including rice, wheat and barley. The recognition of pathogens is an amazing ability of plants including strategies for displacing virulence effectors through the adaption of both conserved and variable pathogen elicitors. The pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) were reported as two main innate immune responses in plants, where PTI gives basal resistance and ETI confers durable resistance. The PTI consists of extracellular surface receptors that are able to recognize PAMPs. PAMPs detect microbial features such as fungal chitin that complete a vital function during the organism's life. In contrast, ETI is mediated by intracellular receptor molecules containing nucleotide-binding (NB) and leucine rich repeat (LRR) domains that specifically recognize effector proteins produced by the pathogen. To enhance crop resistance, understanding the host resistance mechanisms against pathogen infection strategies and having a deeper knowledge of innate immunity system are essential. This review summarizes the recent advances on the molecular mechanism of innate immunity systems of rice against M. oryzae. The discussion will be centered on the latest success reported in plant-pathogen interactions and integrated defense responses in rice. PMID:25198435

  5. Gene Ontology annotation of the rice blast fungus, Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Deng Jixin

    2009-02-01

    Full Text Available Abstract Background Magnaporthe oryzae, the causal agent of blast disease of rice, is the most destructive disease of rice worldwide. The genome of this fungal pathogen has been sequenced and an automated annotation has recently been updated to Version 6 http://www.broad.mit.edu/annotation/genome/magnaporthe_grisea/MultiDownloads.html. However, a comprehensive manual curation remains to be performed. Gene Ontology (GO annotation is a valuable means of assigning functional information using standardized vocabulary. We report an overview of the GO annotation for Version 5 of M. oryzae genome assembly. Methods A similarity-based (i.e., computational GO annotation with manual review was conducted, which was then integrated with a literature-based GO annotation with computational assistance. For similarity-based GO annotation a stringent reciprocal best hits method was used to identify similarity between predicted proteins of M. oryzae and GO proteins from multiple organisms with published associations to GO terms. Significant alignment pairs were manually reviewed. Functional assignments were further cross-validated with manually reviewed data, conserved domains, or data determined by wet lab experiments. Additionally, biological appropriateness of the functional assignments was manually checked. Results In total, 6,286 proteins received GO term assignment via the homology-based annotation, including 2,870 hypothetical proteins. Literature-based experimental evidence, such as microarray, MPSS, T-DNA insertion mutation, or gene knockout mutation, resulted in 2,810 proteins being annotated with GO terms. Of these, 1,673 proteins were annotated with new terms developed for Plant-Associated Microbe Gene Ontology (PAMGO. In addition, 67 experiment-determined secreted proteins were annotated with PAMGO terms. Integration of the two data sets resulted in 7,412 proteins (57% being annotated with 1,957 distinct and specific GO terms. Unannotated proteins

  6. Vinegar rice (Oryza sativa L.) produced by a submerged fermentation process from alcoholic fermented rice

    OpenAIRE

    Wilma Aparecida Spinosa; Vitório dos Santos Júnior; Diego Galvan; Jhonatan Luiz Fiorio; Raul Jorge Hernan Castro Gomez

    2015-01-01

    Considering the limited availability of technology for the production of rice vinegar and also due to the potential consumer product market, this study aimed to use alcoholic fermented rice (rice wine (Oryza sativa L.)) for vinegar production. An alcoholic solution with 6.28% (w/v) ethanol was oxidized by a submerged fermentation process to produce vinegar. The process of acetic acid fermentation occurred at 30 ± 0.3°C in a FRINGS® Acetator (Germany) for the production of vinegar and was foll...

  7. Monitoring homologous recombination in rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Here we describe a system to assay homologous recombination during the complete life cycle of rice (Oryza sativa L.). Rice plants were transformed with two copies of non-functional GUS reporter overlap fragments as recombination substrate. Recombination was observed in all plant organs examined, from the seed stage until the flowering stage of somatic plant development. Embryogenic cells exhibited the highest recombination ability with an average of 3 x 10-5 recombination events per genome, which is about 10-fold of that observed in root cells, and two orders of that observed in leaf cells. Histological analysis revealed that recombination events occurred in diverse cell types, but preferentially in cells with small size. Examples of this included embryogenic cells in callus, phloem cells in the leaf vein, and cells located in the root apical meristem. Steady state RNA analysis revealed that the expression levels of rice Rad51 homologs are positively correlated with increased recombination rates in embryogenic calli, roots and anthers. Finally, radiation treatment of plantlets from distinct recombination lines increased the recombination frequency to different extents. These results showed that homologous recombination frequency can be effectively measured in rice using a transgene reporter assay. This system will facilitate the study of DNA damage signaling and homologous recombination in rice, a model monocot.

  8. Monitoring homologous recombination in rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhuanying; Tang Li [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Li Meiru [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Chen Lei; Xu Jie [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Wu Goujiang [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Li Hongqing, E-mail: hqli@scnu.edu.cn [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China)

    2010-09-10

    Here we describe a system to assay homologous recombination during the complete life cycle of rice (Oryza sativa L.). Rice plants were transformed with two copies of non-functional GUS reporter overlap fragments as recombination substrate. Recombination was observed in all plant organs examined, from the seed stage until the flowering stage of somatic plant development. Embryogenic cells exhibited the highest recombination ability with an average of 3 x 10{sup -5} recombination events per genome, which is about 10-fold of that observed in root cells, and two orders of that observed in leaf cells. Histological analysis revealed that recombination events occurred in diverse cell types, but preferentially in cells with small size. Examples of this included embryogenic cells in callus, phloem cells in the leaf vein, and cells located in the root apical meristem. Steady state RNA analysis revealed that the expression levels of rice Rad51 homologs are positively correlated with increased recombination rates in embryogenic calli, roots and anthers. Finally, radiation treatment of plantlets from distinct recombination lines increased the recombination frequency to different extents. These results showed that homologous recombination frequency can be effectively measured in rice using a transgene reporter assay. This system will facilitate the study of DNA damage signaling and homologous recombination in rice, a model monocot.

  9. Crucial Roles of Abscisic Acid Biogenesis in Virulence of Rice Blast Fungus Magnaporthe oryzae

    OpenAIRE

    Spence, Carla A.; Lakshmanan, Venkatachalam; Donofrio, Nicole; Bais, Harsh P.

    2015-01-01

    Rice suffers dramatic yield losses due to blast pathogen Magnaporthe oryzae. Pseudomonas chlororaphis EA105, a bacterium that was isolated from the rice rhizosphere, inhibits M. oryzae. It was shown previously that pre-treatment of rice with EA105 reduced the size of blast lesions through jasmonic acid (JA)- and ethylene (ETH)-mediated ISR. Abscisic acid (ABA) acts antagonistically toward salicylic acid (SA), JA, and ETH signaling, to impede plant defense responses. EA105 may be reducing the ...

  10. DgcA, a diguanylate cyclase from Xanthomonas oryzae pv. oryzae regulates bacterial pathogenicity on rice

    Science.gov (United States)

    Su, Jianmei; Zou, Xia; Huang, Liangbo; Bai, Tenglong; Liu, Shu; Yuan, Meng; Chou, Shan-Ho; He, Ya-Wen; Wang, Haihong; He, Jin

    2016-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of rice blight disease as well as a serious phytopathogen worldwide. It is also one of the model organisms for studying bacteria-plant interactions. Current progress in bacterial signal transduction pathways has identified cyclic di-GMP as a major second messenger molecule in controlling Xanthomonas pathogenicity. However, it still remains largely unclear how c-di-GMP regulates the secretion of bacterial virulence factors in Xoo. In this study, we focused on the important roles played by DgcA (XOO3988), one of our previously identified diguanylate cyclases in Xoo, through further investigating the phenotypes of several dgcA-related mutants, namely, the dgcA-knockout mutant ΔdgcA, the dgcA overexpression strain OdgcA, the dgcA complemented strain CdgcA and the wild-type strain. The results showed that dgcA negatively affected virulence, EPS production, bacterial autoaggregation and motility, but positively triggered biofilm formation via modulating the intracellular c-di-GMP levels. RNA-seq data further identified 349 differentially expressed genes controlled by DgcA, providing a foundation for a more solid understanding of the signal transduction pathways in Xoo. Collectively, the present study highlights DgcA as a major regulator of Xoo virulence, and can serve as a potential target for preventing rice blight diseases. PMID:27193392

  11. DgcA, a diguanylate cyclase from Xanthomonas oryzae pv. oryzae regulates bacterial pathogenicity on rice.

    Science.gov (United States)

    Su, Jianmei; Zou, Xia; Huang, Liangbo; Bai, Tenglong; Liu, Shu; Yuan, Meng; Chou, Shan-Ho; He, Ya-Wen; Wang, Haihong; He, Jin

    2016-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of rice blight disease as well as a serious phytopathogen worldwide. It is also one of the model organisms for studying bacteria-plant interactions. Current progress in bacterial signal transduction pathways has identified cyclic di-GMP as a major second messenger molecule in controlling Xanthomonas pathogenicity. However, it still remains largely unclear how c-di-GMP regulates the secretion of bacterial virulence factors in Xoo. In this study, we focused on the important roles played by DgcA (XOO3988), one of our previously identified diguanylate cyclases in Xoo, through further investigating the phenotypes of several dgcA-related mutants, namely, the dgcA-knockout mutant ΔdgcA, the dgcA overexpression strain OdgcA, the dgcA complemented strain CdgcA and the wild-type strain. The results showed that dgcA negatively affected virulence, EPS production, bacterial autoaggregation and motility, but positively triggered biofilm formation via modulating the intracellular c-di-GMP levels. RNA-seq data further identified 349 differentially expressed genes controlled by DgcA, providing a foundation for a more solid understanding of the signal transduction pathways in Xoo. Collectively, the present study highlights DgcA as a major regulator of Xoo virulence, and can serve as a potential target for preventing rice blight diseases. PMID:27193392

  12. WRKY transcription factor genes in wild rice Oryza nivara.

    Science.gov (United States)

    Xu, Hengjian; Watanabe, Kenneth A; Zhang, Liyuan; Shen, Qingxi J

    2016-08-01

    The WRKY transcription factor family is one of the largest gene families involved in plant development and stress response. Although many WRKY genes have been studied in cultivated rice (Oryza sativa), the WRKY genes in the wild rice species Oryza nivara, the direct progenitor of O. sativa, have not been studied. O. nivara shows abundant genetic diversity and elite drought and disease resistance features. Herein, a total of 97 O. nivara WRKY (OnWRKY) genes were identified. RNA-sequencing demonstrates that OnWRKY genes were generally expressed at higher levels in the roots of 30-day-old plants. Bioinformatic analyses suggest that most of OnWRKY genes could be induced by salicylic acid, abscisic acid, and drought. Abundant potential MAPK phosphorylation sites in OnWRKYs suggest that activities of most OnWRKYs can be regulated by phosphorylation. Phylogenetic analyses of OnWRKYs support a novel hypothesis that ancient group IIc OnWRKYs were the original ancestors of only some group IIc and group III WRKYs. The analyses also offer strong support that group IIc OnWRKYs containing the HVE sequence in their zinc finger motifs were derived from group Ia WRKYs. This study provides a solid foundation for the study of the evolution and functions of WRKY genes in O. nivara. PMID:27345721

  13. The WRKY Gene Family in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    Christian A. Ross; Yue Liu; Qingxi J. Shen

    2007-01-01

    WRKYgenes encode transcription factors that are involved in the regulation of various biological processes. These zinc-finger proteins, especially those members mediating stress responses, are uniquely expanded in plants. To facilitate the study of the evolutionary history and functions of this supergene family, we performed an exhaustive search for WRKY genes using HMMER and a Hidden Markov Model that was specifically trained for rice. This work resulted in a comprehensive list of WRKY gene models in Oryza sativa L. ssp. indica and L. ssp. japonica. Mapping of these genes to individual chromosomes facilitated elimination of the redundant, leading to the identification of 98 WRKY genes in japonica and 102 in indica rice. These genes were further categorized according to the number and structure of their zinc-finger domains. Based on a phylogenetic tree of the conserved WRKY domains and the graphic display of WRKY loci on corresponding indica and japonica chromosomes, we identified possible WRKY gene duplications within, and losses between the two closely related rice subspecies. Also reviewed are the roles of WRKY genes in disease resistance and responses to salicylic acid and jasmonic acid, seed development and germination mediated by gibberellins, other developmental processes including senescence, and responses to abiotic stresses and abscisic acid in rice and other plants. The signaling pathways mediating WRKY gene expression are also discussed.

  14. Oryza Tag Line, a phenotypic mutant database for the Genoplante rice insertion line library

    OpenAIRE

    Larmande, Pierre; Gay, Celine; Lorieux, Mathias; Perin, Christophe; Bouniol, Matthieu; Droc, Gaëtan; Sallaud, Christophe; Perez, Pascual; Barnola, Isabelle; Biderre-Petit, Corinne; Martin, Jérôme; Morel, Jean-Benoit; Johnson, Alexander A. T.; Bourgis, Fabienne; Ghesquière, Alain

    2008-01-01

    International audience To organize data resulting from the phenotypic characterization of a library of 30,000 T-DNA enhancer trap (ET) insertion lines of rice (Oryza sativa L cv. Nipponbare), we developed the Oryza Tag Line (OTL) database (http://urgi.versailles.inra.fr/OryzaTagLine/). OTL structure facilitates forward genetic search for specific phenotypes, putatively resulting from gene disruption, and/or for GUSA or GFP reporter gene expression patterns, reflecting ET-mediated endogenou...

  15. Characterization of resistance genes to rice blast fungus Magnaporthe oryzae in a “Green Revolution” rice variety

    Science.gov (United States)

    The indica rice variety Dee Geo Woo Gen (DGWG) was the source of the semi-dwarf gene (SD1) which played an important role in the Green Revolution. In the present study, resistance (R) genes to the U.S. race (isolate) IB54 of Magnaporthe oryzae, causal agent of rice blast disease, was investigated. T...

  16. Evidence for biotrophic lifestyle and biocontrol potential of dark septate endophyte Harpophora oryzae to rice blast disease.

    Directory of Open Access Journals (Sweden)

    Zhen-Zhu Su

    Full Text Available The mutualism pattern of the dark septate endophyte (DSE Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the elongation zone, and heavy colonization in the differentiation zone. H. oryzae adopted a biotrophic lifestyle in roots accompanied by programmed cell death. Real-time PCR facilitated the accurate quantification of fungal growth and the respective plant response. The biocontrol potential of H. oryzae was visualized by inoculation with eGFP-tagged M. oryzae in rice. H. oryzae protected rice from M. oryzae root invasion by the accumulation of H2O2 and elevated antioxidative capacity. H. oryzae also induced systemic resistance against rice blast. This systemic resistance was mediated by the OsWRKY45-dependent salicylic acid (SA signaling pathway, as indicated by the strongly upregulated expression of OsWRKY45. The colonization pattern of H. oryzae was consistent with the typical characteristics of DSEs. H. oryzae enhanced local resistance by reactive oxygen species (ROS and high antioxidative level and induced OsWRKY45-dependent SA-mediated systemic resistance against rice blast.

  17. Gamma radiation effects on rice, substrate for Sitophilus oryzae (L.) rearing

    International Nuclear Information System (INIS)

    The gamma radiation effects (800 Krad, 60Co) on rice are studied. Degraded substances by the radiation and how this degradation affects the biology of Sitophilus oryzae (L.) are searched. The vitamins, proteins and stard of the rice are affected by the radiation. (M.A.C.)

  18. Use of Harvested Rice (Oryza Sativa) Fields for Diazinon Runoff Mitigation

    Science.gov (United States)

    In landscapes defined by intensive agriculture, management practices are often needed to abate effects of potential non-point source pollution. Innovative research focuses on using rice (Oryza sativa), a wetland cereal crop, for pesticide mitigation both pre- and post-harvest. Because rice fields ...

  19. Morphological and molecular characterization of Magnaporthe oryzae (fungus) from infected rice leaf samples

    Science.gov (United States)

    Muni, Nurulhidayah Mat; Nadarajah, Kalaivani

    2014-09-01

    Magnaporthe oryzae is a plant-pathogenic fungus that causes a serious disease affecting rice called rice blast. Outbreaks of rice blast have been a threat to the global production of rice. This fungal disease is estimated to cause production losses of US55 million each year in South and Southeast Asia. It has been used as a primary model for elucidating various aspects of the host-pathogen interaction with its host. We have isolated five isolates of Magnaporthe oryzae from diseased leaf samples obtained from the field at Kompleks Latihan MADA, Kedah, Malaysia. We have identified the isolates using morphological and microscopic studies on the fungal spores and the lesions on the diseased leaves. Amplification of the internal transcribed spacer (ITS) was carried out with universal primers ITS1 and ITS4. The sequence of each isolates showed at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaporthe oryzae.

  20. Characterisation of some Accessions of Indigenous Rice (Oryza glaberrima Steud) in Ghana

    International Nuclear Information System (INIS)

    African rice (Oryza glaberrima Steud), a relative of the commonly consumed Asian (white) rice (Oryza sativa L.) is resistant to a number of biotic and abiotic stress factors and contains higher amounts of some essential mineral elements required for human health and growth, compared to the latter. Seventeen local accessions collected from four geographical regions in Ghana were characterised alongside NERICA 1, a high yielding, protein-rich hybrid line purposely bred for Africa, using 32 IBPGR-IRRI agro-botanical traits. Molecular characterisation was done using 24 standard simple sequence repeat markers. The accessions were also evaluated for seven essential mineral elements: calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), Manganese (Mn), potassium (K) and zinc (Zn) in the caryopsis, using Atomic Absorption Spectrophotometry (AAS) supported by Neutron Activation Analysis (NAA). The aim was to assess genetic diversity of the accessions and identify superior ones for incorporation in future breeding programmes. Cluster analysis (UPGMA), principal component analysis (Axes), correlation and population genetic analysis were used to group the accessions. The single link cluster technique classified the qualitative and quantitative traits of 18 accessions into six and four clusters respectively while the use of molecular traits grouped them into four clusters. Principal component analysis (PCA) re-ordered the accessions into four broad groups which had within-cluster and inter-cluster variations. Two pairs of duplicate accessions were revealed from the dendogram generated using morphological characters. SSRs were highly polymorphic, more discriminatory and informative at 77.3% and 80.0% similarity distance respectively, they were able to discriminate between these pairs of accessions earlier identified as duplicates using botanical descriptors. The overall genetic diversity of the accessions was relatively high (He = 0.625; Nei's He = 0.608 and I = 1.178) with

  1. Variability in aggressiveness of rice blast (Magnaporthe oryzae) isolates originating from rice leaves and necks: a case of pathogen specialization?

    OpenAIRE

    Ghatak, Abhijeet; Savary, Serge; Kumar, Jatinder

    2013-01-01

    Rice blast, caused by Magnaporthe oryzae, causes yield losses associated with injuries on leaves and necks, the latter being in general far more important than the former. Many questions remain on the relationships between leaf and neck blast, including questions related to the population biology of the pathogen. Our objective was to test the hypothesis of adaptation of M. oryzae isolates to the type of organ they infect. To that aim, the components of aggressiveness of isolates originating f...

  2. Relationships of wild and domesticated rices (Oryza AA genome species) based upon whole chloroplast genome sequences

    OpenAIRE

    Wambugu, Peterson W.; Marta Brozynska; Agnelo Furtado; Daniel L. Waters; Robert J. Henry

    2015-01-01

    Rice is the most important crop in the world, acting as the staple food for over half of the world’s population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly su...

  3. Vinegar rice (Oryza sativa L. produced by a submerged fermentation process from alcoholic fermented rice

    Directory of Open Access Journals (Sweden)

    Wilma Aparecida Spinosa

    2015-03-01

    Full Text Available Considering the limited availability of technology for the production of rice vinegar and also due to the potential consumer product market, this study aimed to use alcoholic fermented rice (rice wine (Oryza sativa L. for vinegar production. An alcoholic solution with 6.28% (w/v ethanol was oxidized by a submerged fermentation process to produce vinegar. The process of acetic acid fermentation occurred at 30 ± 0.3°C in a FRINGS® Acetator (Germany for the production of vinegar and was followed through 10 cycles. The vinegar had a total acidity of 6.85% (w/v, 0.17% alcohol (w/v, 1.26% (w/v minerals and 1.78% (w/v dry extract. The composition of organic acids present in rice vinegar was: cis-aconitic acid (6 mg/L, maleic acid (3 mg/L, trans-aconitic acid (3 mg/L, shikimic + succinic acid (4 mg/L, lactic acid (300 mg/L, formic acid (180 mg/L, oxalic acid (3 mg/L, fumaric acid (3 mg/L and itaconic acid (1 mg/L.

  4. Growth in rice cells requires de novo purine biosynthesis by the blast fungus Magnaporthe oryzae

    OpenAIRE

    Jessie Fernandez; Kuan Ting Yang; Kathryn M. Cornwell; Wright, Janet D.; Richard A. Wilson

    2013-01-01

    Increasing incidences of human disease, crop destruction and ecosystem perturbations are attributable to fungi and threaten socioeconomic progress and food security on a global scale. The blast fungus Magnaporthe oryzae is the most devastating pathogen of cultivated rice, but its metabolic requirements in the host are unclear. Here we report that a purine-requiring mutant of M. oryzae could develop functional appressoria, penetrate host cells and undergo the morphogenetic transition to elabor...

  5. Rapid diversification of five Oryza AA genomes associated with rice adaptation

    OpenAIRE

    Zhang, Qun-Jie; Zhu, Ting; Xia, En-Hua; Shi, Chao; Liu, Yun-Long; Zhang, Yun; Liu, Yuan; Jiang, Wen-Kai; Zhao, You-Jie; Mao, Shu-Yan; Zhang, Li-Ping; Huang, Hui; Jiao, Jun-Ying; Xu, Ping-Zhen; Yao, Qiu-Yang

    2014-01-01

    Asian rice (Oryza sativa) is among the world’s most important crops. The genus Oryza has become a model for the study of plant genome structure, function, and evolution. We have undertaken de novo, full-genome sequence analysis of five diploid AA-genome species that are closely related to O. sativa. These species are native to quite different environments, representing four continents, thus exhibiting very different adaptations. Our studies identify specific genetic changes, in both gene copy...

  6. Studies on Aspergillus oryzae Mutants for the Production of Single Cell Proteins from Deoiled Rice Bran

    OpenAIRE

    Ravinder, Rudravaram; Venkateshwar Rao, Linga; Ravindra, Pogaku

    2003-01-01

    Ethyl methyl sulphonate was used to induce point mutation in Aspergillus oryzae (MTCC 1846). Incubation with ethyl methyl sulphonate for 1 h resulted in 98 % killing of spores. By screening the survived colonies three hypermorphs were found (Shan1, Shan2 and Shan3). These three mutants along with the A. oryzae (MTCC 1846) were used for the production of single cell proteins. They grew profusely on deoiled rice bran and produced higher percentage of protein. Among the three mutants Shan2 ha...

  7. Data set from the phosphoproteomic analysis of Magnaporthe oryzae-responsive proteins in susceptible and resistant rice cultivars

    Directory of Open Access Journals (Sweden)

    Yunfeng Li

    2015-06-01

    Full Text Available Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is the most destructive disease of rice and causes tremendous losses of rice yield worldwide. To explore the molecular mechanisms involved in the rice–M. oryzae interaction, we conducted a time-course phosphoproteomic analysis of leaf samples from resistant and susceptible rice cultivars infected with M. oryzae. This data article contains additional results and analysis of M. oryzae-regulated phosphoproteins in rice leaves [1]. We report the analysis of M. oryzae-regulated phosphoproteins at all time points, including Venn diagram analysis, close-up views, relative intensities, and functional category, and the MS spectra of representative phosphoprotein and representative phosphorylated peptides.

  8. Transcriptome Analysis of Early Responsive Genes in Rice during Magnaporthe oryzae Infection

    Directory of Open Access Journals (Sweden)

    Yiming Wang

    2014-12-01

    Full Text Available Rice blast disease caused by Magnaporthe oryzae is one of the most serious diseases of cultivated rice (Oryza sativa L. in most rice-growing regions of the world. In order to investigate early response genes in rice, we utilized the transcriptome analysis approach using a 300 K tilling microarray to rice leaves infected with compatible and incompatible M. oryzae strains. Prior to the microarray experiment, total RNA was validated by measuring the differential expression of rice defense-related marker genes (chitinase 2, barwin, PBZ1, and PR-10 by RT-PCR, and phytoalexins (sakuranetin and momilactone A with HPLC. Microarray analysis revealed that 231 genes were up-regulated (>2 fold change, p < 0.05 in the incompatible interaction compared to the compatible one. Highly expressed genes were functionally characterized into metabolic processes and oxidation-reduction categories. The oxidative stress response was induced in both early and later infection stages. Biotic stress overview from MapMan analysis revealed that the phytohormone ethylene as well as signaling molecules jasmonic acid and salicylic acid is important for defense gene regulation. WRKY and Myb transcription factors were also involved in signal transduction processes. Additionally, receptor-like kinases were more likely associated with the defense response, and their expression patterns were validated by RT-PCR. Our results suggest that candidate genes, including receptor-like protein kinases, may play a key role in disease resistance against M. oryzae attack.

  9. Suppression of Rice Blast by Preinoculation with Avirulent Pyricularia oryzae and the Nonrice Pathogen Bipolaris sorokiniana.

    Science.gov (United States)

    Manandhar, H K; Lyngs Jørgensen, H J; Mathur, S B; Smedegaard-Petersen, V

    1998-07-01

    ABSTRACT Avirulent isolates of Pyricularia oryzae and isolates of Bipolaris sorokiniana, a nonrice pathogen, were used to suppress rice blast caused by P. oryzae. In greenhouse experiments, both fungi substantially reduced leaf blast when applied 24 h or more before the pathogen. B. sorokiniana, but not avirulent isolates of P. oryzae, systemically reduced disease in leaf 5 when applied to whole plants at the four-leaf stage. In field experiments, both fungi were able to reduce neck blast significantly. No increase in grain yield was obtained by using avirulent isolates of P. oryzae, whereas five sprays with B. sorokiniana from seedling to heading stages increased the grain yield in two of three experiments conducted at two locations in Nepal. The significant increase in yield was observed under high inoculum pressure of P. oryzae. Induced resistance is suggested to be involved in the suppression of disease. PMID:18944948

  10. Genome analysis of rice-blast fungus Magnaporthe oryzae field isolates from southern India

    OpenAIRE

    Malali Gowda; Meghana D. Shirke; Mahesh, H. B.; Pinal Chandarana; Anantharamanan Rajamani; Chattoo, Bharat B

    2015-01-01

    The Indian subcontinent is the center of origin and diversity for rice (Oryza sativa L.). The O. sativa ssp. indica is a major food crop grown in India, which occupies the first and second position in area and production, respectively. Blast disease caused by Magnaporthe oryzae is a major constraint to rice production. Here, we report the analysis of genome architecture and sequence variation of two field isolates, B157 and MG01, of the blast fungus from southern India. The 40 Mb genome of B1...

  11. The durably resistant rice cultivar Digu activates defence gene expression before the full maturation of Magnaporthe oryzae appressorium.

    Science.gov (United States)

    Li, Weitao; Liu, Ya; Wang, Jing; He, Min; Zhou, Xiaogang; Yang, Chao; Yuan, Can; Wang, Jichun; Chern, Mawsheng; Yin, Junjie; Chen, Weilan; Ma, Bingtian; Wang, Yuping; Qin, Peng; Li, Shigui; Ronald, Pamela; Chen, Xuewei

    2016-04-01

    Rice blast caused by the fungal pathogen Magnaporthe oryzae is one of the most destructive diseases worldwide. Although the rice-M. oryzae interaction has been studied extensively, the early molecular events that occur in rice before full maturation of the appressorium during M. oryzae invasion are unknown. Here, we report a comparative transcriptomics analysis of the durably resistant rice variety Digu and the susceptible rice variety Lijiangxintuanheigu (LTH) in response to infection by M. oryzae (5, 10 and 20 h post-inoculation, prior to full development of the appressorium). We found that the transcriptional responses differed significantly between these two rice varieties. Gene ontology and pathway analyses revealed that many biological processes, including extracellular recognition and biosynthesis of antioxidants, terpenes and hormones, were specifically activated in Digu shortly after infection. Forty-eight genes encoding receptor kinases (RKs) were significantly differentially regulated by M. oryzae infection in Digu. One of these genes, LOC_Os08g10300, encoding a leucine-rich repeat RK from the LRR VIII-2 subfamily, conferred enhanced resistance to M. oryzae when overexpressed in rice. Our study reveals that a multitude of molecular events occur in the durably resistant rice Digu before the full maturation of the appressorium after M. oryzae infection and that membrane-associated RKs play important roles in the early response. PMID:26095454

  12. Rapid evolution of avirulence genes in rice blast fungus Magnaporthe oryzae

    OpenAIRE

    Huang, Ju; Si, Weina; Deng, Qiming; Li, Ping; Yang, Sihai

    2014-01-01

    Background Rice blast fungus Magnaporthe oryzae is one of the most devastating pathogens in rice. Avirulence genes in this fungus share a gene-for-gene relationship with the resistance genes in its host rice. Although numerous studies have shown that rice blast R-genes are extremely diverse and evolve rapidly in their host populations, little is known about the evolutionary patterns of the Avr-genes in the pathogens. Results Here, six well-characterized Avr-genes and seven randomly selected n...

  13. Characterization of High-Value Bioactives in Some Selected Varieties of Pakistani Rice (Oryza sativa L.)

    OpenAIRE

    Md. Kamal Uddin; Muhammad Ashraf; Farooq Anwar; Muhammad Zubair

    2012-01-01

    The present study reports the composition and variation of fatty acids, sterols, tocopherols and γ-oryzanol among selected varieties namely Basmati Super, Basmati 515, Basmati 198, Basmati 385, Basmati 2000, Basmati 370, Basmati Pak, KSK-139, KS-282 and Irri-6 of Pakistani rice (Oryza sativa L). Oil content extracted with n-hexane from different varieties of brown rice seed (unpolished rice) ranged from 1.92% to 2.72%. Total fatty acid contents among rice varieties tested varied between 18240...

  14. South-East Asia is the center of origin, diversity and dispersion of the rice blast fungus, Magnaporthe oryzae

    OpenAIRE

    Saleh, Dounia; Milazzo, Joëlle; Adreit, Henri; Fournier, Elisabeth; Tharreau, Didier

    2013-01-01

    Inferring invasion routes and identifying reservoirs of diversity of plant pathogens are essential in proposing new strategies for their control. Magnaporthe oryzae, the fungus responsible for rice blast disease, has invaded all rice growing areas. Virulent genotypes regularly (re)emerge, causing rapid resistance breakdowns. However, the world-wide genetic subdivision of M. oryzae populations on rice and its past history of invasion have never been elucidated. In order to investigate the cent...

  15. Natural variation of rice blast resistant gene Pi-ta in Oryza species

    Science.gov (United States)

    The Pi-ta gene in rice is a putative NBS type cytoplasmic receptor conferring resistance to races of Magnaporthe oryzae in a gene-for-gene manner. A Functional Nucleotide Polymorphism (FNP) change resulting in an amino acid substitution of Alanine to Serine at position 918 (nucleotide G to T at posi...

  16. Analysis of the temporal variation of radiation balance components in arid rice (Oryza sativa L.) culture

    International Nuclear Information System (INIS)

    The time variation of measured radiation balance components in a cultived rice area (Oryza sativa L.) under arid conditions in the Brazil central-west region was analysed. The relation between global solar radiation, radiation balance, reflected radiation and terrestrial effective radiation in three different stages of the culture development: vegetative stage; blooming and maturation, was determined. (M.C.K.)

  17. STANDARDIZATION OF METHODOLOGY FOR STUDYING PATHOGENECITY OF XANTHOMONAS CAMPESTRIS PV ORYZAE TO RICE

    OpenAIRE

    Jaya Bhagat*, P Shukla and PK Mishra

    2013-01-01

    Rice is the most important food crop of India and its production has increased significantly during last few years. However, Infection of Xanthomonas campestris pv. Oryzae considerably decrease its productivity. It is important to study pathogenecity of causative organism before any defense strategy is decided. Present paper deals with standardization of technology for microscopic study of pathogen.

  18. Suppression of Magnaporthe oryzae and interaction between Bacillus subtilis and rice plants in the control of rice blast.

    Science.gov (United States)

    Sha, Yuexia; Wang, Qi; Li, Yan

    2016-01-01

    Magnaporthe oryzae, the causative pathogen of rice blast, has caused extensive losses to rice cultivation worldwide. Strains of the bacterium Bacillus subtilis have been used as biocontrol agents against rice blast. However, little has been reported about the interaction between B. subtilis and the rice plant and its mechanism of action. Here, the colonization process and induced disease resistance by B. subtilis SYX04 and SYX20 in rice plants was examined. Strains of B. subtilis labeled with green fluorescent protein reached population of more than 5 × 10(6) CFU/g after 20 days on mature rice leaves and were detected after 3 days on newly grown leaves. Results showed that SYX04 and SYX20 not only inhibited spore germination, germ tube length, and appressorial formation but also caused a series of alterations in the structures of hyphae and conidia. The cell walls and membrane structures of the fungus showed ultrastructural abnormalities, which became severely degraded as observed through scanning electron microscopy and transmission electron microscopy. The mixture of both B. subtilis and M. oryzae resulted in enhanced activity of peroxidase, and polyphenol oxidase while there was significantly more superoxide dismutase activity in plants that had been sprayed with B. subtilis alone. The present study suggests that colonized SYX04 and SYX20 strains protected rice plants and exhibited antifungal activity and induced systemic resistance, thus indicating their potential biological control agents. PMID:27536521

  19. Identification of an avirulence gene,avrxa5,from the rice pathogen Xanthomonas oryzae pv.oryzae

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Xanthomonas oryzae pv.oryzae,the causal agent of bacterial blight in rice,interacts with rice plants in a gene-for-gene manner.The specificity of the interaction is dictated by avirulence(avr) genes in the pathogen and resistance(R) genes in the host.To date,no avr genes that correspond to recessive R genes have been isolated.We isolated an avrBs3/pthA family gene,avrxa5,from our previously isolated clone p58,which was originally from strain JXOIII.The avrxa5 gene converted the PXO99A strain from compatible to incompatible in rice cultivars containing the recessive xa5 gene,but not in those containing the dominant Xa5 gene.Sequencing indicated that avrxa5,which is highly similar to members of the avrBs3/pthA family,encodes a protein of 1238 amino acid residues with a conserved carboxy-terminal region containing three nuclear localization signals and a transcription activation domain.It has 19.5 34-amino-acid direct repeats,but the 13th amino acid is missing in the fifth and ninth repetitive units.Domain swapping of the repetitive regions between avrxa5 and avrXa7 changed the avirulence specificity of the genes in xa5 and Xa7 rice lines,respectively.This indicates that avrxa5 is distinct from previously characterized avrBs3/pthA members.The specificity of avrxa5 toward recessive xa5 in rice could help us better understand the molecular mechanisms of plant-pathogen specific interactions.

  20. Methodical characterization of rice ( Oryza sativa bran oil from Pakistan

    Directory of Open Access Journals (Sweden)

    Mahmood, Zahid

    2005-06-01

    Full Text Available The hexane-extracted oil content of four varieties of rice (Oryza sativa viz. Super Kernel, 386, 385 and Basmati, bran was ranged 14.70-19.10 %. Other physical and chemical parameters of the extracted oils were as follow: Iodine value 112.40, 109.80, 105.1 and 103.70; refractive index ( 40 °C 1.4650, 1.4680, 1.4657 and 1.4660; density ( 40 °C 0.919, 0.913, 0.909 and 0.911; saponification value 183, 177, 186 and 190; unsaponifiable matter 6.15, 5.60, 4.98 and 5.40 % respectively. Tocopherols ( α, γ and δ in the oils were: 284.00, 175.12, 180.42, 300.06; 83.40, 98.70, 120.70, 90.60; 75.16, 57.20, 39.32, 83.00 mg/kg respectively. The contents of tocotrienols ( α, γ and δ in the oils were: 120.30, 106.00, 95.20, 135.74; 196.00, 125.00, 210.0, 276.41; 72.50, 20.00, 39.30, 64.00 mg/kg respectively. The amount of γ - Oryzanol in the investigated oils was ranged 415.12-802.05 The induction periods (Rancimat, 20 L/h, 120 °C of the crude oils were 6.81, 5.99, 6.39 and 7.40 h respectively. The major sterol fractions of the oils consisted of campesterol ranged (10.10-19.20%, stigmasterol (14.00-19.28 %, b -sitosterol (49.30-58.20 %, and D5 ,avenasterol (8.14-13.05 %. The investigated varieties ( Super Kernel, 386, 385 and Basmati of rice bran oil were found to contain high levels of oleic acid 42.67, 38.59, 40.68 and 36.78 % followed by linoleic and palmitic acids 31.58, 33.80, 28.70, 30.51 and 17.00, 14.88, 19.63, 20.00 % respectively. The contents of myristic, stearic and arachidic acids was 1.50, 2.02, 4.28, 1.00; 2.64, 2.87, 4.02, 7.48; and 1.28, 3.00, 1.00, 1.00 % respectively. A number of parameters of the investigated rice bran oils indigenous to Pakistan were comparable to those of typical rice bran and some other vegetable oils, reported in the literature. The results of the present analysis as compared with those of different vegetable oils demonstrated rice bran to be a potential oil source and thus could be useful

  1. Cytological aspects of incompatible and compatible interactions between rice, wheat and the blast pathogen Pyricularia oryzae

    Directory of Open Access Journals (Sweden)

    Leonardo Araujo

    2016-04-01

    Full Text Available ABSTRACT Blast, caused by the fungus Pyricularia oryzae, is an important disease affecting rice and wheat yield worldwide. This study investigated the cytological aspects of incompatible (non-host resistance and compatible (host resistance rice- (R_Po and wheat- (W_Po Pyricularia oryzae isolate interactions. Inoculations of rice and wheat with the R_Po and W_Po isolates of P. oryzae, respectively, were expected to be compatible interactions (host resistance, whereas inoculations of rice and wheat with the W_Po and R_Po isolates of P. oryzae, respectively, were considered to be incompatible interactions (non-host resistance. For the compatible interactions (rice-R_Po and wheat-W_Po, fungal hyphae penetrated and colonized the epidermal cells and also invaded many neighboring cells. By contrast, in the case of the incompatible interactions (rice-W_Po and wheat-R_Po, fungal hyphae were not able to penetrate nor colonize the epidermal cells, but when penetration did occur, the hyphae were restricted to the first-invaded epidermal cell. The frequency of appressorial sites exhibiting infection hyphae within the epidermal cell underlying an appressorium was greater in the case of the compatible interactions. By contrast, unsuccessful penetrations with cytoplasmic granulation occurred with high frequency in the incompatible wheat-R_Po and rice-W_Po interactions and the number of necrotic epidermal cells underlying the appressorium was low for the rice-W_Po interaction as well as for the wheat- R_Po interaction, where no symptoms of necrosis were exhibited. However, the opposite was observed for the compatible interactions. The present study presents cytological features associated with incompatible and compatible rice- and wheat-P. oryzae interactions that may be useful to studies involving variability, coevolution, diagnosis, and regulation of quarantine or even in a rice or wheat breeding program whose aim is to transfer genes involved in non

  2. Biological Control of Rice Blast (Magnaporthe oryzae by use of Streptomyces sindeneusis isolate 263 in Greenhouse

    Directory of Open Access Journals (Sweden)

    M. E. Zarandi

    2009-01-01

    Full Text Available Soil Actinomycetes particularly Streptomyces spp. have antagonistic activity against wide range of plant pathogens. In the recent decades they have attracted high interests as biocontrol agents. In search for finding such principles, in vitro suppression of Magnaporthe oryzae the causal agent of rice blast disease was studied by use of Streptomyces sindeneusis isolate 263 in greenhouse. Spray of rice seedling-leaves with of mixed spore suspension of the pathogen and S. sindeneusis isolate 263 resulted in strong inhibition of the pathogen and suppression of leaf symptoms. Propagation of the antagonist crude sap was performed in aqueous cultures and bioactivity was monitored in shaked cultures. Ongoing goals of this research include isolation, characterization and identification of the active metabolites and future goals include identification of active genes for use in development of recombinant DNAs in transgenic rice varieties bearing elevated resistance to infections by M. oryzae.

  3. Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Martin-Urdiroz, Magdalena; Oses-Ruiz, Miriam; Ryder, Lauren S; Talbot, Nicholas J

    2016-05-01

    The rice blast fungus, Magnaporthe oryzae, is responsible for the most serious disease of rice and is a continuing threat to ensuring global food security. The fungus has also, however, emerged as a model experimental organism for understanding plant infection processes by pathogenic fungi. This is largely due to its amenability to both classical and molecular genetics, coupled with the efforts of a very large international research community. This review, which is based on a plenary presentation at the 28th Fungal Genetics Conference in Asilomar, California in March 2015, describes recent progress in understanding how M. oryzae uses specialised cell called appressoria to bring about plant infection and the underlying biology of this developmental process. We also review how the fungus is then able to proliferate within rice tissue, deploying effector proteins to facilitate its spread by suppressing plant immunity and promoting growth and development of the fungus. PMID:26703899

  4. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.).

    Science.gov (United States)

    Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice. PMID:26752408

  5. A MAP kinase gene, BMK1, is required for conidiation and pathogenicity in the rice leaf spot pathogen Bipolaris oryzae.

    Science.gov (United States)

    Moriwaki, Akihiro; Kihara, Junichi; Mori, Chie; Arase, Sakae

    2007-01-01

    We isolated and characterized BMK1, a gene encoding a mitogen-activated protein kinase (MAPK), from the rice leaf spot pathogen Bipolaris oryzae. The deduced amino acid sequence showed significant homology with Fus3/Kss1 MAPK homologues from other phytopathogenic fungi. The BMK1 disruptants showed impaired hyphal growth, no conidial production, and loss of virulence against rice leaves, indicating that the BMK1 is essential for conidiation and pathogenicity in B. oryzae. PMID:16546358

  6. Structure of clusters and building blocks in amylopectin from African rice accessions.

    Science.gov (United States)

    Gayin, Joseph; Abdel-Aal, El-Sayed M; Marcone, Massimo; Manful, John; Bertoft, Eric

    2016-09-01

    Enzymatic hydrolysis in combination with gel-permeation and anion-exchange chromatography techniques were employed to characterise the composition of clusters and building blocks of amylopectin from two African rice (Oryza glaberrima) accessions-IRGC 103759 and TOG 12440. The samples were compared with one Asian rice (Oryza sativa) sample (cv WITA 4) and one O. sativa×O. glaberrima cross (NERICA 4). The average DP of clusters from the African rice accessions (ARAs) was marginally larger (DP=83) than in WITA 4 (DP=81). However, regarding average number of chains, clusters from the ARAs represented both the smallest and largest clusters. Overall, the result suggested that the structure of clusters in TOG 12440 was dense with short chains and high degree of branching, whereas the situation was the opposite in NERICA 4. IRGC 103759 and WITA 4 possessed clusters with intermediate characteristics. The commonest type of building blocks in all samples was group 2 (single branched dextrins) representing 40.3-49.4% of the blocks, while groups 3-6 were found in successively lower numbers. The average number of building blocks in the clusters was significantly larger in NERICA 4 (5.8) and WITA 4 (5.7) than in IRGC 103759 and TOG 12440 (5.1 and 5.3, respectively). PMID:27185123

  7. Physiological and Molecular Alterations Promoted by Schizotetranychus oryzae Mite Infestation in Rice Leaves.

    Science.gov (United States)

    Buffon, Giseli; Blasi, Édina A R; Adamski, Janete M; Ferla, Noeli J; Berger, Markus; Santi, Lucélia; Lavallée-Adam, Mathieu; Yates, John R; Beys-da-Silva, Walter O; Sperotto, Raul A

    2016-02-01

    Infestation of phytophagous mite Schizotetranychus oryzae in rice causes critical yield losses. To better understand this interaction, we employed Multidimensional Protein Identification Technology (MudPIT) approach to identify differentially expressed proteins. We detected 18 and 872 unique proteins in control and infested leaves, respectively, along with 32 proteins more abundant in control leaves. S. oryzae infestation caused decreased abundance of proteins related to photosynthesis (mostly photosystem II-related), carbon assimilation and energy production, chloroplast detoxification, defense, and fatty acid and gibberellin synthesis. On the contrary, infestation caused increased abundance of proteins involved in protein modification and degradation, gene expression at the translation level, protein partitioning to different organelles, lipid metabolism, actin cytoskeleton remodeling, and synthesis of jasmonate, amino acid, and molecular chaperones. Our results also suggest that S. oryzae infestation promotes cell-wall remodeling and interferes with ethylene biosynthesis in rice leaves. Proteomic data were positively correlated with enzymatic assays and RT-qPCR analysis. Our findings describe the protein expression patterns of infested rice leaves and suggest that the acceptor side of PSII is probably the major damaged target in the photosynthetic apparatus. These data will be useful in future biotechnological approaches aiming to induce phytophagous mite resistance in rice. PMID:26667653

  8. OryzaExpress: An Integrated Database of Gene Expression Networks and Omics Annotations in Rice

    Science.gov (United States)

    Hamada, Kazuki; Hongo, Kohei; Suwabe, Keita; Shimizu, Akifumi; Nagayama, Taishi; Abe, Reina; Kikuchi, Shunsuke; Yamamoto, Naoki; Fujii, Takaaki; Yokoyama, Koji; Tsuchida, Hiroko; Sano, Kazumi; Mochizuki, Takako; Oki, Nobuhiko; Horiuchi, Youko; Fujita, Masahiro; Watanabe, Masao; Matsuoka, Makoto; Kurata, Nori; Yano, Kentaro

    2011-01-01

    Similarity of gene expression profiles provides important clues for understanding the biological functions of genes, biological processes and metabolic pathways related to genes. A gene expression network (GEN) is an ideal choice to grasp such expression profile similarities among genes simultaneously. For GEN construction, the Pearson correlation coefficient (PCC) has been widely used as an index to evaluate the similarities of expression profiles for gene pairs. However, calculation of PCCs for all gene pairs requires large amounts of both time and computer resources. Based on correspondence analysis, we developed a new method for GEN construction, which takes minimal time even for large-scale expression data with general computational circumstances. Moreover, our method requires no prior parameters to remove sample redundancies in the data set. Using the new method, we constructed rice GENs from large-scale microarray data stored in a public database. We then collected and integrated various principal rice omics annotations in public and distinct databases. The integrated information contains annotations of genome, transcriptome and metabolic pathways. We thus developed the integrated database OryzaExpress for browsing GENs with an interactive and graphical viewer and principal omics annotations (http://riceball.lab.nig.ac.jp/oryzaexpress/). With integration of Arabidopsis GEN data from ATTED-II, OryzaExpress also allows us to compare GENs between rice and Arabidopsis. Thus, OryzaExpress is a comprehensive rice database that exploits powerful omics approaches from all perspectives in plant science and leads to systems biology. PMID:21186175

  9. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae

    OpenAIRE

    Azizi, Parisa; Rafii, Mohd Y.; Mahmood, Maziah; Abdullah, Siti N. A.; Hanafi, Mohamed M.; Nejat, Naghmeh; Latif, Muhammad A.; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world’s most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects t...

  10. Evolution of Compatibility Range in the Rice-Magnaporthe oryzae System: An Uneven Distribution of R Genes Between Rice Subspecies.

    Science.gov (United States)

    Gallet, Romain; Fontaine, Colin; Bonnot, François; Milazzo, Joëlle; Tertois, Christophe; Adreit, Henri; Ravigné, Virginie; Fournier, Elisabeth; Tharreau, Didier

    2016-04-01

    Efficient strategies for limiting the impact of pathogens on crops require a good understanding of the factors underlying the evolution of compatibility range for the pathogens and host plants, i.e., the set of host genotypes that a particular pathogen genotype can infect and the set of pathogen genotypes that can infect a particular host genotype. Until now, little is known about the evolutionary and ecological factors driving compatibility ranges in systems implicating crop plants. We studied the evolution of host and pathogen compatibility ranges for rice blast disease, which is caused by the ascomycete Magnaporthe oryzae. We challenged 61 rice varieties from three rice subspecies with 31 strains of M. oryzae collected worldwide from all major known genetic groups. We determined the compatibility range of each plant variety and pathogen genotype and the severity of each plant-pathogen interaction. Compatibility ranges differed between rice subspecies, with the most resistant subspecies selecting for pathogens with broader compatibility ranges and the least resistant subspecies selecting for pathogens with narrower compatibility ranges. These results are consistent with a nested distribution of R genes between rice subspecies. PMID:26667186

  11. Magnaporthe oryzae-Secreted Protein MSP1 Induces Cell Death and Elicits Defense Responses in Rice.

    Science.gov (United States)

    Wang, Yiming; Wu, Jingni; Kim, Sang Gon; Tsuda, Kenichi; Gupta, Ravi; Park, Sook-Young; Kim, Sun Tae; Kang, Kyu Young

    2016-04-01

    The Magnaporthe oryzae snodprot1 homolog (MSP1), secreted by M. oryzae, is a cerato-platanin family protein. msp1-knockout mutants have reduced virulence on barley leaves, indicating that MSP1 is required for the pathogenicity of rice blast fungus. To investigate the functional roles of MSP1 and its downstream signaling in rice, recombinant MSP1 was produced in Escherichia coli and was assayed for its functionality. Application of MSP1 triggered cell death and elicited defense responses in rice. MSP1 also induced H2O2 production and autophagic cell death in both suspension-cultured cells and rice leaves. One or more protein kinases triggered cell death, jasmonic acid and abscisic acid enhanced cell death, while salicylic acid suppressed it. We demonstrated that the secretion of MSP1 into the apoplast is a prerequisite for triggering cell death and activating defense-related gene expression. Furthermore, pretreatment of rice with a sublethal MSP1 concentration potentiated resistance to the pathogen. Taken together, our results showed that MSP1 induces a high degree of cell death in plants, which might be essential for its virulence. Moreover, rice can recognize MSP1, resulting in the induction of pathogen-associated molecular pattern-triggered immunity. PMID:26780420

  12. Quantitative phosphoproteomic analysis of early seed development in rice (Oryza sativa L.).

    Science.gov (United States)

    Qiu, Jiehua; Hou, Yuxuan; Tong, Xiaohong; Wang, Yifeng; Lin, Haiyan; Liu, Qing; Zhang, Wen; Li, Zhiyong; Nallamilli, Babi R; Zhang, Jian

    2016-02-01

    Rice (Oryza sativa L.) seed serves as a major food source for over half of the global population. Though it has been long recognized that phosphorylation plays an essential role in rice seed development, the phosphorylation events and dynamics in this process remain largely unknown so far. Here, we report the first large scale identification of rice seed phosphoproteins and phosphosites by using a quantitative phosphoproteomic approach. Thorough proteomic studies in pistils and seeds at 3, 7 days after pollination resulted in the successful identification of 3885, 4313 and 4135 phosphopeptides respectively. A total of 2487 proteins were differentially phosphorylated among the three stages, including Kip related protein 1, Rice basic leucine zipper factor 1, Rice prolamin box binding factor and numerous other master regulators of rice seed development. Moreover, differentially phosphorylated proteins may be extensively involved in the biosynthesis and signaling pathways of phytohormones such as auxin, gibberellin, abscisic acid and brassinosteroid. Our results strongly indicated that protein phosphorylation is a key mechanism regulating cell proliferation and enlargement, phytohormone biosynthesis and signaling, grain filling and grain quality during rice seed development. Overall, the current study enhanced our understanding of the rice phosphoproteome and shed novel insight into the regulatory mechanism of rice seed development. PMID:26613898

  13. Two distinct secretion systems facilitate tissue invasion by the rice blast fungus Magnaporthe oryzae.

    OpenAIRE

    Giraldo, Martha C.; Dagdas, Yasin F.; Gupta, Yogesh K.; Mentlak, Thomas A.; Yi, Mihwa; Martinez-Rocha, Ana Lilia; Saitoh, Hiromasa; Terauchi, Ryohei; Talbot, Nicholas J.; Valent, Barbara

    2013-01-01

    To cause plant diseases, pathogenic micro-organisms secrete effector proteins into host tissue to suppress immunity and support pathogen growth. Bacterial pathogens have evolved several distinct secretion systems to target effector proteins, but whether fungi, which cause the major diseases of most crop species, also require different secretory mechanisms is not known. Here we report that the rice blast fungus Magnaporthe oryzae possesses two distinct secretion systems to target effectors dur...

  14. Germination and infectivity of microconidia in the rice blast fungus Magnaporthe oryzae

    OpenAIRE

    Zhang, Huili; Wu, Zhongshou; Wang, Chenfang; Li, Yang; Xu, Jin-Rong

    2014-01-01

    The rice blast fungus Magnaporthe oryzae is a model for studying fungal–plant interactions. Although it produces two types of spores (microconidia and macroconidia), previous infection studies have exclusively dealt with macroconidia. Germination of microconidia has not been reported, and their role in plant infection is not defined. Here we show that approximately 10% of microconidia germinate on plant surfaces, and that colonies derived from germinated microconidia are normal in growth and ...

  15. Isolation and Characterization of Microsatellite Loci in the Asian Rice Gall Midge (Orseolia oryzae) (Diptera: Cecidomyiidae)

    OpenAIRE

    Jagadish S. Bentur; Sinha, Deepak Kumar; Padmavathy,; Revathy, Charagonda; Muthulakshmi, Mayandi; Nagaraju, Javaregowda

    2011-01-01

    Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason) using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR) markers represented di (72%), tri (15.3%), and complex repeats (12.7%). Three biotypes of gall midge (20 individuals for each biotype) were screened using these SSRs. The results revealed that 15 loci were hyper variable and ...

  16. OryzaPG-DB: Rice Proteome Database based on Shotgun Proteogenomics

    Directory of Open Access Journals (Sweden)

    Tomita Masaru

    2011-04-01

    Full Text Available Abstract Background Proteogenomics aims to utilize experimental proteome information for refinement of genome annotation. Since mass spectrometry-based shotgun proteomics approaches provide large-scale peptide sequencing data with high throughput, a data repository for shotgun proteogenomics would represent a valuable source of gene expression evidence at the translational level for genome re-annotation. Description Here, we present OryzaPG-DB, a rice proteome database based on shotgun proteogenomics, which incorporates the genomic features of experimental shotgun proteomics data. This version of the database was created from the results of 27 nanoLC-MS/MS runs on a hybrid ion trap-orbitrap mass spectrometer, which offers high accuracy for analyzing tryptic digests from undifferentiated cultured rice cells. Peptides were identified by searching the product ion spectra against the protein, cDNA, transcript and genome databases from Michigan State University, and were mapped to the rice genome. Approximately 3200 genes were covered by these peptides and 40 of them contained novel genomic features. Users can search, download or navigate the database per chromosome, gene, protein, cDNA or transcript and download the updated annotations in standard GFF3 format, with visualization in PNG format. In addition, the database scheme of OryzaPG was designed to be generic and can be reused to host similar proteogenomic information for other species. OryzaPG is the first proteogenomics-based database of the rice proteome, providing peptide-based expression profiles, together with the corresponding genomic origin, including the annotation of novelty for each peptide. Conclusions The OryzaPG database was constructed and is freely available at http://oryzapg.iab.keio.ac.jp/.

  17. Physiological changes promoted by a strobilurin fungicide in the rice-Bipolaris oryzae interaction.

    Science.gov (United States)

    Debona, D; Nascimento, K J T; Gomes, J G O; Aucique-Perez, C E; Rodrigues, F A

    2016-06-01

    Strobilurins are among the most important fungicides that are used for plant disease control worldwide. In addition to their fungicide effect, strobilurins can also improve crop physiology. Nonetheless, the impact of azoxystrobin (Az), the main marketed strobilurin, on rice physiology is still unknown. Detailed gas exchange measurements and chlorophyll a fluorescence analysis were used to examine the Az effects on the photosynthetic performance of rice plants (cultivar Metica-1) either challenged or not with Bipolaris oryzae, the causal agent of brown spot. Az impaired carbon (C) fixation in the non-inoculated plants in a manner that was not related to photochemical or biochemical limitations, but rather to decreased stomatal conductance that limited the CO2 influx into the mesophyll cells. The photosynthesis of rice plants that were not sprayed with Az dramatically decreased upon B. oryzae infection, which was chiefly governed by photochemical and biochemical limitations. The energy surplus that was caused by limited C fixation in the rice plants that were treated with Az and inoculated with B. oryzae was thermally and effectively dissipated until 72h after inoculation. In Az absence, however, this mechanism was not sufficient to prevent chronic photoinhibition to photosynthesis. The inoculated plants were not able to fully capture and exploit the collected light energy, but these constraints were greatly limited in the presence of Az. In conclusion, Az impaired the photosynthetic performance of non-infected plants by diffusive constraints, but prevented, to a greater extent, the damage to the photosynthetic apparatus during the infection process of B. oryzae. PMID:27155478

  18. Oxygen dynamics in submerged rice (Oryza sativa L.)

    DEFF Research Database (Denmark)

    Colmer, Timothy D.; Pedersen, Ole

    2008-01-01

    Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...... was one order of magnitude higher than in darkness, enhancing also pO2 in roots.The initial peak in pO2 following illumination of submerged rice was likely to result from high initial rates of net photosynthesis, fuelled by CO2 accumulated during the dark period. Nevertheless, since sugars decline...... from roots showed an initial peak following shoot illumination.  O2 dynamics in shoots and roots of submerged rice were monitored during light and dark periods, using O2 microelectrodes. Tissue sugar concentrations were also measured.  On illumination of shoots of submerged rice, pO2 increased rapidly...

  19. Lipid binding in rice nonspecific lipid transfer protein-1 complexes from Oryza sativa

    OpenAIRE

    Cheng, Hui-Chun; Cheng, Pei-Tsung; Peng, Peiyu; Lyu, Ping-Chiang; Sun, Yuh-Ju

    2004-01-01

    Nonspecific lipid transfer proteins (nsLTPs) facilitate the transfer of phospholipids, glycolipids, fatty acids and steroids between membranes, with wide-ranging binding affinities. Three crystal structures of rice nsLTP1 from Oryza sativa, complexed with myristic (MYR), palmitic (PAL) or stearic acid (STE) were determined. The overall structures of the rice nsLTP1 complexes belong to the four-helix bundle folding with a long C-terminal loop. The nsLTP1–MYR and the nsLTP1–STE complexes bind a...

  20. Genomic organization of a novel victorivirus from the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Tang, Lihua; Hu, Yanping; Liu, Lijiang; Wu, Songsong; Xie, Jiatao; Cheng, Jiasen; Fu, Yanping; Zhang, Guoming; Ma, Juntao; Wang, Yongli; Zhang, Liyan

    2015-11-01

    Two double-stranded RNA (dsRNA) mycoviruses were found in isolate QSP5 of the rice blast fungus Magnaporthe oryzae. Sequence analysis of the two dsRNA mycoviruses revealed that one is closely related to Magnaporthe oryzae virus 2 (MoV2), and the other one is related to Magnaporthe oryzae chrysovirus 1-A (MoCV1-A). Therefore, they were named Magnaporthe oryzae virus 3 (MoV3) and Magnaporthe oryzae chrysovirus 1-C (MoCV1-C), respectively. In this paper, the molecular and structural characteristics of MoV3 were analyzed in detail. The full genome sequence (5181 bp) of MoV3 was obtained by cDNA cloning. Sequence analysis indicated that MoV3 has two overlapping open reading frames (ORF1 and ORF2). The 5'-proximal ORF1 encodes a putative coat protein (CP) with a molecular weight of 80,939 Da; the 3'-proximal ORF2 encodes a putative RNA-dependent RNA polymerase (RdRp) with a molecular weight of 90,506 Da. The stop codon of ORF1 overlaps the start codon of ORF2, with the tetranucleotide sequence AUGA, which is characteristic of members of the genus Victorivirus of the family Totiviridae. Phylogenetic analysis of RdRp and CP further supported the view that MoV3, a novel mycovirus, belongs to the genus Victorivirus of the family Totiviridae. PMID:26271150

  1. Genomewide survey and characterization of metacaspase gene family in rice (Oryza sativa)

    Indian Academy of Sciences (India)

    Likai Wang; Hua Zhang

    2014-04-01

    Metacaspases (MCs), which are cysteine-dependent proteases found in plants, fungi, and protozoa, may be involved in programmed cell death processes, being distant relatives of metazoan caspases. In this study, we analysed the structures, phylogenetic relationship, genome localizations, expression patterns and domestic selections of eight MC genes identified in rice (OsMC). Alignment analysis of the corresponding protein sequences suggested OsMC proteins can be classified into two sub-types. The expression profiles of eight OsMC genes were analysed in 27 tissues covering the whole life cycle of rice. There are four OsMC genes uniquely expressed in mature tissues, indicating that these genes might play certain roles in senescence. Under abiotic and biotic stresses, four OsMC genes were expressed with treatments of one or more of Magnaporthe oryzae (M. oryzae) infected, pest damaged, cold stress and drought stress, indicating they might be involved in plant defense. In addition, gene trees and genetic diversity $(\\pi)$ were performed to measure whether candidate genes were selected during rice domestication. The results suggested that all the type I genes could not be domestication genes. However, two of five type II OsMC genes showed strong evidence for selective sweep, suggesting that these genes might be involved in cultivated rice domestication. These results provide a foundation for future functional genomic studies of this family in rice.

  2. Molecular Evolution of the TAC1 Gene from Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Jiahuan Jiang; Lubin Tan; Zuofeng Zhu; Yongcai Fu; Fengxia Liu; Hongwei Cai; Chuanqing Sun

    2012-01-01

    Tiller angle is a key feature of the architecture of cultivated rice (Oryza sativa),since it determines planting density and influences rice yield.Our previous work identified Tiller Angle Control 1 (TAC1) as a major quantitative trait locus that controls rice tiller angle.To further clarify the evolutionary characterization of the TAC1 gene,we compared a TAC1-containing 3164-bp genomic region among 113 cultivated varieties and 48 accessions of wild rice,including 43 accessions of O.rufipogon and five accessions of O.nivara.Only one single nucleotide polymorphism (SNP),a synonymous substitution,was detected in TAC1 coding regions of the cultivated rice varieties,whereas one synonymous and one nonsynonymous SNP were detected among the TAC1 coding regions of wild rice accessions.These data indicate that little natural mutation and modification in the TAC1 coding region occurred within the cultivated rice and its progenitor during evolution.Nucleotide diversities in the TAC1 gene regions of O.sativa and O.rufipogon of 0.00116 and 0.00112,respectively,further indicate that TAC1 has been highly conserved during the course of rice domestication.A functional nucleotide polymorphism (FNP) of TAC1 was only found in the japonica rice group.A neutrality test revealed strong selection,especially in the 3'-flanking region of the TAC1 coding region containing the FNP in the japonica rice group.However,no selection occurred in the indica and wild-rice groups.A phylogenetic tree derived from TAC1 sequence analysis suggests that the indica and japonica subspecies arose independently during the domestication of wild rice.

  3. Control of brown spot pathogen of rice (Bipolaris oryzae) using some phenolic antioxidants.

    Science.gov (United States)

    Shabana, Y M; Abdel-Fattah, G M; Ismail, A E; Rashad, Y M

    2008-07-01

    Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone). The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS) and disease incidence (DI) on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves and in the total carbohydrate and protein contents of the yielded grains. PMID:24031243

  4. The rice proteogenomics database OryzaPG-DB: development, expansion and new features

    Directory of Open Access Journals (Sweden)

    Mohamed eHelmy

    2012-04-01

    Full Text Available Proteogenomics is the utilization of large-scale proteome data in genome annotation refinement. Our recently developed rice proteogenomics database (OryzaPG-DB is the first sustainable resource for rice shotgun-based proteogenomics, providing information on peptides identified in rice protein digested peptides measured by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS, and mapping of the peptides to their genomic origins and the genomic novelty of each peptide. The sequences of the peptides, proteins, cDNAs and genes, and the gene annotations are available for download in FASTA and GFF3 formats, respectively. Further, an annotated visualization of the gene models, corresponding peptides and genomic novelty is available for each gene, and MS/MS spectra are available for each peptide. In this article, we discuss the utilization of OryzaPG-DB and report on its development, recent content expansions and newly added features in the current version (OryzaPG-DB v1.1.

  5. Comprehensive phenotypic analysis of rice (Oryza sativa) response to salinity stress

    KAUST Repository

    Pires, Inês S.

    2015-07-22

    Increase in soil salinity levels is becoming a major cause of crop yield losses worldwide. Rice (Oryza sativa) is the most salt-sensitive cereal crop, and many studies have focused on rice salinity tolerance, but a global understanding of this crop\\'s response to salinity is still lacking. We systematically analyzed phenotypic data previously collected for 56 rice genotypes to assess the extent to which rice uses three known salinity tolerance mechanisms: shoot-ion independent tolerance (or osmotic tolerance), ion exclusion, and tissue tolerance. In general, our analyses of different phenotypic traits agree with results of previous rice salinity tolerance studies. However, we also established that the three salinity tolerance mechanisms mentioned earlier appear among rice genotypes and that none of them is predominant. Against the pervasive view in the literature that the K+/Na+ ratio is the most important trait in salinity tolerance, we found that the K+ concentration was not significantly affected by salt stress in rice, which puts in question the importance of K+/Na+ when analyzing rice salt stress response. Not only do our results contribute to improve our global understanding of salt stress response in an important crop, but we also use our results together with an extensive literature research to highlight some issues commonly observed in salinity stress tolerance studies and to propose solutions for future experiments.

  6. Understanding the coevolution of rice blast resistance gene Pi-ta and Magnaporthe oryzae avirulence gene AVR-Pita

    Science.gov (United States)

    Rice blast disease caused by the filamentous ascomycetous fungus Magnaporthe oryzae remains to be one of the most serious threats for food security globally. Using resistance (R) genes in integrated cultural practices has been the most powerful practice for rice crop protection. Genetic analysis s...

  7. The Fd-GOGAT1 mutant gene lc7 confers resistance to Xanthomonas oryzae pv. Oryzae in rice.

    Science.gov (United States)

    Chen, Honglin; Li, Chunrong; Liu, Liping; Zhao, Jiying; Cheng, Xuzhen; Jiang, Guanghuai; Zhai, Wenxue

    2016-01-01

    Disease resistance is an important goal of crop improvement. The molecular mechanism of resistance requires further study. Here, we report the identification of a rice leaf color mutant, lc7, which is defective in chlorophyll synthesis and photosynthesis but confers resistance to Xanthomonas oryzae pv. Oryzae (Xoo). Map-based cloning revealed that lc7 encodes a mutant ferredoxin-dependent glutamate synthase1 (Fd-GOGAT1). Fd-GOGAT1 has been proposed to have great potential for improving nitrogen-use efficiency, but its function in bacterial resistance has not been reported. The lc7 mutant accumulates excessive levels of ROS (reactive oxygen species) in the leaves, causing the leaf color to become yellow after the four-leaf stage. Compared to the wild type, lc7 mutants have a broad-spectrum high resistance to seven Xoo strains. Differentially expressed genes (DEGs) and qRT-PCR analysis indicate that many defense pathways that are involved in this broad-spectrum resistance are activated in the lc7 mutant. These results suggest that Fd-GOGAT1 plays an important role in broad-spectrum bacterial blight resistance, in addition to modulating nitrogen assimilation and chloroplast development. PMID:27211925

  8. Characterization of High-Value Bioactives in Some Selected Varieties of Pakistani Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Md. Kamal Uddin

    2012-04-01

    Full Text Available The present study reports the composition and variation of fatty acids, sterols, tocopherols and γ-oryzanol among selected varieties namely Basmati Super, Basmati 515, Basmati 198, Basmati 385, Basmati 2000, Basmati 370, Basmati Pak, KSK-139, KS-282 and Irri-6 of Pakistani rice (Oryza sativa L. Oil content extracted with n-hexane from different varieties of brown rice seed (unpolished rice ranged from 1.92% to 2.72%. Total fatty acid contents among rice varieties tested varied between 18240 and 25840 mg/kg brown rice seed. The rice tested mainly contained oleic (6841–10952 mg/kg linoleic (5453–7874 mg/kg and palmitic acid (3613–5489 mg/kg. The amounts of total phytosterols (GC and GC-MS analysis, with main contribution from β-sitosterol (445–656 mg/kg, campesterol (116–242 mg/kg, ∆5-avenasterol (89–178 mg/kg and stigmasterol (75–180 mg/kg were established to be 739.4 to 1330.4 mg/kg rice seed. The content of α-, γ- and δ-tocopherols as analyzed by HPLC varied from 39.0–76.1, 21.6–28.1 and 6.5–16.5 mg/kg rice seed, respectively. The amounts of different γ-oryzanol components (HPLC data, identified as cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate and β-sitosteryl ferulate, were in the range of 65.5–103.6, 140.2–183.1, 29.8–45.5 and 8.6–10.4 mg/kg rice seed, respectively. Overall, the concentration of these bioactives was higher in the Basmati rice cultivars showing their functional food superiority. In conclusion, the tested varieties of Pakistani rice, especially the Basmati cultivars, can provide best ingredients for functional foods.

  9. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff..

    Directory of Open Access Journals (Sweden)

    Yi Zhou

    Full Text Available Dongxiang wild rice (Oryza rufipogon Griff. is the progenitor of cultivated rice (Oryza sativa L., and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated. Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

  10. Influence of growing location and cultivar on Rhyzopertha dominica (Coleoptera: Bostrichidae) and Sitophilus oryzae (Coleoptera: Curculionidae) infestation of rough rice

    Institute of Scientific and Technical Information of China (English)

    FRANK H. ARTHUR; RUSTY C. BAUTISTA; TERRENCE J. SIEBENMORGEN

    2007-01-01

    Long-grain rice cultivars Cocodrie, Wells, and XP 723 grown in three locations (Hazen, MO; Essex and Newport, AR, USA), and medium-grain rice cultivars Bengal and XP 713 grown in two locations (Jonesboro and Lodge Corner, AR, USA), were harvested and assayed for susceptibility to Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), the lesser grain borer, and Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the rice weevil, on rice held at 27℃ 57% and 75% relative humidity (RH).Separate samples from the same harvest lots were also analyzed for the physical characteristics of brown rice yield, percentage whole kernels and kernel thickness. Progeny production and feeding damage of R. dominica were significantly different among long-grain cultivars within two of the three locations (P < 0.05), but not for location or RH (P ≥ 0.05), while progeny production of S. oryzae was different among cultivars, location, and RH (P < 0.05). On medium-grain rice, both cultivar and location were significant for progeny production of R. dominica, but not RH, while cultivar and RH were significant for progeny production of S. oryzae, but not location. On both rice types, feeding damage of R. dominica followed the same trends and was always strongly positively correlated with progeny production (P < 0.05), but for S. oryzae there were several instances in which progeny production was not correlated with feeding damage (P ≥ 0.05). Physical characteristics of both rice types were statistically significant (P < 0.01) but actual numerical differences were extremely small, and were generally not correlated with progeny production of either species. Results indicate that the location in which a particular rice cultivar is grown, along with its characteristics, could affect susceptibility of the rice to R. dominica and S. oryzae.

  11. Transgenic Expression of the Recombinant Phytase in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    LIU Qiao-quan; LI Qian-feng; JIANG Li; ZHANG Da-jiang; WANG Hong-mei; GU Ming-hong; YAO Quan-hong

    2006-01-01

    In most of the cereal crop, phytic acid is the main storage form of phosphorus, which can decrease the bioavailability of phosphate. Transgenic expression of phytase is regarded as an efficient way to release phosphate from phytate in transgenic plants.In this study, a plant expression vector, containing the recombinant phytase gene driven by the maize ubiquitin (Ubi) promoter was constructed and introduced into an elite rice variety via Agrobacterium-mediated transformation. During the experiment, a total of 15 independent transgenic rice lines were regenerated. The results of PCR and Southern blot indicated that the target gene was integrated into the genome of transgenic rice plants. Moreover, the RT-PCR analysis of total RNAs extracted from the immature seeds of several transgenic lines showed that the recombinant phytase gene could be normally expressed. The inorganic phosphorus content, both in the mature seeds and the leaf was significantly higher in the transgenic plants than in the untransformed wild type.

  12. Translocation of Magnaporthe oryzae effectors into rice cells and their subsequent cell-to-cell movement.

    Science.gov (United States)

    Khang, Chang Hyun; Berruyer, Romain; Giraldo, Martha C; Kankanala, Prasanna; Park, Sook-Young; Czymmek, Kirk; Kang, Seogchan; Valent, Barbara

    2010-04-01

    Knowledge remains limited about how fungal pathogens that colonize living plant cells translocate effector proteins inside host cells to regulate cellular processes and neutralize defense responses. To cause the globally important rice blast disease, specialized invasive hyphae (IH) invade successive living rice (Oryza sativa) cells while enclosed in host-derived extrainvasive hyphal membrane. Using live-cell imaging, we identified a highly localized structure, the biotrophic interfacial complex (BIC), which accumulates fluorescently labeled effectors secreted by IH. In each newly entered rice cell, effectors were first secreted into BICs at the tips of the initially filamentous hyphae in the cell. These tip BICs were left behind beside the first-differentiated bulbous IH cells as the fungus continued to colonize the host cell. Fluorescence recovery after photobleaching experiments showed that the effector protein PWL2 (for prevents pathogenicity toward weeping lovegrass [Eragrostis curvula]) continued to accumulate in BICs after IH were growing elsewhere. PWL2 and BAS1 (for biotrophy-associated secreted protein 1), BIC-localized secreted proteins, were translocated into the rice cytoplasm. By contrast, BAS4, which uniformly outlines the IH, was not translocated into the host cytoplasm. Fluorescent PWL2 and BAS1 proteins that reached the rice cytoplasm moved into uninvaded neighbors, presumably preparing host cells before invasion. We report robust assays for elucidating the molecular mechanisms that underpin effector secretion into BICs, translocation to the rice cytoplasm, and cell-to-cell movement in rice. PMID:20435900

  13. Use of local rice cultivars as additional differentials to identify pathotypes of Pyricularia oryzae

    Directory of Open Access Journals (Sweden)

    Gisele Barata da Silva

    2011-01-01

    Full Text Available Eight additional rice cultivars as differentials were selected to identify pathotypes occurring in the Tocantins State. They were BRS Jaburu, BRS Taim, BRS Biguá, BR IRGA-417, Epagri 109, Javaé, Metica-1 and Supremo. These differentials were used in addition to the international set to determine the pathogenic diversity of 193 Pyricularia oryzae isolates collected during 1994-2002 from irrigated rice cultivars. They were conserved in Pyricularia culture collection of Embrapa Rice and Bean Research center. From 193 P. oryzae isolates 38 pathotypes were identified based on leaf blast reactions of international set and 29 pathotypes based on these additional differentials. The predominant pathotypes (TI-1, TG-2, TD-15 and TF-2 were represented by 53% of the tested isolates. The major international pathotypes (IB-45, IB-41, II-1 and ID-13 were represented by 43% of the isolates tested. The virulence pattern of 28 isolates belonging to the pathotype IB-45 was further differentiated into nine local pathotypes using additional set of differentials. The irrigated rice cultivars used as additional differentials serve as complementary set to identify pathotypes of interest for breeding blast resistant cultivars for Tocantins State.

  14. Mapping of a new gene for brown planthopper resistance in cultivated rice introgressed from Oryza eichingeri

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Wild rice species is an important source of useful genes for cultivated rice improvement. Some accessions of Oryza eichingeri (2n = 24, CC) from Africa confer strong resistance to brown planthopper (BPH), whitebacked planthopper (WBPH) and bacterial blight (BB). In the present study, restriction fragments length polymorphism (RFLP) and simple sequence repeats (SSR) analysis were performed on disomic backcross plants between Oryza sativa (2n = 24, AA) and O. eichingeri in order to identify the presenee of O. eichingeri segments and further to localize BPH-resistant gene. In the introgression lines, 1-6O. eichingeri segments were detected on rice chromosomes 1, 2, 6, or/and 10. The dominant BPH resistant gene, tentatively named Bph13(t), was mapped to chromosome 2, being 6.1 and 5.5 cM away from two microsatellite markers RM240 and RM250, respectively. The transfer and localization of this gene from O. eichingeri will contribute to the improvement of BPH resistance in cultivated rice.``

  15. Dissection of the genetic architecture of rice resistance to the blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Kang, Houxiang; Wang, Yue; Peng, Shasha; Zhang, Yanli; Xiao, Yinghui; Wang, Dan; Qu, Shaohong; Li, Zhiqiang; Yan, Shuangyong; Wang, Zhilong; Liu, Wende; Ning, Yuese; Korniliev, Pavel; Leung, Hei; Mezey, Jason; McCouch, Susan R; Wang, Guo-Liang

    2016-08-01

    Resistance in rice cultivars to the rice blast fungus Magnaporthe oryzae is complex and is controlled by both major genes and quantitative trait loci (QTLs). We undertook a genome-wide association study (GWAS) using the rice diversity panel 1 (RDP1) that was genotyped using a high-density (700 000 single nucleotide polymorphisms) array and inoculated with five diverse M. oryzae isolates. We identified 97 loci associated with blast resistance (LABRs). Among them, 82 were new regions and 15 co-localized with known blast resistance loci. The top 72 LABRs explained up to 98% of the phenotypic variation. The candidate genes in the LABRs encode nucleotide-binding site leucine-rich repeat (NBS-LRR) resistance proteins, receptor-like protein kinases, transcription factors and defence-related proteins. Among them, LABR_64 was strongly associated with resistance to all five isolates. We analysed the function of candidate genes underlying LABR_64 using RNA interference (RNAi) technology and identified two new resistance alleles at the Pi5 locus. We demonstrate an efficient strategy for rapid allele discovery using the power of GWAS, coupled with RNAi technology, for the dissection of complex blast resistance in rice. PMID:26574735

  16. The oryza map alignment project: the golden path to unlocking the genetic potential of wild rice species.

    Science.gov (United States)

    Wing, Rod A; Ammiraju, Jetty S S; Luo, Meizhong; Kim, Hyeran; Yu, Yeisoo; Kudrna, Dave; Goicoechea, Jose L; Wang, Wenming; Nelson, Will; Rao, Kiran; Brar, Darshan; Mackill, Dave J; Han, Bin; Soderlund, Cari; Stein, Lincoln; SanMiguel, Phillip; Jackson, Scott

    2005-09-01

    The wild species of the genus Oryza offer enormous potential to make a significant impact on agricultural productivity of the cultivated rice species Oryza sativa and Oryza glaberrima. To unlock the genetic potential of wild rice we have initiated a project entitled the 'Oryza Map Alignment Project' (OMAP) with the ultimate goal of constructing and aligning BAC/STC based physical maps of 11 wild and one cultivated rice species to the International Rice Genome Sequencing Project's finished reference genome--O. sativa ssp. japonica c. v. Nipponbare. The 11 wild rice species comprise nine different genome types and include six diploid genomes (AA, BB, CC, EE, FF and GG) and four tetrapliod genomes (BBCC, CCDD, HHKK and HHJJ) with broad geographical distribution and ecological adaptation. In this paper we describe our strategy to construct robust physical maps of all 12 rice species with an emphasis on the AA diploid O. nivara--thought to be the progenitor of modern cultivated rice. PMID:16217601

  17. Arsenic accumulation and phosphorus status in two rice (Oryza sativa L.) cultivars surveyed from fields in South China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Ying [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Dong, Fei [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); Deacon, Claire [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Chen Huojun [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); Raab, Andrea [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Meharg, Andrew A., E-mail: a.meharg@abdn.ac.u [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom)

    2010-05-15

    The consumption of paddy rice (Oryza sativa L.) is a major inorganic arsenic exposure pathway in S.E. Asia. A multi-location survey was undertaken in Guangdong Province, South China to assess arsenic accumulation and speciation in 2 rice cultivars, one an Indica and the other a hybrid Indica. The results showed that arsenic concentrations in rice tissue increased in the order grain < husk < straw < root. Rice grain arsenic content of 2 rice cultivars was significant different and correlated with phosphorus concentration and molar ratio of P/As in shoot, being higher for the Indica cultivar than for the hybrid Indica, which suggests altering shoot phosphorus status as a promising route for breeding rice cultivars with reduced grain arsenic. Speciation of grain arsenic, performed using HPLC-ICP-MS, identified inorganic arsenic as the dominant arsenic species present in the rice grain. - Altering rice shoot phosphorus status is a promising route for breeding rice cultivars with reduced grain arsenic.

  18. A systems-wide comparison of red rice (Oryza longistaminata) tissues identifies rhizome specific genes and proteins that are targets for cultivated rice improvement

    OpenAIRE

    He, Ruifeng; Salvato, Fernanda; Park, Jeong-Jin; Kim, Min-Jeong; Nelson, William; Balbuena, Tiago S; Willer, Mark; Crow, John A; May, Greg D.; Soderlund, Carol A.; Thelen, Jay J.; Gang, David R.

    2014-01-01

    Background The rhizome, the original stem of land plants, enables species to invade new territory and is a critical component of perenniality, especially in grasses. Red rice (Oryza longistaminata) is a perennial wild rice species with many valuable traits that could be used to improve cultivated rice cultivars, including rhizomatousness, disease resistance and drought tolerance. Despite these features, little is known about the molecular mechanisms that contribute to rhizome growth, developm...

  19. EFFECT OF FUNGICIDES IN THE CONTROL OF RICE BLAST Pyricularia oryzae AND Helminthosporium oryzae EFEITO DE FUNGICIDAS NO CONTROLE DE BRUSONE (Pyricularia oryzae E MANCHA PARDA (Helminthosporium oryzae NO ARROZ

    Directory of Open Access Journals (Sweden)

    Cláudio Aparecido da Silveira

    2007-09-01

    Full Text Available

    The effect of the fungicides ethiltrianol and edifenphos was evaluated, on level of field, aiming control rice blast (Pyricularia oryzae and Helminthosporium oryzae in variety IAC - 47. The fungicides were pulverized one or two times in different concentrations in the stage of panicles emission. The results showed that, as to infection level in the panicles, grain lesions and productivity there was no significant statistical difference between treatments. Refering to infection level in the banner leaves, there was significant statistical difference between treatments and the control.

    Foi avaliado, a nível de campo, o efeito dos fungicidas ethiltrianol e edifienphos no controle de brusone (Pyricularia oryzae Cav. e Helminthosporium oryzae Breda de Haan na cultura do arroz, variedade IAC - 47. Os fungicidas foram pulverizados uma ou duas vezes, em diferentes concentrações a partir da emissão das panículas. Os resultados apurados indicaram que quanto a lesões nas panículas, nos grãos e produtividade, não houve diferença significativa entre os tratamentos. Com relação ao parâmetro lesões nas folhas bandeiras houve diferença entre todos os tratamentos com fungicidas e a testemunha.

  20. Data for global lysine-acetylation analysis in rice (Oryza sativa).

    Science.gov (United States)

    Xiong, Yehui; Zhang, Kai; Cheng, Zhongyi; Wang, Guo-Liang; Liu, Wende

    2016-06-01

    Rice is one of the most important crops for human consumption and is a staple food for over half of the world׳s population (Yu et al., 2002) [1]. A systematic identification of the lysine acetylome was performed by our research (Xiong et al., 2016) [2]. Rice plant samples were collected from 5 weeks old seedlings (Oryza sativa, Nipponbare). After the trypsin digestion and immunoaffinity precipitation, LC-MS/MS approach was used to identify acetylated peptides. After the collected MS/MS data procession and GO annotation, the InterProScan was used to annotate protein domain. Subcellular localization of the identified acetylated proteins was predicted by WoLF PSORT. The KEGG pathway database was used to annotate identified acetylated protein interactions, reactions, and relations. The data, supplied in this article, are related to "A comprehensive catalog of the lysine-acetylation targets in rice (O. sativa) based on proteomic analyses" by Xiong et al. (2016) [2]. PMID:26977447

  1. Genome analysis of rice-blast fungus Magnaporthe oryzae field isolates from southern India

    Directory of Open Access Journals (Sweden)

    Malali Gowda

    2015-09-01

    Full Text Available The Indian subcontinent is the center of origin and diversity for rice (Oryza sativa L.. The O. sativa ssp. indica is a major food crop grown in India, which occupies the first and second position in area and production, respectively. Blast disease caused by Magnaporthe oryzae is a major constraint to rice production. Here, we report the analysis of genome architecture and sequence variation of two field isolates, B157 and MG01, of the blast fungus from southern India. The 40 Mb genome of B157 and 43 Mb genome of MG01 contained 11,344 and 11,733 predicted genes, respectively. Genomic comparisons unveiled a large set of SNPs and several isolate specific genes in the Indian blast isolates. Avr genes were analyzed in several sequenced Magnaporthe strains; this analysis revealed the presence of Avr-Pizt and Avr-Ace1 genes in all the sequenced isolates. Availability of whole genomes of field isolates from India will contribute to global efforts to understand genetic diversity of M. oryzae population and to track the emergence of virulent pathotypes.

  2. Anacardic acid induces apoptosis-like cell death in the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Muzaffar, Suhail; Bose, Chinchu; Banerji, Ashok; Nair, Bipin G; Chattoo, Bharat B

    2016-01-01

    Anacardic acid (6-pentadecylsalicylic acid), extracted from cashew nut shell liquid, is a natural phenolic lipid well known for its strong antibacterial, antioxidant, and anticancer activities. Its effect has been well studied in bacterial and mammalian systems but remains largely unexplored in fungi. The present study identifies antifungal, cytotoxic, and antioxidant activities of anacardic acid in the rice blast fungus Magnaporthe oryzae. It was found that anacardic acid causes inhibition of conidial germination and mycelial growth in this ascomycetous fungus. Phosphatidylserine externalization, chromatin condensation, DNA degradation, and loss of mitochondrial membrane potential suggest that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that anacardic acid induces caspase-independent apoptosis in M. oryzae. Expression of a predicted ortholog of apoptosis-inducing factor (AIF) was upregulated during the process of apoptosis, suggesting the possibility of mitochondria dependent apoptosis via activation of apoptosis-inducing factor. Anacardic acid treatment leads to decrease in reactive oxygen species rather than increase in reactive oxygen species (ROS) accumulation normally observed during apoptosis, confirming the antioxidant properties of anacardic acid as suggested by earlier reports. Our study also shows that anacardic acid renders the fungus highly sensitive to DNA damaging agents like ethyl methanesulfonate (EMS). Treatment of rice leaves with anacardic acid prevents M. oryzae from infecting the plant without affecting the leaf, suggesting that anacardic acid can be an effective antifungal agent. PMID:26381667

  3. Alteration of TGA factor activity in rice results in enhanced tolerance to Xanthomonas oryzae pv. oryzae.

    OpenAIRE

    Fitzgerald, Heather A; Canlas, Patrick E.; Chern, Maw-Sheng; Ronald, Pamela C

    2005-01-01

    In dicotyledonous plants broad-spectrum resistance to pathogens is established after the induction of the systemic acquired resistance (SAR) response. In Arabidopsis the NPR1 protein can regulate SAR by interacting with members of the TGA class of basic, leucine-zipper transcription factors to alter pathogenesis-related (PR) gene expression. Overexpression of (At)NPR1 in Arabidopsis enhances resistance to multiple pathogens. Similarly, overexpression of (At)NPR1 in rice enhances resistance to...

  4. Genetic improvement of rice (oryza sativa l.) by induced mutations

    International Nuclear Information System (INIS)

    In 1989 was initiated at Rice Research Institute of Cuba, a mutation breeding programme, in order to obtain new germoplasm with improved characters such as milling quality, earliness, resistance to the Hoja Blanca virus disease and salt tolerance. Seven varieties has been irradiated and two different sources of radiation were used: gamma rays from 60Co and fast neutrons of a 14 MeV neutron generator. In 1995, was released the variety IACuba 23 for low inputs conditions. Another four varieties IACuba 21, IACuba 22, IACuba 27 and IACuba 28 are in validation trials in rice production areas under irrigated condition. The last two have showed resistance to Steneotarsonemus spinki. Also, a group of mutants was selected to be used as parents. These mutants have been used in 953 crosses

  5. Improvement results of rice (Oryza glaberima) by induced mutation

    International Nuclear Information System (INIS)

    In Mali, rice (Orzya glaberima) is still largely cultivated under conditions of natural semi-controlled submersion. To improve productivity the local varieties have been gradually replaced by new varieties, but the yields of these became lower because of the irregularity of the rain and the comparative weakness of the strain. For this reason a programme to improve the local varieties by means of gamma radiation has been undertaken. This document presents the results obtained to date

  6. Epigenetic responses to drought stress in rice (Oryza sativa L.)

    OpenAIRE

    Gayacharan; Joel, A. John

    2013-01-01

    Cytosine methylation polymorphism plays a key role in gene regulation, mainly in expression of genes in crop plants. The differential expression of cytosine methylation over drought stress response was analyzed in rice using drought susceptible but agronomically superior lines IR 20 and CO 43, and drought tolerant genotypes PL and PMK 3 and their F1 hybrids. The parents and hybrids were subjected to two moisture regimes viz., one under drought condition and another under control condition. Th...

  7. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae.

    Science.gov (United States)

    Azizi, Parisa; Rafii, Mohd Y; Mahmood, Maziah; Abdullah, Siti N A; Hanafi, Mohamed M; Nejat, Naghmeh; Latif, Muhammad A; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world's most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  8. The genetics analysis of rice mutant R917 with resistance to rice blast (pyricularia oryza)

    International Nuclear Information System (INIS)

    Rice mutant R917 with resistance to rice blast was selected by induced mutation with irradiation. The F2 segregation of R917/NF6, XS11, XS861 crosses with resistance to rice blast ZB15, ZC13, ZE3 showed that the rice blast resistance is controlled by one dominant gene. The identification of the disease resistance for the progenies of R917 crosses with XS11, XS861 showed that R917 could be used as a good material for resistance to rice blast in rice breeding

  9. Development of rice (Oryza sativa L) with low phytic acid

    International Nuclear Information System (INIS)

    Phytic acid, myo-isositol 1,2,3,4,5,6 - hexakisphosphate ( IP 6) is the major storage compound of phosphorous (P) in plants. Rice grain contain anti-nutritional factors, which reduce the bioavailability of iron and zinc. Phytate has for long time been known to lower the absorption of these and other minerals in humans and non ruminant and animals. Induced mutations in the most important cereals have been utilized to reduce the phytate content of resting grains. The following is develop the mutants with low phytic acid content have been isolated from four varieties with different genetic backgrounds: OMCS 2000, OM 1490, Rice grains were induced by gamma radiation (200Gy) then screened for height levels of inorganic phosphate in order to identify low phytic acid were analyzed and compared to 101 improve varieties and 600 traditional varieties. LP mutants derived from OM 1490, OMCS 2000 at M5, M4 and M3 advanced generations were uniform in agronomic traits and other improved ones by lines (47, 64, 144, 158, and 274). Three genotypes OM 4498, OM 2517, OM 5731 and 6 local varieties Nang guoc do, Ca Ro, Lua Lun, Nep ao vang, Nep mau luon, Nep Hat to were found to low levels of phytate with level = 0465 μg P. Lua Vang =0.930 μg P and Lua Hoang =(v) 1.395 μg P. Our findings may help rice breeders develop low phytic acid genotypes with improved nutritional value to overcome anemia symptom and adapt to biofortification strategy demands. (author)

  10. The Subtelomere of Oryza sativa Chromosome 3 Short Arm as a Hot Bed of New Gene Origination in Rice

    Institute of Scientific and Technical Information of China (English)

    Chuanzhu Fan; Yong Zhang; Yeisoo Yu; Steve Rounsley; Manyuan Long; Rod A.Wing

    2008-01-01

    Despite general observations of non-random genomic distribution of new genes,it is unclear whether or not new genes preferentially occur in certain genomic regions driven by related molecular mechanisms.Using 1.5 Mb of genomic sequences from short arms of chromosome 3 of Oryza glaberrima and O.punctata,we conducted a comparative genomic analysis with the reference O.sativa ssp-japonica genome.We identified a 60-kb segment Iocated in the middle of the subtelomeric region of chromosome 3,which is unique to the species O.sativa.The region contained gene duplicares that occurred in Asian cultivated rice species that diverged from the ancestor of Asian and African cultivated rice one million years ago(MYA).For the 12 genes and one complete retrotransposon identified in this segment in O.sativa ssp.japonica,we searched for their parental genes.The high similarity between duplicated paralogs further supports the recent origination of these genes.We found that this segment was recently generated through multiple independent gene recombination and transposon insertion events.Among the 12 genes,we found that five had chimeric gene structures derived from multiple parental genes.Nine out of the 12 new genes seem to be functional,as suggested by Ka/Ks analysis and the presence of cDNA and/or MPSS data.Furthermore,for the eight transcribed genes,at least two genes could be classified as defense or stress response-related genes.Given these findings,and the fact that subtelomeres are associated with high rates of recombination and transcription,it is likely that subtelomeres may facilitate gene recombination and transposon insertions and serve as hot spots for new gene origination in rice genomes.

  11. Isolation and Characterization of Microsatellite Loci in the Asian Rice Gall Midge (Orseolia oryzae) (Diptera: Cecidomyiidae)

    OpenAIRE

    Charagonda Revathy; Javaregowda Nagaraju; Ch. Padmavathy; Mayandi Muthulakshmi; Deepak Kumar Sinha; Jagadish S. Bentur

    2011-01-01

    Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason) using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR) markers represented di (72%), tri (15.3%), and complex repeats (12.7%). Three biotypes of gall midge (20 individuals for each biotype) were screened using these SSRs. The results revealed that 15 loci were hyper variable and ...

  12. Factors affecting the outcrossing rate between Clearfield rice and red rice (Oryza sativa)

    Science.gov (United States)

    The commercialization of imazethapyr-resistant (Clearfield[TM], CL) rice in the southern United States has raised serious concerns about gene flow to red rice, producing imazethapyr-resistant red rice populations. Our objectives were to determine the impact of planting date, CL cultivars, and red ri...

  13. Resistência de cultivares de arroz a Rhizoctonia solani e Rhizoctonia oryzae Resistance of rice cultivars to Rhizoctonia solani and Rhizoctonia oryzae

    Directory of Open Access Journals (Sweden)

    Anne Sitarama Prabhu

    2002-05-01

    Full Text Available Isolados de Rhizoctonia solani e Rhizoctonia oryzae, agentes causais da queima-da-bainha e mancha-da-bainha, respectivamente, foram coletados em lavouras de arroz irrigado no Estado do Tocantins. O objetivo deste trabalho foi avaliar a resistência de 12 cultivares de arroz a essas doenças, sob condições artificiais de inoculação, em casa de vegetação. Não houve correlação entre resistência das cultivares a R. oryzae e R. solani quanto ao comprimento da lesão na bainha infectada pelo método de palito de dentes. A relação entre tamanho da lesão na bainha e folha foi linear e significativamente negativa (r = -0,66, PIsolates of Rhizoctonia solani and Rhizoctonia oryzae, the causal agents of sheath blight and sheath rot diseases, respectively, were collected from irrigated rice fields in the State of Tocantins, Brazil. The main objective of the investigation was to assess the resistance of 12 genotypes to these diseases, under artificial inoculation tests in greenhouse condition. There was no correlation between the resistance of cultivars to R. oryzae and R. solani for lesion extension on sheath infection obtained by the toothpick method. The relationship between lesion size on sheath and leaf was linear and significantly negative (r = -0.66, P<=0.05, thereby indicating that there is no relationship between resistance of sheath and leaf to infection by R. solani in rice cultivars. Among the early maturing genotypes Labelle was highly susceptible in all methods of inoculation. The area under disease progress curve based on lesion height on the culm and the inoculation method with rice husk and grain were found more adequate for determining the differences in the degree of resistance among cultivars. Leaves exhibited resistance to infection by R. oryzae in inoculation tests with mycelial discs.

  14. Mutagenic effects of Pingyangmycin on rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    The mutagenic effects of Pingyangmycin (PYM) on rice were studied by means of seed treatment with 5, 10, 15, 20 and 25 μg/ml of PYM. The results showed that PYM could induce high frequency of chromosome aberrations, produce physiological damages of various degrees in terms of seed germination, seedling growth and spikelet fertility in M1 generation, and induce high frequency of chlorophyll-deficient mutation and mutation in plant height and heading date in M2 generation. With 15 μg/ml of treatment, the highest total mutation frequency, higher than that of the widely used chemical mutagen EMS, was reached. As induction of beneficial mutations was concerned, PYM was inferior to EMS in inducing early heading mutation, but superior to EMS in inducing short straw mutation

  15. Molecular Cloning and Characterization of Citrate Synthase Gene in Rice( Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shan-shan; MING Feng; LU Qun; GUO Bin; SHEN Da-leng

    2005-01-01

    The full-length OsCS encoding citrate synthase was isolated from rice (Oryza sativa L. subsp. japonica). OsCS is 1477-bp long and encodes a 474 amino acid polypeptide. Its putative protein sequence is highly identical to Daucus carota, Nicotiana tabacum,Beta vulgaris subsp., Arabidopsis thaliana, and Citrus junos (>70%). The deduced amino-terminal sequence of OsCS showes characteristics of mitochondrial targeting signal. Southern blot analysis using ORF of the OsCS as the probe indicated that this gene exists in multiple copies in rice genome. The band with predicated size of 82 kD was detected by Western blot after being induced by 0.4 mmol/L IPTG.

  16. EFFECT OF CHEMICAL SEED TREATMENT IN THE CONTROL OF BLAST DISEASE AND BROWN SPOT OF RICE EFEITO DO TRATAMENTO QUÍMICO DE SEMENTES NO CONTROLE DE BRUSONE (Pyricularia oryzae) E MANCHA PARDA (Helminthosporium oryzae) DO ARROZ

    OpenAIRE

    Valácia Lemes da Silva; Wilson Ferreira de Oliveira; Meire Aparecida Damaceno

    2007-01-01

    With the objective of controlling blast disease (Pyricularia oryzae) and brown spot (Helminthosporium oryzae) of rice (Oryza sativa), different fungicides were tested, through seeds treatment, at field culture in low land soil. The results showed, preliminarily and in general terms that fungicides dichlofluanid and terbuconazole propitiated in the stand increase superior to 30% when confronted with standard fungici...

  17. The influence of soil water status on Oryza Sativa Var. MR220 in KADA rice agroecosystem

    International Nuclear Information System (INIS)

    A study to determine the influence of soil water status on rice plant Oryza sativa var. MR220 after panicle initiation stage was carried out at Ladang Merdeka Mulong Lating in the Kemubu Agricultural Development Authority (KADA) area, Kelantan. Five water management treatments imposed on direct seeded rice were; T1. Continuous flooding, T2. Early flooding up to panicle initiation stage followed by saturated (F55-saturated), T3. Early flooding for the first month followed by saturated (F-30 saturated), T4. Continuous saturated, and T5. Continuous field capacity condition throughout the growth stage. The treatments were arranged in Randomized Complete Block Design (RCBD) with four replicates. Results showed significant differences in soil moisture content in the order of T1>T2>T3>T4>T5. Significant differences were also observed in rice plant water content at 68 DAS (days after seeding) in the order of T2>T3>T4>T1>T5. Moisture content also showed significant differences between replicates in the order of R1>R2>R3>R4 and R2>R1>R3>R4; in rice plant and ricefield soil, respectively. Results however showed no significant difference in leaf stomatal conductance due to water stress. Rice plant moisture, soil moisture and leaf stomatal conductance showed no interaction. Published results show that even though overall crop yield was reduced by sheath blight and panicle blast incidence that occur at later stage in 2004-2005 field trials, highest grain yields were obtained from T2 (off season) and T4 (main season). Saturated condition seems to be the most suitable method of growing rice under minimal water input in KADA rice agroecosystem. (Author)

  18. Contribution to the improvement of rice (Oryza sativa L.) by mutation induction with gamma radiation

    International Nuclear Information System (INIS)

    The study involved inducing mutations in the varieties Icta-Virginia and Precozicta to obtain genotypes that mature early, are resistant or tolerant to Pyricularia oryzae and have a high yield potential. To optimize the radiation dose for each variety, seeds were irradiated with doses of 0, 150, 200, 250, 300 and 400 Gy. Six thousand seeds of each variety were irradiated with the above doses to establish the M1 generation, in which the physiological effects and somatic mutations were observed. The M2 generation was sown in progeny groups and as the crop developed, mutants with chlorophyll changes, morphological changes, improved yield, tolerance to Phyricularia oryzae and mutants which matured earlier than the original variety were identified and selected. In the M3 generation, derived from the Icta-Virginia and Precozicta varieties, the genetic stability of mutants with morphological changes, chlorophyll changes, tolerance to Pyricularia oryzae (classified as 0-1 on the 0 to 9 scale of the standard rice evaluation system) and those which matured earlier (15 to 20 days) than the original variety was confirmed. (author). 7 refs, 3 tabs

  19. Genotypic differences in phosphate nutrition of rice (Oryza Sativa L.)

    International Nuclear Information System (INIS)

    Phosphate uptake and use by five genotypes of paddy rice were studied at five phosphate levels in pot studies for 49 days. For all five P levels there were marked genotypic differences in shoot growth, plant dry weight, root/shoot ratios, phosphate uptake and translocation, P content of roots and shoots, and phosphorus use efficiency of shoots (PUE, g shoot mg P-1 in shoot). There were significant genotypic differences in root weight (4 P levels) and in uptake/mg root (all P levels). These latter may have resulted from differences in root weight/root length conversion, root hair development or uptake characteristics, factors which were not studied specifically. Differences between genotypes and P levels in the percentage translocation were partly explicable by differences in P uptake/plant (r = 0.72) but especially by differences in root/shoot ratios (r = 0.89). Differences in PUE were largely a factor of P percentage of the tops (r = 0.94) but significant differences between genotypes were shown as a function of % P. Differences in net photosynthesis rates were largely, but not entirely, due to differences in P % of the shoots. Key factors in P uptake and use and genotypic differences are root growth, uptake/mg root, root/shoot ratios and PUE. (author). 9 refs, 2 figs, 3 tabs

  20. Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Carey, Anne-Marie; Scheckel, Kirk G.; Lombi, Enzo; Newville, Matt; Choi, Yongseong; Norton, Gareth J.; Price, Adam H.; Meharg, Andrew A. (EPA); (U. South Australia); (Aberdeen); (UC)

    2012-09-05

    Efficient Se biofortification programs require a thorough understanding of the accumulation and distribution of Se species within the rice grain. Therefore, the translocation of Se species to the filling grain and their spatial unloading were investigated. Se species were supplied via cut flag leaves of intact plants and excised panicle stems subjected to a {+-} stem-girdling treatment during grain fill. Total Se concentrations in the flag leaves and grain were quantified by inductively coupled plasma mass spectrometry. Spatial accumulation was investigated using synchrotron X-ray fluorescence microtomography. Selenomethionine (SeMet) and selenomethylcysteine (SeMeSeCys) were transported to the grain more efficiently than selenite and selenate. SeMet and SeMeSeCys were translocated exclusively via the phloem, while inorganic Se was transported via both the phloem and xylem. For SeMet- and SeMeSeCys-fed grain, Se dispersed throughout the external grain layers and into the endosperm and, for SeMeSeCys, into the embryo. Selenite was retained at the point of grain entry. These results demonstrate that the organic Se species SeMet and SeMeSeCys are rapidly loaded into the phloem and transported to the grain far more efficiently than inorganic species. Organic Se species are distributed more readily, and extensively, throughout the grain than selenite.

  1. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

    OpenAIRE

    Elkheir H.A; Yunus M; Muslimin M; Rinaldi Sjahril; Nurlina Kasim; Muhammad Riadi

    2015-01-01

    Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8...

  2. In vitro screening for salt tolerance in Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    P .Shanthi, S. Jebaraj and S. Geetha

    2010-07-01

    Full Text Available An experiment was conducted to study the performance of rice genotypes for salt tolerance under in vitro condition. Sevengenotypes include salt tolerant (Pokkali, CSR 10, TRY 1 and TRY2, moderately tolerant to salt (White Ponni and BPT5204 and susceptible (IR 29 were used for this study through embryo culture technique. Callus was initiated in MS medium+ 2 mgl-1 2,4D + 0.5 mgl-1 Kin and different concentration of Nacl viz., 50mM, 100mM and 150mM were added with themedium to create salt stress. Statistical analysis revealed that all the genotypes and treatments and their interaction effectwere significantly different from each other. Among the seven genotypes studied Pokkali was significantly superior for callusinduction with 62 % followed by CSR 10, TRY(R 2 and TRY1 with 58 %, 54.5 % and 53 % respectively. Pokkali registeredthe highest level of callus development (35% even at high level of Nacl stress (150mM followed by TRY 2 (25% and CSR10 (24%. When the callus for these genotypes were transferred to regeneration media in the same level of Nacl stress(50mm, 100mM and 150mM highest level of regeneration of green islets was realized in Pokkali (37.5 % followed by CSR10 (31 % and TRY (R2 (25 %. From these observation, it was concluded that somaclones obtained form the varieties ofPokkali, CSR 10 and TRY(R 2 could be evaluated further in the natural field condition to develop a high yielding salttolerant varieties or could be used as a donor for the development of salt tolerant varieties. This in vitro screening techniquewith different concentration of Nacl stress could also be used as a goof screening technique for salt tolerances rather than thefield screening because of less time, little space and less labour and the results also very accurate than the field screening.

  3. Glycogen Metabolic Genes Are Involved in Trehalose-6-Phosphate Synthase-Mediated Regulation of Pathogenicity by the Rice Blast Fungus Magnaporthe oryzae

    OpenAIRE

    Badaruddin, Muhammad; Holcombe, Lucy J.; Richard A. Wilson; Wang, Zheng-Yi; Kershaw, Michael J.; Talbot, Nicholas J.

    2013-01-01

    Author Summary The fungus Magnaporthe oryzae causes a devastating disease of rice called blast. Each year, rice blast disease destroys almost a quarter of the potential global rice harvest. The fungus infects rice plants by elaborating a special infection structure called an appressorium, which physically breaks the tough outer cuticle of a rice leaf. Magnaporthe can develop appressoria in the absence of a nutrient source. We are therefore studying how the fungus utilizes energy stores in its...

  4. Molecular cloning and expression analysis of a monosaccharide transporter gene OsMST4 from rice (Oryza sativa L.)

    NARCIS (Netherlands)

    Wang, Y.; Xu, H.; Wei, X.; Chai, C.; Xiao, Y.; Zhang, Y.; Chen, B.; Xiao, G.; Ouwerkerk, P.B.F.; Wang, M.; Zhu, Z.

    2007-01-01

    Monosaccharide transporters mediate the membrane transport of a variable range of monosaccharides, which plays a crucial role in sugar distribution throughout the plant. To investigate the significance of monosaccharide transporters for rice (Oryza sativa L.) seed development, cDNA of a new putative

  5. Effector-mediated suppression of chitin-triggered immunity by Magnaporthe oryzae is necessary for rice blast disease

    NARCIS (Netherlands)

    Mentlak, T.A.; Kombrink, A.; Shinya, T.; Ryder, L.S.; Otomo, I.; Saitoh, H.; Terauchi, R.; Nishizawa, Y.; Shibuya, N.; Thomma, B.P.H.J.; Talbot, N.J.

    2012-01-01

    Plants use pattern recognition receptors to defend themselves from microbial pathogens. These receptors recognize pathogen-associated molecular patterns (PAMPs) and activate signaling pathways that lead to immunity. In rice (Oryza sativa), the chitin elicitor binding protein (CEBiP) recognizes chiti

  6. Comparative analysis of the genomes of two field isolates of the rice blast fungus Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Minfeng Xue

    Full Text Available Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice worldwide. The fungal pathogen is notorious for its ability to overcome host resistance. To better understand its genetic variation in nature, we sequenced the genomes of two field isolates, Y34 and P131. In comparison with the previously sequenced laboratory strain 70-15, both field isolates had a similar genome size but slightly more genes. Sequences from the field isolates were used to improve genome assembly and gene prediction of 70-15. Although the overall genome structure is similar, a number of gene families that are likely involved in plant-fungal interactions are expanded in the field isolates. Genome-wide analysis on asynonymous to synonymous nucleotide substitution rates revealed that many infection-related genes underwent diversifying selection. The field isolates also have hundreds of isolate-specific genes and a number of isolate-specific gene duplication events. Functional characterization of randomly selected isolate-specific genes revealed that they play diverse roles, some of which affect virulence. Furthermore, each genome contains thousands of loci of transposon-like elements, but less than 30% of them are conserved among different isolates, suggesting active transposition events in M. oryzae. A total of approximately 200 genes were disrupted in these three strains by transposable elements. Interestingly, transposon-like elements tend to be associated with isolate-specific or duplicated sequences. Overall, our results indicate that gain or loss of unique genes, DNA duplication, gene family expansion, and frequent translocation of transposon-like elements are important factors in genome variation of the rice blast fungus.

  7. Soybean-Enriched Snacks Based on African Rice

    OpenAIRE

    Mauro Marengo; Hannah F. Akoto; Miriam Zanoletti; Aristodemo Carpen; Simona Buratti; Simona Benedetti; Alberto Barbiroli; Johnson, Paa-Nii T.; Esther O. Sakyi-Dawson; Firibu K. Saalia; Francesco Bonomi; Maria Ambrogina Pagani; John Manful; Stefania Iametti

    2016-01-01

    Snacks were produced by extruding blends of partially-defatted soybean flour with flours from milled or parboiled African-grown rice. The interplay between composition and processing in producing snacks with a satisfactory sensory profile was addressed by e-sensing, and by molecular and rheological approaches. Soybean proteins play a main role in defining the properties of the protein network in the products. At the same content in soybean flour, use of parboiled rice flour increases the snac...

  8. Study on the induction and selection of rice mutant R917 for blast disease (Piricularia oryzae) resistance

    International Nuclear Information System (INIS)

    Rice F0 seeds were treated with 10 krad of 60Co γ-rays, and blast resistance mutant R917 was selected in the following generations. The blast resistance was tested by inoculating the mutant with 138 strains of Piricularia oryzae artificially from nine blast regions in Zhejiang Province, scale of blast resistance was only 0.89 and 1.0 in 1991 and 1992 respectively. The rice mutant R917 was resistant to 136 blast fungus strains. The rate of blast resistance for R917 was higher than that of its parents. The mutant is likely to be used in rice breeding for variety improvement

  9. Silicon-Mediated Amelioration of Fe2+ Toxicity in Rice (Oryza sativa L.) Roots

    Institute of Scientific and Technical Information of China (English)

    FU You-Qiang; SHEN Hong; WU Dao-Ming; CAI Kun-Zheng

    2012-01-01

    Silicon (Si) can enhance the resistance of plants to many abiotic stresses. To explore whether Si ameliorates Fe2+ toxicity,a hydroponic experiment was performed to investigate whether and how Si detoxifies Fe2+ toxicity in rice (Oryza sativa L.) roots.Results indicated that rice cultivar Tianyou 998 (TY998) showed greater sensitivity to Fe2+ toxicity than rice cultivar Peizataifeng (PZTF).Treatment with 0.1 mmol L-1 Fe2+ inhibited TY998 root elongation and root biomass significantly.Reddish iron plaque was formed on root surface of both cultivars.TY998 had a higher amount of iron plaque than PZTF.Addition of Si to the solution of Fe treatment decreased the amount of iron plaque on root surface by 17.6% to 37.1% and iron uptake in rice roots by 37.0% to 40.3%,and subsequently restored root elongation triggered by Fe2+ toxicity by 13.5% in the TY998.Compared with Fe treatment,the addition of 1 mmol L-1 Si to the solution of Fe treatment increased xylem sap flow by 19.3% to 24.8% and root-shoot Fe transportation by 45.0% to 78.6%.Furthermore,Si addition to the solution of Fe treatment induced root cell wall to thicken.These results suggested that Si could detoxify Fe2+ toxicity and Si-mediated amelioration of Fe2+ toxicity in rice roots was associated with less iron plaque on root surface and more Fe transportation from roots to shoots.

  10. Characterization and Mapping of a Salt-Sensitive Mutant in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Jingwei Zhou; Fuzheng Wang; Ping Deng; Wen Jing; Wenhua Zhang

    2013-01-01

    A salt-sensitive mutant designated rice salt sensitive 2 (rss2) was isolated from the M2 generation of the rice cultivar Nipponbare (Oryza sativa L.ssp.japonica) mutagenized with ethyl methanesulfonate (EMS).This mutant exhibited a greater decrease in salt tolerance with a significant increase in Na+ content in its shoots.Genetic analysis indicated that the increase in Na+ in rss2 was controlled by a single recessive gene.Further genome-wide analysis of the linkage map constructed from the F2 population of rss2/Zhaiyeqing 8 (ZYQ8) showed that two quantitative trait loci (QTLs) on chromosomes 1 and 6 were responsible for the Na+ concentration in shoots,which explained 14.5% and 53.3%,respectively,of the phenotypic variance.The locus on chromosome 1,but not that on chromosome 6,was also detected in the F2 population of Nipponbare/ZYQ8,suggesting that the QTL on chromosome 6 was responsible for the salt sensitivity in rss2.By analyzing the recombination events in 220 mutant individuals of an enlarged mapping population of rss2/ZYQ8,the rss2 locus was precisely mapped to an interval of 605.3 kb between insertion/deletion (InDel) markers IM21962 and IM22567.This finding will facilitate the cloning of the rss2 locus and provide insight into the physiological mechanisms of salt sensitivity in rice.

  11. Gene interactions and genetics of blast resistance and yield attributes in rice (Oryza sativa L.)

    Indian Academy of Sciences (India)

    B. Divya; A. Biswas; S. Robin; R. Rabindran; A. John Joel

    2014-08-01

    Blast disease caused by the pathogen Pyricularia oryzae is a serious threat to rice production. Six generations viz., P1, P2, F1, F2, B1 and B2 of a cross between blast susceptible high-yielding rice cultivar ADT 43 and resistant near isogenic line (NIL) CT13432-3R, carrying four blast resistance genes Pi1, Pi2, Pi33 and Pi54 in combination were used to study the nature and magnitude of gene action for disease resistance and yield attributes. The epistatic interaction model was found adequate to explain the gene action in most of the traits. The interaction was complementary for number of productive tillers, economic yield, lesion number, infected leaf area and potential disease incidence but duplicate epistasis was observed for the remaining traits. Among the genotypes tested under epiphytotic conditions, gene pyramided lines were highly resistant to blast compared to individuals with single genes indicating that the nonallelic genes have a complementary effect when present together. The information on genetics of various contributing traits of resistance will further aid plant breeders in choosing appropriate breeding strategy for blast resistance and yield enhancement in rice.

  12. Purification, crystallization and preliminary X-ray crystallographic analysis of rice Bowman–Birk inhibitor from Oryza sativa

    International Nuclear Information System (INIS)

    Rice Bowman–Birk inhibitor was expressed and crystallized. Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P212121, with unit-cell parameters a = 74.37, b = 96.69, c = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%

  13. Purification, crystallization and preliminary X-ray crystallographic analysis of rice Bowman–Birk inhibitor from Oryza sativa

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Hung [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Li, Hsin-Tai [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Huang, Yen-Chieh [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Hsieh, Ying-Cheng; Guan, Hong-Hsiang [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Chang, Tschining; Wang, Andrew H.-J., E-mail: ahjwang@gate.sinica.edu.tw [Institute of Biological Chemistry, Academia Sinica, Taipei 11529,Taiwan (China); Chen, Chun-Jung, E-mail: ahjwang@gate.sinica.edu.tw [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China)

    2006-06-01

    Rice Bowman–Birk inhibitor was expressed and crystallized. Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 74.37, b = 96.69, c = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%.

  14. Multiple forms of α-glucosidase in rice seeds (Oryza sativa L., var Nipponbare)

    OpenAIRE

    Nakai, Hiroyuki; Ito, Tatsuya; Hayashi, Masatoshi; Kamiya, Koutarou; Yamamoto, Takeshi; Matsubara, Kazuki; Kim, Young-Min; Jintanart, Wongchawalit; Okuyama, Masayuki; Mori, Haruhide; Chiba, Seiya; Sanoa, Yoshio; Kimura, Atsuo

    2007-01-01

    Two isoforms of α-glucosidases (ONG2-I and ONG2-II) were purified from dry rice seeds (Oryza sativa L., var Nipponbare). Both ONG2-I and ONG2-II were the gene products of ONG2 mRNA expressed in ripening seeds. Each enzyme consisted of two components of 6 kDa-peptide and 88 kDa-peptide encoded by this order in ONG2 cDNA (ong2), and generated by post-translational proteolysis. The 88 kDa-peptide of ONG2-II had 10 additional N-terminal amino acids compared with the 88 kDa-peptide of ONG2-I. The ...

  15. Protein kinase C is essential for viability of the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Penn, Tina J; Wood, Mark E; Soanes, Darren M; Csukai, Michael; Corran, Andrew John; Talbot, Nicholas J

    2015-10-01

    Protein kinase C constitutes a family of serine-threonine kinases found in all eukaryotes and implicated in a wide range of cellular functions, including regulation of cell growth, cellular differentiation and immunity. Here, we present three independent lines of evidence which indicate that protein kinase C is essential for viability of Magnaporthe oryzae. First, all attempts to generate a target deletion of PKC1, the single copy protein kinase C-encoding gene, proved unsuccessful. Secondly, conditional gene silencing of PKC1 by RNA interference led to severely reduced growth of the fungus, which was reversed by targeted deletion of the Dicer2-encoding gene, MDL2. Finally, selective kinase inhibition of protein kinase C by targeted allelic replacement with an analogue-sensitive PKC1(AS) allele led to specific loss of fungal viability in the presence of the PP1 inhibitor. Global transcriptional profiling following selective PKC inhibition identified significant changes in gene expression associated with cell wall re-modelling, autophagy, signal transduction and secondary metabolism. When considered together, these results suggest protein kinase C is essential for growth and development of M. oryzae with extensive downstream targets in addition to the cell integrity pathway. Targeting protein kinase C signalling may therefore prove an effective means of controlling rice blast disease. PMID:26192090

  16. A novel 5-enolpyruvoylshikimate-3-phosphate (EPSP) synthase transgene for glyphosate resistance stimulates growth and fecundity in weedy rice (Oryza sativa) without herbicide

    OpenAIRE

    Wang, Wei; XIA, HUI; Yang, Xiao; Xu, Ting; Si, Hong Jiang; Cai, Xing Xing; Wang, Feng; Su, Jun; Allison A Snow; Lu, Bao-Rong

    2013-01-01

    Understanding evolutionary interactions among crops and weeds can facilitate effective weed management. For example, gene flow from crops to their wild or weedy relatives can lead to rapid evolution in recipient populations. In rice (Oryza sativa), transgenic herbicide resistance is expected to spread to conspecific weedy rice (Oryza sativa f. spontanea) via hybridization. Here, we studied fitness effects of transgenic over-expression of a native 5-enolpyruvoylshikimate-3-phosphate synthase (...

  17. Arsenic, cadmium, and lead pollution and uptake by rice (Oryza sativa L.) grown in greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    Lei Ming [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-Environmental Sciences; Hunan Agricultural Univ., Changsha (China). College of Resource and Environment; Tie Baiqing [Hunan Agricultural Univ., Changsha (China). College of Resource and Environment; Williams, Paul N.; Zheng Yuanming; Huang Yizong [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-Environmental Sciences

    2011-01-15

    Purpose: Hunan province is well-known for its extensive base-metal extraction and smelting industries. However, the legacies of excavation operations, transportation, and selective smelting activities within Hunan have resulted in the generation of large quantities of mine wastes, which will become the sources of metal contamination in the environment. Thus, there is an increasingly important health issue underlying the study of arable land pollution and transfer of As, Cd, and Pb in the paddy soil-rice system. Materials and methods: Paddy soils collected from mining- and smelting-impacted areas in Hunan province and rice seed (Oryza sativa L. cv Jia Hua-1) were used for pot experiments under greenhouse conditions. One 30-day-old seedling was transplanted into one pot containing 5.0 kg pretreated soil. At harvest, rice grains and shoots were washed with distilled water to remove surface soil, and oven-dried at 65 C for 96 h until a constant weight was reached. Roots were washed carefully with distilled water for the next process of extracting iron plaque using dithionite-citrate-bicarbonate solution. Total concentrations of As, Cd, and Pb in soil and rice plant tissues were measured by inductively coupled plasma mass spectrometer. Results and discussion: Total concentrations of As, Cd, and Pb in the soils collected from 12 mining- and smelting-impacted areas in Hunan province were much higher than Hunan background values and exceeded the maximum concentration limit for soils set by the Ministry of Environmental Protection. The yields of rice grain from Pb/Zn mining and smelting sites were negatively correlated to overall pollution scores. Distributions of As, Cd, and Pb in rice plant followed: root >> shoot > husk > whole grain. About 30.1-88.1% of As, 11.2-43.5% of Cd, and 14.0-33.9% of Pb were accumulated in iron plaque on root surfaces. Conclusions: High concentrations of As, Cd, and Pb are observed in paddy soils from mining- and smelting-impacted areas in

  18. Identification and Genetic Analysis of Fertility Restoration Ability in Dongxiang Wild Rice(Oryza rufipogon)

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-rong; YANG Kong-song; Fu Jun-ru; ZHU Chang-lan; PENG Xiao-song; HE Xiao-peng; HE Hao-hua

    2008-01-01

    Two populations of Dongxiang wild rice(Oryza rufipogon),Shuitaoshu and Dongtangshang,were crossed with five male sterile rice lines with different cytoplasmic backgrounds(B06S,Zhenshan 97A,Xieqingzao A,Zhong 9A,and Yuetai A),and the seed setting rate of the F1 was used to judge the fertility restoration ability in the Dongxiang wild rice.With P1.F1,P2,and F2 populations as materials,the Akaike's Information Criterion(AIC)was used to identify the major genes affecting quantitative traits,and when the major genes existed,the genetic effects of the major gene and the polygene and their genetic variance were estimated through segregation analysis.The seed setting rates of the F1 generation varied from 45.98%to 76.57%,suggesting that the Dongxiang wild rice had the fertility restoration ability.One major gone plus polygene mixed inheritance model was the most fitted genetic model for this trait in all the F2 populations.The heritability values of the major genes varied from 56.63%to 88.29%and those of the polygenes from 2.74%to 30.97%,and the total heritability values were from 63.1 7%to 94.01%.The major gone inheritance of the combination Zhong 9A/Dongtangshang was controlled by the additive effect without dominant effect,and the other nine combinations were by the completely dominant inheritance.

  19. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

    Directory of Open Access Journals (Sweden)

    Kouki eYoshida

    2013-10-01

    Full Text Available Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs can regulate secondary wall formation in rice (Oryza sativa and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S has very low transcriptional activation ability, but the longer protein (OsSWN2L and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications.

  20. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation.

    Science.gov (United States)

    Yoshida, Kouki; Sakamoto, Shingo; Kawai, Tetsushi; Kobayashi, Yoshinori; Sato, Kazuhito; Ichinose, Yasunori; Yaoi, Katsuro; Akiyoshi-Endo, Miho; Sato, Hiroko; Takamizo, Tadashi; Ohme-Takagi, Masaru; Mitsuda, Nobutaka

    2013-01-01

    Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs) can regulate secondary wall formation in rice (Oryza sativa) and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S) has very low transcriptional activation ability, but the longer protein (OsSWN2L) and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions) due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications. PMID:24098302

  1. Evaluation of environment on rice production for the rice [Oryza sativa] terraces in Hoshino Village

    International Nuclear Information System (INIS)

    Variables characterizing ambient environmental conditions (such as barometric pressure, solar radiation, rainfall, temperature, relative humidity, and wind speed) were measured between June and October in 2006 at the rice terraces in Hoshino village, Fukuoka prefecture. Differences in the environmental conditions of the three paddy fields located at different elevations in the same water system were assessed. Also, environmental factors that affected rice quality were identified using data collected during the beginning of a ripening period (20 days after heading) by principal component analysis. The study results demonstrated that the paddy field midstream in the water system had the least solar radiation because it was surrounded by slightly elevated mountains and forest. Average temperatures at three paddy fields during the ripening stage were in the range of an optimal temperature while the temperature during the tillering stage was below the optimal range at the fields upstream and midstream. The field downstream was the only case that the diurnal range of temperature was larger than that in the plain area. As the results of principal component analysis, average temperature, average relative humidity, and solar radiation during the beginning of a ripening season were shown as major environmental factors that affected rice quality. Average temperature had a positive effect on rice quality, and this effect could be explained by the negative correlation between temperature and amylose content. Relative humidity had positive effect, and solar radiation had positive effect

  2. Using ORYZA2000 to model cold rice yield response to climate change in the Heilongjiang province, China

    Directory of Open Access Journals (Sweden)

    Jingting Zhang

    2015-08-01

    Full Text Available Rice (Oryza sativa L. is one of the most important staple crops in China. Increasing atmospheric greenhouse gas concentrations and associated climate change may greatly affect rice production. We assessed the potential impacts of climate change on cold rice production in the Heilongjiang province, one of China's most important rice production regions. Data for a baseline period (1961–1990 and the period 2010–2050 in A2 and B2 scenarios were used as input to drive the rice model ORYZA2000 with and without accounting for the effects of increasing atmospheric CO2 concentration. The results indicate that mean, maximum, and minimum temperature during the rice growing season, in the future period considered, would increase by 1.8 °C under the A2 scenario and by 2.2 °C under the B2 scenario compared with those in the baseline. The rate of change in average maximum and minimum temperatures would increase by 0.6 °C per 10-year period under the A2 scenario and by 0.4 °C per 10-year period under the B2 scenario. Precipitation would increase slightly in the rice growing season over the next 40 years. The rice growing season would be shortened and the yield would increase in most areas in the Heilongjiang province. Without accounting for CO2 effect, the rice growing season in the period 2010–2050 would be shortened by 4.7 and 5.8 days, and rice yields would increase by 11.9% and 7.9%, under the A2 and B2 scenarios, respectively. Areas with simulated rice yield increases greater than 30.0% were in the Xiaoxing'an Mountain region. The simulation indicated a decrease in yield of less than 15% in the southwestern Songnen Plain. The rate of change in simulated rice yield was 5.0% and 2.5% per 10 years under the A2 and B2 scenarios, respectively. When CO2 effect was accounted for, rice yield increased by 44.5% and 31.3% under the A2 and B2 scenarios, respectively. The areas of increasing yield were sharply expanded. The area of decreasing yield in the

  3. Characterization of Interspecific Hybrids Between Oryza sativa L. and Three Wild Rice Species of China by Genomic In Situ Hybridization

    Institute of Scientific and Technical Information of China (English)

    Guang-Xuan Tan; Zhi-Yong Xiong; Hua-Jun Jin; Gang Li; Li-Li Zhu; Li-Hui Shu; Guang-Cun He

    2006-01-01

    In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice (Oryza sativa L.). In the present study, hybrids between O. sativa (AA genome)and three Chinese wild rices, namely O. rufipogon (AA genome), O. officinalis (CC genome), and O. meyeriana (GG genome), were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid,the other F1 hybrids were completely sterile. Genomic in situ hybridization (GISH) was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4',6'-Diamidino2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatln compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.

  4. Isolation and characterization of microsatellite loci in the Asian rice gall midge (Orseolia oryzae) (Diptera: Cecidomyiidae).

    Science.gov (United States)

    Bentur, Jagadish S; Sinha, Deepak Kumar; Padmavathy; Revathy, Charagonda; Muthulakshmi, Mayandi; Nagaraju, Javaregowda

    2011-01-01

    Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason) using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR) markers represented di (72%), tri (15.3%), and complex repeats (12.7%). Three biotypes of gall midge (20 individuals for each biotype) were screened using these SSRs. The results revealed that 15 loci were hyper variable and showed polymorphism among different biotypes of this pest. The number of alleles ranged from two to 11 and expected heterozygosity was above 0.5. Inheritance studies with three markers (observed to be polymorphic between sexes) revealed sex linked inheritance of two SSRs (Oosat55 and Oosat59) and autosomal inheritance of one marker (Oosat43). These markers will prove to be a useful tool to devise strategies for integrated pest management and in the study of biotype evolution in this important rice pest. PMID:21340012

  5. Isolation and Characterization of Microsatellite Loci in the Asian Rice Gall Midge (Orseolia oryzae (Diptera: Cecidomyiidae

    Directory of Open Access Journals (Sweden)

    Charagonda Revathy

    2011-01-01

    Full Text Available Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR markers represented di (72%, tri (15.3%, and complex repeats (12.7%. Three biotypes of gall midge (20 individuals for each biotype were screened using these SSRs. The results revealed that 15 loci were hyper variable and showed polymorphism among different biotypes of this pest. The number of alleles ranged from two to 11 and expected heterozygosity was above 0.5. Inheritance studies with three markers (observed to be polymorphic between sexes revealed sex linked inheritance of two SSRs (Oosat55 and Oosat59 and autosomal inheritance of one marker (Oosat43. These markers will prove to be a useful tool to devise strategies for integrated pest management and in the study of biotype evolution in this important rice pest.

  6. Mitochondrial Genome Analysis of Wild Rice (Oryza minuta) and Its Comparison with Other Related Species

    Science.gov (United States)

    Asaf, Sajjad; Khan, Abdul Latif; Khan, Abdur Rahim; Waqas, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Shahzad, Raheem; Seo, Chang-Woo; Shin, Jae-Ho; Lee, In-Jung

    2016-01-01

    Oryza minuta (Poaceae family) is a tetraploid wild relative of cultivated rice with a BBCC genome. O. minuta has the potential to resist against various pathogenic diseases such as bacterial blight (BB), white backed planthopper (WBPH) and brown plant hopper (BPH). Here, we sequenced and annotated the complete mitochondrial genome of O. minuta. The mtDNA genome is 515,022 bp, containing 60 protein coding genes, 31 tRNA genes and two rRNA genes. The mitochondrial genome organization and the gene content at the nucleotide level are highly similar (89%) to that of O. rufipogon. Comparison with other related species revealed that most of the genes with known function are conserved among the Poaceae members. Similarly, O. minuta mt genome shared 24 protein-coding genes, 15 tRNA genes and 1 ribosomal RNA gene with other rice species (indica and japonica). The evolutionary relationship and phylogenetic analysis revealed that O. minuta is more closely related to O. rufipogon than to any other related species. Such studies are essential to understand the evolutionary divergence among species and analyze common gene pools to combat risks in the current scenario of a changing environment. PMID:27045847

  7. LINE × TESTER ANALYSIS USING CMS SYSTEM IN RICE (ORYZA SATIVA L.

    Directory of Open Access Journals (Sweden)

    I S THAKARE

    2013-12-01

    Full Text Available Eighteen rice (Oryza sativa L. genotypes consisting three CMS lines were crossed in a line × tester mating design. The 45F1’s and their parents were evaluated with three standard checks in a randomized complete block design with three replications at the Main Rice Research Station, Anand Agricultural University, Nawagam, Gujarat in kharif 2007. The estimates of gca effects indicated that, among females, IR 68886 A and IR 68897 A and among males IR-44, IR-60, IR-9761, IR-4266-29-4-2-2-2, IR-5638-139-2-2, IR-69701-9-3-1 and IR-71138-49-2-2 were found as good general combiners for grain yield per plant. High sca effects were observed in the crosses, IR 68886 A × IR-44, IR 68897 A × IET-15554, IR 68897 A × IR–56455-206-2, IR 68902 A × IR-4266-29-4-2-2-2 and IR 68897 A × IR–62161-184-3-1-3-2. They were found to be the best combinations for grain yield per plant and quality traits. The preponderance of non-additive type of gene actions clearly indicated that selection of superior plants should be use for further improvement.

  8. Monoclonal Antibody Production and Immunolocalization of a Salinity Stress-Related Protein in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    Jackson MARCONDES; Ana Beatriz GARCIA

    2011-01-01

    Among various physiological responses to salt stress,the synthesis of a lectin-related protein of 14.5 kDa was observed in rice plants (Oryza sativa L.) under the treatment of 170 mmol/L NaCl.In order to better understand the role of the SALT protein in the physiological processes involving salinity,it was immunolocalized in mesophilic cells of leaf sheath and blade of a rice variety IAC-4440 following monoclonal antibodies produced by hybridome culture technique.This variety turned out to be an excellent model for that purpose,since it accumulates SALT protein even in absence of salt treatment and it has been classified as moderately sensitive to salinity and a superior grain producer.This feature was relevant for this work since it allowed the use of plants without the deleterious effects caused by salinity.Immunocytochemistry assays revealed that the SALT protein is located in the stroma of chloroplasts under non-stressing condition.Since the chloroplast is the main target affected by salinity and considering that the SALT protein does not present any apparent signal peptide for organelle localization,its lectin-like activity seems to play an important role in the establishment of stable complexes,either to other proteins or to oligosaccharides that are translocated to the chloroplast.

  9. Molecular progress on the mapping and cloning of functional genes for blast disease in rice (Oryza sativa L.): current status and future considerations.

    Science.gov (United States)

    Ashkani, S; Rafii, M Y; Shabanimofrad, M; Ghasemzadeh, A; Ravanfar, S A; Latif, M A

    2016-01-01

    Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes. PMID:25394538

  10. Studies on root traits for drought tolerance in rice (Oryza sative L.) under controlled (PVC pipes) condition

    OpenAIRE

    S.Ganapathy, S. K Ganesh, P. Shanmugasundaram, and R. Chandra Babu

    2010-01-01

    Rice (Oryza sativa L.) is the most important food crop of the world; but drought stress is a serious limiting factor to riceproduction and yield stability in rainfed areas. In order to design an efficient breeding program for synthesis of new varietieswith virtues of drought tolerance and high yielding ability, it is necessary to identify potential parents that combine well forboth yield and drought tolerance. Hence, the present investigation was undertaken to evaluate genetic potentiality of...

  11. DYNAMICS OF K +, NA +, CA2 + IONS IN RICE PLANTS (Oryza sativa L. IN ONTOGENESIS UNDER SOIL SALINITY

    Directory of Open Access Journals (Sweden)

    Tkacheva M. S.

    2014-06-01

    Full Text Available Under conditions of vegetation experiment at soil artificial chloride salinization the dynamics of accumulation and distribution of sodium, potassium and calcium in organs of rice plants (Oryza sativa L. have been studied, as well as their correlation with tissue hydration in ontogenesis. The significant restriction of salinization ions transport and accumulation, particularly sodium, in the actively functioning upper leaves and panicles has been observed. Whereas the content of calcium and potassium in the experimental and control plants differed slightly

  12. DYNAMICS OF K +, NA +, CA2 + IONS IN RICE PLANTS (Oryza sativa L.) IN ONTOGENESIS UNDER SOIL SALINITY

    OpenAIRE

    Tkacheva M. S.; Ladatko N. A.; Doseeva O. A.; Zelenskiy G. L.

    2014-01-01

    Under conditions of vegetation experiment at soil artificial chloride salinization the dynamics of accumulation and distribution of sodium, potassium and calcium in organs of rice plants (Oryza sativa L.) have been studied, as well as their correlation with tissue hydration in ontogenesis. The significant restriction of salinization ions transport and accumulation, particularly sodium, in the actively functioning upper leaves and panicles has been observed. Whereas the content of calcium and ...

  13. Infection-associated nuclear degeneration in the rice blast fungus Magnaporthe oryzae requires non-selective macro-autophagy.

    Directory of Open Access Journals (Sweden)

    Min He

    Full Text Available BACKGROUND: The rice blast fungus Magnaporthe oryzae elaborates a specialized infection structure called an appressorium to breach the rice leaf surface and gain access to plant tissue. Appressorium development is controlled by cell cycle progression, and a single round of nuclear division occurs prior to appressorium formation. Mitosis is always followed by programmed cell death of the spore from which the appressorium develops. Nuclear degeneration in the spore is known to be essential for plant infection, but the precise mechanism by which it occurs is not known. METHODOLOGY/PRINCIPAL FINDINGS: In yeast, nuclear breakdown requires a specific form of autophagy, known as piecemeal microautophagy of the nucleus (PMN, and we therefore investigated whether this process occurs in the rice blast fungus. Here, we report that M. oryzae possesses two conserved components of a putative PMN pathway, MoVac8 and MoTsc13, but that both are dispensable for nuclear breakdown during plant infection. MoVAC8 encodes a vacuolar membrane protein and MoTSC13 a peri-nuclear and peripheral ER protein. CONCLUSIONS/SIGNIFICANCE: We show that MoVAC8 is necessary for caffeine resistance, but dispensable for pathogenicity of M. oryzae, while MoTSC13 is involved in cell wall stress responses and is an important virulence determinant. By functional analysis of ΔMoatg1 and ΔMoatg4 mutants, we demonstrate that infection-associated nuclear degeneration in M. oryzae instead occurs by non-selective macroautophagy, which is necessary for rice blast disease.

  14. Purification and characterization of a novel hypersensitive response-inducing elicitor from Magnaporthe oryzae that triggers defense response in rice.

    Directory of Open Access Journals (Sweden)

    Mingjia Chen

    Full Text Available BACKGROUND: Magnaporthe oryzae, the rice blast fungus, might secrete certain proteins related to plant-fungal pathogen interactions. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report the purification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip1 secreted by M. oryzae. The protein fraction was purified and identified by de novo sequencing, and the sequence matched the genomic sequence of a putative protein from M. oryzae strain 70-15 (GenBank accession No. XP_366602.1. The elicitor-encoding gene mohrip1 was isolated; it consisted of a 429 bp cDNA, which encodes a polypeptide of 142 amino acids with a molecular weight of 14.322 kDa and a pI of 4.53. The deduced protein, MoHrip1, was expressed in E. coli. And the expression protein collected from bacterium also forms necrotic lesions in tobacco. MoHrip1 could induce the early events of the defense response, including hydrogen peroxide production, callose deposition, and alkalization of the extracellular medium, in tobacco. Moreover, MoHrip1-treated rice seedlings possessed significantly enhanced systemic resistance to M. oryzae compared to the control seedlings. The real-time PCR results indicated that the expression of some pathogenesis-related genes and genes involved in signal transduction could also be induced by MoHrip1. CONCLUSION/SIGNIFICANCE: The results demonstrate that MoHrip1 triggers defense responses in rice and could be used for controlling rice blast disease.

  15. Purification, crystallization and preliminary X-ray crystallographic analysis of rice Bowman–Birk inhibitor from Oryza sativa

    Science.gov (United States)

    Lin, Yi-Hung; Li, Hsin-Tai; Huang, Yen-Chieh; Hsieh, Ying-Cheng; Guan, Hong-Hsiang; Liu, Ming-Yih; Chang, Tschining; Wang, Andrew H.-J.; Chen, Chun-Jung

    2006-01-01

    Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P212121, with unit-cell parameters a = 74.37, b = 96.69, c = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%. PMID:16754971

  16. Extraction of anthocyanins and polyphenols from black rice (Oryza sativa L.) by modeling and assessing their reversibility and stability.

    Science.gov (United States)

    Pedro, Alessandra Cristina; Granato, Daniel; Rosso, Neiva Deliberali

    2016-01-15

    This study was aimed the extraction of total flavonoids, anthocyanins and phenolics, as well as the antioxidant activity of black rice (Oryza sativa) and to study the stability in relation to pH, light and copigmentation. Variations in temperature (10-50°C), time (20-80min), and solid-solvent ratio (1:15-1:45) were studied using a Box-Behnken design. The regression models were significant (Pphytic and gallic acids in the optimized extract exposed to light displayed an intermolecular copigmentation. The main anthocyanin identified in black rice was cyanidin-3-glucoside. PMID:26258696

  17. Functional conservation and diversification of class E floral homeotic genes in rice (Oryza sativa).

    Science.gov (United States)

    Cui, Rongfeng; Han, Jiakun; Zhao, Suzhen; Su, Kunmei; Wu, Feng; Du, Xiaoqiu; Xu, Qijiang; Chong, Kang; Theissen, Günter; Meng, Zheng

    2010-03-01

    Mutant analyses in different eudicotyledonous flowering plants demonstrated that SEPALLATA-like MADS-box genes are required for the specification of sepals, petals, stamens and carpels, and for floral determinacy, thus defining class E floral organ identity genes. SEP-like genes encode MADS-domain transcription factors and constitute an angiosperm-specific gene clade whose members show remarkably different degrees of redundancy and sub-functionalization within eudicots. To better understand the evolutionary dynamics of SEP-like genes throughout the angiosperms we have knocked down SEP-like genes of rice (Oryza sativa), a distant relative of eudicots within the flowering plants. Plants affected in both OsMADS7 and OsMADS8 show severe phenotypes including late flowering, homeotic changes of lodicules, stamens and carpels into palea/lemma-like organs, and a loss of floral determinacy. Simultaneous knockdown of the four rice SEP-like genes OsMADS1, OsMADS5, OsMADS7 and OsMADS8, leads to homeotic transformation of all floral organs except the lemma into leaf-like organs. This mimics the phenotype observed with the sep1 sep2 sep3 sep4 quadruple mutant of Arabidopsis. Detailed analyses of the spatial and temporal mRNA expression and protein interaction patterns corresponding to the different rice SEP-like genes show strong similarities, but also gene-specific differences. These findings reveal conservation of SEP-like genes in specifying floral determinacy and organ identities since the separation of eudicots and monocots about 150 million years ago. However, they indicate also monocot-specific neo- and sub-functionalization events and hence underscore the evolutionary dynamics of SEP-like genes. Moreover, our findings corroborate the view that the lodicules of grasses are homologous to eudicot petals. PMID:20003164

  18. EFICIÊNCIA DE FUNGICIDAS NO CONTROLE DE MANCHA PARDA (Bipolaris oryzae EM ARROZ (Oryza sativa EFFICIENCY OF FUNGICIDES IN THE CONTROL OF RICE (Oryza sativa BROWN SPOT (Bipolaris oryzae

    Directory of Open Access Journals (Sweden)

    Eric Guicherit

    2007-09-01

    Full Text Available

    Em situações nas quais a brusone tem pouca importância na sanidade da lavoura de arroz, o controle da mancha parda (Bipolaris Oryzõe pode mostrar-se altamente eficiente com pulverizações de fungicidas no campo. Assim, realizou-se um experimento em Indiara (GO com o objetivo de comparar a eficácia de diferentes produtos fungicidas no controle da mancha parda em condições pouco favoráveis à brusone. Foram comparados difenoconazole, propiconazole e tryfloxystrobin em diferentes combinações e dosagens, e os resultados mostraram que, em situações nas quais a brusone tem pouca importância na sanidade da lavoura do arroz, o controle da mancha parda pode mostrar-se altamente eficiente com pulverizações de fungicidas no campo.

    PALAVRAS-CHAVE: Helminthosporium oryzae; controle químico; patógeno; doença.

    In situations where the blight (Pyricularia grisea is not limiting the rice crop, the brown spot (Bipolaris oryzae control can be extremely efficient with field sprayings. This experiment was conduced in Indiara (GO aiming to compare the efficiency of different fungicides in one or two dosages in the control of brown spot under low blight conditions. All treatments showed efficiency in the control of brown spot, with no signifficant difference among them.

    KEY-WORDS: Chemical control; pathogens; disease.

  19. Two overlapping two-component systems in Xanthomonas oryzae pv. oryzae contribute to full fitness in rice by regulating virulence factors expression.

    Science.gov (United States)

    Zheng, Dehong; Yao, Xiaoyan; Duan, Meng; Luo, Yufeng; Liu, Biao; Qi, Pengyuan; Sun, Ming; Ruan, Lifang

    2016-01-01

    Two-component signal transduction systems (TCSs) are widely used by bacteria to adapt to the environment. In the present study, StoS (stress tolerance-related oxygen sensor) and SreKRS (salt response kinase, regulator, and sensor) were found to positively regulate extracellular polysaccharide (EPS) production and swarming in the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). Surprisingly, the absence of stoS or sreKRS did not attenuate virulence. To better understand the intrinsic functions of StoS and SreKRS, quantitative proteomics isobaric tags for relative and absolute quantitation (iTRAQ) was employed. Consistent with stoS and sreK mutants exhibiting a similar phenotype, the signalling circuits of StoS and SreKRS overlapped. Carbohydrate metabolism proteins and chemotaxis proteins, which could be responsible for EPS and swarming regulation, respectively, were reprogrammed in stoS and sreK mutants. Moreover, StoS and SreKRS demonstrated moderate expression of the major virulence factor, hypersensitive response and pathogenicity (Hrp) proteins through the HrpG-HrpX circuit. Most importantly, Xoo equipped with StoS and SreKRS outcompetes strains without StoS or SreKRS in co-infected rice and grows outside the host. Therefore, we propose that StoS and SreKRS adopt a novel strategy involving the moderation of Hrp protein expression and the promotion of EPS and motility to adapt to the environment. PMID:26957113

  20. Rice Snl6, a cinnamoyl-CoA reductase-like gene family member, is required for NH1-mediated immunity to Xanthomonas oryzae pv. oryzae.

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    Rebecca S Bart

    2010-09-01

    Full Text Available Rice NH1 (NPR1 homolog 1 is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo, constitutive expression of defense related genes and enhanced benzothiadiazole (BTH- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development.

  1. Structural and functional analysis of the avirulence gene AVR-Pita1 of the rice blast fungus in isolates of Magnaporthe oryzae worldwide

    Science.gov (United States)

    The avirulence gene AVR-Pita1 of the rice blast fungus triggers race-specific resistance when races of Magnaporthe oryzae that contain AVR-Pita1 infect rice cultivars that contain the resistance gene Pi-ta. In the present study, a panel of 221 isolates from the US, China, Colombia, Egypt, India and ...

  2. Determination of contents and antioxidant activity of free and bound phenolics compounds and in vitro digestibility of commercial black and red rice (Oryza sativa L.) varieties.

    Science.gov (United States)

    Sumczynski, Daniela; Kotásková, Eva; Družbíková, Helena; Mlček, Jiří

    2016-11-15

    Black and red rices (Oryza sativa L.) were analysed for total flavonoids and phenolics and the HPLC profile including both free and bound phenolic fractions. Moreover, antioxidant activity and in vitro digestibility was determined. Content of flavonoids and polyphenols as well as antioxidant activity was higher in free phenolic fractions. Bound flavonoids in black rices were not significant contributors to antioxidant activity. The main free phenolics in black rices were ferulic, protocatechuic and trans-p-coumaric acids, while the major free phenolics in red rices were catechin, protocatechuic and caffeic acids. The main bound phenolics in black rices were ferulic and vanillic acids and quercetin, in red rice types, they were ferulic, syringic, trans-p-coumaric acids and quercetin. Newly, the presence of m-coumaric acid in red rices was detected. Steam cooked rices showed very high levels of organic matter digestibility, whereas red rices were significantly more digestible than black rices (p<0.05). PMID:27283641

  3. HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

    Directory of Open Access Journals (Sweden)

    Xiaoping Zhang

    2013-12-01

    Full Text Available Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo, is one of the most destructive diseases of rice (Oryza sativa L. worldwide. The type III secretion system (T3SS of Xoo, encoded by the hrp (hypersensitive response and pathogenicity genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response (HR in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation. Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc (hrp-conserved gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99A mutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into

  4. Quantitative Genetic Analysis for Yield and Yield Components in Boro Rice (Oryza sativa L.

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    Supriyo CHAKRABORTY

    2010-03-01

    Full Text Available Twenty-nine genotypes of boro rice (Oryza sativa L. were grown in a randomized block design with three replications in plots of 4m x 1m with a crop geometry of 20 cm x 20 cm between November-April, in Regional Agricultural Research Station, Nagaon, India. Quantitative data were collected on five randomly selected plants of each genotype per replication for yield/plant, and six other yield components, namely plant height, panicles/plant, panicle length, effective grains/panicle, 100 grain weight and harvest index. Mean values of the characters for each genotype were used for analysis of variance and covariance to obtain information on genotypic and phenotypic correlation along with coheritability between two characters. Path analyses were carried out to estimate the direct and indirect effects of boro rice�s yield components. The objective of the study was to identify the characters that mostly influence the yield for increasing boro rice productivity through breeding program. Correlation analysis revealed significant positive genotypic correlation of yield/plant with plant height (0.21, panicles/plant (0.53, panicle length (0.53, effective grains/panicle (0.57 and harvest index (0.86. Path analysis based on genotypic correlation coefficients elucidated high positive direct effect of harvest index (0.8631, panicle length (0.2560 and 100 grain weight (0.1632 on yield/plant with a residual effect of 0.33. Plant height and panicles/plant recorded high positive indirect effect on yield/plant via harvest index whereas effective grains/panicle on yield/plant via harvest index and panicle length. Results of the present study suggested that five component characters, namely harvest index, effective grains/plant, panicle length, panicles/plant and plant height influenced the yield of boro rice. A genotype with higher magnitude of these component characters could be either selected from the existing genotypes or evolved by breeding program for genetic

  5. Identifying neutral allele Sb at pollen-sterility loci in cultivated rice with Oryza rufipogon origin

    Institute of Scientific and Technical Information of China (English)

    SHI LeiGang; LIU XiangDong; LIU Bo; ZHAO XingJuan; WANG Lan; LI JinQuan; LU YongGen

    2009-01-01

    Pollen sterility is commonly found in the intra-specific hybrids of indica and japonica rice, which is one of the main constrains for the utilization of heterosis between indica and japonica. Six loci controlling the pollen sterility of F1 between indica and japonica have been identified from previous studies. Neu-tral alleles at each locus are potential to overcome the F1 pollen sterility associated with the locus. Therefore, exploitation and utilization of neutral alleles are of significant importance. The present re-search was based on fine mapping of the F_1 pollen-sterility gene Sb and the abundant genetic diversity of Oryza rufipogon Griff. indigenous to Gaozhou, Guangdong Province (referred to as Gaozhou wild rice). Crosses were made using Taichung65 (with the genotype of S_b~jS_b~j and referred to as E_1) and its near-isogenic line of F_1 pollen sterility gene Sb(with the genotype of S_b~iS_b~i, E_2) as female parents, and 12 different accessions of Gaozhou wild rice as male parents. F_1 pollen fertility was examined to identify the materials having the neutral alleles at the F_1 pollen-sterility locus. Segregation of 4 molecular markers tightly linked with the Sb locus was analyzed in the F_2 populations derived from the F_1s car-rying the neutral gene. The pollen fertility related to the 3 genotypes of the molecular markers was also checked by statistical test to determine whether it was consistent with the hypothesis. The results showed that the pollen fertility of two F_1s from one accession of Gaozhou wild rice (GZW099) with E_1 and E_2 was (89.22±1.07)% and (85.65±1.05)%, respectively. Both of them were fertile and showed no significant difference by t-test. Segregation of the 3 genotypes of the 4 molecular markers followed the expected Mendelian ratio (1:2:1) in the F_2 populations. There was no significant difference for the av-eraged pollen fertility of the plants related to the 3 genotypes, suggesting that no interaction exists between the

  6. Combined Mass Spectrometry-Based Metabolite Profiling of Different Pigmented Rice (Oryza sativa L. Seeds and Correlation with Antioxidant Activities

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    Ga Ryun Kim

    2014-09-01

    Full Text Available Nine varieties of pigmented rice (Oryza sativa L. seeds that were black, red, or white were used to perform metabolite profiling by using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS and gas chromatography (GC TOF-MS, to measure antioxidant activities. Clear grouping patterns determined by the color of the rice seeds were identified in principle component analysis (PCA derived from UPLC-Q-TOF-MS. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimer, proanthocyanidin trimer, apigenin-6-C-glugosyl-8-C-arabiboside, tricin-O-rhamnoside-O-hexoside, and lipids were identified as significantly different secondary metabolites. In PCA score plots derived from GC-TOF-MS, Jakwangdo (JKD and Ilpoom (IP species were discriminated from the other rice seeds by PC1 and PC2. Valine, phenylalanine, adenosine, pyruvate, nicotinic acid, succinic acid, maleic acid, malonic acid, gluconic acid, xylose, fructose, glucose, maltose, and myo-inositol were significantly different primary metabolites in JKD species, while GABA, asparagine, xylitol, and sucrose were significantly distributed in IP species. Analysis of antioxidant activities revealed that black and red rice seeds had higher activity than white rice seeds. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimers, proanthocyanidin trimers, and catechin were highly correlated with antioxidant activities, and were more plentiful in black and red rice seeds. These results are expected to provide valuable information that could help improve and develop rice-breeding techniques.

  7. Resistance to rice blast(Pyricularia oryzae) caused by the expression of trichosanthin gene in transgenic rice plants transferred through agrobacterium method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The gene of trichosanthin has been transferred into rice plants through agrobacterium method.The single copy insertion and the expression of foreign gene have been proved in regenerated plants.In antifungal assay the degrees of rice blast (Pyricularia oryzae) infection of the transgenic plants expressing trichosanthin and expressing GUS gene as control have been evaluated.The differences such as the time of disease symptom observed,the number of infected plants and damaged leaves,the growth of infected plants of the two transgenic plants after being inoculated by rice blast (Pyricularia oryzae) are significant.The transgenic plants with trichosanthin gene grew faster than the plants with GUS gene,even when humidity environment was removed.The results show that the transgenic plants that expressed trichosanthin are able to delay the infection of rice blast compared with the plants as control.In addition,no damage caused by the expression of trichosanthin gene in transgenic plants has been observed.

  8. Genetic study of resistance to inhibitory effects of UV radiation in rice (Oryza sativa)

    International Nuclear Information System (INIS)

    Genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice (Oryza sativa L.) cultivars was carried out. Some experimental plants were grown in visible radiation supplemented with UV radiation containing a large amount of UV-B and a small amount of UV-C in a phytotron, while others were grown without UV radiation. The degree of resistance to UV radiation was estimated in terms of the degree of reduction caused by supplemental UV radiation in the fresh weight of the aboveground plant parts and the chlorophyll content per unit fresh weight. Fresh weight and chlorophyll content in F2 plants generated by reciprocally crossing cv. Sasanishiki, a cultivar more resistant to UV radiation, and Norin 1, a cultivar less resistant to such radiation exhibited a normal frequency distribution. The heritabilities of these two properties in F2 plants were low under conditions of non-supplemental UV radiation. Under elevated UV radiation, the F2 population shifted to the lower range of fresh weight and chlorophyll content, and the means were close to those of Norin 1. The heritabilities of these two properties were the same in the reciprocal crosses, indicating that maternal inheritance was not involved. Inheritance of chlorophyll content per unit fresh weight was further determined in F3 lines generated by self-fertilizing F2 plants of Sasanishiki and Norin 1. The results showed that the F3 population was segregated into three genotypes, namely, resistant homozygotes, segregated heterozygotes and sensitive homozygotes, with a ratio of 1:65:16. It was thus evident that the resistance to the inhibitory effect of elevated UV radiation in these rice plants was controlled by recessive polygenes. (author)

  9. Exploring the hidden threat of gaseous pollutants using rice (oryza sativa l.) plants in Pakistan

    International Nuclear Information System (INIS)

    Three rice (Oryza sativa L.) varieties (Basmati-Pak, Basmati-370 and IRRI-9) of Pakistan were grown for their entire life cycle in open top field chambers to investigate the impacts of ambient ozone (O/sub 3/), nitrogen dioxide (NO/sub 2/), and sulphur dioxide (SO/sub 2/) on the biomass, growth physiology, and yield. The treatments were charcoal filtered air (FA), unfiltered air (UFA) and ambient air (AA). O/sub 3/, NO/sub 2/, and SO/sub 2/ concentrations recorded at the experimental site were 75, 29 and 18 ppb as 8 h daily mean, respectively. Microclimate conditions inside and outside the chamber environment remained virtually similar. All the rice cultivars showed severe depression in biomass (20-30%) due to reductions in number of tillers (20-27%) and leaves per plant (21-29%) during vegetative growth phase with maximum reductions seen in both Basmati-370 and IRRI-9 in UFA treatments compared with FA. These reductions were primarily due to decreased transpiration rate (10-20%), stomatal conductance (12-23%), net photosynthetic rate (9-22%) and photosynthetic efficiency (6-12%) of plants in UFA. Yield losses in total seed weight per plant in UFA were more or less similar in IRRI-9 (37%) and Basmati-370 (36%), followed by lower reduction in cv. Basmati-Pak (29%). Reductions in number of panicles per plant (18-25%), filled seeds per panicles (8-11%), seeds weight per panicle (13-17%) and 1000-seeds weight (5-8%) in UFA contributed significantly towards greater yield depression. Percent seed sterility was also higher in UFA and AA treatment plants. Starch contents of seeds in UFA were reduced by 14%, 19% and 21% in Basmati-Pak, Basmati-370 and IRRI-9, respectively when compared to FA control. (author)

  10. Comparative Analysis of the Endosperm Proteins Separated by 2-D Electrophoresis for Two Cultivars of Hybrid Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Pingfang Yang; Shihua Shen; Tingyun Kuang

    2006-01-01

    Liangyoupeijiu is a two-parental-line, and Shanyou63 is a three-parental-line hybrid rice (Oryza sativa L.).Although both belong to the indica subspecies, they have obvious differences with respect to morphology,physiology and grain quality. Variations in endosperm protein compositions were studied by comparing the 2-D electrophoresis (2-DE) maps for these two cultivars of hybrid rice. After matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) analysis, a 21-kDa precursor of 19-kDa globulin was identified as the major storage protein for both cultivars. Some isoforms of peroxiredoxin and seed maturation protein were found to only exist in Shanyou63, whereas aldose reductase and starch granule-bound starch synthase were only detected in Liangyoupeijiu. These data might provide a foundation for further comparative studies of these two cultivars of hybrid rice.

  11. Genetic diversity analysis of Cuban traditional rice (Oryza sativa L. varieties based on microsatellite markers

    Directory of Open Access Journals (Sweden)

    Alba Alvarez

    2007-01-01

    Full Text Available Microsatellite polymorphism was studied in a sample of 39 traditional rice (Oryza sativa L. varieties and 11 improved varieties widely planted in Cuba. The study was aimed at assessing the extent of genetic variation in traditional and improved varieties and to establish their genetic relationship for breeding purposes. Heterozygosity was analyzed at each microsatellite loci and for each genotype using 10 microsatellite primer pairs. Between varieties genetic relationship was estimated. The number of alleles per microsatellite loci was 4 to 8, averaging 6.6 alleles per locus. Higher heterozygosity (H was found in traditional varieties (H TV = 0.72 than in improved varieties (H IV = 0.42, and 68% of the total microsatellite alleles were found exclusively in the traditional varieties. Genetic diversity, represented by cluster analysis, indicated three different genetic groups based on their origin. Genetic relationship estimates based on the proportion of microsatellite loci with shared alleles indicated that the majority of traditional varieties were poorly related to the improved varieties. We also discuss the more efficient use of the available genetic diversity in future programs involving genetic crosses.

  12. Biochemical and Anatomical Changes and Yield Reduction in Rice (Oryza sativa L. under Varied Salinity Regimes

    Directory of Open Access Journals (Sweden)

    M. A. Hakim

    2014-01-01

    Full Text Available Five Malaysian rice (Oryza sativa L. varieties, MR33, MR52, MR211, MR219, and MR232, were tested in pot culture under different salinity regimes for biochemical response, physiological activity, and grain yield. Three different levels of salt stresses, namely, 4, 8, and 12 dS m−1, were used in a randomized complete block design with four replications under glass house conditions. The results revealed that the chlorophyll content, proline, sugar content, soluble protein, free amino acid, and yield per plant of all the genotypes were influenced by different salinity levels. The chlorophyll content was observed to decrease with salinity level but the proline increased with salinity levels in all varieties. Reducing sugar and total sugar increased up to 8 dS m−1 and decreased up to 12 dS m−1. Nonreducing sugar decreased with increasing the salinity levels in all varieties. Soluble protein and free amino acid also decreased with increasing salinity levels. Cortical cells of MR211 and MR232 did not show cell collapse up to 8 dS m−1 salinity levels compared to susceptible checks (IR20 and BRRI dhan29. Therefore, considering all parameters, MR211 and MR232 showed better salinity tolerance among the tested varieties. Both cluster and principal component analyses depict the similar results.

  13. Identification of quantitative trait loci affecting tolerance to low phosphorus in rice (Oryza Sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Phosphorus (P)-deficiency in rice (Oryza.Sativa.L) may cause yield reductions.This research has been conducted to map quantitative trait loci (QTLs) for tolerance to low phosphorus stress in a doubled haploid (DH) population.By using the linkage map of this population,the QTLs for relative dry weight,relative P content and relative P utilization efficiency have been located.The results indicate that one RFLP marker located on chromosome 6 is closely associated with relative root dry weight,relative shoot dry weight and relative total dry weight,which explain 24.9%,20.5% and 25.2% of the total phenotypic variations,respectively.Two QTLs affect relative P uptake content,which account for 20.7% of the total phenotypic variations.One micro-effect QTL has been found to be associated with relative P utilization efficiency.It is suggested that the P uptake efficiency is more associated with P efficiency.Among the secondary physiological indices of P uptake efficiency,the root dry weight is more important than others.

  14. Antimicrobial compounds from endophytic Streptomyces sp. BCC72023 isolated from rice (Oryza sativa L.).

    Science.gov (United States)

    Supong, Khomsan; Thawai, Chitti; Choowong, Wilunda; Kittiwongwattana, Chokchai; Thanaboripat, Dusanee; Laosinwattana, Chamroon; Koohakan, Prommart; Parinthawong, Nonglak; Pittayakhajonwut, Pattama

    2016-05-01

    An endophytic actinomycete strain BCC72023 was isolated from rice (Oryza sativa L.) and identified as the genus Streptomyces, based on phenotypic, chemotaxonomic and 16S rRNA gene sequence analyses. The strain showed 99.80% similarity compared with Streptomyces samsunensis M1463(T). Chemical investigation led to the isolation of three macrolides, efomycins M (1), G (2) and oxohygrolidin (3), along with two polyethers, abierixin (4) and 29-O-methylabierixin (5). To our knowledge, this is the first report of efomycin M being isolated from a natural source. The compounds were identified using spectroscopic techniques and comparison with previously published data. All compounds exhibited antimalarial activity against the Plasmodium falciparum, K-1 strain, a multidrug-resistant strain, with IC50 values in a range of 1.40-5.23 μg/ml. In addition, these compounds were evaluated for biological activity against Mycobacterium tuberculosis, Bacillus cereus, Colletotrichum gloeosporioides and Colletotrichum capsici, as well as cytotoxicity against both cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells. PMID:26809052

  15. A novel l-arabinose-responsive regulator discovered in the rice-blast fungus Pyricularia oryzae (Magnaporthe oryzae).

    Science.gov (United States)

    Klaubauf, Sylvia; Zhou, Miaomiao; Lebrun, Marc-Henri; de Vries, Ronald P; Battaglia, Evy

    2016-02-01

    In this study we identified the l-arabinose-responsive regulator of Pyricularia oryzae that regulates l-arabinose release and catabolism. Previously we identified the Zn2Cys6 transcription factor (TF), AraR, that has this role in the Trichocomaceae family (Eurotiales), but is absent in other fungi. Candidate Zn2Cys6 TF genes were selected according to their transcript profiles on l-arabinose. Deletion mutants of these genes were screened for their growth phenotype on l-arabinose. One mutant, named Δara1, was further analyzed. Our analysis demonstrated that Ara1 from P. oryzae is the functional analog of AraR from A. niger, while there is no significant sequence similarity between them. PMID:26790567

  16. Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae

    Directory of Open Access Journals (Sweden)

    Wiler Ribas Moreira

    2015-08-01

    Full Text Available Brown spot (BS, caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L. plants (cv. Metica-1 grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids, were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.

  17. Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae

    Directory of Open Access Journals (Sweden)

    Sung-Woong Kim

    2016-03-01

    Full Text Available To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis, majoram (Origanum majorana, and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively.

  18. Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae.

    Science.gov (United States)

    Kim, Sung-Woong; Lee, Hyo-Rim; Jang, Myeong-Jin; Jung, Chan-Sik; Park, Il-Kwon

    2016-01-01

    To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis), majoram (Origanum majorana), and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID) and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively. PMID:26999084

  19. Ultraviolet-B sensitivities in Japanese lowland rice [Oryza sativa] cultivars: Cyclobutane pyrimidine dimer photolyase activity and gene mutation

    International Nuclear Information System (INIS)

    There is a cultivar difference in the response to ultraviolet-B (UVB: 280-320 um) in rice (Oryza saliva L.). Among Japanese lowland rice cultivars, Sasanishiki, a leading Japanese rice cultivar, is resistant to the damaging effects of UVB while Norin 1, a close relative, is less resistant. We found previously that Norin 1 was deficient in cyclobutane pyrimidine dimer (CPD) photorepair ability and suggested that the UVB sensitivity in rice depends largely on CPD photorepair ability. In order to verify that suggestion, we examined the correlation between UVB sensitivity and CPD photolyase activity in 17 rice cultivars of progenitors and relatives in breeding of UV-resistant Sasanishiki and UV- sensitive Norin 1. The amino acid at position 126 of the deduced amino acid sequence of CPD photolyase in cultivars including such as Norin 1 was found to be arginine, the CPD photolyase activities of which were lower. The amino acid at that position in cultivars including such as Sasanishiki was glutamine. Furthermore, cultivars more resistant to UVB were found to exhibit higher photolyase activities than less resistant cultivars. These results emphasize that single amino acid alteration from glutamine to arginine leads to a deficit of CPD photolyase activity and that CPD photolyase activity is one of the main factors determining UVB sensitivity in rice

  20. MoMyb1 is required for asexual development and tissue-specific infection in the rice blast fungus Magnaporthe oryzae

    OpenAIRE

    Dong, Yanhan; Zhao, Qian; Liu, Xinyu; Zhang, Xiaofang; Qi, Zhongqiang; Zhang, Haifeng; Zheng, Xiaobo; Zhang, Zhengguang

    2015-01-01

    Background The Myb super-family of proteins contain a group of functionally diverse transcriptional activators found in plant, animal and fungus. Myb proteins are involved in cell proliferation, differentiation and apoptosis, and have crucial roles in telomeres. The purpose of this study was to characterize the biological function of Myb1 protein in the rice blast fungus Magnaporthe oryzae. Results We identified the Saccharomyces cerevisiae BAS1 homolog MYB1 in M. oryzae, named MoMyb1. MoMyb1...

  1. Modulation of some quantitative and qualitative characteristics in rice (Oryza sativa L.) and mung (Phaseolus mungo L.) by ionizing radiation

    International Nuclear Information System (INIS)

    The present work describes radiation-induced effects on some morphological characters of a cereal and a pulse-producing crop in India. 6Co gamma source is used for irradiating (from 50 to 350 Gy) the rice (Oryza sativa L., Cv-2233) and mung (Phaseolus mungo L.). Irradiation at lower doses of gamma rays effectively influences improving the morphological traits like seedling/plant height, tiller number, panicle number, panicle length, seed per panicle, seed per pod, pod length, pod number, while exposure at higher doses results in depletion of such parameters. Effective stimulatory dose for Oryza sativa L. Cv-2233 is 50 Gy and that for Phaseolus mungo L. is 200 Gy. Significance of such stimulation correlated with yielding ability of the plant concerned is discussed in the light of newer aspects in agricultural research

  2. Modulation of some quantitative and qualitative characteristics in rice (Oryza sativa L.) and mung (Phaseolus mungo L.) by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Maity, J.P. [Department of Atomic Energy Facilities, Inter University Consortium, Calcutta Center, 3/LB-8, Salt Lake, Calcutta 98, WB (India); Mishra, D. [Department of Atomic Energy Facilities, Inter University Consortium, Calcutta Center, 3/LB-8, Salt Lake, Calcutta 98, WB (India); Chakraborty, A. [Department of Atomic Energy Facilities, Inter University Consortium, Calcutta Center, 3/LB-8, Salt Lake, Calcutta 98, WB (India)]. E-mail: ani@alpha.iuc.res.in; Saha, A. [Department of Atomic Energy Facilities, Inter University Consortium, Calcutta Center, 3/LB-8, Salt Lake, Calcutta 98, WB (India); Santra, S.C. [Department of Environmental Science, University of Kalyani, Nadia 741235, WB (India); Chanda, S. [Center for Study of Man and Environment, CK-11, Sector -II, Salt Lake, Calcutta 91, WB (India)

    2005-12-15

    The present work describes radiation-induced effects on some morphological characters of a cereal and a pulse-producing crop in India. {sup 6}Co gamma source is used for irradiating (from 50 to 350 Gy) the rice (Oryza sativa L., Cv-2233) and mung (Phaseolus mungo L.). Irradiation at lower doses of gamma rays effectively influences improving the morphological traits like seedling/plant height, tiller number, panicle number, panicle length, seed per panicle, seed per pod, pod length, pod number, while exposure at higher doses results in depletion of such parameters. Effective stimulatory dose for Oryza sativa L. Cv-2233 is 50 Gy and that for Phaseolus mungo L. is 200 Gy. Significance of such stimulation correlated with yielding ability of the plant concerned is discussed in the light of newer aspects in agricultural research.

  3. EFICIÊNCIA DE FUNGICIDAS NO CONTROLE DE BRUSONE (Pyricularia oryzae DO ARROZ EFFICIENCY OF FUNGICIDES IN THE CONTROL OF RICE BLAST (Pyricularia oryzae Cav.

    Directory of Open Access Journals (Sweden)

    Wilson Ferreira de Oliveira

    2007-09-01

    Full Text Available

    A eficiência dos fungicidas ethiltrianol e edifenphos, em diferentes dosagens, foi avaliada na cultura de arroz (Var. IAC 165, visando ao controle da Brusone (Pyricularia oryzae Cav. a nível de campo. Os fungicidas foram pulverizados uma ou duas vezes, na fase do emborrachamento e 15 dias após a 1ª aplicação. Os resultados demonstraram que, quanto ao nível de infecção das folhas bandeiras, das panículas e lesões nos grãos, houve diferença estatística significativa entre a testemunha e a maioria dos tratamentos com ethiltrianol e uns poucos com edifenphos. Os melhores resultados foram conseguidos com ethiltrianol na maior concentração em duas épocas de aplicação. Com relação à produtividade não houve diferença significativa entre os tratamentos.

    Efficiency of fungicides ethiltrianol and edifenphos, at different concentrations, was evaluated in rice culture (Var. IAC-165, aiming control of rice blast (Pyricularia oryzae Cav. at field situation. Fungicides were pulverized one or two times, at seasoning phase and 15 days after first treatment. The results showed that, as to infection level of banner leaves, panicles and grain lesions there was significant statistical difference between testimony and majority of treatments with ethiltrianol and a few ones with edifenphos. The best results were obtained with ethiltrianol at maximum concentration in two treatments phases. Referring to productiveness, there was no significant difference between treatments.

  4. Serotonin attenuates biotic stress and leads to lesion browning caused by a hypersensitive response to Magnaporthe oryzae penetration in rice.

    Science.gov (United States)

    Hayashi, Keiko; Fujita, Yoshikatsu; Ashizawa, Taketo; Suzuki, Fumihiko; Nagamura, Yoshiaki; Hayano-Saito, Yuriko

    2016-01-01

    The hypersensitive response (HR) of plants is one of the earliest responses to prevent pathogen invasion. A brown dot lesion on a leaf is visual evidence of the HR against the blast fungus Magnaporthe oryzae in rice, but tracking the browning process has been difficult. In this study, we induced the HR in rice cultivars harboring the blast resistance gene Pit by inoculation of an incompatible M. oryzae strain, which generated a unique resistance lesion with a brown ring (halo) around the brown fungal penetration site. Inoculation analysis using a plant harboring Pit but lacking an enzyme that catalyzes tryptamine to serotonin showed that high accumulation of the oxidized form of serotonin was the cause of the browning at the halo and penetration site. Our analysis of the halo browning process in the rice leaf revealed that abscisic acid enhanced biosynthesis of serotonin under light conditions, and serotonin changed to the oxidized form via hydrogen peroxide produced by light. The dramatic increase in serotonin, which has a high antioxidant activity, suppressed leaf damage outside the halo, blocked expansion of the browning area and attenuated inhibition of plant growth. These results suggest that serotonin helps to reduce biotic stress in the plant by acting as a scavenger of oxygen radicals to protect uninfected tissues from oxidative damage caused by the HR. The deposition of its oxide at the HR lesion is observed as lesion browning. PMID:26603141

  5. Phytoextraction of cadmium by rice (Oryza sativa L.), soybean (Glycine max (L.) Merr.), and maize (Zea mays L.)

    International Nuclear Information System (INIS)

    Selecting a phytoextraction plant with high Cd-accumulating ability based on the plant's compatibility with mechanized cultivation techniques may yield more immediately practical results than selection based on high tolerance to Cd. Rice (Oryza sativa L., cv. Nipponbare and Milyang 23), soybean (Glycine max [L.] Merr., cv. Enrei and Suzuyutaka), and maize (Zea mays L., cv. Gold Dent) were grown on one Andosol and two Fluvisols with low concentration of Cd contamination ranging from 0.83 to 4.29 mg Cd kg-1, during 60 days in pots (550 mL) placed in a greenhouse. Shoot Cd uptake was as follows: Gold Dent < Enrei and Nipponbare < Suzuyutaka and Milyang 23. Several soil Cd fractions after Milyang 23 harvesting decreased most. Milyang 23 accumulated 10-15% of the total soil Cd in its shoot. The Milyang 23 rice is thus promising for phytoextraction of Cd from paddy soils with low contamination level. - Milyang 23 rice (Oryza sativa L.) accumulated 10-15% of the total soil Cd in its shoot

  6. Evaluation of Estimated Daily Intake (EDI of Cadmium and Lead for Rice (Oryza sativa L. in Calcareous Soils

    Directory of Open Access Journals (Sweden)

    Ali Chamannejadian

    2013-04-01

    Full Text Available The excessive amounts of cadmium and lead in food chain can cause health problems for humans and ecosystem. Rice is an important food in human diet. Therefore this study was conducted in order to investigate cadmium and Lead concentrations in seed rice (Oryza saliva of paddy fields in southwest of Iran. A total of 70 rice seed samples were collected from paddy fields in five regions of Khuzestan province, Southwest Iran, during harvesting time. In the samples cadmium and Lead concentrations were measured. To assess the daily intake of Cadmium and Lead by rice, daily consumption of rice was calculated. The results showed that average concentrations of Cadmium and Lead in rice seeds were 273.6 and 121.8 μg/kg, respectively. Less than 72% of rice seed samples had Cadmium concentrations above 200 μg/kg (i.e. Guide value for cadmium; and less than 3% had Lead concentrations above 150 μg/kg (i.e. Guide value for Lead. The estimated daily intakes of cadmium by the local population was calculated to 0.59 μg/day kg bw, which corresponds to 59% of the tolerable daily intakes (i.e. 1 μg/day kg bw. Eleven out of 70 samples (15.71% exceed the tolerable daily intakes. The dietary intakes for Lead in the local population ranged from 0.22 to 0.47 μg/day kg bw. Tolerable daily intakes for Lead is 3.6 μg/day kg bw. As a whole, long term consumption of the local rice may bear high risk of heavy metal exposure to the consumer in the study region.

  7. Elucidation of the hrp Clusters of Xanthomonas oryzae pv. oryzicola That Control the Hypersensitive Response in Nonhost Tobacco and Pathogenicity in Susceptible Host Rice

    OpenAIRE

    Zou, Li-fang; Wang, Xing-ping; Xiang, Yong; Zhang, Bing; Li, Yu-Rong; Xiao, You-lun; Wang, Jin-sheng; Walmsley, Adrian R; Chen, Gong-You

    2006-01-01

    Xanthomonas oryzae pv. oryzicola, the cause of bacterial leaf streak in rice, possesses clusters of hrp genes that determine its ability to elicit a hypersensitive response (HR) in nonhost tobacco and pathogenicity in host rice. A 27-kb region of the genome of X. oryzae pv. oryzicola (RS105) was identified and sequenced, revealing 10 hrp, 9 hrc (hrp conserved), and 8 hpa (hrp-associated) genes and 7 regulatory plant-inducible promoter boxes. While the region from hpa2 to hpaB and the hrpF ope...

  8. Identification of a Rice stripe necrosis virus resistance locus and yield component QTLs using Oryza sativa × O. glaberrima introgression lines

    Directory of Open Access Journals (Sweden)

    Prado Gustavo

    2010-01-01

    Full Text Available Abstract Background Developing new population types based on interspecific introgressions has been suggested by several authors to facilitate the discovery of novel allelic sources for traits of agronomic importance. Chromosome segment substitution lines from interspecific crosses represent a powerful and useful genetic resource for QTL detection and breeding programs. Results We built a set of 64 chromosome segment substitution lines carrying contiguous chromosomal segments of African rice Oryza glaberrima MG12 (acc. IRGC103544 in the genetic background of Oryza sativa ssp. tropical japonica (cv. Caiapó. Well-distributed simple-sequence repeats markers were used to characterize the introgression events. Average size of the substituted chromosomal segments in the substitution lines was about 10 cM and covered the whole donor genome, except for small regions on chromosome 2 and 4. Proportions of recurrent and donor genome in the substitution lines were 87.59% and 7.64%, respectively. The remaining 4.78% corresponded to heterozygotes and missing data. Strong segregation distortion was found on chromosomes 3 and 6, indicating the presence of interspecific sterility genes. To illustrate the advantages and the power of quantitative trait loci (QTL detection using substitution lines, a QTL detection was performed for scored traits. Transgressive segregation was observed for several traits measured in the population. Fourteen QTLs for plant height, tiller number per plant, panicle length, sterility percentage, 1000-grain weight and grain yield were located on chromosomes 1, 3, 4, 6 and 9. Furthermore, a highly significant QTL controlling resistance to the Rice stripe necrosis virus was located between SSR markers RM202-RM26406 (44.5-44.8 cM on chromosome 11. Conclusions Development and phenotyping of CSSL libraries with entire genome coverage represents a useful strategy for QTL discovery. Mapping of the RSNV locus represents the first identification

  9. Production of superoxide from Photosystem II in a rice (Oryza sativa L.) mutant lacking PsbS

    OpenAIRE

    Zulfugarov, Ismayil S; Tovuu, Altanzaya; Eu, Young-Jae; Dogsom, Bolormaa; Poudyal, Roshan Sharma; Nath, Krishna; Hall, Michael; Banerjee, Mainak; Yoon, Ung Chan; Moon, Yong-Hwan; An, Gynheung; Jansson, Stefan; Lee, Choon-Hwan

    2014-01-01

    Background PsbS is a 22-kDa Photosystem (PS) II protein involved in non-photochemical quenching (NPQ) of chlorophyll fluorescence. Rice (Oryza sativa L.) has two PsbS genes, PsbS1 and PsbS2. However, only inactivation of PsbS1, through a knockout (PsbS1-KO) or in RNAi transgenic plants, results in plants deficient in qE, the energy-dependent component of NPQ. Results In studies presented here, under fluctuating high light, growth of young seedlings lacking PsbS is retarded, and PSII in detach...

  10. Solid-state fermentation for the enrichment and extraction of proteins and antioxidant compounds in rice bran by Rhizopus oryzae

    OpenAIRE

    Larine Kupski; Eliane Cipolatti; Meritaine da Rocha; Melissa dos Santos Oliveira; Leonor Almeida de Souza-Soares; Eliana Badiale-Furlong

    2012-01-01

    The objective of this work was to evaluate the solid-state fermentation with Rhizopus oryzae CCT 7560 of rice bran for the enrichment of proteins and the antioxidant compounds in the fermented biomass. Fermentation was performed in tray bioreactors at 30ºC for 120 h. Protein extraction was done at alkaline pH, followed by precipitation with acetone. Phenolic compounds were extracted with cold methanol. The maximum protein was recovered from after 120 h (26.6%). The content of total phenolic c...

  11. Identification of Novel and Conserved miRNAs from Extreme Halophyte, Oryza coarctata, a Wild Relative of Rice

    OpenAIRE

    Mondal, Tapan Kumar; Ganie, Showkat Ahmad; Debnath, Ananda Bhusan

    2015-01-01

    Oryza coarctata, a halophyte and wild relative of rice, is grown normally in saline water. MicroRNAs (miRNAs) are non-coding RNAs that play pivotal roles in every domain of life including stress response. There are very few reports on the discovery of salt-responsive miRNAs from halophytes. In this study, two small RNA libraries, one each from the control and salt-treated (450 mM NaCl for 24 h) leaves of O. coarctata were sequenced, which yielded 338 known and 95 novel miRNAs. Additionally, w...

  12. LHD1, an Allele of DTH8/Ghd8, Controls Late Heading Date in Common Wild Rice (Oryza rufipogon)

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Dai; Hongwei Cai; Chuanqing Sun; Younian Ding; Lubin Tan; Yongcai Fu; Fengxia Liu; Zuofeng Zhu; Xianyou Sun; Xuewen Sun; Ping Gu

    2012-01-01

    Flowering at suitable time is very important for plants to adapt to complicated environments and produce their seeds successfully for reproduction.In rice (Oryza rufipogon Griff.) photoperiod regulation is one of the important factors for controlling heading date.Common wild rice,the ancestor of cultivated rice,exhibits a late heading date and a more sensitive photoperiodic response than cultivated rice.Here,through map-based cloning,we identified a major quantitative trait loci (QTL) LHD1 (Late Heading Date 1),an allele of DTH8/Ghd8,which controls the late heading date of wild rice and encodes a putative HAP3/NF-YB/CBF-A subunit of the CCAAT-box-binding transcription factor.Sequence analysis revealed that several variants in the coding region of LHD1 were correlated with a late heading date,and a further complementary study successfully rescued the phenotype.These results suggest that a functional site for LHD1 could be among those variants present in the coding region.We also found that LHD1 could down-regulate the expression of several floral transition activators such as Ehd1,Hd3a and RFT1 under long-day conditions,but not under short-day conditions.This indicates that LHD1 may delay flowering by repressing the expression of Ehd1,Hd3a and RFT1 under long-day conditions.

  13. Crystal Structure of Manganese Lipoxygenase of the Rice Blast Fungus Magnaporthe oryzae.

    Science.gov (United States)

    Wennman, Anneli; Oliw, Ernst H; Karkehabadi, Saeid; Chen, Yang

    2016-04-01

    Lipoxygenases (LOX) are non-heme metal enzymes, which oxidize polyunsaturated fatty acids to hydroperoxides. All LOX belong to the same gene family, and they are widely distributed. LOX of animals, plants, and prokaryotes contain iron as the catalytic metal, whereas fungi express LOX with iron or with manganese. Little is known about metal selection by LOX and the adjustment of the redox potentials of their protein-bound catalytic metals. Thirteen three-dimensional structures of animal, plant, and prokaryotic FeLOX are available, but none of MnLOX. The MnLOX of the most important plant pathogen, the rice blast fungusMagnaporthe oryzae(Mo), was expressed inPichia pastoris.Mo-MnLOX was deglycosylated, purified to homogeneity, and subjected to crystal screening and x-ray diffraction. The structure was solved by sulfur and manganese single wavelength anomalous dispersion to a resolution of 2.0 Å. The manganese coordinating sphere is similar to iron ligands of coral 8R-LOX and soybean LOX-1 but is not overlapping. The Asn-473 is positioned on a short loop (Asn-Gln-Gly-Glu-Pro) instead of an α-helix and forms hydrogen bonds with Gln-281. Comparison with FeLOX suggests that Phe-332 and Phe-525 might contribute to the unique suprafacial hydrogen abstraction and oxygenation mechanism of Mo-MnLOX by controlling oxygen access to the pentadiene radical. Modeling suggests that Arg-525 is positioned close to Arg-182 of 8R-LOX, and both residues likely tether the carboxylate group of the substrate. An oxygen channel could not be identified. We conclude that Mo-MnLOX illustrates a partly unique variation of the structural theme of FeLOX. PMID:26783260

  14. Micromonospora endophytica sp. nov., an endophytic actinobacteria of Thai upland rice (Oryza sativa).

    Science.gov (United States)

    Thanaboripat, Dusanee; Thawai, Chitti; Kittiwongwattana, Chokchai; Laosinwattana, Chamroon; Koohakan, Prommart; Parinthawong, Nonglak

    2015-11-01

    An actinobacterial strain, DCWR9-8-2(T), was isolated from a leaf of Thai upland rice (Oryza sativa) collected in Chumporn province, Thailand. Strain DCWR9-8-2(T) is Gram-stain-positive aerobic bacteria that produce single spores directly on the vegetative hypha. Cell wall peptidoglycan of this strain exhibits meso-diaminopimelic acid and glycine, the reducing sugars of whole-cell hydrolysate are arabinose, glucose, ribose, xylose and small amount of mannose. The phospholipid profiles in the membrane are comprised of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides. The major menaquinones are MK-9(H4) and MK-10(H6). The diagnostic cellular fatty acids are iso-C16:0 and iso-C15:0. The G+C content of the genomic DNA is 72.5 mol%. The result of 16S rRNA sequence analysis of the strain revealed that this strain was closely related to Micromonospora auratinigra TT1-11(T) (99.25%). On the other hand, the result of gyrB gene sequence analysis revealed that this strain was closed to M. eburnea JCM 12345(T) (96.30%). In addition, a combination of DNA-DNA hybridization results and some phenotypic properties supported that this strain should be judged as a novel species of the genus Micromonospora, for which the name M. endophytica sp. nov. is proposed. The type strain is DCWR9-8-2(T) (=BCC 67267(T)=NBRC 110008(T)). PMID:25966850

  15. Microbacterium oryzae sp. nov., an actinobacterium isolated from rice field soil.

    Science.gov (United States)

    Kumari, Prabla; Bandyopadhyay, Saumya; Das, Subrata K

    2013-07-01

    A novel aerobic soil actinobacterium (strain MB10(T)) belonging to the genus Microbacterium was isolated from rice field soil samples collected from Jagatpur, Orissa, India. Cells were Gram-stain positive, short rod-shaped and motile. The strain was oxidase-negative and catalase-positive. Heterotrophic growth was observed at pH 5.0-11.0 and at 16-37 °C; optimum growth was observed at 28 °C and pH 7.0-9.0. The DNA G+C content was 71.6 mol%. Predominant cellular fatty acids of strain MB10(T) were iso-C14 : 0, anteiso-C15 : 0, C16 : 0, iso-C16 : 0 and anteiso-C17 : 0. Cell wall sugars were galactose, glucose and rhamnose. The major isoprenoid quinones were MK-9 (10 %), MK-10 (43 %) and MK-11 (36 %). The peptidoglycan represents the peptidoglycan type B2β. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phospholipid and unknown glycolipids. 16S rRNA gene sequence identity revealed the strain MB10(T) clustered within the radiation of the genus Microbacterium and showed 99.2 % similarity with Microbacterium barkeri DSM 20145(T). However, DNA-DNA similarity study was 37.0 % with Microbacterium barkeri DSM 20145(T), the nearest phylogenetic relative. On the basis of phenotypic and chemotaxonomic properties, 16S rRNA gene sequence analysis and DNA-DNA reassociation studies, it is proposed that strain MB10(T) represents a novel species of the genus Microbacterium, for which the name Microbacterium oryzae sp. nov. is proposed; the type strain is MB10(T) ( = JCM 16837(T) = DSM 23396(T)). PMID:23203624

  16. Determination of residues of imazapic and imazaphic in rice (Oryza sativa) by HPLC

    International Nuclear Information System (INIS)

    A requirement to introduce a pesticide in the harvest of any product for the human consume is imperative to determine that it will not leave residues that can injure the human healthy. In this research the residues of imazapic and imazapyr, both systemic herbicides of the imidazolinone family, were determined in rice (Oryza sativa) by extraction of the samples with the extraction solvent prepared by mixing 40 mL of HC1 1 N, 2400 mL of methanol pesticide grade and 1560 mL of bidistilled water. An aliquot of the extract was concentrated approximately to 10 mL in a rotary evaporator; water was added to the concentrated extract and dissolution to 10 % m/v of lead acetate and it was regulated the pH to 6,2 with dissolution of NaOH 1 N. This dissolution was centrifuged and from the floating liquid and aliquot was measured to regulate the pH to 2,1 with dissolution of HC1 1 N. After it was extracted with dichlormethan and the join extracts were carried to dryness in the rotary evaporator. The residues were dissolved in ultrapure water of pH 2,5 and they were injected in HPLC chromatograph with a C8 column. The validation of the analytical method obtained were: 5,1 x 10-2 to 5,1 x 10-3 μg/mL for linearity; (1,5 x 10-3, 5,0 x 10-3, 7,8 x 10-3, 2,6 x 10-2) μg/mL for imazapyr and imazapic for the detection and quantification limits equivalent to 5,0 x 10-2 mg/kg in rice; the percent of recovery were 80 % and 125 %, for imazapyr and imazapic and finally, the precision for the retention time, the area and for concentration were: 0,003 % standard deviations, 18 500 and 0,008, respectively. (author)

  17. EFFECT OF EPS RICH PGPR CELLS ON THE GROWTH CHARACTERISTICS AND THEIR ENHANCED DEFENSIVE MECHANISM IN RICE (PYRICULARIA ORYZAE PATHOSYSTEM UNDER LOWLAND CONDITION

    Directory of Open Access Journals (Sweden)

    S. Kalaiarasu

    2014-03-01

    Full Text Available The Effect of EPS rich PGPR cells viz., vegetative cell application, co-inoculation and cofloculation Pseudomonas fluorescens and Azospirillum together with challenge inoculation of Pyricularia oryzae on the enhancement of induced systemic resistance (ISR in Rice-Pyricularia oryzae pathosystem was studied under pot culture condition with rice cv.IR.50. It was observed that the application of Pseudomonas fluorescens and Azospirillum as co-floculation, altered the biochemical and physiological parameters viz., reducing and non-reducing sugars, total phenol content and defense enzymes activities such as peroxidase (PO, Polyphenol oxidase (PPO, of rice plant to a significant level followed by co-inoculation and vegetative cell application of PGPR cells. The application of PGPR cells, as co-floculation, was found to augment the total phenol content and defense enzyme activities such as PO and PPO content of rice plant to a higher level whereas a reduction in reducing and non-reducing sugar level was recorded, which ultimately lead to a reduction of Pyricularia oryzae incidence in lowland rice. It has been postulated that the EPS biosynthesis of PGPR cells during co-floculation processes might act as elicitor for the enhancement of ISR in Rice- Pyricularia oryzae pathosystem whereas the vegetative cells and co-inoculation processes, without any involvement of EPS, responded poorly for the enhancement of ISR in the same pathosystem. This is the first comprehensive report on the role of bacterial EPS, as a determinant of ISR, in Rice - Pyricularia oryzae pathosytem and it needs further elaborate research on the topic.

  18. Transgenic rice with inducible ethylene production exhibits broad-spectrum disease resistance to the fungal pathogens Magnaporthe oryzae and Rhizoctonia solani.

    Science.gov (United States)

    Helliwell, Emily E; Wang, Qin; Yang, Yinong

    2013-01-01

    Rice blast (Magnaporthe oryzae) and sheath blight (Rhizoctonia solani) are the two most devastating diseases of rice (Oryza sativa), and have severe impacts on crop yield and grain quality. Recent evidence suggests that ethylene (ET) may play a more prominent role than salicylic acid and jasmonic acid in mediating rice disease resistance. In this study, we attempt to genetically manipulate endogenous ET levels in rice for enhancing resistance to rice blast and sheath blight diseases. Transgenic lines with inducible production of ET were generated by expressing the rice ACS2 (1-aminocyclopropane-1-carboxylic acid synthase, a key enzyme of ET biosynthesis) transgene under control of a strong pathogen-inducible promoter. In comparison with the wild-type plant, the OsACS2-overexpression lines showed significantly increased levels of the OsACS2 transcripts, endogenous ET and defence gene expression, especially in response to pathogen infection. More importantly, the transgenic lines exhibited increased resistance to a field isolate of R. solani, as well as different races of M. oryzae. Assessment of the growth rate, generational time and seed production revealed little or no differences between wild type and transgenic lines. These results suggest that pathogen-inducible production of ET in transgenic rice can enhance resistance to necrotrophic and hemibiotrophic fungal pathogens without negatively impacting crop productivity. PMID:23031077

  19. Mutants induced in rice (Oryza sativa L.) for the study of their reaction to Sclerotium oryzae Catt. and Sclerotium hydrophilum Sacc

    International Nuclear Information System (INIS)

    A series of families selected from the progeny of rice of the Arlesienne variety - from the National Institute for Agricultural Research (INRA) - after mutagenic treatment was studied with regard to their reaction to artificial infection by two types of pathogenic cryptogam which are found in France and which cause sclerotial diseases in rice. The mutagenic treatment was carried out in 1970, at the Montpellier Plant Improvement Station, with gamma rays from a cobalt source provided by the French Commissariat a l'energie atomique. The aim was to improve the Arlesienne variety, which, although of excellent quality for culinary purposes, was difficult to thresh (excessive resistance to extraction of kernels from husks) and to handle in the mill (pronounced villosity). Screening, done in 1971, and consecutive selection produced mutants which did not entail these difficulties; 28 families (M6 in 1975) were finally chosen for their superiority to the control. The Plant Biology and Pathology Laboratory at Montpellier has analysed the extent to which these mutants would be resistant in the event of an epidemic of Sclerotium. Eight families exhibited low or very low overall susceptibility to S. oryzae, 21 to S. hydrophilum and seven to both at once. From the practical point of view, four families are clearly superior to the Arlesienne control, one of them possessing great agronomic value. Several families proved to be less resistant than the parent variety, which confirms the mutation direction symmetry rule. (author)

  20. Responses of rice (Oryza sativa L.) genotypes to repeated drought stress under contrasting temperatures

    OpenAIRE

    Mukamuhirwa, Alphonsine

    2016-01-01

    Abstract Rice is an important staple food crop for a large part of the world population. Rice is a good source of dietary energy and provides a good proportion of proteins and minerals. Rice is adapted to diverse environments, although its semi-aquatic characteristic makes paddy rice producing better at high soil moisture content. Rice is largely grown in irrigated systems and drought is one of the most damaging abiotic stress factors, affecting rice growth, productivity and grain quali...

  1. Splicing-site recognition of riceOryza sativa L. ) DNA sequences by support vector machines

    Institute of Scientific and Technical Information of China (English)

    彭司华; 彭小宁; 庄树林; 杜维; 陈良标

    2003-01-01

    Motivation: It was found that high accuracy splicing-site recognition of rice ( Oryza satlva L. ) DNA sequence is especially difficult. We described a new method for the splicing-site recognition of rice DNA sequences. Method: Based on the intron in eukaryotic organisms conforming to the principle of GT-AG, we used support vector machines (SVM) to predict the splicing sites. By machine learning, we built a model and used it to test the effect of the test data set of true and pseudo splicing sites. Results : The prediction accuracy we obtained was 87.53% at the true 5' end splicing site and 87.37% at the true 3' end splicing sites. The results suggested that the SVM approach could achieve higher accuracy than the previous approaches.

  2. Distribution of Water Channel Protein RWC3 and Its Regulation by GA and Sucrose in RiceOryza sativa)

    Institute of Scientific and Technical Information of China (English)

    SUNMei-Hao; ZHANGMin-Hua; LIUHong-Yan; LILe-Gong; YUXin; SUWei-Ai; TANGZhang-Cheng

    2004-01-01

    Water channel proteins facilitate water flux across cell membranes and play important roles in plant growth and development. By GUS histochemical assay in RWC3 promoter-GUS transgenic rice (Oryza sativa L. cv. Shenxiangjin 4), one of the members of water channel proteins in rice, RWC3, was found to distribute widely in variety of organs, from vegetative and reproductive organs. Further studies showed that gibberellin (GA) enhanced the GUS activity in the transgenic calli, suspension cells and leaves, whereas ancymidol (anc), an inhibitor of GA synthesis, reduced the GUS activity. Sucrose was found to inhibit the effects induced by addition of GA, suggesting a possible cross-talk between GA and sucrose signaling on regulation of the RWC3 gene expression.

  3. Evidence for the Emergence of New Rice Types of Interspecific Hybrid Origin in West African Farmers' Fields

    OpenAIRE

    Edwin Nuijten; Robbert van Treuren; Struik, Paul C.; Alfred Mokuwa; Florent Okry; Béla Teeken; Paul Richards

    2009-01-01

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo) using 315 rice samples morphologically classified prior to ...

  4. Two novel transcriptional regulators are essential for infection-related morphogenesis and pathogenicity of the rice blast fungus Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Xia Yan

    2011-12-01

    Full Text Available The cyclic AMP-dependent protein kinase A signaling pathway plays a major role in regulating plant infection by the rice blast fungus Magnaporthe oryzae. Here, we report the identification of two novel genes, MoSOM1 and MoCDTF1, which were discovered in an insertional mutagenesis screen for non-pathogenic mutants of M. oryzae. MoSOM1 or MoCDTF1 are both necessary for development of spores and appressoria by M. oryzae and play roles in cell wall differentiation, regulating melanin pigmentation and cell surface hydrophobicity during spore formation. MoSom1 strongly interacts with MoStu1 (Mstu1, an APSES transcription factor protein, and with MoCdtf1, while also interacting more weakly with the catalytic subunit of protein kinase A (CpkA in yeast two hybrid assays. Furthermore, the expression levels of MoSOM1 and MoCDTF1 were significantly reduced in both Δmac1 and ΔcpkA mutants, consistent with regulation by the cAMP/PKA signaling pathway. MoSom1-GFP and MoCdtf1-GFP fusion proteins localized to the nucleus of fungal cells. Site-directed mutagenesis confirmed that nuclear localization signal sequences in MoSom1 and MoCdtf1 are essential for their sub-cellular localization and biological functions. Transcriptional profiling revealed major changes in gene expression associated with loss of MoSOM1 during infection-related development. We conclude that MoSom1 and MoCdtf1 functions downstream of the cAMP/PKA signaling pathway and are novel transcriptional regulators associated with cellular differentiation during plant infection by the rice blast fungus.

  5. Ecofriendly Approaches of Potential Microbial Bioagents in Management of Sheath Rot Disease in Rice Caused by Sarocladium oryzae (Sawada

    Directory of Open Access Journals (Sweden)

    Thiruvengadam Raguchander

    2013-01-01

    Full Text Available There is growing interest in the use of effective microbial bioformulations that might be useful in the development of ecologically sustainable biocontrol strategies for the management of several plant pathogens. Recent studies suggest that the combination of several bio control agents could be more effective in controlling plant pathogens than individual strains. The new microbial consortia of Plant Growth Promoting Rhizobacteria Pseudomonas fluorescens strains Pf1, TDK1, TV5 and Bacillus subtilis isolate TH10 was developed and tested for their bioefficacy against the sheath rot (Sarocladium oryzae (Sawada diseases in rice. The microbial consortia (Pf1+TDK1+TV-5+TH 10 effectively reduced sheath rot disease incidence in rice compared to individual bioformulations and control treatments under glasshouse and field conditions. Further, the significant increase in growth parameters and yield were observed in rice plants treated with microbial consortia (Pf1+TDK1+TV5+TH10 compared to individual bioformulations and untreated control. The present study revealed the probable influence of antagonism and plant growth promotion by the mixture of microbial consortia in enhancing the disease resistance in rice plants against sheath rot disease. Plant Growth Promoting Rhizobacteria (PGPR metabolism which might be useful for development of ecologically sustainable biocontrol strategy for the management of plant pathogens in sustainable manner.

  6. Uptake of selected PAHs from contaminated soils by rice seedlings (Oryza sativa) and influence of rhizosphere on PAH distribution

    International Nuclear Information System (INIS)

    The uptake of selected polycyclic aromatic hydrocarbons (PAHs) by rice (Oryza sativa) seedlings from spiked aged soils was investigated. When applied to soils aged for 4 months, naphthalene, phenanthrene, and pyrene exhibited volatilization loss of 98, 95, and 30%, respectively, with the remaining fraction being fixed by soil organic matter and/or degraded by soil microbes. In general, concentrations of the three PAHs in rice roots were greater than those in the shoots. The concentrations of root associated PHN and PYR increased proportionally with both soil solution and rhizosphere concentrations. PAH concentrations in shoots were largely independent of those in soil solution, rice roots, or rhizosphere soil. The relative contributions of plant uptake and plant-promoted rhizosphere microbial biodegradation to the total mass balance were 0.24 and 14%, respectively, based on PYR concentrations in rhizosphere and non-rhizosphere soils, the biomass of rice roots, and the dry soil weight. - Contributions of plant uptake and rhizosphere effect on removal of PAHs from soils are relatively insignificant

  7. Role of salicylic acid in alleviating oxidative damage in rice roots (Oryza sativa) subjected to cadmium stress

    International Nuclear Information System (INIS)

    Time-dependent changes in enzymatic and non-enzymatic antioxidants, and lipid peroxidation were investigated in roots of rice (Oryza sativa) grown hydroponically with Cd, with or without pretreatment of salicylic acid (SA). Exposure to 50 μM Cd significantly decreased root growth, and activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), but increased the concentrations of H2O2, malondialdehyde (MDA), ascorbic acid (AsA), glutathione (GSH) and non-protein thiols (NPT). However, pretreatment with 10 μM SA enhanced the activities of antioxidant enzymes and the concentrations of non-enzymatic antioxidants, but lowered the concentrations of H2O2 and MDA in the Cd-stressed rice compared with the Cd treatment alone. Pretreatment with SA alleviated the Cd-induced inhibition of root growth. The results showed that pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. The possible mechanism of SA-induced H2O2 signaling in mediating Cd tolerance was discussed. - Pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance

  8. Variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps biosynthetic locus in Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice

    Directory of Open Access Journals (Sweden)

    Sonti Ramesh V

    2004-10-01

    Full Text Available Abstract Background In animal pathogenic bacteria, horizontal gene transfer events (HGT have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (LPS. As a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. Since LPS is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. Although LPS has been suggested as a potentiator of plant defense responses, interstrain variation at lps biosynthetic gene clusters has not been reported for any plant pathogenic bacterium. Results We report here the complete sequence of a 12.2 kb virulence locus of Xanthomonas oryzae pv. oryzae (Xoo encoding six genes whose products are homologous to functions involved in LPS biosynthesis and transport. All six open reading frames (ORFs have atypical G+C content and altered codon usage, which are the hallmarks of genomic islands that are acquired by horizontal gene transfer. The lps locus is flanked by highly conserved genes, metB and etfA, respectively encoding cystathionine gamma lyase and electron transport flavoprotein. Interestingly, two different sets of lps genes are present at this locus in the plant pathogens, Xanthomonas campestris pv. campestris (Xcc and Xanthomonas axonopodis pv. citri (Xac. The genomic island is present in a number of Xoo strains from India and other Asian countries but is not present in two strains, one from India (BXO8 and another from Nepal (Nepal624 as well as the closely related rice pathogen, Xanthomonas oryzae pv. oryzicola (Xoor. TAIL-PCR analysis indicates that sequences related to Xac are present at the lps locus in both BXO8 and Nepal624. The Xoor strain has a hybrid lps gene cluster, with sequences at the metB and etfA ends, being most closely related to sequences from Xac and the tomato pathogen, Pseudomonas syringae pv. tomato

  9. Co-evolution of the rice blast resistance gene Pi-ta and Magnaporthe oryzae avirulence gene AVR-Pita1

    Science.gov (United States)

    The Pi-ta gene in rice provides resistance to races of Magnaporthe oryzae that contain the corresponding avirulence gene AVR-Pita1. Pi-ta encodes a predicted receptor protein with nucleotide binding site and leucine rich repeat domain (NBS-LRR) that directly recognizes the products of AVR-Pita1 insi...

  10. Molecular cloning, functional characterization and expression analysis of a novel monosaccharide transporter gene OsMST6 from rice (Oryza sativa L.)

    NARCIS (Netherlands)

    Wang, Y.; Xiao, Y.; Zhang, Y.; Chai, C.; Wei, G.; Wei, X.; Xu, H.; Wang, M.; Ouwerkerk, P.B.F.; Zhu, Z.

    2008-01-01

    Monosaccharides transporters play important roles in assimilate supply for sink tissue development. In this study, a new monosaccharide transporter gene OsMST6 was identified from rice (Oryza sativa L.). The predicted OsMST6 protein shows typical features of sugar transporters and shares 79.6% ident

  11. The organelle genomes of Hassawi rice (Oryza sativa L.) and its hybrid in saudi arabia: genome variation, rearrangement, and origins.

    Science.gov (United States)

    Zhang, Tongwu; Hu, Songnian; Zhang, Guangyu; Pan, Linlin; Zhang, Xiaowei; Al-Mssallem, Ibrahim S; Yu, Jun

    2012-01-01

    Hassawi rice (Oryza sativa L.) is a landrace adapted to the climate of Saudi Arabia, characterized by its strong resistance to soil salinity and drought. Using high quality sequencing reads extracted from raw data of a whole genome sequencing project, we assembled both chloroplast (cp) and mitochondrial (mt) genomes of the wild-type Hassawi rice (Hassawi-1) and its dwarf hybrid (Hassawi-2). We discovered 16 InDels (insertions and deletions) but no SNP (single nucleotide polymorphism) is present between the two Hassawi cp genomes. We identified 48 InDels and 26 SNPs in the two Hassawi mt genomes and a new type of sequence variation, termed reverse complementary variation (RCV) in the rice cp genomes. There are two and four RCVs identified in Hassawi-1 when compared to 93-11 (indica) and Nipponbare (japonica), respectively. Microsatellite sequence analysis showed there are more SSRs in the genic regions of both cp and mt genomes in the Hassawi rice than in the other rice varieties. There are also large repeats in the Hassawi mt genomes, with the longest length of 96,168 bp and 96,165 bp in Hassawi-1 and Hassawi-2, respectively. We believe that frequent DNA rearrangement in the Hassawi mt and cp genomes indicate ongoing dynamic processes to reach genetic stability under strong environmental pressures. Based on sequence variation analysis and the breeding history, we suggest that both Hassawi-1 and Hassawi-2 originated from the Indonesian variety Peta since genetic diversity between the two Hassawi cultivars is very low albeit an unknown historic origin of the wild-type Hassawi rice. PMID:22870184

  12. Genome-wide gene responses in a transgenic rice line carrying the maize resistance gene Rxo1 to the rice bacterial streak pathogen, Xanthomonas oryzae pv. oryzicola

    Directory of Open Access Journals (Sweden)

    Fu Bin-Ying

    2010-02-01

    Full Text Available Abstract Background Non-host resistance in rice to its bacterial pathogen, Xanthomonas oryzae pv. oryzicola (Xoc, mediated by a maize NBS-LRR type R gene, Rxo1 shows a typical hypersensitive reaction (HR phenotype, but the molecular mechanism(s underlying this type of non-host resistance remain largely unknown. Results A microarray experiment was performed to reveal the molecular mechanisms underlying HR of rice to Xoc mediated by Rxo1 using a pair of transgenic and non-transgenic rice lines. Our results indicated that Rxo1 appeared to function in the very early step of the interaction between rice and Xoc, and could specifically activate large numbers of genes involved in signaling pathways leading to HR and some basal defensive pathways such as SA and ET pathways. In the former case, Rxo1 appeared to differ from the typical host R genes in that it could lead to HR without activating NDR1. In the latter cases, Rxo1 was able to induce a unique group of WRKY TF genes and a large set of genes encoding PPR and RRM proteins that share the same G-box in their promoter regions with possible functions in post-transcriptional regulation. Conclusions In conclusion, Rxo1, like most host R genes, was able to trigger HR against Xoc in the heterologous rice plants by activating multiple defensive pathways related to HR, providing useful information on the evolution of plant resistance genes. Maize non-host resistance gene Rxo1 could trigger the pathogen-specific HR in heterologous rice, and ultimately leading to a localized programmed cell death which exhibits the characteristics consistent with those mediated by host resistance genes, but a number of genes encoding pentatricopeptide repeat and RNA recognition motif protein were found specifically up-regulated in the Rxo1 mediated disease resistance. These results add to our understanding the evolution of plant resistance genes.

  13. Hot spots for diversity of Magnaporthe oryzae physiological races in irrigated rice fields in Brazil Alta diversidade de raças fisiológicas de Magnaporthe oryzae em áreas de arroz irrigado em Tocantins, Brasil

    Directory of Open Access Journals (Sweden)

    Justino José Dias Neto

    2010-03-01

    Full Text Available The objective of this work was to evaluate the Magnaporthe oryzae pathotype diversity in new commercial irrigated rice fields in the Araguaia River Valley, state of Tocantins, Brazil. The causal agent of rice blast has heavily affected rice production in the region. Despite the efforts of breeding programs, blast resistance breakdown has been recorded shortly after the release of new resistant cultivars developed for the region. Among the causes of resistance breakage is the capacity of the fungus to rapidly develop new pathotypes. A sample of 479 M. oryzae monosporic isolates was obtained and tested using the international rice blast differential set. Isolate collections were made in small areas designed as trap nurseries and in scattered sites in their vicinity. Analysis of 250 M. oryzae isolates from three trap nurseries indicated the presence of 45 international M. oryzae races belonging to seven pathotype groups (IA-IG. In the isolates tested, 61 M. oryzae pathotypes belonging to all but the IH group were detected. The new areas of irrigated rice in the Araguaia River Valley have the highest diversity of M. oryzae pathotypes reported so far in Brazil.O objetivo deste trabalho foi avaliar a diversidade de patótipos de Magnaporthe oryzae em novas áreas comerciais de arroz irrigado instaladas no Vale do Rio Araguaia, Estado do Tocantins, Brasil. A produção de arroz nessa região vem sendo significativamente afetada pelo agente causal da brusone do arroz. Apesar dos esforços de programas de melhoramento genético, a ocorrência de quebra de resistência tem sido registrada logo após o lançamento de novas cultivares desenvolvidas para a região. Entre as causas de quebra de resistência está incluída a capacidade do fungo de desenvolver novos patótipos rapidamente. Uma amostra de 479 isolados monospóricos de M. oryzae foi obtida e testada no conjunto internacional de cultivares diferenciadoras de raças de brusone. As coletas de

  14. Controle de arroz-vermelho em dois genótipos de arroz (Oryza sativa tolerantes a herbicidas do grupo das imidazolinonas Red rice control in two rice (Oryza sativa genotypes tolerant to imidazolinone herbicides

    Directory of Open Access Journals (Sweden)

    S.C.C. Villa

    2006-09-01

    Full Text Available A infestação por arroz-vermelho (Oryza spp. constitui-se num dos principais fatores limitantes da produtividade de grãos do arroz irrigado. Este trabalho teve como objetivo avaliar o controle de arroz-vermelho e o desempenho de dois genótipos de arroz irrigado, IRGA 422 CL e Tuno CL, tolerantes a herbicidas do grupo das imidazolinonas em resposta a doses e épocas de aplicações da mistura formulada de imazethapyr (75 g L-1 + imazapic (25 g L-1 (produto comercial Only®, em áreas com alta infestação de arroz-vermelho. O experimento foi conduzido em Santa Maria-RS no ano agrícola 2004/05. O delineamento experimental foi de blocos ao acaso em esquema bifatorial (2 x 10, com quatro repetições. O fator A foi composto por dois genótipos de arroz tolerantes às imidazolinonas, um cultivar (IRGA 422 CL e um híbrido (Tuno CL; e o fator D, pelos tratamentos para controle de arroz-vermelho oriundos de combinações de doses e épocas de aplicação do herbicida. Constatou-se que o híbrido é mais tolerante ao herbicida Only®, quando comparado ao cultivar, sendo possível a utilização de dose total de até 200% no híbrido, em áreas com alta infestação de arroz-vermelho, sem afetar a produtividade. Porém é importante salientar que o incremento da dose do herbicida pode causar problemas de residual a culturas não tolerantes semeadas na seqüência.O controle de arroz-vermelho é total com aplicação fracionada do herbicida em pré e pós-emergência (PRÉ + PÓS, desde que o total aplicado não seja inferior a 125%. Essa condição é atendida pelo tratamento com 75% em PRÉ seguido de 50% em PÓS, o qual propicia a menor dose total entre aqueles com 100% de controle, não afetando a produtividade e apresentando fitotoxicidade semelhante ao tratamento com 100% em PÓS, utilizado como referência.Red rice (Oryza spp. is one of the main limiting factors to rice (O. sativa yield. An experiment was carried out to evaluate red rice

  15. SET DOMAIN GROUP 708, a histone H3 lysine 36-specific methyltransferase, controls flowering time in rice (Oryza sativa).

    Science.gov (United States)

    Liu, Bing; Wei, Gang; Shi, Jinlei; Jin, Jing; Shen, Ting; Ni, Ting; Shen, Wen-Hui; Yu, Yu; Dong, Aiwu

    2016-04-01

    As a key epigenetic modification, the methylation of histone H3 lysine 36 (H3K36) modulates chromatin structure and is involved in diverse biological processes. To better understand the language of H3K36 methylation in rice (Oryza sativa), we chose potential histone methylation enzymes for functional exploration. In particular, we characterized rice SET DOMAIN GROUP 708 (SDG708) as an H3K36-specific methyltransferase possessing the ability to deposit up to three methyl groups on H3K36. Compared with the wild-type, SDG708-knockdown rice mutants displayed a late-flowering phenotype under both long-day and short-day conditions because of the down-regulation of the key flowering regulatory genes Heading date 3a (Hd3a), RICE FLOWERING LOCUS T1 (RFT1), and Early heading date 1 (Ehd1). Chromatin immunoprecipitation experiments indicated that H3K36me1, H3K36me2, and H3K36me3 levels were reduced at these loci in SDG708-deficient plants. More importantly, SDG708 was able to directly target and effect H3K36 methylation on specific flowering genes. In fact, knockdown of SDG708 led to misexpression of a set of functional genes and a genome-wide decrease in H3K36me1/2/3 levels during the early growth stages of rice. SDG708 is a methyltransferase that catalyses genome-wide deposition of all three methyl groups on H3K36 and is involved in many biological processes in addition to flowering promotion. PMID:26639303

  16. Association Mapping for Drought Tolerance of RiceOryza sativa L.) at Vegetative Stage

    Institute of Scientific and Technical Information of China (English)

    Yulong XIAO; Chuanyuan YU; Jianguo LEI; Quirino D; DELA CRUZ; Jonalyn M.YABES; Dindo A.TABANAo

    2012-01-01

    [Objective] This study aimed to identify possible quantitative trait loci (QTL) for vegetative drought tolerance traits of riceOryza sativa L.). [Method] A total of 184 rice genotypes were field screened and 156 SSR markers randomly distributed at each 3 Mb bin were used through genome-wide scanning method and association analysis to detect QTLs for vegetative drought tolerance traits leaf rolling (LER), leaf drying (LED) and drought recovery rate (DRR). [Result] The experimental rice geno- types showed varied response under vegetative drought, LER, LED and DRR were highly correlated. Population structure was detected at K=3 and K=7, certain extent of admixture existed in the experimental rice genotypes, relative kinship of the rice genotypes ranged from 0 to 0.924 5. Significant linkage disequilibrium among SSR markers was detected. Sixteen SSR markers have been detected to be associated with vegetative drought tolerance traits, four for LER, eight for LED and four for DDR. Most of the markers were associated with more than one trait, indicating a single mechanism might involve in expression of several related traits, i.e. osmotic adjustment. RM107 (Chr.9) was associated with all the three traits and fell exactly within or closely nearby to previous reported regions, was a major QTL for vegeta- tive drought tolerance, RM477 (Chr.8) was significantly associated with DRR and ex- tremely significantly associated with LER was probably another major QTL for vege- tative drought tolerance. [Conclusion] Association mapping is a very effective method for describing complex traits like drought tolerance.

  17. Cloning and characterization of the serotonin N-acetyltransferase-2 gene (SNAT2) in rice (Oryza sativa).

    Science.gov (United States)

    Byeon, Yeong; Lee, Hyoung Yool; Back, Kyoungwhan

    2016-09-01

    The penultimate enzyme in melatonin synthesis is serotonin N-acetyltransferase (SNAT), which exists as a single copy in mammals and plants. Our recent studies of the Arabidopsis snat-knockout mutant and SNAT RNAi rice (Oryza sativa) plants predicted the presence of at least one other SNAT isogene in plants; that is, the snat-knockout mutant of Arabidopsis and the SNAT RNAi rice plants still produced melatonin, even in the absence or the suppression of SNAT expression. Here, we report a molecular cloning of an SNAT isogene (OsSNAT2) from rice. The mature amino acid sequences of SNAT proteins indicated that OsSNAT2 and OsSNAT1 proteins had 39% identity values and 60% similarity. The Km and Vmax values of the purified recombinant OsSNAT2 were 371 μm and 4700 pmol/min/mg protein, respectively; the enzyme's optimal activity temperature was 45°C. Confocal microscopy showed that the OsSNAT2 protein was localized to both the cytoplasm and chloroplasts. The in vitro enzyme activity of OsSNAT2 was severely inhibited by melatonin, but the activities of sheep SNAT (OaSNAT) and rice OsSNAT1 proteins were not. The enzyme activity of OsSNAT2 was threefold higher than that of OsSNAT1, but 232-fold lower than that of OaSNAT. The OsSNAT1 and OsSNAT2 transcripts were similarly suppressed in rice leaves during the melatonin induction after cadmium treatment. Phylogenetic analyses indicated that OsSNAT1 and OsSNAT2 are distantly related, suggesting that they evolved independently from Cyanobacteria prior to the endosymbiosis event. PMID:27121038

  18. Effects of high night temperature and abscisic acid (ABA) on rice (Oryza sativa L.) physiology

    Science.gov (United States)

    High night temperature (HNT) is known to decrease rice yields. The impact of abscisic acid (ABA) on plants has been the subject of many studies. However, little or no work has been carried out on rice response to ABA under HNT-stress conditions. This study determined the effects of ABA on rice leaf ...

  19. Monitoring expression profiles of rice (Oryza sativa L.) genes under abiotic stresses using cDNA Microarray Analysis (abstract)

    International Nuclear Information System (INIS)

    Transcript regulation in response to cold, drought, high salinity and ABA application was investigated in rice (Oryza sativa L., Nipponbare) with microarray analysis including approx. 1700 independent DNA elements derived from three cDNA libraries constructed from 15-day old rice seedlings stressed with drought, cold and high salinity. A total of 141 non-redundant genes were identified, whose expression ratios were more than three-fold compared with the control genes for at least one of stress treatments in microarray analysis. However, after RNA gel blot analysis, a total of 73 genes were identified, among them the transcripts of 36, 62, 57 and 43 genes were found increased after cold, drought, high salinity and ABA application, respectively. Sixteen of these identified genes have been reported previously to be stress inducible in rice, while 57 of which are novel that have not been reported earlier as stress responsive in rice. We observed a strong association in the expression patterns of stress responsive genes and found 15 stress inducible genes that responded to all four treatments. Based on Venn diagram analysis, 56 genes were induced by both drought and high salinity, whereas 22 genes were upregulated by both cold and high salinity stress. Similarly 43 genes were induced by both drought stress and ABA application, while only 17 genes were identified as cold and ABA inducible genes. These results indicated the existence of greater cross talk between drought, ABA and high salinity stress signaling processes than those between cold and ABA, and cold and high salinity stress signaling pathways. The cold, drought, high salinity and ABA inducible genes were classified into four gene groups from their expression profiles. Analysis of data enabled us to identify a number of promoters and possible cis-acting DNA elements of several genes induced by a variety of abiotic stresses by combining expression data with genomic sequence data of rice. Comparative analysis of

  20. Effect of gamma irradiation on physico-chemical and sensorial characteristics of rice (Oryza sativa L.) and on the development of Sitophilus oryzae L; Efeito da irradiacao gama nas caracteristicas fisico-quimicas e sensoriais do arroz (Oryza sativa L.) e no desenvolvimento de Sitophilus oryzae L

    Energy Technology Data Exchange (ETDEWEB)

    Zanao, Cintia Fernanda Pedroso; Canniatti-Brazaca, Solange Guidolin; Sarmento, Silene Bruder Silveira [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao], e-mail: sgcbrazaca@esalq.usp.br, e-mail: cpedroso@claretianas.com.br, e-mail: sbssarme@esalq.usp.br; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia], e-mail: arthur@cena.usp.br

    2009-01-15

    The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L.) conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental), and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p {<=} 0.05) was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b{sup *} indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best to meet the objectives of this study. (author)

  1. iTRAQ-based proteomic analysis reveals the mechanisms of silicon-mediated cadmium tolerance in rice (Oryza sativa) cells.

    Science.gov (United States)

    Ma, Jie; Sheng, Huachun; Li, Xiuli; Wang, Lijun

    2016-07-01

    Silicon (Si) can alleviate cadmium (Cd) stress in rice (Oryza sativa) plants, however, the understanding of the molecular mechanisms at the single-cell level remains limited. To address these questions, we investigated suspension cells of rice cultured in the dark environment in the absence and presence of Si with either short- (12 h) or long-term (5 d) Cd treatments using a combination of isobaric tags for relative and absolute quantitation (iTRAQ), fluorescent staining, and inductively coupled plasma mass spectroscopy (ICP-MS). We identified 100 proteins differentially regulated by Si under the short- or long-term Cd stress. 70% of these proteins were down-regulated, suggesting that Si may improve protein use efficiency by maintaining cells in the normal physiological status. Furthermore, we showed two different mechanisms for Si-mediated Cd tolerance. Under the short-term Cd stress, the Si-modified cell walls inhibited the uptake of Cd ions into cells and consequently reduced the expressions of glycosidase, cell surface non-specific lipid-transfer proteins (nsLTPs), and several stress-related proteins. Under the long-term Cd stress, the amount of Cd in the cytoplasm in Si-accumulating (+Si) cells was decreased by compartmentation of Cd into vacuoles, thus leading to a lower expression of glutathione S-transferases (GST). These results provide protein-level insights into the Si-mediated Cd detoxification in rice single cells. PMID:27017433

  2. High frequency plant regeneration from mature seed of elite, recalcitrant Malaysian indica rice ( Oryza sativa L.) CV. MR 219.

    Science.gov (United States)

    Sivakumar, P; Law, Y S; Ho, C-L; Harikrishna, Jennifer Ann

    2010-09-01

    An efficient in vitro plant regeneration system was established for elite, recalcitrant Malaysian indica rice, Oryza sativa L. CV. MR 219 using mature seeds as explant on Murashige and Skoog and Chu N6 media containing 2,4-dichlorophenoxy acetic acid and kinetin either alone or in different combinations. L-proline, casein hydrolysate and L-glutamine were added to callus induction media for enhancement of embryogenic callus induction. The highest frequency of friable callus induction (84%) was observed in N6 medium containing 2.5 mg l(-1) 2,4-dichlorophenoxy acetic acid, 0.2 mg l(-1) kinetin, 2.5 mg l(-1) L-proline, 300 mg l(-1) casein hydrolysate, 20 mg l(-1) L-glutamine and 30 g l(-1) sucrose under culture in continuous lighting conditions. The maximum regeneration frequency (71%) was observed, when 30-day-old N6 friable calli were cultured on MS medium supplemented with 3 mg l(-1) 6-benzyl aminopurine, 1 mg l(-1) naphthalene acetic acid, 2.5 mg l(-1) L-proline, 300 mg l(-1) casein hydrolysate and 3% maltose. Developed shoots were rooted in half strength MS medium supplemented with 2% sucrose and were successfully transplanted to soil with 95% survival. This protocol may be used for other recalcitrant indica rice genotypes and to transfer desirable genes in to Malaysian indica rice cultivar MR219 for crop improvement. PMID:20724277

  3. Influence of chelating ligands on arsenic uptake by hydroponically grown rice seedlings (Oryza sativa L.): a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Mohammad A.; Hasegawa, Hiroshi; Ueda, Kazumasa; Maki, Teruya [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa (Japan); Rahman, M.M. [Department of Botany, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka (Bangladesh)

    2008-06-15

    Ferric (oxyhydro-)oxides (FeO{sub x}) precipitate in the rhizosphere at neutral or alkaline pH and are adsorbed on the plant root surfaces. Consequently, the higher binding affinity of arsenate to FeO{sub x} and the low iron phytoavailability of the precipitated FeO{sub x} make the phytoremediation of arsenic difficult. In the present study, the influence of chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. When chelating ligands were not treated to the growth medium, about 63 and 71% of the total arsenic and iron were distributed in the root extract (outer root surfaces) of rice, respectively. On the other hand, ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS) and hydroxyiminodisuccinic acid (HIDS) desorbed a significant amount of arsenic from FeO{sub x} of the outer root surfaces. Therefore, the uptake of arsenic and iron into the roots and their subsequent translocation to the shoots of the rice seedlings increased significantly. The order of increasing arsenic uptake by chelating ligands was HIDS > EDTA > EDDS. Methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) might not be effective in arsenic solubilization from FeO{sub x}. The results suggest that EDDS and HIDS would be a good and environmentally safe choice to accelerate arsenic phytoavailability in the phytoremediation process because of their biodegradability and would be a competent alternative to the widely used non-biodegradable and environmentally persistent EDTA. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  4. Genetic diversity of rice cultivars (Oryza sativa L.) in China and the temporal trends in recent fifty years

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To understand geographical distribution of the genetic diversity of rice cultivars (Oryza sativa L.) and its trends in recent fifty years in China, 453 accessions were analyzed by 36 microsatellites loci and 42 phenotypic traits. Results revealed that the genetic diversity by SSRs is highly consistent with that by phenotypic traits and the genetic diversity of indica cultivars was higher than that of japonica cultivars; the genetic diversity of cultivars declined from 1950s to 1980s and then increased greatly; among the six rice ecological zones (REZs), genetic diversity of REZⅡ was the highest and those of REZⅤ and REZⅥ were the lowest at both DNA and phenotypic level. Jiangsu and Jiangxi provinces in the middle and lower reaches of Yangtze River and Sichuan province in southwest of China were the areas with the highest genetic diversity. Breeders in REZⅤ which is an important japonica rice area but with very low genetic diversity should explore more gene resources to widen the genetic backgrounds of cultivars.

  5. In vitro Antimicrobial Assay of Actinomycetes in Rice AgainstXanthomonas oryzae pv. oryzicola and as Potential Plant Growth Promoter

    Directory of Open Access Journals (Sweden)

    Erneeza Mohd Hata

    2015-12-01

    Full Text Available ABSTRACT The aim of this work was to invitro assay the antimicrobial activity of actinomycetes in rice against Xanthomonas oryzae pv. oryzicola and as potential plant growth promoter. A total of 92 actinomycete strains were isolated from different rice plant components and field locations. Of these, only 21.74% showed antagonistic activity against the Xoc pathogen. Molecular identification via 16s rRNA amplification revealed that 60% of the active antagonistic strains belonged to the genus Streptomyces. Isolates that demonstrated the highest antagonistic activity were also able to produce hydrolytic enzymes and plant growth-promoting hormones. Combination of preliminary screening based on in vitro antagonistic, hydrolytic enzyme and plant growth hormone activity facilitated the best selection of actinomycete candidates as evidenced by strains classification using cluster analysis (Ward's Method. Results from the preliminary screening showed that actinomycetes, especially Streptomycetes, could offer a promising source for both biocontrol and plant growth-promotion agents against BLS disease in rice.

  6. Genome-wide association study of rice (Oryza sativa L.) leaf traits with a high-throughput leaf scorer.

    Science.gov (United States)

    Yang, Wanneng; Guo, Zilong; Huang, Chenglong; Wang, Ke; Jiang, Ni; Feng, Hui; Chen, Guoxing; Liu, Qian; Xiong, Lizhong

    2015-09-01

    Leaves are the plant's solar panel and food factory, and leaf traits are always key issues to investigate in plant research. Traditional methods for leaf trait measurement are time-consuming. In this work, an engineering prototype has been established for high-throughput leaf scoring (HLS) of a large number of Oryza sativa accessions. The mean absolute per cent of errors in traditional measurements versus HLS were below 5% for leaf number, area, shape, and colour. Moreover, HLS can measure up to 30 leaves per minute. To demonstrate the usefulness of HLS in dissecting the genetic bases of leaf traits, a genome-wide association study (GWAS) was performed for 29 leaf traits related to leaf size, shape, and colour at three growth stages using HLS on a panel of 533 rice accessions. Nine associated loci contained known leaf-related genes, such as Nal1 for controlling the leaf width. In addition, a total of 73, 123, and 177 new loci were detected for traits associated with leaf size, colour, and shape, respectively. In summary, after evaluating the performance with a large number of rice accessions, the combination of GWAS and high-throughput leaf phenotyping (HLS) has proven a valuable strategy to identify the genetic loci controlling rice leaf traits. PMID:25796084

  7. Identification of a candidate gene for panicle length in rice (Oryza sativa L. via association and linkage analysis

    Directory of Open Access Journals (Sweden)

    Erbao eLiu

    2016-05-01

    Full Text Available Panicle length (PL is an important trait for improving panicle architecture and grain yield in rice (Oryza sativa L.. Three populations were used to identify QTLs and candidate genes associated with PL. Four QTLs for PL were detected on chromosomes 4, 6 and 9 through linkage mapping in the recombinant inbred line population derived from a cross between the cultivars Xiushui79 (short panicle and C-bao (long panicle. Ten SSR markers associated with PL were detected on chromosomes 2, 3, 5, 6, 8, 9 and 10 in the natural population consisting of 540 accessions collected from East and Southeast Asia. A major locus on chromosome 9 with the largest effect was identified via both linkage and association mapping. LONG PANICLE 1 (LP1 locus was delimited to a 90-kb region of the long arm of chromosome 9 through fine mapping using a single segment segregating F2 population. Two single nucleotide polymorphisms (SNPs leading to amino acid changes were detected in the third and fifth exons of LP1. LP1encodes a Remorin_C-containing protein of unknown function with homologs in a variety of species. Sequencing analysis of LP1 in two parents and 103 rice accessions indicated that SNP1 is associated with panicle length. The LP1 allele of Xiushui79 leads to reduced panicle length, whereas the allele of C-bao relieves the suppression of panicle length. LP1 and the elite alleles can be used to improve panicle length in rice.

  8. Physico-chemical and sensorial characteristics of rice (Oryza sativa L.) irradiated and the effect in Sitophilus oryzae L. development;Caracteristicas fisico-quimicas e sensoriais do arroz (Oryza sativa L.) irradiado e o efeito no desenvolvimento de Sitophilus oryzae L.

    Energy Technology Data Exchange (ETDEWEB)

    Zanao, Cintia Fernanda Pedroso

    2007-07-01

    Rice is exposed to injuries especially due to the attack of insects, which represent great qualitative and quantitative losses. The aim of the present research was to verify the viability of the gamma irradiation as rice (Oryza sativa L.) conservation method; its efficiency in the control of an important pest for stored grains Sitophilus oryzae L. and the effects that irradiation may present in irradiated grains in relation to the sensory aspect and starch alterations. Samples were composed of polished rice and the gamma irradiation dosages used were 0.5; 1.0; 3.0; and 5.0 kGy, and kept at room temperature. Analyses of the grain breakage percentages during processing and the longevity and reproduction of the rice weevil were performed. Analyses of the centesimal composition, phytic acid, apparent amylose content and starch paste properties were also conducted, as well as analyses of the rice color (instrumental) and acceptability (hedonic test), aimed at the determination of the raw and cooked rice sensory quality. It was verified that the gamma irradiation did not change the grain breakage percentage significantly and caused a negative effect on the insect development. Irradiation did not change the centesimal composition significantly. No significant values of phytic acid were found because during rice processing, the outer part (bran) containing 85-92% of total phytates was removed. Values from 17.33 to 18.44% for the apparent amylose content were found, and irradiation did not affect the rice starch amylose content significantly. The paste properties results were significantly changed, where reduction on the paste temperature, decrease on the time for the occurrence of the peak viscosity, reduction on the final viscosity values were observed. The retrogradation tendency became less intense in starches with increasing irradiation dosages. Statistical differences (p<0.05) were detected in the sensory aspect between irradiated and non-irradiated samples, and the

  9. Characterization of 47 Cys2 -His2 zinc finger proteins required for the development and pathogenicity of the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Cao, Huijuan; Huang, Pengyun; Zhang, Lilin; Shi, Yongkai; Sun, Dandan; Yan, Yuxin; Liu, Xiaohong; Dong, Bo; Chen, Guoqing; Snyder, John Hugh; Lin, Fucheng; Lu, Jianping

    2016-08-01

    The Cys2 -His2 (C2H2) zinc finger protein family is the second-largest family of transcription factors (TFs) in Magnaporthe oryzae, the causal fungus responsible for the destructive rice blast disease. However, little is known about the roles of most C2H2 TFs in the development and pathogenicity of M. oryzae. The roles of 47 C2H2 genes in development and pathogenicity were investigated by gene deletion in M. oryzae. The TF-dependent genes in mycelia or appressoria were analyzed with RNA sequencing and quantitative PCR (qPCR). Forty-four C2H2 genes are involved in growth (20 genes), conidiation (28 genes), appressorium formation (four genes) and pathogenicity (22 genes) in M. oryzae. Of these, MGG_14931, named as VRF1, is required for pathogenicity, specifically controlling appressorium maturation by affecting the expression of genes related to appressorial structure and function, including melanin biosynthesis, chitin catabolism, lipid metabolism, proteolysis, transmembrane transport, and response to oxidative stress; MGG_01776, named as VRF2, is required for plant penetration and invasive growth; conidiation-related gene CON7 is required for conidial differentiation; and MoCREA, encoding a carbon catabolite repression protein, is a novel repressor of lipid catabolism when glucose obtainable in M. oryzae. This study provides many insights into the regulation of growth, asexual development, appressorium formation, and pathogenicity by C2H2 TFs in M. oryzae. PMID:27041000

  10. Effect of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3)

    International Nuclear Information System (INIS)

    The effects of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3) in pot cultures have been studied. Compared to plants grown only in soil, shoot length, root length, fresh weight, dry weight, total proteins, total soluble sugars, starch and chlorophyll content of plants grown in soil supplemented with unirradiated or gamma-irradiated sludge were found to be significantly increased. Irradiation of sludge significantly stimulated the linear growth of shoot and root systems as well as fresh and dry weights of plants, compared to those grown in soil containing unirradiated sludge. There was also an improvement in the grain yield (weight of seed) when plants were grown in soil supplemented with irradiated sludge. The results obtained suggest that the gamma-irradiated sewage sludge can be beneficially recycled for agricultural uses. (author)

  11. Gamma ray, EMS and sodium azide induced effectiveness and efficiency of chlorophyll mutations in basmati rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    The effectiveness and efficiency of gamma ray, EMS, sodium azide alone or in combination in relation to chlorophyll mutations in two varieties of Basmati rice (Oryza sativa L.) in M2 generation were studied. The chlorophyll mutations were induced by all the doses of mutagens alone or in combination relatively at a fair frequency in both the varieties in M2 generation. In general, it was found that combination treatments of gamma rays and EMS were observed to be more efficient in Taraori Basmati, while EMS alone and combination treatment of gamma rays and EMS were more efficient in Pusa Basmati 1 on sterility and growth injury basis both. Sodium azide at 0.5 mM was found as the most effective dose in both Taraori Basmati and Pusa Basmati 1 cultivars. (author)

  12. Solid-state fermentation for the enrichment and extraction of proteins and antioxidant compounds in rice bran by Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    Larine Kupski

    2012-12-01

    Full Text Available The objective of this work was to evaluate the solid-state fermentation with Rhizopus oryzae CCT 7560 of rice bran for the enrichment of proteins and the antioxidant compounds in the fermented biomass. Fermentation was performed in tray bioreactors at 30ºC for 120 h. Protein extraction was done at alkaline pH, followed by precipitation with acetone. Phenolic compounds were extracted with cold methanol. The maximum protein was recovered from after 120 h (26.6%. The content of total phenolic compounds increased during the fermentation and was maximum after 96 h, which inhibited the DPPH radical by 87%. The promising characteristics of the protein and phenolic extracts of the biomass suggested the application in the coating composition for vegetal tissues preservation.

  13. Germination Time Dependence of Bioactive Compounds and Antioxidant Activity in Germinated Rough Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Anuchita Moongngarm

    2011-01-01

    Full Text Available Problem statement: Germinated rice has been recognized as a functional food and its health benefits. However, most related studies were on germinated brown rice but our previous study indicated that germination of rough rice was an effective method to obtain high concentrations of bioactive compounds. Germination time is one of the most important factors affecting the level of biochemical compositions and antioxidant activity. Approach: Rough rice seeds were soaked in water for 2 days and germinated for four different days (1- 4 days. Total phenolic compounds, phytic acid, á-tocopherol, á- tocopherol, á-tocotrienol and á-oryzanol were investigated compared with those of ungerminated brown rice. The antioxidant activity of germinated rice was evaluated through four different methods, the 1, 1- Diphenyl-2-Picrylhydrazyl (DPPH free radical scavenging assay, hydroxyl radical scavenging activity, lipid peroxidation assay and linoleic acid emulsion system-thiocyanate method. Results: The results showed that the germination for 2 days or longer, after soaking, yielded significantly higher level of total phenolic, á-tocopherol, á-tocopherol, á-tocotrienol and á-oryzanol than those of ungerminated brown rice and soaked rice, whilst the concentration of phytic acid was reduced significantly when germination time was increased. The samples germinated for one day or longer also revealed greater antioxidant activity than those of ungerminated rice. Conclusion: The level of bioactive compounds and antioxidant activity of germinated rough rice were affected by germination time. Germination for 2 and 3 days was the optimum time for germination rough rice to obtain high concentration of bioactive compounds and high antioxidant activity. The germination process of rough rice could be a potential method to obtain functional germinated rice flour with high bioactive compounds and health beneficial properties and could be applied to produce

  14. Genetic determinants of semi-dwarf characters induced in Oryza sativa for upland rice cultivation

    International Nuclear Information System (INIS)

    Numerous semi-dwarf mutants have been obtained by applying gamma irradiation to tall upland varieties. They show better lodging resistance and retain their adaptation to upland cultivation conditions (MARIE, 1974). These mutants are also of interest as cross breeding parents. If the breeder knows the genes for semi-dwarfness, he can use different ones so as to avoid the risk of a narrow genetic base. Five induced mutants and one deviant from a sixth one, were used in this study. The semi-dwarf characters were analysed in two steps: Comparison of the stem morphology of the conventional varieties and of the induced mutants; Studying the behaviour of hybrid F1 and F2 segregations. Three types of genetic control for induced semi-dwarfness have been found on the basis of the six mutants used: A recessive single-gene determinant in IRAT 115; A recessive single-gene determinant different from the preceding one and common to IRAT 13, IRAT 177, IRAT 250 and IRAT 257; A semi-dominant single-gene determinant in IRAT 194. For his hybridization programme, the rice breeder therefore has at his disposal various upland semi-dwarf mutants, which are capable of transmitting this character in accordance with simple Mendelian rules. However, he has to test also their general cross breeding value. IRAT 13, from which most IRAT varieties released so far originated (including IRAT 104, IRAT 170 and IRAT 112), is undoubtedly a good parent. Mutants IRAT 177, IRAT 250 and IRAT 257, which have the same gene for semi-dwarfness, have been used more recently. They exhibit an excellent ability for combination with tall upland varieties, while being differentiated by a few features (better recombination for seed shedding or resistance to Pyricularia oryzae with IRAT 257 and for grain character with IRAT 177 or 250). The recombination observed in the crosses involving IRAT 115 and conventional upland varieties seems poor. Paradoxically, IRAT 115 has been found to become an excellent parent after

  15. Proteins interacting with mitochondrial ATP-dependent Lon protease (MAP1) in Magnaporthe oryzae are involved in rice blast disease.

    Science.gov (United States)

    Cui, Xiao; Wei, Yi; Wang, Yu-Han; Li, Jian; Wong, Fuk-Ling; Zheng, Ya-Jie; Yan, Hai; Liu, Shao-Shuai; Liu, Jin-Liang; Jia, Bao-Lei; Zhang, Shi-Hong

    2015-10-01

    The ATP-dependent Lon protease is involved in many physiological processes. In bacteria, Lon regulates pathogenesis and, in yeast, Lon protects mitochondia from oxidative damage. However, little is known about Lon in fungal phytopathogens. MAP1, a homologue of Lon in Magnaporthe oryzae, was recently identified to be important for stress resistance and pathogenesis. Here, we focus on a novel pathogenic pathway mediated by MAP1. Based on an interaction system between rice and a tandem affinity purification (TAP)-tagged MAP1 complementation strain, we identified 23 novel fungal proteins from infected leaves using a TAP approach with mass spectrometry, and confirmed that 14 of these proteins physically interact with MAP1 in vivo. Among these 14 proteins, 11 candidates, presumably localized to the mitochondria, were biochemically determined to be substrates of MAP1 hydrolysis. Deletion mutants were created and functionally analysed to further confirm the involvement of these proteins in pathogenesis. The results indicated that all mutants showed reduced conidiation and sensitivity to hydrogen peroxide. Appressorial formations were not affected, although conidia from certain mutants were morphologically altered. In addition, virulence was reduced in four mutants, enhanced (with lesions forming earlier) in two mutants and remained unchanged in one mutant. Together with the known virulence-related proteins alternative oxidase and enoyl-CoA hydratase, we propose that most of the Lon-interacting proteins are involved in the pathogenic regulation pathway mediated by MAP1 in M. oryzae. Perturbation of this pathway may represent an effective approach for the inhibition of rice blast disease. PMID:25605006

  16. Peroxisomal alanine: glyoxylate aminotransferase AGT1 is indispensable for appressorium function of the rice blast pathogen, Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Vijai Bhadauria

    Full Text Available The role of β-oxidation and the glyoxylate cycle in fungal pathogenesis is well documented. However, an ambiguity still remains over their interaction in peroxisomes to facilitate fungal pathogenicity and virulence. In this report, we characterize a gene encoding an alanine, glyoxylate aminotransferase 1 (AGT1 in Magnaporthe oryzae, the causative agent of rice blast disease, and demonstrate that AGT1 is required for pathogenicity of M. oryzae. Targeted deletion of AGT1 resulted in the failure of penetration via appressoria; therefore, mutants lacking the gene were unable to induce blast symptoms on the hosts rice and barley. This penetration failure may be associated with a disruption in lipid mobilization during conidial germination as turgor generation in the appressorium requires mobilization of lipid reserves from the conidium. Analysis of enhanced green fluorescent protein expression using the transcriptional and translational fusion with the AGT1 promoter and open reading frame, respectively, revealed that AGT1 expressed constitutively in all in vitro grown cell types and during in planta colonization, and localized in peroxisomes. Peroxisomal localization was further confirmed by colocalization with red fluorescent protein fused with the peroxisomal targeting signal 1. Surprisingly, conidia produced by the Δagt1 mutant were unable to form appressoria on artificial inductive surfaces, even after prolonged incubation. When supplemented with nicotinamide adenine dinucleotide (NAD(++pyruvate, appressorium formation was restored on an artificial inductive surface. Taken together, our data indicate that AGT1-dependent pyruvate formation by transferring an amino group of alanine to glyoxylate, an intermediate of the glyoxylate cycle is required for lipid mobilization and utilization. This pyruvate can be converted to non-fermentable carbon sources, which may require reoxidation of NADH generated by the β-oxidation of fatty acids to NAD(+ in

  17. Spectroscopic determination of essential elements in unpolished rice (oryza sativa l.), grown at rri, Dokri

    International Nuclear Information System (INIS)

    seven rice varieties collected from, Rice Research institute (RRI) Dokri, Sindh in Pakistan. Agricultural soil samples was also collected to evaluate the bioavailability of eight essential elements to seven varieties of rice grown in the same agricultural plot. The agricultural soil and rice varieties were digested by wet acid digestion method. Homogeneity of the prepared materials was evaluated through the determination of eight essential elements i.e., Na, K, Mg, Ca, Fe, Mn, Zn, using flame atomic absorption spectrophotometer. The unpolished rice varieties contained high amount of essential micro nutrients such as Na, K, Mg, Ca, Fe, Mn, Zn, and Cu (616.01, 4097.15, 626.20, 73.90, 1829.88, 50.34, 42.72 and 7.21 mg/kg) in seven different varieties of rice i.e. DR-82, DR83, DR92, Kanwal-95, Lateefi, Sadahayat and Sarshar respectively. (author)

  18. Construction of a DNA library from chromosome 4 of riceOryza sativa) by microdissection

    Institute of Scientific and Technical Information of China (English)

    MAOYINGWEI; SIYUANLIANG; 等

    1998-01-01

    A simple method to create a chromosome-specific DNA librqary of rice,including microdissection,amplification,charterization and cloning,is described.Rice chromosome 4 from a metaphase cell has been isolated and amplified by the Linker Adapter PCR (LA-PCR).The PCR products were labeled as probes with DIG-11-dUTP using the random priming method.Southern blot analysis with rice genomic DNA and specific RFLP markers demonstrated that the PCR products were derived from rice chromosome 4.A large library comprising over 100,000 recombinant plasmid microclones from rice chromosome 4 was constructed.Colony hybridization showed that 58% of the clones contained single or low-copy sequences and 42% contained repetitive sequences.The size of inserts generated by PCR ranged from 140bp to 500bp.This method will facilitate cloning of the specific chromosome DNA markers and important genes of rice.

  19. Preformed expression of defense is a hallmark of partial resistance to rice blast fungal pathogen Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Tharreau D

    2010-09-01

    Full Text Available Abstract Background Partial resistance to plant pathogens is extensively used in breeding programs since it could contribute to resistance durability. Partial resistance often builds up during plant development and confers quantitative and usually broad-spectrum resistance. However, very little is known on the mechanisms underlying partial resistance. Partial resistance is often explained by poorly effective induction of plant defense systems. By exploring rice natural diversity, we asked whether expression of defense systems before infection could explain partial resistance towards the major fungal pathogen Magnaporthe oryzae. The constitutive expression of 21 defense-related genes belonging to the defense system was monitored in 23 randomly sampled rice cultivars for which partial resistance was measured. Results We identified a strong correlation between the expression of defense-related genes before infection and partial resistance. Only a weak correlation was found between the induction of defense genes and partial resistance. Increasing constitutive expression of defense-related genes also correlated with the establishment of partial resistance during plant development. Some rice genetic sub-groups displayed a particular pattern of constitutive expression, suggesting a strong natural polymorphism for constitutive expression of defense. Constitutive levels of hormones like salicylic acid and ethylene cannot explain constitutive expression of defense. We could identify an area of the genome that contributes to explain both preformed defense and partial resistance. Conclusion These results indicate that constitutive expression of defense-related genes is likely responsible for a large part of partial resistance in rice. The finding of this preformed defense system should help guide future breeding programs and open the possibility to identify the molecular mechanisms behind partial resistance.

  20. Excavation of Pid3 Orthologs with Differential Resistance Spectra to Magnaporthe oryzae in Rice Resource

    OpenAIRE

    Xu, Xiao; Lv, Qiming; Shang, Junjun; Pang, Zhiqian; Zhou, Zhuangzhi; Wang, Jing; Jiang, Guanghuai; Tao, Yong; Xu, Qian; Li, Xiaobing; Zhao, Xianfeng; Li, Shigui; Xu, Jichen; Zhu, Lihuang

    2014-01-01

    Twenty-six orthologs of the rice blast resistance gene Pid3 from cultivated varieties and wild rice accessions distributed in different areas were cloned by allele mining. Sequence analysis showed that while each of the orthologous genes from indica varieties and most wild accessions encodes a complete NBS-LRR protein, each of the proteins encoded by those from japonica varieties and few wild rice accessions presents a premature termination. Eleven of the 26 orthologs were selected for blast ...

  1. Seed Germination Ecology of Echinochloa glabrescens and Its Implication for Management in Rice (Oryza sativa L.)

    OpenAIRE

    Jhoana L. Opeña; Chauhan, Bhagirath S.; Baltazar, Aurora M.

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth o...

  2. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae

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    Ga Young Jung

    2016-08-01

    Full Text Available ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1 is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus.

  3. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae.

    Science.gov (United States)

    Jung, Ga Young; Park, Ju Yeon; Choi, Hyo Ju; Yoo, Sung-Je; Park, Jung-Kwon; Jung, Ho Won

    2016-08-01

    ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1) is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s) for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM) plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus. PMID:27493611

  4. Evaluation of soil characteristics potentially affecting arsenic concentration in paddy rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, Katja, E-mail: katja.bogdan@pflern.uni-hannover.d [Institute of Plant Nutrition, Leibniz Universitaet Hannover, Herrenhaeuser Str. 2, 30419 Hannover (Germany); Schenk, Manfred K., E-mail: schenk@pflern.uni-hannover.d [Institute of Plant Nutrition, Leibniz Universitaet Hannover, Herrenhaeuser Str. 2, 30419 Hannover (Germany)

    2009-10-15

    Paddy rice may contribute considerably to the human intake of As. The knowledge of soil characteristics affecting the As content of the rice plant enables the development of agricultural measures for controlling As uptake. During field surveys in 2004 and 2006, plant samples from 68 fields (Italy, Po-area) revealed markedly differing As concentration in polished rice. The soil factors total As{sub (aquaregia)}, pH, grain size fractions, total C, plant available P{sub (CAL)}, poorly crystalline Fe{sub (oxal.)} and plant available Si{sub (Na-acetate)} content that potentially affect As content of rice were determined. A multiple linear regression analysis showed a significant positive influence of the total As{sub (aquaregia)} and plant available P{sub (CAL)} content and a negative influence of the poorly crystalline Fe{sub (oxal.)} content of the soil on the As content in polished rice and rice straw. Si concentration in rice straw varied widely and was negatively related to As content in straw and polished rice. - Field selection for total As, poorly crystalline Fe and plant available P in soil might contribute to control As content of paddy rice.

  5. Identification and functional analysis of flowering related microRNAs in common wild rice (Oryza rufipogon Griff..

    Directory of Open Access Journals (Sweden)

    Zongxiang Chen

    Full Text Available BACKGROUND: MicroRNAs (miRNAs is a class of non-coding RNAs involved in post- transcriptional control of gene expression, via degradation and/or translational inhibition. Six-hundred sixty-one rice miRNAs are known that are important in plant development. However, flowering-related miRNAs have not been characterized in Oryza rufipogon Griff. It was approved by supervision department of Guangdong wild rice protection. We analyzed flowering-related miRNAs in O. rufipogon using high-throughput sequencing (deep sequencing to understand the changes that occurred during rice domestication, and to elucidate their functions in flowering. RESULTS: Three O. rufipogon sRNA libraries, two vegetative stage (CWR-V1 and CWR-V2 and one flowering stage (CWR-F2 were sequenced using Illumina deep sequencing. A total of 20,156,098, 21,531,511 and 20,995,942 high quality sRNA reads were obtained from CWR-V1, CWR-V2 and CWR-F2, respectively, of which 3,448,185, 4,265,048 and 2,833,527 reads matched known miRNAs. We identified 512 known rice miRNAs in 214 miRNA families and predicted 290 new miRNAs. Targeted functional annotation, GO and KEGG pathway analyses predicted that 187 miRNAs regulate expression of flowering-related genes. Differential expression analysis of flowering-related miRNAs showed that: expression of 95 miRNAs varied significantly between the libraries, 66 are flowering-related miRNAs, such as oru-miR97, oru-miR117, oru-miR135, oru-miR137, et al. 17 are early-flowering -related miRNAs, including osa-miR160f, osa-miR164d, osa-miR167d, osa-miR169a, osa-miR172b, oru-miR4, et al., induced during the floral transition. Real-time PCR revealed the same expression patterns as deep sequencing. miRNAs targets were confirmed for cleavage by 5'-RACE in vivo, and were negatively regulated by miRNAs. CONCLUSIONS: This is the first investigation of flowering miRNAs in wild rice. The result indicates that variation in miRNAs occurred during rice domestication and

  6. EFFECT OF CHEMICAL SEED TREATMENT IN THE CONTROL OF BLAST DISEASE AND BROWN SPOT OF RICE EFEITO DO TRATAMENTO QUÍMICO DE SEMENTES NO CONTROLE DE BRUSONE (Pyricularia oryzae E MANCHA PARDA (Helminthosporium oryzae DO ARROZ

    Directory of Open Access Journals (Sweden)

    Valácia Lemes da Silva

    2007-09-01

    Full Text Available

    With the objective of controlling blast disease (Pyricularia oryzae and brown spot (Helminthosporium oryzae of rice (Oryza sativa, different fungicides were tested, through seeds treatment, at field culture in low land soil. The results showed, preliminarily and in general terms that fungicides dichlofluanid and terbuconazole propitiated in the stand increase superior to 30% when confronted with standard fungicide mancozeb and testimony with regard to infection level at plants the best results were presented by terbuconazole. Refering to production there was no significative difference between both treatments. Treatments with fungicide terbuconazole individually or in mixture with dichlofluanid showed superiority over testimonies.

    Com o objetivo de controlar brusone (Pyricularia oryzae e mancha parda (Helminthosporium oryzae do arroz (Oryza sativa, diferentes fungicidas foram testados, através do tratamento de sementes, a nível de campo em solo de várzea (glei pouco húmico. Os resultados mostraram, preliminarmente e de modo geral, que os fungicidas dichlofluanid e terbuconazole propiciaram aumento no “stand” superiores a 30% quando comparados com o fungicida padrão mancozeb e a testemunha. Com relação ao nível de infecção nas plantas, o terbuconazole foi o que melhores resultados apresentou. E quanto à produção não houve diferença significativa entre os tratamentos. Os tratamentos com o fungicida terbuconazole individualmente ou em mistura com dichlofluanid mostraram-se superiores às testemunhas.

  7. Structural and functional analysis of rice blast avirulence gene AVR-Pita1 in Magnaporthe oryzae

    Science.gov (United States)

    The resistance gene Pi-ta in rice has been effectively deployed around the globe to prevent the rice blast disease. It was previously known that Pi-ta interacts with the avirulence gene AVR-Pita1 in the fungus in triggering effective resistance responses. In order to predict the stability of deploy...

  8. DNA methylation affected by male sterile cytoplasm in rice (Oryza sativa L.)

    Science.gov (United States)

    Male sterile cytoplasm plays an important role in hybrid rice and cytoplasmic effects are sufficiently documented. However, no reports are available on DNA methylation affected by male sterile cytoplasm in hybrid rice. We used a methylation sensitive amplified polymorphism (MSAP) technique to charac...

  9. Assessment of genetic variability in rice (oryza sativa l.) germplasm from Pakistan using rapd markers

    International Nuclear Information System (INIS)

    Information on genetic diversity and relationships among rice genotypes from Pakistan is currently very limited. Molecular marker analysis can truly be beneficial in analyzing the diversity of rice germplasm providing useful information to broaden the genetic base of modern rice cultivars. The objective of this study was to evaluate the genetic polymorphism of 75 rice accessions and improved cultivars using random amplified polymorphic DNA (RAPD) technique. Twenty-eight decamer-primers generated a total of 145 RAPD fragments, of which 116 (80%) were polymorphic. The number of amplification products produced by each primer varied from 3 to 9 with an average of 5.2 alleles primer-1. The size of amplified fragments ranged from 250 to 4000bp. A dendrogram was generated from minimal variance algorithm using Ward method. All the 75 genotypes were grouped into two main groups corresponding to aromatic and non-aromatic types of indica rice. Clustering of accessions did not show any significant pattern of association between the RAPD fingerprints and collection sites. This type of analysis grouping different rice accessions in relation to fragrance, a major rice quality determinant, and varietal group is extremely useful to develop a core collection and gene bank management. Further more, the information revealed by the RAPDs regarding genetic variation is helpful to the plant breeder in selecting diverse parents and for future orientation of rice breeding program. (author)

  10. RICE (Oryza sativa L. CULTIVATION AND IT’S GEOGRAPHICAL DISTRIBUTIONIN TURKEY

    Directory of Open Access Journals (Sweden)

    Nuran TAŞLIGİL

    2011-06-01

    Full Text Available Rice is one of the staple foods in the world. Rice in the husk is a cereal whose breeding depends on a special access because of the climate it needs can create a malaria epidemic. Turkey is one of the major countries in rice in the husk breeding. In Turkey, the accretion in the amount of the rice for each person especially after 1980, caused an accretion in the export of the notch. As a matter of fact, the production and the breeding of the notch changes every year acording to the economy, ecology and the marketing channels. However, according to the last istatistics it has been understood that the rice plantation areas in Marmara Region and Edirne showed distinction among the whole country.

  11. Analysis of Male Sterility-Related Proteins of Young Panicle in Rice (Oryza sativa L.) by Two-Dimensional Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    HU Yao-jun; WEI Lei; LIU Shu-nan; YU Jin-hong; DING Yi

    2005-01-01

    For searching out male sterility-related proteins (polypeptides) in rice (Oryza sativa L.), we examined the difference of panicle protein (polypeptides) between hybrid rice (Wujin2A/R168, Wujin5A/R988) and their parents (male-sterile line Wujin2A, Wujin5A, and restorer line R168, R988) at the formation stage of pollen mother cell by two-dimensional electrophoresis (2-DE). The results revealed that the 2-DE polypeptide maps were similar among these experimental materials. A small group of polypeptides were disappeared in 2-DE polypeptide maps of male-sterile line (Wujin2A, Wujin5A) by comparing to restorer line (R168, R988) and the first filial (F1) generation (Wujin2A/R168, Wujin5A/R988). The isoelectric points of these polypeptides were pI 5.8-6.5, molecular weight 42.7×103-66.2×103.

  12. Characterization of 14C-(Lignin)-Lignocellulose from rice (Oryza sativa L. var. Ratna) for Lignolytic studies

    International Nuclear Information System (INIS)

    The present study was undertaken for preparation and characterization of 14C-(lignin)-lignocellulose from rice (Oryza sativa L. var. Ratna) seedling (direct sown and transplanted) of different ages viz. 2-4 weeks for use as a substrate for lignolytic studies. It involves uptake of 14C-phenylalanine as a precursor by cut shoots through transpiration stream followed by drying and powering of the tissues and exhaustive extraction with hot water, ethanol and benzene to remove the radioactivity in non-lignin fractions. The radioactivity in protein fraction was removed by treatment with protcase. The results showed that the total recovery of 14C of the administered activity in the lignocellulose fraction ranges from 17.5 - 7.3 percent in direct sown and 6.1-3.3 percent in transplanted plants. Klason lignin content was found to range from 35.5-48.0 percent in direct sown and 52.9-59.7 percent in transplanted seedlings. The final 14C-lignocellulose specific activity was found maximal in 2 weeks old seedling under direct sown conditions (1.73 x 103 dpm/mg). The results of present investigation shows that younger rice plants were more suited for preparing 14C-(lignin)-substrate for biodegradation studies and the plants of direct sown were much suited than plants of transplanted nature. (author)

  13. Influence of Mn and Fe Counteraction on RiceOryza Sativa L.) Oranging Physiological Disease

    Institute of Scientific and Technical Information of China (English)

    LIAOZHONG-WEN; LINDONG-JIAO; 等

    1994-01-01

    Mn and Fe are two important micronutrients of paddy soils derived from red earths.Rice(Oryza sativa L.)oranging physiological diease in newly reclaimed red rarths is related to Fe toxicity.There have been considerable studies on Mn and Fe counteraction,but influence of Mn and Fe counteration on rice oranging physiological disease still remains unknown.This paper is to study,using two soils from USA and China respectively,the relationship between Nn and Fe counteraction and the physiological disease.Analysis for water soluble and extractable Fe and Mn showed that Mn/Fe ratios of the red earths were lower than those of the paddy soils.Fertilizing with Mn raised Mn/Fe and reduced oranging leaves,improved growth and increased yields.Analysis with electron probe showed that Mn treatment had less Fe deposit in root epidermis and more Ca and Si in roots.The results indicated that fertilizing with Mn could correct Fe toxicity.How to apply Mn and Fe counteraction in practice is worth further studying.

  14. Studies on the physiological changes in the rice plants infected with Xanthomonas campestris pv. of oryzae, (4)

    International Nuclear Information System (INIS)

    The translocation and accumulation of 14C-photosynthetic assimilates in rice plants infected with Xanthomonas campestris pv. oryzae were investigated. Approximately the same quantities of assimilates were detected in healthy and infected leaves 1 day after photosynthesis, but 1.7 times as much as healthy leaves assimilates were still remained in infected leaves 7 days after photosynthesis. Much more 14C-photosynthetic assimilates were generally detected in leaf blade than in leaf sheath or in root within 1 day after photosynthesis, but detected in leaf sheath than in leaf blade later than 2 days after photosynthesis. The rates of translocation of 14C-assimilates from leaf blade to leaf sheath were lower in inoculated rice plants than in healthy ones. In both healthy and inoculated leaves of susceptible and resistant cultivars, there was a tendency that 14C-sugar contents decreased, but 14C-organic acid and -amino acid contents increased gradually after photosynthesis. Incorporation of 14C-photosynthetic assimilates into invading bacterial cells which were separated from leaf tissues by the methods of leakage and Millipore filtration was not detected immediately after photosynthesis, but became apparent 5 days after photosynthesis. The leakage of 14C-photosynthetic assimilates from leaf tissues into bathing solution was about 4 times higher in infected leaves than in healthy ones 5 days after photosynthesis, suggesting that the permeability in infected leaf tissues would increase. (author)

  15. Multiple translocation of the AVR-Pita effector gene among chromosomes of the rice blast fungus Magnaporthe oryzae and related species.

    Directory of Open Access Journals (Sweden)

    Izumi Chuma

    2011-07-01

    Full Text Available Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family corresponding to the Pita resistance gene, in various isolates of M. oryzae (including wheat and millet pathogens and its related species. We found that AVR-Pita (AVR-Pita1 and AVR-Pita2 is highly variable in its genome location, occurring in chromosomes 1, 3, 4, 5, 6, 7, and supernumerary chromosomes, particularly in rice-infecting isolates. When expressed in M. oryzae, most of the AVR-Pita homologs could elicit Pita-mediated resistance, even those from non-rice isolates. AVR-Pita was flanked by a retrotransposon, which presumably contributed to its multiple translocation across the genome. On the other hand, family member AVR-Pita3, which lacks avirulence activity, was stably located on chromosome 7 in a vast majority of isolates. These results suggest that the diversification in genome location of AVR-Pita in the rice isolates is a consequence of recognition by Pita in rice. We propose a model that the multiple translocation of AVR-Pita may be associated with its frequent loss and recovery mediated by its transfer among individuals in asexual populations. This model implies that the high mobility of AVR-Pita is a key mechanism accounting for the rapid adaptation toward Pita. Dynamic adaptation of some fungal plant pathogens may be achieved by deletion and recovery of avirulence genes using a population as a unit of adaptation.

  16. Efeito da irradiação gama nas características físico-químicas e sensoriais do arroz (Oryza sativa L. e no desenvolvimento de Sitophilus oryzae L. Effect of gamma irradiation on physico-chemical and sensorial characteristics of rice (Oryza sativa L. and on the development of Sitophilus oryzae L.

    Directory of Open Access Journals (Sweden)

    Cíntia Fernanda Pedroso Zanão

    2009-03-01

    Full Text Available A pesquisa teve como objetivo verificar a viabilidade da radiação gama como método de conservação do arroz polido (Oryza sativa L.. As amostras foram irradiadas com doses 0,5; 1,0; 3,0; e 5,0 kGy. Foram realizadas análises da quebra do grão no beneficiamento, da longevidade e reprodução do Sitophilus oryzae L., a composição centesimal, o conteúdo de amilose aparente e propriedades de pasta dos amidos, e análises para cor (instrumental e análise sensorial do arroz cru e cozido. Foi utilizado teste de Tukey (p The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L. conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental, and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p < 0.05 was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b* indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best

  17. Mitotic stopwatch for the blast fungus Magnaporthe oryzae during invasion of rice cells.

    Science.gov (United States)

    Jones, Kiersun; Jenkinson, Cory B; Borges Araújo, Maíra; Zhu, Jie; Kim, Rebecca Y; Kim, Dong Won; Khang, Chang Hyun

    2016-08-01

    To study nuclear dynamics of Magnaporthe oryzae, we developed a novel mitotic reporter strain with GFP-NLS (localized in nuclei during interphase but in the cytoplasm during mitosis) and H1-tdTomato (localized in nuclei throughout the cell cycle). Time-lapse confocal microscopy of the reporter strain during host cell invasion provided several new insights into nuclear division and migration in M. oryzae: (i) mitosis lasts about 5min; (ii) mitosis is semi-closed; (iii) septal pores are closed during mitosis; and (iv) a nucleus exhibits extreme constriction (approximately from 2μm to 0.5μm), elongation (over 5μm), and long migration (over 16μm). Our observations raise new questions about mechanisms controlling the mitotic dynamics, and the answers to these questions may result in new means to prevent fungal proliferation without negatively affecting the host cell cycle. PMID:27321562

  18. Screening of Drought Resistance Identification Indexes for Rice (Oryza sativa L.) Cultivars in Ningxia

    Institute of Scientific and Technical Information of China (English)

    Changkai LAI; Wenyin ZHANG; Qi HE; Jianchang SUN; Xingsheng WANG; Yanbo YIN

    2016-01-01

    The morphological characters, physiological characters, yield traits and yield per plant of total 49 rice cultivars from Ningxia were investigated under conditions of water stress and non-water stress so as to determine the relationship between each trait and yield per plant under water stress and the relationship between each relative character and drought resistance coefficient under water stress and non-water stress. The correlation, grey correlation, stepwise regression and path analyses showed that the til er number per plant, plant height, grain density, effective panicle number per plant and grain number per pan-icle, total 5 traits, were significantly correlated with the drought resistance of rice, and they could be used to identify the drought resistance of rice in Ningxia. In addition, the drought resistance of rice was graded qualitatively according to the subordinate function value of corresponding drought resistance coefficient. The results showed that among the 49 rice cultivars from Ningxia, 6 rice cultivars were highly drought resistant, and 9 rice cultivars were moderately drought resistant, suggesting that the evalua-tion method was feasible and effective.

  19. Quantitative Trait Loci for Resistance to Stripe Disease in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to map the quantitative trait loci for rice stripe resistance, a molecular linkage map was constructed based on the lines to rice stripe were investigated by both artificial inoculation at laboratory and natural infection in the field, and the ratios of ranged from 0 to 134.08 and from 6.25 to 133.6 under artificial inoculation at laboratory and natural infection in the field, respectively,and showed a marked bias towards resistant parent (Zhaiyeqing 8), indicating that the resistance to rice stripe was controlled by quantitative trait loci (QTL). QTL analysis showed that the QTLs detected by the two inoculation methods were completely different.Only one QTL, qSTV7, was detected under artificial inoculation, at which the Zhaiyeqing 8 allele increased the resistance to rice stripe, while two QTLs, qSTV5 and qSTV1, were detected under natural infection, in which resistant alleles came from Zhaiyeqing 8and Wuyujing 3, respectively. These results showed that resistant parent Zhaiyeqing 8 carried the alleles associated with the resistance to rice stripe virus and the small brown planthopper, and susceptible parent Wuyujing 3 also carried the resistant allele to rice stripe virus. In comparison with the results previously reported, QTLs detected in the study were new resistant genes to rice stripe disease. This will provide a new resistant resource for avoiding genetic vulnerability for single utilization of the resistant gene Stvb-i.

  20. Fine mapping and candidate gene analysis of purple pericarp gene Pb in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Purple rice is a type of rice with anthocyanins deposited in its grain pericarp. The rice Pb gene controlling purple pericarp character is known to be on chromosome 4, and the purple color is dominant over white color. In this study, we fine mapped the Pb gene using two F2 segregating populations, i.e. Pei'ai 64S (white) × Yunanheixiannuo (purple) and Pei'ai 64S × Chuanheinuo (purple). In the first-pass mapping, the Pb gene was located in the region downstream the SSR marker RM3820. In the fine mapping, the candidate region was saturated with InDel and CAPS markers developed specifically for this study. Eventually, the Pb gene was mapped within the 25-kb region delimited by the upstream marker RID3 and the downstream marker RID4. The delimited region contained two annotated genes, Ra and bhlh16 (TIGR Rice Genome, R.5). The former is a homologue of the Myc transcription factor Lc controlling anthocyanin biosynthesis in maize, and the latter is a homologue of the TT8 gene, which is also an Myc transcription factor gene controlling the pericarp pigmentation in Arabidopsis thaliana. Sequence analysis showed that the exon 7 of the Ra gene of Yunanheixiannuo and Chuanheinuo had a 2-bp (GT) deletion compared with those of the white rice varieties Pei'ai 64S, 9311 and Nipponbare. A CAPS marker, CAPSRa, was developed according to the GT deletion for analysis of the two F2 segregating populations and 106 rice lines. The results showed that all F2 plants with white pericarp, and all non-purple rice lines (63 white and 22 red) contained no GT deletion, but all 20 purple rice lines contained the GT deletion. These results suggested that the Ra gene may be the Pb gene and the purple pericarp characteristic of rice is caused by the GT deletion within exon 7 of the Ra gene.

  1. Production and Optimization of Oleic Acid Ethyl Ester Synthesis Using Lipase From Rice Bran (Oryza sativa L.) and Germinated Jatropha Seeds (Jatropha curcas L.) by Response Surface Methodology

    OpenAIRE

    Indro Prastowo; Chusnul Hidayat; Pramudji Hastuti

    2015-01-01

    Recently, the fatty acid ethyl ester has been synthesized in place of fatty acid methyl ester since ethanol has been more renewable. In this research, oleic acid ethyl ester (OAEE) was synthesized using germinated jatropha seeds (Jatropha curcas.L) and rice bran (Oryza sativa) as source of lipase. The objective of the research was to optimize the synthesis conditions using Response Surface Methodology. Factors, such as crude enzyme concentration, molar ratio of oleic acid to ethanol, and the...

  2. The Effect of Silicon on Photosynthesis and Expression of Its Relevant Genes in Rice (Oryza sativa L.) under High-Zinc Stress

    OpenAIRE

    Song, Alin; Li, Ping; Fan, Fenliang; LI, ZHAOJUN; LIANG, Yongchao

    2014-01-01

    The main objectives of this study were to elucidate the roles of silicon (Si) in alleviating the effects of 2 mM zinc (high Zn) stress on photosynthesis and its related gene expression levels in leaves of rice (Oryza sativa L.) grown hydroponically with high-Zn stress. The results showed that photosynthetic parameters, including net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, chlorophyll concentration and the chlorophyll fluorescence, were d...

  3. Multiple loci and epistases control genetic variation for seed dormancy in weedy rice (Oryza sativa).

    OpenAIRE

    Gu, Xing-You; Kianian, Shahryar F.; Foley, Michael E.

    2004-01-01

    Weedy rice has much stronger seed dormancy than cultivated rice. A wild-like weedy strain SS18-2 was selected to investigate the genetic architecture underlying seed dormancy, a critical adaptive trait in plants. A framework genetic map covering the rice genome was constructed on the basis of 156 BC(1) [EM93-1 (nondormant breeding line)//EM93-1/SS18-2] individuals. The mapping population was replicated using a split-tiller technique to control and better estimate the environmental variation. ...

  4. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

    Directory of Open Access Journals (Sweden)

    Elkheir H.A

    2015-08-01

    Full Text Available Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8 V1 Ir64 V2 And Situbagendit V3 Combine With 4 Levels Of Peg Concentrations 0100 And 200 Gl-1 And Control With No Treatment. Experiment Was Repeated 4 Times So Total Number Of Experimental Units Were 48. Germination Parameters Measured Were Germination Percentage Germination Index Days Of 50 Germination Seedling Fresh Weight Mg Seedling Shoot Fresh Weight And Root Fresh Weight Mg Seedling Dry Weigh Mg Seedling Shoot Dry Weight And Root Dry Weight Mg ShootRoot Ratio Seedling Length Cm Seedling Root Length Cm And Shoot Length Cm And Seed Vigor Index. The Results Indicated That Seed Priming Significantly Affected Germination Behaviors Compared With Control Depending Upon Varieties. The Highest Germination Was Obtained Under Laboratory And Greenhouse Condition By The Treatment Of Peg 200 G L-1 On The Situbagendit And Ir-64 Variety 90.25 And 93.33 Respectively Compared To Control In Inpago-8 In Both Laboratory 75.75 And Greenhouse 80 . As Implementation To Increase Seed And Seedling Vigor Of Rice It Is A Best Practice To Use Peg Priming With 200 Gl-1 Solutions Depend Upon Varietal Response And We Suggest That More Research About The Effect Of Peg As Seed Priming Techniques On Seed Germination Behavior Of Many Grain Crops Is Needed To Confirm The Methodology.

  5. Probing the role of tryptophan-derived secondary metabolism in defense responses against Bipolaris oryzae infection in rice leaves by a suicide substrate of tryptophan decarboxylase.

    Science.gov (United States)

    Ishihara, Atsushi; Nakao, Takahito; Mashimo, Yuko; Murai, Masatoshi; Ichimaru, Naoya; Tanaka, Chihiro; Nakajima, Hiromitsu; Wakasa, Kyo; Miyagawa, Hisashi

    2011-01-01

    Tryptophan-derived secondary metabolites, including serotonin and its hydroxycinnamic acid amides, markedly accumulate in rice leaves in response to pathogen attack. These compounds have been implicated in the physical defense system against pathogen invasion by being deposited in cell walls. Serotonin is biosynthesized from tryptophan via tryptamine, and tryptophan decarboxylase (TDC) catalyzes the first committed reaction. In this study, (S)-α-(fluoromethyl)tryptophan (S-αFMT) was utilized to investigate the effects of the inhibition of TDC on the defense responses of rice leaves. S-αFMT, enantiospecifically synthesized from L-tryptophan, effectively inhibited TDC activity extracted from rice leaves infected by Bipolaris oryzae. The inhibition rate increased dependently on the incubation time, indicating that S-αFMT served as a suicide substrate. Treatment of rice seedlings with S-αFMT suppressed accumulation of serotonin, tryptamine, and hydroxycinnamic acid amides of serotonin in a dose-dependent manner in B. oryzae-inoculated leaves. The lesions formed on seedlings treated with S-αFMT lacked deposition of brown materials, and those leaves were severely damaged in comparison with leaves without S-αFMT treatment. Administrating tryptamine to S-αFMT-treated leaves restored accumulation of tryptophan-derived secondary metabolites as well as deposition of brown material. In addition, tryptamine administration reduced damage caused by fungal infection. Accordingly, the accumulation of tryptophan-derived secondary metabolites was suggested to be part of the effective defense mechanism of rice. PMID:21112065

  6. Sustainable enhancement of rice (Oryza sativa L.) production through the use of mutation breeding

    International Nuclear Information System (INIS)

    Four new high yield rice varieties with excellent quality were developed through mutagenesis at Nuclear Institute of Agriculture (NIA), Tando Jam, Pakistan, and released by the Provincial Seed Council, Government of Sindh for general cultivation. Both chemical and physical mutagenesis is proven to be useful in mutation induction. The first mutant rice variety 'Shadab', released in 1987, is a mutant of IR6 induced using ethyl methane sulphonate (EMS 0.5%); the 2nd variety 'Shua- 92', released in 1993, evolved from IR8 by irradiation of 15 Gy fast neutrons; the third variety Khushboo-95, released in 1996, was selected from gamma rays (200 Gy) treated progenies of Jajai-77 (aromatic). The most recent mutant variety 'Sarshar', released in 2001, was also developed from IR8 after treatment of 150 Gy gamma rays. These varieties have substantially increased the yield potential of rice production in Sindh and Balochistan provinces, and brought significant economic impact to rice farmers. (author)

  7. Effect of Microbial (Jeevatu) Treatment on Rice (Oryza sativa L.) Production

    OpenAIRE

    Suraj Raj Adhikari; Khadga Bhakta Paudel; Kusum Pokhrel; Amrita Paudel

    2013-01-01

    JeevatuTM is a consortium of beneficial natural microbes, available in liquid form. The yield of rice was observed vigorously high in Jeevatu based rice cultivated plant. The seed production in per spikelet is 237.1±44.92 in Jeevatu based and 179.4±25.26 in chemical based rice plant. In case of vegetative growth, 173.1±6.34 cm and 140.9±11.11 cm in Jeevatu based rice plant and chemical based methods respectively. Similarly the length of stalk of spikelet is 27±1.63cm and 22.1±2.23 cm was obs...

  8. Market testing and consumer acceptance of irradiated rice (Oryza sativa indica Linn.)

    International Nuclear Information System (INIS)

    Special grade A fragrant rice (Jasmine rice) of 13% moisture content was obtained from a local miller in Bangkok. Low density polyethylene, 29.5 cm in width x 45 cm in length and 200 micron in thickness, was used to pack the rice with a net weight of 5 kg. The irradiated food label was printed on one side of the bag to comply with food control regulations. The color and the ink for marking were tested for gamma radiation compatibility. A total of 800 bags of rice, with a total gross weight of 4,000 kg, were irradiated at a minimum absorbed dose at 0.5 kGy for insect disinfestation. Radiation treatment was carried out using a multi-purpose, carrier type gamma irradiator (Model JS-8900, Serial No. IR-155) located at the Thai Irradiation Center. Irradiated rice was distributed on a weekly basis to food stores in Bangkok and Pathum Thani, as well as to various governmental organizations and interested individuals. The product was sold at 60 bahts per bag (approx. US$ 2.4) to retailers. Various commercial brands of non-irradiated rice of 5 kg size, were available in the market at 52 to 78 bahts per bag (approx. US $ 2.08 to 3.12), depending on quality and brand name. During the distribution, a leaflet of educational information was given to the consumer. A simple questionnaire used in the marketing trial indicated that 72% of the consumers bought irradiated rice because of the good quality of the product based on visual inspection, and 28% of them were willing to try the new product. Most consumers preferred irradiated rice to chemical treatment (fumigation) for insect disinfestation. However, most consumers were not sure if they would like to buy irradiated rice again unless its cooking quality was acceptable. Market testing of irradiated rice in the upper-class market or supermarket was unsuccessful because of limitations in the sale and service conditions. To meet the requirement of the supermarket retailer, irradiated rice had to be supplied on a monthly basis, with

  9. Role of root and yield characters under drought stress in rice (Oryza sativa L.)

    OpenAIRE

    V. Karpagam, S. Jebaraj, S. Rajeswari and C. Vanniarajan

    2014-01-01

    Drought is the major constraint to rice production and yield stability in rainfed areas. Association analysis was performed in F1 generation of rice in order to understand the nature and extent of association among various traits and grain yield under drought stress condition. Grain yield per plant had positive association with number of productive tillers per plant, root length and root volume. Panicle length had positively correlated with 1000 grain weight, biomass yield, root leng...

  10. Adaptation of irrigated rice (oryza sativa l.) in the colombian caribbean

    OpenAIRE

    Aramendiz Tatis, Hermes; Espitia Camacho, Miguel; Cardona Ayala, Carlos

    2011-01-01

    In Colombia, the rice crop under irrigation system ranks first in food security, economic value and employment offer among annual crops, becoming the most important. The objective of this study was to quantify increasing, stability and adaptability of irrigated rice in five departments of the Colombian Caribbean area. Data from the Ministry of Agriculture and Rural Development for the departments of Cordoba, Bolivar, Magdalena, Cesar and Guajira, during the year period 1987 to 2008 were used....

  11. The origin and evolution of fragrance in rice (Oryza sativa L.)

    OpenAIRE

    Kovach, Michael J.; Calingacion, Mariafe N.; Fitzgerald, Melissa A.; McCouch, Susan R

    2009-01-01

    Fragrance in the grain is one of the most highly valued grain quality traits in rice, yet the origin and evolution of the betaine aldehyde dehydrogenase gene (BADH2) underlying this trait remains unclear. In this study, we identify eight putatively nonfunctional alleles of the BADH2 gene and show that these alleles have distinct geographic and genetic origins. Despite multiple origins of the fragrance trait, a single allele, badh2.1, is the predominant allele in virtually all fragrant rice va...

  12. Tracing the allocation of water in rainfed rice ecosystem by partitioning evapotranspiration of rainfed rice (Oryza Sativa L.)

    Science.gov (United States)

    Nay-Htoon, Bhone; Dubbert, Maren; Wei, Xue; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    To understand productive and unproductive water use of crop production, partitioning evapotranspiration (ET ) into evaporation (E) and transpiration (T ) is important. Water movements within the eco-hydrologic cycle of agroecosystems can be traced by stable oxygen isotopes of water (δ18O) and plant transpiration and soil evaporation can also be estimated by tracing the δ18O. We quantified the contribution of transpiration to total ecosystem evapotranspiration of rainfed rice field by a stable oxygen isotope approach and FAO 56 dual crop modelling approach. Our study aims to provide quantification of ecosystem water cycle of rainfed rice by partitioning productive and unproductive water use since productivity and water use of rice which is a highly water demanding agroecosystem, is under intense research. Crop season total evapotranspiration fluxes from rainfed rice was mainly dominated by transpiration (T to ET contribution (T /ET ) = 65%) and domination of transpiration over evaporation fluxes was noted since early vegetative stage (Leaf Area Index = 0.8 m2 m-2) until harvesting. T /ET of rainfed rice fluctuated with changes in soil water content (SWC) and the highest T /ET was found at SWC of 0.34 m3 m-3, during seedling stage. Our results demonstrate that partitioning ET by FAO 56 dual crop model is in a good agreement with δ18O isotope based ET partitioning results. Using monthly mean values of leaf resistance and vegetation index derived crop coefficients instead of original fixed parameters of the FAO 56 dual crop model resulted better agreement with δ18O isotope based ET partitioning.

  13. Genetic analysis of starch paste viscosity parameters in glutinous rice (Oryza sativa L.).

    Science.gov (United States)

    Yan, Chang-Jie; Tian, Zhi-Xi; Fang, Yu-Wei; Yang, Ya-Chun; Li, Jian; Zeng, Sheng-Yuan; Gu, Shi-Liang; Xu, Chen-Wu; Tang, Shu-Zhu; Gu, Ming-Hong

    2011-01-01

    Starch paste viscosity plays an important role in estimating the cooking, eating, and processing quality of rice. The inheritance of starch paste viscosity in glutinous rice remains undefined. In the present study, 118 glutinous rice accessions were collected, and the genotypes of 17 starch synthesis-related genes (SSRG) were analyzed by using 43 gene-specific molecular markers. Association analysis indicated that 10 of 17 SSRGs were involved in controlling the rapid visco analyzer (RVA) profile parameters. Among these, the PUL gene was identified to play an important role in control of peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), breakdown viscosity (BDV), peak time (PeT), and paste temperature (PaT) in glutinous rice. Other SSRGs involved only a few RVA profile parameters. Furthermore, interactions between SSRGs were found being responsible for PeT, PaT, and BDV. Some of the RVA parameters, including PKV, HPV, CPV, CSV, and PaT, were mainly governed by single SSRG, whereas other parameters, such as BDV, SBV, and PeT, were controlled by a few SSRGs, functioning cooperatively. Further, three near-isogenic lines (NIL) of a japonica glutinous cv. Suyunuo as genetic background, with PUL, SSIII-1, and SSIII-2 alleles replaced with those of indica cv. Guichao 2, were employed to verify the genetic effects of the various genes, and the results were consistent with those obtained from the association analysis. These findings indicated that starch paste viscosity in glutinous rice had a complex genetic system, and the PUL gene played an important role in determining the RVA profile parameters in glutinous rice. These results provide important information for potentially improving the quality of glutinous rice. PMID:20737264

  14. Agronomic and molecular evaluation of induced mutant rice (oryza sativa l.) lines in Egypt

    International Nuclear Information System (INIS)

    The present study was conducted at the farm of the Rice Research and Training Center, Sakha, Kafr El-Sheikh, Egypt, during 2000-2007 rice sowing seasons. Five rice varieties viz., Giza 171, Giza 175, Giza 176, Giza 181 and GZ 1368 were the most widely grown Japonica and Indica types in Egypt during the last period, possesses at that time many positive agronomic characteristics including wide adaptability, high yield potential, tolerance to stresses and good eating quality. But with the passage of time it has lost its vigor. In Rice Research Program, Egypt, dry seeds of the above mentioned varieties were treated with different doses of gamma rays (100, 200, 300, 400, and 500 Gy) for raising M1 generation. M1 plants were established by transplanting in the year 2000 season. One hundred independent lines have been advanced to M5 generation enabling evaluation of quantitative traits by replicated trials and promising lines were selected and tested in multi-location trials as M6, M7 and M8 generations. Morphological variations at vegetative and reproductive stages including plant type and various physiological characters were observed in the five populations. The mutant lines characteristics consisted of better resistance to lodging, blast disease, high yield potential, as well as early maturity. Results from yield trials and molecular assessments indicated that the mutants differed genetically from their parents. So, these mutants could be used as a donor parents in rice breeding program and some of them can be recommended as new rice varieties suitable for rice belt in Egypt. (author)

  15. Hybridization study of wild rice Oryza glumaepatula with varieties of cultivated rice (O. sativa) and wild (O. grandiglumis)

    International Nuclear Information System (INIS)

    The process of interspecific hybridization of the wild species O. glumaepatula is studied with commercial varieties of the species O. sativa and O. grandiglumis, by morphological evaluation and hybrid flow cytometry. Hybrid plants were evaluated of cross between O. glumaepatula, located in the wetlands of Rio Medio Queso and two varieties of O. sativa, Puita Inta and CFX 18 resistant to a herbicide. The technique of Polymerase Chain Reaction Allele Specifies Oligonucleotide (PCR-ASO) was used to detect allelic mutations in the ALS gene conferring herbicide resistance, and it is confirmed the hybrid nature of the plants obtained at crossings. 68 hybrids were obtained: O. glumaepatula x P. Inta, 21 hybrids P. Inta x O. glumaepatula, 4 hybrids O. glumaepatula x CFX-18 and 15 hybrids CFX-18 x O. glumaepatula. 10 morphological descriptors of the genus Oryza were evaluated and determined that are indifferent to the direction and type of crossing, the hybrids resemble to the wild species O. glumaepatula for characters: height, panicle length and ligule length. All hybrids have showed similarity to commercial varieties in flag leaf length. Other characters evaluated in the hybrids have presented maternal effect, heterosis and intermediate values. The protocol of flow cytometry (FCM) is standardized species for Oryza genus analyzing nuclear DNA content of 106 samples of leaf tissue of wild species O. glumaepatula, O. grandiglumis; whose average has been of 0.73 picograms, and natural hybrids product of the cross of these species. The result has been intermediate compared with O. grandiglumis and O. glumaepatula that have made available to 1.0 picograms and 0.50 of DNA respectively. The molecular nature of the hybrids was confirmed in this way. (author)

  16. Effect of Preharvest Chemical Desiccation on Harvest Time and Grain Quality in Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    M. Esfahany

    2008-01-01

    Full Text Available   In order to reduce the rainfall damages on rice yield at harvest stage, a field experiment was conducted at Rice Research Institute of Iran, Rasht, in 2004 by using Sodium Chlorate as a chemical desiccant. Five seed moisture contents of Dorfak rice cultivar were considered as experimantal treatments [24 - 28% (M1, 22 - 24% (M2, 20 -22% (M3. 18 - 20% (M4 and control (M5= conventional harvesting]. The experiment was carried out in a randomized complete block design with three replications and the effects of treatments on grain yield, head rice yield,seed germination rate and percentage, kernel breakage, kernel cracking, amylose content, gelatinization temperature and gel consistency were evaluated. Results showed that the whole plant and grain moisture contents were significantly reduced in all experimental treatments compared with control. M2 and M3 both cosiderably reduced the plant moisture content in which harvesting occurred 12 and 8 days respectively sooner than the control. In M1, due to high grain moisture and non - simultaneous grain filling in different tillers, many of panicles desiccated prior to maturity lost their quality. In M4, the crop harvested was only 2 days earlier than the control. Analysis of variance showed that there were no significant effects of treatments on evaluated traits. It seems that rice plant could be reliably desiccated by Sodium Chlorat and harvested earlier without any adverse effects on its quality and quantity.

  17. Deciphering the proteomic profile of rice (Oryza sativa) bran: a pilot study.

    Science.gov (United States)

    Ferrari, Fabio; Fumagalli, Marco; Profumo, Antonella; Viglio, Simona; Sala, Alberto; Dolcini, Lorenzo; Temporini, Caterina; Nicolis, Stefania; Merli, Daniele; Corana, Federica; Casado, Begona; Iadarola, Paolo

    2009-12-01

    The exact knowledge of the qualitative and quantitative protein components of rice bran is an essential aspect to be considered for a better understanding of the functional properties of this resource. Aim of the present investigation was to extract the largest number of rice bran proteins and to obtain their qualitative characterization. For this purpose, three different extraction protocols have been applied either on full-fat or on defatted rice bran. Likewise, to identify the highest number of proteins, MS data collected from 1-DE, 2-DE and gel-free procedures have been combined. These approaches allowed to unambiguously identify 43 proteins that were classified as signalling/regulation proteins (30%), proteins with enzymatic activity (30%), storage proteins (30%), transfer (5%) and structural (5%) proteins. The fact that all extraction and identification procedures have been performed in triplicate with an excellent reproducibility provides a rationale for considering the platform of proteins shown in this study as the potential proteome profile of rice bran. It also represents a source of information to evaluate better the qualities of rice bran as food resource. PMID:19960476

  18. Suppressive effects of mycoviral proteins encoded by Magnaporthe oryzae chrysovirus 1 strain A on conidial germination of the rice blast fungus.

    Science.gov (United States)

    Urayama, Syun-Ichi; Kimura, Yuri; Katoh, Yu; Ohta, Tomoko; Onozuka, Nobuya; Fukuhara, Toshiyuki; Arie, Tsutomu; Teraoka, Tohru; Komatsu, Ken; Moriyama, Hiromitsu

    2016-09-01

    Magnaporthe oryzae chrysovirus 1 strain A (MoCV1-A) is the causal agent of growth repression and attenuated virulence (hypovirulence) of the rice blast fungus, Magnaporthe oryzae. We previously revealed that heterologous expression of the MoCV1-A ORF4 protein resulted in cytological damage to the yeasts Saccharomyces cerevisiae and Cryptococcus neoformans. Since the ORF4 protein is one of the components of viral particles, we evaluated the inhibitory effects of the purified virus particle against the conidial germination of M. oryzae, and confirmed its suppressive effects. Recombinant MoCV1-A ORF4 protein produced in Pichia pastoris was also effective for suppression of conidial germination of M. oryzae. MoCV1-A ORF4 protein sequence showed significant similarity to 6 related mycoviral proteins; Botrysphaeria dothidea chrysovirus 1, two Fusarium graminearum viruses, Fusarium oxysporum f. sp. dianthi mycovirus 1, Penicillium janczewski chrysovirus and Agaricus bisporus virus 1 in the Chrysoviridae family. Multiple alignments of the ORF4-related protein sequences showed that their central regions (210-591 aa in MoCV1-A ORF4) are relatively conserved. Indeed, yeast transformants expressing the conserved central region of MoCV1-A ORF4 protein (325-575 aa) showed similar impaired growth phenotypes as those observed in yeasts expressing the full-length MoCV1-A ORF4 protein. These data suggest that the mycovirus itself and its encoded viral protein can be useful as anti-fungal proteins to control rice blast disease caused by M. oryzae and other pathogenic fungi. PMID:27329666

  19. Salinity induced metabolic changes in rice (oryza sativa l.) seeds during germination

    International Nuclear Information System (INIS)

    Six inbred lines of rice exhibiting differential tolerance to salinity were exposed to 0, 50, 75, 100 and 200 mM NaCl for 24, 48, 72 and 96 h. The salinity induced metabolic changes (solute leakage, K efflux and a-amylase activity) were studied during germination. Germination of rice seeds was not affected by NaCl concentration less than 100 mM. At higher salinity levels (100 and 200 mM NaCl), a delay of 3-6 days in germination was observed. In the present study, comparatively higher values of solute leakage were observed in those lines in which germination was comparatively affected more adversely (sensitive). Sodium chloride reduced alpha-amylase activity in germinating rice seeds to varying degree even at low NaCl concentrations (50 and 75 mM), where germination was not affected greatly. The tolerant lines exhibited higher enzymatic activity than the sensitive ones. (author)

  20. Pressurized liquid extraction of phenolic compounds from rice (Oryza sativa) grains.

    Science.gov (United States)

    Setyaningsih, W; Saputro, I E; Palma, M; Barroso, C G

    2016-02-01

    An analytical pressurized liquid extraction (PLE) process has been studied for the extraction of phenolic compounds from rice grains. A fractional factorial design (2(7-2)) with a centre point was used to optimize PLE parameters such as solvent composition (EtOAc in MeOH), extraction temperature, pressure, flushing, static extraction time, solvent-purge and sample weight. Extraction temperature, solvent and static extraction time were found to have a significant effect on the response value. The optimized method was validated for selectivity, linearity, limits of detection and quantification, recovery and precision. The validated method was successfully applied for the analysis of a wide variety of rice grains. Seventeen phenolic compounds were detected in the sample and guaiacol, ellagic acid, vanillic acid and protocatechuic acid were identified as the most abundant compounds. Nonetheless, different species of rice show very varied compound diversity and levels of compounds in their grain compositions. PMID:26304372

  1. Variability, heritability and genetic advance studies in some indigenous genotypes of basmati rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    C. R. Allam, H.K. Jaiswal , A. Qamar , Challa Venkateshwarlu and Y.S. Reddy

    2015-06-01

    Full Text Available The investigation conducted with 25 rice genotypes comprising both Basmati and non-basmati types revealed significant differences among the genotypes for the yield, its components and some grain quality characteristics. The magnitude of differences between PCV and GCV was relatively low for all the traits, indicating less environmental influence. The GCV was higher for the characters alkali spread value, yield per plant and effective panicles. High heritability coupled with high genetic advance as per cent of mean was recorded for days to 50% flowering, plant height, panicle length, effective panicles per plant, spikelets per panicle, filled grains per panicle, test weight, yield per plant, brown rice length, brown rice L/B ratio, kernel length, kernel L/B ratio, kernel length after cooking, elongation ratio and alkali spread value indicating the additive gene effects in the genetic control of these traits and can be improved by simple selection in the present breeding material.

  2. Sulfur (S)-induced enhancement of iron plaque formation in the rhizosphere reduces arsenic accumulation in rice (Oryza sativa L.) seedlings

    International Nuclear Information System (INIS)

    The effects of two sulfur (S) sources (SO42-, S0), and three rates of S application (0, 30, 120 mg S/kg) on the formation of iron plaque in the rhizosphere, and on the root surface of rice, and As (arsenic) uptake into rice (Oryza sativa L.) were studied in a combined soil-sand culture experiment. Significant differences in As uptake into rice between +S and -S treatments were observed in relation to S sources, and rates of S application. Concentrations of As in rice shoots decreased with increasing rates of S application. The mechanism could be ascribed to sulfur, induced the formation of iron plaque, since concentrations of Fe in iron plaque on quartz sands in the rhizosphere, and on the root surface of rice increased with increasing rates of S application. The results suggest that sulfur fertilization may be important for the development approaches to reducing As accumulation in rice. - Sulfur-induced enhancement of iron plaque formation on the root surface of rice

  3. Resequencing Reveals Different Domestication Rate for BADH1 and BADH2 in Rice (Oryza sativa.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available BADH1 and BADH2 are two homologous genes, encoding betaine aldehyde dehydrogenase in rice. In the present study, we scanned BADHs sequences of 295 rice cultivars, and 10 wild rice accessions to determine the polymorphisms, gene functions and domestication of these two genes. A total of 16 alleles for BADH1 and 10 alleles for BADH2 were detected in transcribed region of cultivars and wild species. Association study showed that BADH1 has significant correlation with salt tolerance in rice during germination stage, the SNP (T/A in exon 4 is highly correlated with salt tolerance index (STI (P<10(-4. While, BADH2 was only responsible for rice fragrance, of which two BADH2 alleles (8 bp deletion in exon 7 and C/T SNP in exon 13 explain 97% of aroma variation in our germplasm. Theses indicate that there are no overlapping functions between the two homologous genes. In addition, a large LD block was detected in BADH2 region, however, there was no large LD blocks in a 4-Mb region of BADH1. We found that BADH2 region only showed significant bias in Tajima's D value from the balance. Extended haplotype homozygosity study revealed fragrant accessions had a large LD block that extended around the mutation site (8 bp deletion in exon 7 of BADH2, while both of the BADH1 alleles (T/A in exon 4 did not show large extended LD block. All these results suggested that BADH2 was domesticated during rice evolution, while BADH1 was not selected by human beings.

  4. Lethal and sterilizing effect of gamma radiation on the rice weevil, sitophilus oryzae (L.)

    International Nuclear Information System (INIS)

    Lethal and sterilizing effects of ionizing radiation on a laboratory strain of sitophilus oryzae (L.) were studied. The insects were reared on wheat, variety Giza 155, at 30 degree C and 70% R.H. The developmental stages used were 1 and 3-day old eggs, 1 and 2-weeks old larvae, 3-days old pupae and one week old adults. Results obtained showed that : 1) Adults resulted from irradiated 1 and 3-days old eggs failed to give new progeny the dosage used was 12 Gy 2) Female adults resulting from 1 and 2-weeks old larvae treated at 22.5 Gy were sterile 3) Female adults resulting from treated 3-days old pupae failed to give any progeny when the dose used was 40 Gy 4) Adults were much more tolerant than all other stages 5) A dosage of 72 Gy caused complete sterility to adults, and this dose seems to be reliable for the control of sitophilus oryzae (L.) in infested stored wheat.5 tab

  5. Germination behaviour of red rice (Oryza sativa L.) seeds in field and laboratory conditions

    OpenAIRE

    Vidotto, Francesco; Ferrero, Aldo

    2000-01-01

    Two experiments were carried out in 1996-1998 to study (1) the germination behaviour of red rice seeds kept for different periods of time in field and laboratory conditions, and (2) the weed emergence behaviour in response to different burial depths. The first experiment was carried out considering mature red rice seeds of two biotypes which were exposed to field conditions and to 20 oC, for different periods of time, and then tested for their germinability over 6 months. The time required fo...

  6. Infection Mechanism of Neovossaia horrida in Male Sterile Lines of Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Zhu Jianqing(朱建清); Liu Zhu; Liao Jinhua; Tao Jiafeng; Yang Zhirong; Zhao Jian

    2004-01-01

    After male sterile rice plants are inoculated with secondary sporidia of Neovossia horrida in the field, the process of infection is comparatively studied in four male sterile rice lines by scanning electronmicroscope. The infection process of Neovossia horrida is similar in these four male sterile lines. The results show, that the hyphae of fungus penetrates directly to the stigma, and then to the ovary after inoculation for 8h. The initial teliospore is formed between the aleurone layer and seed coat after 7d and matured in 9d. Although fungus penetrates through stigma without pollination, teliospore occurs only in the healthy developing endosperma.

  7. PLANT SPACING AND WEED MANAGEMENT TECHNIQUES INFLUENCE WEED COMPETITIVENESS OF DRUM SEEDED RICE (Oryza sativa L.)

    OpenAIRE

    B N Sandeep Nayak; Md Mujeeb Khan; K Mosha; P Prasuna Rani

    2014-01-01

    Direct wet seeded-rice sown through drum seeder, a potential wise rice production system in the present-day scenario, is subject to severe weed infestation and, therefore, development of a sustainable weed management strategy is crucial for its wide spread adoption. The present study was conducted in kharif 2012 at department of agronomy division with NLR-33358 (SOMASILA) using six planting densities under five weed management conditions. The plant spacing tried were: 20cm x 7cm, 20 cm x 10.5...

  8. Leaf senescence and protective enzyme activities of a xantha mutant rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    The relationship between leaf senescence and the activities of protective enzymes was studied through comparion of a xanthan rice mutant HuangyuB with its wild type parent Longtefu B. During 5-25 days after flowering, compared to the wild type the decreases in the contents of chlorophyll and protein, and increases in the content of malondialdehyde (MDA) were significantly slower in the mutant. The activities of three protective enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), were relatively stable in the mutant, indicating the stronger ability in removing free radicals and active oxygen in HuangyuB than the wild type. The criterion of rice senescence was also discussed. (authors)

  9. A novel 5-enolpyruvoylshikimate-3-phosphate (EPSP) synthase transgene for glyphosate resistance stimulates growth and fecundity in weedy rice (Oryza sativa) without herbicide.

    Science.gov (United States)

    Wang, Wei; Xia, Hui; Yang, Xiao; Xu, Ting; Si, Hong Jiang; Cai, Xing Xing; Wang, Feng; Su, Jun; Snow, Allison A; Lu, Bao-Rong

    2014-04-01

    Understanding evolutionary interactions among crops and weeds can facilitate effective weed management. For example, gene flow from crops to their wild or weedy relatives can lead to rapid evolution in recipient populations. In rice (Oryza sativa), transgenic herbicide resistance is expected to spread to conspecific weedy rice (Oryza sativa f. spontanea) via hybridization. Here, we studied fitness effects of transgenic over-expression of a native 5-enolpyruvoylshikimate-3-phosphate synthase (epsps) gene developed to confer glyphosate resistance in rice. Controlling for genetic background, we examined physiological traits and field performance of crop-weed hybrid lineages that segregated for the presence or absence of this novel epsps transgene. Surprisingly, we found that transgenic F2 crop-weed hybrids produced 48-125% more seeds per plant than nontransgenic controls in monoculture- and mixed-planting designs without glyphosate application. Transgenic plants also had greater EPSPS protein levels, tryptophan concentrations, photosynthetic rates, and per cent seed germination compared with nontransgenic controls. Our findings suggest that over-expression of a native rice epsps gene can lead to fitness advantages, even without exposure to glyphosate. We hypothesize that over-expressed epsps may be useful to breeders and, if deployed, could result in fitness benefits in weedy relatives following transgene introgression. PMID:23905647

  10. Characterization of Xanthomonas oryzae-Responsive cis-Acting Element in the Promoter of Rice Race-Specific Susceptibility Gene Xa13

    Institute of Scientific and Technical Information of China (English)

    Ting Yuan; Xianghua Li; Jinghua Xiao; Shiping Wang

    2011-01-01

    The rice Xa13 gene,whose promoter harbors a UPT (up-regulated by transcription activator-like [TAL] effector) box,UPTPthXo1,plays a pivotal role in the race-specific pathogenicity caused by Xanthomonas oryzae pv. Oryzae (Xoo) strain PXO99. PXO99 causes rice disease by inducing Xa13. It is unknown,however,whether the UPTPthXo1 box is the only PXO99-responsive c/s-regulating elements in the activation of Xa13 expression. We analyzed the expression of a series of end- and site-truncated and site-mutated Xa 13 promoters in rice and the binding of PXO99 protein to the intact,partial,or site-mutated UPTPthXo1 boxes. In the Xa13 promoter,UPTPthXo1 box is the only Xoo-responsive cis-acting element that results in PXO99-induced Xa13 expression. The 5'-terminal second,third,and fourth nucleotides of the box are important for bacterial protein binding and gene activation;mutation of any one of these sites abolished PXO99-induced gene expression. Furthermore,the 3'-half of the UPTPthXo1 box is also required for protein binding and gene activation. These findings will enhance our understanding of the molecular mechanism of the interaction of rice and Xoo via UPT boxes and TAL effectors.

  11. Identification and gene prediction of a 24 kb region containing xa5, a recessive bacterial blight resistance gene in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yiming; JIANG Guanghuai; CHEN Xuewei; XIA Zhihui; LI Xiaobing; ZHU Lihuang; ZHAI Wenxue

    2003-01-01

    Rice xa5 gene provides recessive, race-specific resistance to bacterial blight disease caused by the pathogen Xanthomonas oryzae pv. oryzae and has great value for research and breeding. In an effort to clone xa5, an F2 population of 4892 individuals was developed from the xa5 near isogenic lines, IR24 and IRBB5. A fine mapping procedure was conducted and tightly linked RFLP markers were used to screen a BAC library of IRBB56, a resistant rice line containing the xa5 gene. A 213 kb contig covering the xa5 locus was constructed. According to the sequences from the International Rice Genome Sequening Project (IRGSP), the Chinese Superhybrid Rice Genome Project (SRGP) and some sub-clones of the contig, twelve SSLP and CAPS markers were developed for fine mapping. The xa5 gene was mapped to a 0.3 cM interval between markers K5 and T4, which spanned an interval of approximately 24 kb, co-segregating with marker T2. Sequence analysis of the 24 kb region revealed that an ABC transporter and a basal transcription factor (TFIIa) were potential candidates for the xa5 resistance gene product. The molecular mechanism by which the xa5 gene provides recessive, race-specific resistance to bacterial blight will be elucidated by the functional tests of the 24 kb DNA and the candidate genes.

  12. Deficiency in silicon uptake affects cytological, physiological, and biochemical events in the rice--Bipolaris oryzae interaction.

    Science.gov (United States)

    Dallagnol, Leandro J; Rodrigues, Fabrício A; DaMatta, Fábio M; Mielli, Mateus V B; Pereira, Sandra C

    2011-01-01

    This study investigated how a defect in the active uptake of silicon (Si) affects rice resistance to brown spot. Plants from a rice mutant (low silicon 1 [lsi1]) and its wild-type counterpart (cv. Oochikara), growing in hydroponic culture with (+Si; 2 mM) or without (-Si) Si, were inoculated with Bipolaris oryzae. Si concentration in leaf tissue of cv. Oochikara and the lsi1 mutant increased by 381 and 263%, respectively, for the +Si treatment compared with the -Si treatment. The incubation period was 6 h longer in the presence of Si. The area under brown spot progress curve for plants from cv. Oochikara and the lsi1 mutant was reduced 81 and 50%, respectively, in the presence of Si. The reduced number of brown epidermal cells on leaves from cv. Oochikara and the lsi1 mutant supplied with Si contributed to the lower lipid peroxidation and electrolyte leakage. The concentration of total soluble phenolics in cv. Oochikara supplied with Si (values of 4.2 to 15.4 μg g(-1) fresh weight) was greater compared with plants not supplied with Si (values of 1.9 to 11.5 μg g(-1) fresh weight). The concentration of lignin was also important to the resistance of cv. Oochikara and the lsi1 mutant. Polyphenoloxidase activity did not contribute to the resistance of cv. Oochikara and the lsi1 mutant to brown spot, regardless of Si supply. Peroxidase and chitinase activities were higher in cv. Oochikara and the lsi1 mutant supplied with Si. These results bring novel evidence of the involvement of Si in a more complex defense mechanism than simply the formation of a physical barrier to avoid or delay fungal penetration. PMID:20879842

  13. Salicylic acid modulates arsenic toxicity by reducing its root to shoot translocation in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Amit Pal Singh

    2015-05-01

    Full Text Available Arsenic (As is posing serious health concerns in South East Asia where rice, an efficient accumulator of As, is prominent crop. Salicylic acid (SA is an important signalling molecule and plays a crucial role in resistance against biotic and abiotic stress in plants. In present study, ameliorative effect of SA against arsenate (AsV toxicity has been investigated in rice (Oryza sativa L.. Arsenate stress hampered the plant growth in terms of root, shoots length and biomass as well as it enhanced the level of H2O2 and MDA in dose dependent manner in shoot. Exogenous application of SA, reverted the growth and oxidative stress caused byAsV and significantly decreased As translocation to the shoots. Level of As in shoot was positively correlated with the expression of OsLsi2, efflux transporter responsible for root to shoot translocation of arsenic in the form of arsenite (AsIII. Salicylic acid also overcame AsV induced oxidative stress and modulated the activities of antioxidant enzymes in a differential manner in shoots. Arsenic treatment hampered the translocation of Fe in the shoot which was compensated by the SA treatment. The level of Fe in root and shoot was positively correlated with the transcript level of transporters responsible for the accumulation of Fe,OsNRAMP5 and OsFRDL1, in the root and shoot respectively. Co-application of SA was more effective than pre-treatment for reducing As accumulation as well as imposed toxicity.

  14. Accumulation and distribution of polycyclic aromatic hydrocarbons in rice (Oryza sativa)

    International Nuclear Information System (INIS)

    Various tissues of rice plants were sampled from a PAH contaminated site in Tianjin, China at different growth stages of the ripening period and analyzed for PAHs. PAHs were much higher in roots than in the exposed tissues. Grains and internodes accumulated much smaller amounts of PAHs than leaves, hulls or ear axes. No specific gradient trends along roots, stem, ear axes, and grains were observed, suggesting that systematic translocation among them is unlikely. Over the ripening period, PAH concentrations were increased in rice roots and decreased in most above-ground tissues. Significant correlations between PAH and lipid contents can only be observed during full mature stage. The spectra of individual PAH compounds in rice organs including roots were similar to those in air, rather than those in soil. There was also a significant correlation between bioconcentration factor (BCF, plant over air) and octanol/air partitioning coefficient (K oa). - PAHs in various tissues of rice plants from various growth stages were investigated

  15. Effects of Soil Copper Concentration on Growth, Development and Yield Formation of Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    XU Jia-kuan; YANG Lian-xin; WANG Zi-qiang; DONG Gui-chun; HUANG Jian-ye; WANG Yu-long

    2005-01-01

    Pot experiments were conducted in 2002 and 2003 to investigate the effects of soil copper(Cu) concentration on growth, development and yield formation of rice by using the japonica cultivar Wuxiangjing 14 and hybrid rice combination Shanyou 63. The plant height, leaf number, elongated internode number and heading date of rice plants were not affected at soil Cu levels below 200 mg/kg, but affected significantly at above 400 mg/kg. The inhibitory effects on rice growth and development were increased with the increment of soil Cu levels. The grain yields decreased significantly with raising soil Cu levels. The main reasons for the grain yield reductions under lower soil Cu levels (100, 200 mg/kg) were mainly due to the decrease of number of spikelets per panicle, however, under higher soil Cu levels (more than 400 mg/kg), both panicle number and number of spikelets per panicle contributed to the yield loss. The decreases of panicle number by Cu stress were mainly attributed to slow recovery from transplanting, delayed tillering and reduced maximum tiller numbers. The reduction of number of spikelets per panicle under soil Gu stress resulted from the decreases of both shoot dry weight (SDW) at the heading date and the ratio of spikelets to SDW.Total biomass at maturity decreased significantly with the increase of soil Cu levels, while economic coefficient showed non-significant decrease except under soil Cu levels above 800 mg/kg.

  16. Antidiabetic Potential of Purple and Red Rice (Oryza sativa L.) Bran Extracts.

    Science.gov (United States)

    Boue, Stephen M; Daigle, Kim W; Chen, Ming-Hsuan; Cao, Heping; Heiman, Mark L

    2016-07-01

    Pigmented rice contains anthocyanins and proanthocyanidins that are concentrated in the bran layer. In this study, we determined the phenolic, flavonoid, anthocyanin, and proanthocyanidin content of five rice bran (1 brown, 2 red, and 2 purple) extracts. Each bran extract was evaluated for inhibitory effects on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. All purple and red bran extracts inhibited α-glucosidase activity, however only the red rice bran extracts inhibited α-amylase activity. Additionally, each bran extract was examined for their ability to stimulate glucose uptake in 3T3-L1 adipocytes, a key function in glucose homeostasis. Basal glucose uptake was increased between 2.3- and 2.7-fold by exposure to the red bran extracts, and between 1.9- and 3.1-fold by exposure to the purple bran extracts. In red rice bran, the highest enzyme inhibition and glucose uptake was observed with a proanthocyanidin-enriched fraction. Both IITA red bran and IAC purple bran increased expression of GLUT1 and GLUT4 mRNA, and genes encoding insulin-signaling pathway proteins. PMID:27285791

  17. Optimization of Electroporation Parameters for Immature Embryos of indica Rice(Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    REN Yu-jun; ZHAO Jie

    2008-01-01

    To obtain a suitable condition for electroporation transformation in indica rice.the 10-day-old immature embryos were selected for optimization experiments.The results showed that one pulse at 850 V/cm,950 μF capacitance,200 μL electreporation buffer with 70 mmol/L sodium glutamate,100 μg/mL plasmid,50 pg/mL carrier DNA,20 embryos per cuvette,0°C treatment and CC medium were the best parameters,which not only jmprovecl the transformation efficiency to 30.89%,but also ameliorated the embryo survival ratio to 95.92%.To further verify the practicability of this condition,the embryes from another indica rice variety and a rice type Ⅱ metallothionein-like gene(OsMT2bL)promoter::mgfp5::gusA construct were tested,and specific GUS expression on the embryos was visualized by histochemical staining.The results showed that the GUS expression on the embryos activated by the OsMT2bL promoter was mainly concentrated on the apical point of the plumule whereas the expression driven by CaMV35S promoter was distributed on nearly all areas of the electroporated tissues.These results indicated that the optimized embryo electroporation conditions could be used not only in genetic transformation of indica rice but also in assay of gene regulation on embryos.

  18. PLANT SPACING AND WEED MANAGEMENT TECHNIQUES INFLUENCE WEED COMPETITIVENESS OF DRUM SEEDED RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    B N Sandeep Nayak

    2014-11-01

    Full Text Available Direct wet seeded-rice sown through drum seeder, a potential wise rice production system in the present-day scenario, is subject to severe weed infestation and, therefore, development of a sustainable weed management strategy is crucial for its wide spread adoption. The present study was conducted in kharif 2012 at department of agronomy division with NLR-33358 (SOMASILA using six planting densities under five weed management conditions. The plant spacing tried were: 20cm x 7cm, 20 cm x 10.5 cm, 20 cm x 14 cm, 20 cm x 17.5 cm and 20 cm x 24.5cm and 20 cm x15cm. with a plant density of 71, 47, 35, 28, 20 and 33 hills m-2, respectively and five weed management practices viz., weedy check (W1, hand weeding at 20 and 40 DAS (W2, cono weeding at 20 and 40 with modified cono weeder (W3, pre-emergence application of anilofos @ 0.375 kg a.i ha-1 followed by post-emergence application of 2, 4 D sodium salt @ 1.0 kg a.i ha-1 20-25 DAS (W4, pre-emergence application of pendimethalin @1.0 kg a.i ha-1 followed by post-emergence application of bispyribac sodium @ 20 g a.i ha-1 30 DAS ( W5. . The experiment was laid out in strip- plot design with three replications assigning weed management techniques in vertical factor and plant spacing in horizontal factor. Direct wet seeded rice field was infested with 12 and 22 weed species, kharif -2012 season having Echinochloa colona, Leptochloa chinensis, Digitaria aescendens, Cyperus iriaand Eleusine indicaas the predominant weeds. Rice spacing exerted significant influence on both weed pressure and yield performance of crop. With the increase in plant spacing weed dry matter decreased but rice yield increased. In this season, among different plant densities, the highest density of 71 hills m-2(D1 resulted in minimum weed density, weed drymatter, and more number of tillers m-2 and maximum drymatter production at all stages of plant growth. closest spacing resulted in maximum weed suppression, but among various rice

  19. Effect of Nitric Oxide on Alleviating Cadmium Toxicity in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-feng; CHEN Lin; Muhammad IA Rehmani; WANG Qiang-sheng; WANG Shao-hua; HOU Peng-fu; LI Gang-hua; DING Yan-feng

    2013-01-01

    Nitric oxide (NO) is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside (SNP), an NO donor, on cadmium (Cd)-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress (0.2 mmol L-1 CdCl2) and different concentrations of SNP (0.05, 0.1, 0.2, and 0.4 mmol L-1). A SNP concentration of 0.1 mmol L-1 (SNP10) significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde (MDA), hydrogen peroxide (H2O2) and ascorbic acid (ASA) concentrations. However, the reduction in glutathione (GSH) concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide (Cd+Fe) or sodium nitrate and nitrite (Cd+N) (without NO release), did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin (an NO scavenger). Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.

  20. Effects of gamma radiation on the response of the rice weevil, sitophilus oryzae to heat and humidity

    International Nuclear Information System (INIS)

    The rice weevil, sitophilus oryzae L.was irradiated with 4 doses of gamma radiation (20,40,60 and 80 krad) and then examined for its response towards two different temperatures (45 and 25 degree C) or humidities (10 and 70% R.H.) For this purpose, two different apparatus were used. Each two temperature or humidity combinations were given to the weevils at the same time. The irradiated insects with 20 or 40 krad showed a marked increase in their speed at the warm side (45 degree C) than the controls. Those irradiated with 60 and 80 krad decreased their speed to about the control level. When the irradiated weevils were given the choice between 45 degree C and 25 degree C, their intensity of reaction towards the cooler side was decreased with increasing the doses. The rate of movement at 10% R.H. was not changed at 20 krad. However, at 40, 60 or 80 krad, it was increased with increasing the dose. The intensity of reaction of the irradiated weevils increased towards the dry side with increasing the dose.2 tab

  1. Adsorption studies for the amputation of lead from squander water by using straws of oryza sativa (rice)

    International Nuclear Information System (INIS)

    Adsorption is potentially an attractive technology for the treatment of waste water for retaining the heavy metals from dilute solutions. And it is one of the most common phenomenons for the treatment of lead-polluted water. The study evaluated here presents the experiments to determine the suitable conditions of Temperature, Contact Time, pH, Agitation Speed, Adsorbent Dose, Mesh Size and Metal Ion Concentration, for the use of Oryza Sativa (Rice) Straw, as adsorbent for the exclusion of lead from aqueous solution. The results revealed that maximum adsorption was observed at 20 degrees Celsius and at a contact time of 1.5 hr and an equilibrium time for keeping the ions adsorbed was observed between 0.5-1.5 hrs at a pH range of 6.9-7.0 and at an agitation speed of 150 rpm, with an adsorbent dose of 3.5 grams and mesh size 50-80, for as dilute metal ion concentrations as 16 ppm. (author)

  2. Studies on root traits for drought tolerance in rice (Oryza sative L. under controlled (PVC pipes condition

    Directory of Open Access Journals (Sweden)

    S.Ganapathy, S. K Ganesh, P. Shanmugasundaram, and R. Chandra Babu

    2010-07-01

    Full Text Available Rice (Oryza sativa L. is the most important food crop of the world; but drought stress is a serious limiting factor to riceproduction and yield stability in rainfed areas. In order to design an efficient breeding program for synthesis of new varietieswith virtues of drought tolerance and high yielding ability, it is necessary to identify potential parents that combine well forboth yield and drought tolerance. Hence, the present investigation was undertaken to evaluate genetic potentiality of eight linesand five testers along with 40 hybrids were evaluated under PVC pipes (controlled Condition for root traits in order to usethem in drought resistance breeding programmes. The parents and hybrids were raised in PVC pipes, where the plants weresubjected to drought for a period of 20 days during tillering stage starting on 60 days after sowing. Observations were recordedon seven important root traits viz., root length, root volume, root length density, total number of roots, root thickness, root dryweight and root:shoot ratio. Five genotypes viz., Norungan, CT 9993, Moroberekan, Nootripathu and MDU 5 showedsignificantly superior mean values than grand mean for most of the root traits included in the study. Therefore, these genotypescan be used as potential donors in drought resistance breeding programme. Among the hybrids, CT 9993 / ASD 18,Moroberekan / ASD 16, CT 9993 / IR 50, Moroberekan / Co 47, Noungan / ASD 16, Nootripathu / MDU and Nootripathu / CO47 were identified as outstanding ones for improving drought tolerance as they registered significant higher mean value formajority of the root traits.

  3. Oryza sativa H+-ATPase (OSA) is Involved in the Regulation of Dumbbell-Shaped Guard Cells of Rice.

    Science.gov (United States)

    Toda, Yosuke; Wang, Yin; Takahashi, Akira; Kawai, Yuya; Tada, Yasuomi; Yamaji, Naoki; Feng Ma, Jian; Ashikari, Motoyuki; Kinoshita, Toshinori

    2016-06-01

    The stomatal apparatus consists of a pair of guard cells and regulates gas exchange between the leaf and atmosphere. In guard cells, blue light (BL) activates H(+)-ATPase in the plasma membrane through the phosphorylation of its penultimate threonine, mediating stomatal opening. Although this regulation is thought to be widely adopted among kidney-shaped guard cells in dicots, the molecular basis underlying that of dumbbell-shaped guard cells in monocots remains unclear. Here, we show that H(+)-ATPases are involved in the regulation of dumbbell-shaped guard cells. Stomatal opening of rice was promoted by the H(+)-ATPase activator fusicoccin and by BL, and the latter was suppressed by the H(+)-ATPase inhibitor vanadate. Using H(+)-ATPase antibodies, we showed the presence of phosphoregulation of the penultimate threonine in Oryza sativa H(+)-ATPases (OSAs) and localization of OSAs in the plasma membrane of guard cells. Interestingly, we identified one H(+)-ATPase isoform, OSA7, that is preferentially expressed among the OSA genes in guard cells, and found that loss of function of OSA7 resulted in partial insensitivity to BL. We conclude that H(+)-ATPase is involved in BL-induced stomatal opening of dumbbell-shaped guard cells in monocotyledon species. PMID:27048369

  4. Fine mapping of a gene for low-tiller number, Ltn, in japonica rice (Oryza sativa L.) variety Aikawa 1.

    Science.gov (United States)

    Fujita, Daisuke; Ebron, Leodegario A; Araki, Etsuko; Kato, Hiroshi; Khush, Gurdev S; Sheehy, John E; Lafarge, Tanguy; Fukuta, Yoshimichi; Kobayashi, Nobuya

    2010-04-01

    Tillering is one of the most important agronomic traits related to grain production in rice (Oryza sativa L.). A japonica-type variety, Aikawa 1, is known to have low-tiller number. The detailed location of a low-tillering gene, Ltn, which has been localized on chromosome 8 in Aikawa 1, was confirmed by molecular mapping. Using BC5F2 individuals derived from a cross between IR64 and Aikawa 1, the low-tillering gene was mapped to an interval defined by SSR markers ssr5816-3 and A4765. This was designated as Ltn because there was no reported gene for tillering in the region of chromosome 8. Through high-resolution linkage analysis, the candidate region of Ltn was located between DNA markers ssr6049-23 and ind6049-1 corresponding to 38.6 kbp on the Nipponbare genome sequence. These DNA markers, which were tightly linked to Ltn, are useful for marker-assisted selection in breeding studies. PMID:20062964

  5. ZNF1 Encodes a Putative C2H2 Zinc-Finger Protein Essential for Appressorium Differentiation by the Rice Blast Fungus Magnaporthe oryzae.

    Science.gov (United States)

    Yue, Xiaofeng; Que, Yawei; Xu, Lin; Deng, Shuzhen; Peng, Youliang; Talbot, Nicholas J; Wang, Zhengyi

    2016-01-01

    The rice blast fungus Magnaporthe oryzae forms specialized infection structures called appressoria which are essential for gaining entry to plant tissue. Here, we report the identification of a novel nonpathogenic T-DNA-tagged mutant XF696 of M. oryzae with a single insertion in the promoter of ZNF1, which encodes a putative transcription factor (TF). Targeted gene deletion mutants of ZNF1 are nonpathogenic and unable to develop appressoria. However, Δznf1 mutants still respond to exogenous cyclic AMP on hydrophilic surfaces and can sense hydrophobic surfaces, initiating the differentiation of germ tubes. Interestingly, Δznf1 mutants also produce significantly more conidia compared with the isogenic wild-type strain. Quantitative reverse-transcription polymerase chain reaction analysis and green fluorescent protein fusion experiments revealed that expression of ZNF1 was highly induced during germination and appressorium development in M. oryzae and potentially regulated by the Pmk1 mitogen-activated protein kinase pathway. We observed that Δznf1 mutants are affected in mitosis and impaired in mobilization and degradation of lipid droplets and glycogen reserves during appressorium differentiation. Site-directed mutagenesis confirmed that three of the four C2H2 zinc-finger domains are essential for the function of Znf1. Taken together, we conclude that a C2H2 zinc-finger TF encoded by ZNF1 is essential for appressorium development by the rice blast fungus. PMID:26441322

  6. Induction of bacterial blight resistance in elite Indian rice (Oryza sativa L.) cultivars using gamma irradiation and ethyl methane sulfonate

    International Nuclear Information System (INIS)

    Rice is one of the most important crops in the world, feeding more than 50% of the human population. During the last 30 years, mutation breeding has played a significant role in rice breeding programmes. Rice mutants with higher yield, greater tolerance to diseases and pests and other agronomic qualities have been released for commercial cultivation in many countries. By the year 1991, as many as 278 rice cultivars had been released world-wide out of which 24 were from India. Bacterial blight (BB) caused by Xanthomonas oryzae pv oryzae is the second most important disease in southeast Asia, causing an average of 21 kg/ha yield loss. In the Basmati field yield loss can reach up to 100%. Moreover, there is no resistant source of Basmati rice known for its quality and aroma. Induction of bacterial blight resistance in basmati rice will not only help in developing high yielding Basmati cultivars without compromising the quality but will also be a good source of resistance for other Basmati rice varieties. Therefore, seeds of two Indian rice varieties viz. PR106 and Pusa Basmati 1 were treated with EMS (0.25% and 0.5%) at pH 7.0 at 25 ± 1 deg C for 12 h and gamma rays (100 and 200 Gy). A 3500-curie 60Co gamma cell with a dose rate of 3200 radians per minute was used for gamma irradiation of the paddy seeds containing 13% moisture. After mutagenic treatment seeds were germinated along with corresponding controls in petri dishes lined with wet filter paper. The seeds from the M1 generation were grown in the plant-to- progeny method for the M2 generation at Kapurthala, Punjab Agricultural University. Each progeny had 22-25 plants. The plant-to-plant distance was 20 cm and row-to-row distance was 30 cm. For every 20 lines, one line of check (parent variety) was grown. Screening against BB was made in the M2 generation by inoculating the plants at maximum tillering stage, following Kauffman et al. (1973). Observations for disease severity were recorded after 14 days of

  7. Molecular cloning and expression of a cDNA encoding Lon protease from rice (Oryza sativa).

    Science.gov (United States)

    Su, Wei; Lin, Changfa; Wu, Jiaxue; Li, Kegui; He, Guangming; Qian, Xiaoyin; Wei, Chun; Yang, Jinshui

    2006-06-01

    The ATP-dependent Lon protease is a highly conserved enzyme that is present in archeae, eubacteria, and eukaryotes, and plays an important role in intracellular protein degradation. We have isolated a Lon protease gene, OsLon1, from Oryza sativa. The cDNA contained a 2,655 bp ORF. Comparative analysis showed that OsLon1 shared significant similarity with the previously reported Lon proteases from maize, Arabidopsis, human, and bacteria. Tissue expression pattern analysis revealed that OsLon1 was highly expressed in young leaves, mature leaves, and leaf sheaths but only weakly in young roots, mature roots, and young panicles. The OsLon1 gene was successfully expressed in E. coli and the detected protein size, about 120 kDa, matched the expected molecular mass of the His-tagged OsLon1 protein. PMID:16786279

  8. Evaluation and characterization of advanced rice mutant line of rice (Oryza sativa), MR219-4 and MR219-9 under drought condition

    International Nuclear Information System (INIS)

    Two advance rice mutant lines, MR219-4 and MR219-9 derived from mutagenesis of Oryza sativa cv. MR219 with gamma radiation at 300 Gy were evaluated in simulated drought condition in the greenhouse at Malaysian Nuclear Agency. The mutants were evaluated simultaneously with ARN1, a drought resistant variety and MR211 a susceptible cultivar as a check. Randomized complete block design with three replicates was used in the experiment. The evaluation and selection were done based on leaf rolling and leaf drying as well as other agronomic traits, such as, number of tillers per plant, plant height, flag leaf area, grain weight per plant, grain yield per plant, 100-grain weight, harvest index, panicle length and plant biomass. The mutants MR219-4 showed moderate tolerance and MR219-9 showed tolerance to drought respectively as compare to the check variety (ARN1, MR211) and control MR219. Leaf rolling, leaf drying, days to flowering and days to maturity are valuable secondary traits that may provide additional information for selection because of associating with the plant survival under water stress. Further research on expression of drought-tolerant lines under different drought conditions is essential in order to identify particular traits that are associated with drought tolerance and high yield potential. Similarly the importance of secondary traits, relative to other putative traits for drought tolerance, needs to be tested in various environments. (author)

  9. Comparison Between AFLP and RFLP Markers in Detecting the Diversity of Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    CHEN Liang; LIANG Chun-yang; SUN Chuan-qing; JIN De-min; JIANG Ting-bo; WANG Bin; WANG Xiang-kun

    2002-01-01

    AFLP and RFLP were used to study the diversity of 20 rice cultivars. 15 primer combinations were used in the AFLP analysis and 47 - 118 bands were amplified in each lane. A total of 107 polymorphic bands were detected in the RFLP analysis using 49 RFLP probes. The cluster analysis based on RFLP data showed that 20 rice cultivars could be divided into an indica group and a japonica group, as did the AFLP data; however AFLP is more suitable in detecting the difference of pedigree and ecotype among the 20 cultivars.The genetic distance based on AFLP and RFLP data showed the same tendency, but AFLP markers increased the measure of genetic distance among intra-subspecific cultivars and decreased the measure of genetic distance among inter-subspecific cultivars relative to RFLP markers. That indicated that AFLP is more suitable than RFLP in the diversity study and RFLP is more suitable to study the indica-japonica differentiation of cultivars.

  10. Structural and histochemical studies on grain-filling in the caryopsis of rice (Oryza sativa L.)

    Indian Academy of Sciences (India)

    S Krishnan; P Dayanandan

    2003-06-01

    The endosperm and embryo that constitute the filial tissues of rice caryopsis are isolated from the maternal tissues by the absence of any symplastic continuity. Nutrients are transported to the endosperm through a single ovular vascular trace present on the ventral side of the ovary. Initially solute enters through the chalaza into the nucellar projection and then into the endosperm. At later stages transport occurs through the nucellar epidermis, centripetally towards the endosperm. The cell walls of the nucellar epidermis are provided with rib-like thickenings. A comparison of grain-filling in C3 and C4 cereals suggests that rice has structural features allied to C3 cereals, such as wheat, but with significant differences.

  11. Anti-diabetic related health food properties of traditional rice (Oryza sativa L.) in Sri Lanka

    Institute of Scientific and Technical Information of China (English)

    Wanigasekara Daya Ratnasooriya; Muhammad Iqbal Choudhary; Kourosh Dalvandi

    2015-01-01

    Objective:To evaluate a range of anti-diabetic related properties and some consumer preferred physicochemical properties of selected Sri Lankan traditional rice varieties. Methods: Sudu Heeneti, Goda Heeneti, Masuran and Dik Wee varieties were used in this study. Anti-diabetic related properties of bran extracts of selected varieties were studied for methylglyoxal mediated protein glycation inhibition, acetyl and butyryl-cholinesterase inhibitionin vitro and anti-hyperglycemic activityin vivo. Further, selected varieties were studied for starch hydrolysis ratein vitro. Physicochemical properties including grain color, size, shape, crude protein, crude fat, ash, dietary fiber and total carbohydrate contents were studied. Results: Brans of selected varieties had significant (P Conclusions: It is concluded that selected varieties could be promoted as physicochemically sound rices with a range of anti-diabetic related properties in the management of diabetes and its complications.

  12. Abiotic stresses affect differently the intron splicing and expression of chloroplast genes in coffee plants (Coffea arabica) and rice (Oryza sativa).

    Science.gov (United States)

    Nguyen Dinh, Sy; Sai, Than Zaw Tun; Nawaz, Ghazala; Lee, Kwanuk; Kang, Hunseung

    2016-08-20

    Despite the increasing understanding of the regulation of chloroplast gene expression in plants, the importance of intron splicing and processing of chloroplast RNA transcripts under stress conditions is largely unknown. Here, to understand how abiotic stresses affect the intron splicing and expression patterns of chloroplast genes in dicots and monocots, we carried out a comprehensive analysis of the intron splicing and expression patterns of chloroplast genes in the coffee plant (Coffea arabica) as a dicot and rice (Oryza sativa) as a monocot under abiotic stresses, including drought, cold, or combined drought and heat stresses. The photosynthetic activity of both coffee plants and rice seedlings was significantly reduced under all stress conditions tested. Analysis of the transcript levels of chloroplast genes revealed that the splicing of tRNAs and mRNAs in coffee plants and rice seedlings were significantly affected by abiotic stresses. Notably, abiotic stresses affected differently the splicing of chloroplast tRNAs and mRNAs in coffee plants and rice seedlings. The transcript levels of most chloroplast genes were markedly downregulated in both coffee plants and rice seedlings upon stress treatment. Taken together, these results suggest that coffee and rice plants respond to abiotic stresses via regulating the intron splicing and expression of different sets of chloroplast genes. PMID:27448724

  13. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Science.gov (United States)

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

    2013-07-01

    Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

  14. Seed germination ecology of Echinochloa glabrescens and its implication for management in rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Jhoana L Opeña

    Full Text Available Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE and Los Baños (IR] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88% from light stimulation than did the IR population (34%. The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and -0.24 MPa, respectively, for the NE population and 254 mM and -0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha(-1 of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha(-1 followed by shallow flooding (2-cm depth reduced seedling emergence by 94-96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85-100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses.

  15. Seed germination ecology of Echinochloa glabrescens and its implication for management in rice (Oryza sativa L.).

    Science.gov (United States)

    Opeña, Jhoana L; Chauhan, Bhagirath S; Baltazar, Aurora M

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and -0.24 MPa, respectively, for the NE population and 254 mM and -0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha(-1) of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha(-1) followed by shallow flooding (2-cm depth) reduced seedling emergence by 94-96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85-100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses. PMID:24642568

  16. Extraction And Stability Of Natural Colorant From Red Glutinous Rice Bran (Oryza Sativa Glutinosa)

    OpenAIRE

    Tirza Hanum

    2001-01-01

    Three extraction methods were studied to isolate natural colorant from red glutinous rice bran. Stability of extracts in relation to processing conditions and in the model beverages was determined at room temperature. Identifications of anthocyanidins was performed using reversed phase HPLC. Extraction method using acidified methanol solvent showed the highest yield (260,24+28,64 mg/100g). HPLC patern indicated the presence of six major anthocyanidins, two of them were identified as apigenidi...

  17. Protein markers associated with fertility restoration in japonica rice (Oryza sativaL.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@As genetic markers, seed storage proteins have characters of high level of polymorphism, less environmental influence, and simple genetic control. In this study, Kinmaze (CK), Liuqianxin A, Liuqianxin B, Liuqianxin R, 77302-1, Ninghui3-2, C57, Chinsurah Boro Ⅱ, TN1, IR8, IR2A, and F1 and F2 of Liuqianxin A/77302-1 were used to detect protein markers associated with fertility restoration in japonica rice.

  18. MORPHO-MOLECULAR SCREENING OF RICE (ORYZA SATIVA L. GENOTYPES AT SEEDLING STAGE FOR SALT TOLERANCE

    Directory of Open Access Journals (Sweden)

    Ali Julfiker Md. Masud

    2014-10-01

    Full Text Available Providing adequate food to meet an escalating population is one of the gravest problems the humankind is now facing. To resolve this crisis identification of salt tolerant rice variety is very vital. So, in this research, ten rice genotypes were used to screen salinity tolerance at the seedling stage in hydroponic system using SSR markers. Salinity screening was done at glasshouse following IRRI standard protocol using two setups of salinized and non-salinized conditions. Genotypes under controlled condition had longer root and shoot length then salt stress genotypes. Parental polymorphism survey was done with ten SSR markers viz., RM336, RM510, RM7075, RM407, RM3201b, RM10748, AP3206f, RM3412, RM585, RM11504 and all were selected to evaluate salt tolerance in rice genotypes. The number of alleles per locus ranged from 3 (AP3206f to 9 (RM336, with an average of 6.1 alleles across 10 loci obtained in the study. The polymorphic information content values ranged from of 0.54 (AP3206f to a high of 0.86 (RM336 with an average of 0.74. The pair-wise comparisons of Nei’s (1973 genetic distance (D between varieties were computed from combined data for the 10 primers, ranged from 0.30 to 0.90 with an average of 0.86, while the similarity index based analysis ranged from 0.00 to 0.70. Finally, the FL-478, FL-378, Binadhan-8 and Binadhan-10 were selected as salt tolerant because they showed tolerance in phenotypic analysis. These phenotypically selected tolerant genotypes could be used for the selection of suitable parents and development of salt tolerant rice varieties.

  19. Improved plant growth and Zn accumulation in grains of rice (Oryza sativa L.) by inoculation of endophytic microbes isolated from a Zn Hyperaccumulator, Sedum alfredii H.

    Science.gov (United States)

    Wang, Yuyan; Yang, Xiaoe; Zhang, Xincheng; Dong, Lanxue; Zhang, Jie; Wei, Yanyan; Feng, Ying; Lu, Lingli

    2014-02-26

    This study is to investigate the possibility of zinc (Zn) biofortification in the grains of rice (Oryza sativa L.) by inoculation of endophytic strains isolated from a Zn hyperaccumulator, Sedum alfredii Hance. Five endophytic strains, Burkholderia sp. SaZR4, Burkholderia sp. SaMR10, Sphingomonas sp. SaMR12, Variovorax sp. SaNR1, and Enterobacter sp. SaCS20, isolated from S. alfredii, were inoculated in the roots of Japonica rice Nipponbare under hydroponic condition. Fluorescence images showed that endophytic strains successfully colonized rice roots after 72 h. Improved root morphology and plant growth of rice was observed after inoculation with endophytic strains especially SaMR12 and SaCS20. Under hydroponic conditions, endophytic inoculation with SaMR12 and SaCS20 increased Zn concentration by 44.4% and 51.1% in shoots, and by 73.6% and 83.4% in roots, respectively. Under soil conditions, endophytic inoculation with SaMR12 and SaCS20 resulted in an increase of grain yields and elevated Zn concentrations by 20.3% and 21.9% in brown rice and by 13.7% and 11.2% in polished rice, respectively. After inoculation of SaMR12 and SaCS20, rhizosphere soils of rice plants contained higher concentration of DTPA-Zn by 10.4% and 20.6%, respectively. In situ micro-X-ray fluorescence mapping of Zn confirmed the elevated Zn content in the rhizosphere zone of rice treated with SaMR12 as compared with the control. The above results suggested that endophytic microbes isolated from S. alfredii could successfully colonize rice roots, resulting in improved root morphology and plant growth, increased Zn bioavailability in rhizosphere soils, and elevated grain yields and Zn densities in grains. PMID:24447030

  20. Raps markers for genetic diversity analysis in rice (Oryza sativa L)

    International Nuclear Information System (INIS)

    The establishment of relationships between genotypes existing in gene banks that may be used in new crosses, and about genetic diversity in available germplasm, is very useful for plant breeders. In this work, a genetic diversity analysis among 20 varieties of the Cuban rice germplasm bank was performed by using RAPD markers. Twenty four decamer primers were screened which produced 61 polymorphic bands out of 105 consistent and reproducible amplified fragments (58.1 %). The proportion of polymorphic bands varied for each primer, with an average of 3 polymorphic bands per primer, these results agreed with previous reports on RAPD polymorphism in rice germplasm. Depending on the primer, 1 to 7 distinct patterns were obtained among the screened genotypes. Pair-wise genetic distances between genotypes were computed based on Dice's coefficient. Three major, statistically robust groups were obtained in the UPGMA dendrogram (A, B and C) which clearly corresponded to different genetic pools. Additionally, more insight could be gained according to the sub-grouping pattern within group A, which included the principal semi-dwarf commercial varieties. The present study allowed to prove the efficiency of RAPD markers for genetic diversity analysis in closely related germplasm, particularly for the semi-dwarf Cuban commercial rice cultivars. Also, the existence of a narrow genetic base among these varieties has been confirmed, pointing at the urgent necessity of widen it

  1. Characterization and mapping of a lesion mimicmutant in rice(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A rice initiation-type lesion mimic mutant (imi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutant spontaneously developed lesions on the leaves in a develop mentally regulated and light-dependent manner. Genetic analysis indicated that the lesion mimic trait was controlled by a single resessive locus. Using public molecular markers and an F2 population derived from lmi and 93-11, we mapped the lmi locus to the short arm of chromosome 8, nearby the centromere, between two SSR markers RM547 and RM331. The genetic distance was 1.2 and 3.2 Cm, respectively. Then according to the public rice genomic sequence between the two SSR markers, lmi was further finely tagged by three CAPS markers: C4135-8, C4135-9 and C4135-10. And lmi locus was a co-segregated with marker C4135-10, providing a starting point for imi gene cloning.

  2. Rice (Oryza sativa L.) Seed Sterilization and Germination Enhancement via Atmospheric Hybrid Nonthermal Discharge Plasma.

    Science.gov (United States)

    Khamsen, Natthaporn; Onwimol, Damrongvudhi; Teerakawanich, Nithiphat; Dechanupaprittha, Sanchai; Kanokbannakorn, Weerawoot; Hongesombut, Komsan; Srisonphan, Siwapon

    2016-08-01

    We designed a system to produce atmospheric hybrid cold-discharge plasma (HCP) based on microcorona discharge on a single dielectric barrier and applied it to inactivate microorganisms that commonly attach the rice seed husk. The cold-plasma treatment modified the surface of the rice seeds, resulting in accelerated germination and enhanced water imbibition. The treatment can operate under air-based ambient conditions without the need for a vacuum. The cold-plasma treatment completely inactivated pathogenic fungi and other microorganisms, enhancing the germination percentage and seedling quality. The final germination percentage of the treated rice seeds was ∼98%, whereas that of the nontreated seeds was ∼90%. Microcorona discharge on a single dielectric barrier provides a nonaggressive cold plasma that can be applied to organic materials without causing thermal and electrical damage. The hybrid nonthermal plasma is cost effective and consumes relatively little power, making it suitable for the surface sterilization and disinfection of organic and biological materials with large-scale compatibility. PMID:27404121

  3. The performance of lowland rice (Oryza sativa L. cultivars on iron toxic soil augmented with compost

    Directory of Open Access Journals (Sweden)

    O.A. Dada

    2013-11-01

    Full Text Available Performance of lowland rice grown on anaerobic wetland soil is greatly affected by iron toxicity disorder in Nigeria. Better nutrient management and cultivation of resistant varieties have been recommended as strategy to manage this nutrient disorder. Information on intraspecific lowland NERICA cultivars grown on iron toxic soil augmented with compost is scanty. Therefore, the effect of different rates of compost on growth, dry matter and grain yield of lowland NERICA cultivars grown on iron toxic soil was investigated. A greenhouse experiment comprising of three (two NERICAs and ITA 212 lowland rice cultivars and four varying rates of compost arranged in completely randomized design with six replicates was conducted in greenhouse of Botany Department, University of Ibadan. Data collected on growth and yield parameters were analysed using ANOVA and LSD at P≤ 0.05. Correlation and simple linear regression were used to establish relationship between growth and iron toxicity scores. Results showed that iron toxicity significantly (p≤0.05 reduced growth and yield of lowland rice. Growth and grain yield of NERICA cultivars were significantly better (P ≤0.05 on soil augmented with compost than control. Grain yield was significantly related to the number of leaves affected by iron toxicity. Cultivating lowland NERICA-L-1 on iron toxic soil augmented with 8t ha -1 of compost will enhance better growth, dry matter characteristics and increase lowland NERICA grain yield.

  4. Differential Proteomic Analysis of Leaf Development at Rice (Oryza sativa)Seedling Stage

    Institute of Scientific and Technical Information of China (English)

    SHAO Cai-hong; LIU Guang-rong; WANG Jing-yuan; YUE Cai-fei; LIN Wen-xiong

    2008-01-01

    To identify the function of differential expression proteins in different leaves of rice seedlings extracted from 2- to 5-leaf stages,the leaf proteins at the seedling stage of hybrid rice Shanyou 63 were studied by using the approach of plant proteomics,and those proteins were separated with two-dimensional electrophoresis (2-DE) and then analyzed with an imagemaster 2D Elite 5.0.The results showed that the 41 protein spots were detected differential expression,of which 17 new protein spots appeared after the 3-leaf stage,including 9 special protein spots,which were only detected at the 3-leaf stage.Thirteen protein spots increased first and then decreased in expression abundance gradually and finally even disappeared.For the other 11 protein spots,3 protein spots decreased,but 6 protein spots were opposite in expression abundance,however,2 protein spots expressed in an irregular pattern after the 2-leaf stage.Of the 41 differential leaf proteins,15 protein spots were identified by ESI-Q MS/MS and categorized into 4 groups of functions.The results indicated that proteins were the carders of the functions in cells,but were significantly influenced by the changes in cell function or intercellular environment;hence,the reason that caused the proteomic changes as mentioned earlier might be related to the occurrence of tillers at the rice seedling stage after the 3-leaf stage.

  5. Mutation Breeding for Low Phytic Acid Content in Rice (Oryza sativa, L.)

    International Nuclear Information System (INIS)

    Phytic acid, myo-inositol 1,2,3,4,5,6-hexakisphosphate (Ins P6), is the most abundant phosphorous-containing compound in mature seeds, and antinutrient compound in plant. It is considered as a compound, which can strongly absorbs metal ions, forming salts that largely are excreted through urine and faeces. It can reduce the potential absorption of minerals by human and animal. Rice with low phytic acid is a good nutrient source for people suffering from malnutrition, and also has a potential value for use in infant, and eldery people feed. Low phytic acid of rice can be produced through induced mutation technique. Mutation breeding for low phytic acid contents in rice was conducted using three high yielding varieties (BATAN varieties) which are Atomita 1, Atomita 4 and Diah Suci. The seeds of these varieties were irradiated by gamma rays with a dose of 0,2 kGy. The selection for low phytic acid mutan started on M2 panicles. Among the selected lines only line No.873, derived from irradiated Diah Suci, was homogeneous on standard 3 and maintained stable from generation to generation. This line is now under the agronomical and genetical evaluation. (author)

  6. EFFECT OF HERBICIDES ON WEED CONTROL AND YIELD OF WET SEEDED RICE (ORYZA SATIVA L.

    Directory of Open Access Journals (Sweden)

    MALLIKARJUN

    2014-06-01

    Full Text Available To study effect of herbicides on weed control and yield of wet seeded rice which involves three pre-emergent herbicides viz., butachlor, anilophos and oxyflurofen applied as alone and each these followed by two post emergent herbicides 2, 4- sodium salt, bispyribac sodium and one hand weeding at 25 days. The results revealed that sequential application of butachlor and anilophos fb bispyribac sodium, 2, 4-D sodium salt and one hand weeding at 25 days was recorded significantly lower weed population and dry weight of weeds viz., monocots, dicots and sedges in equal manner which ultimately indicates that higher weed control efficiency over rest of the treatments except weed free check and hand weeding thrice. further, grain and straw yield of rice was followed the same trend as well influenced by yield parameters like number of panicles per sq.m and number of seeds/ panicle ultimately sequential application butachlor and anilophos fb 2, 4-D sodium salt and bispyribac sodium and one hand weeding at 25 DAS resulted higher grain yield and profitable rice production.

  7. Enzymatic properties of the glycine D-alanine [corrected] aminopeptidase of Aspergillus oryzae and its activity profiles in liquid-cultured mycelia and solid-state rice culture (rice koji).

    Science.gov (United States)

    Marui, Junichiro; Matsushita-Morita, Mayumi; Tada, Sawaki; Hattori, Ryota; Suzuki, Satoshi; Amano, Hitoshi; Ishida, Hiroki; Yamagata, Youhei; Takeuchi, Michio; Kusumoto, Ken-Ichi

    2012-01-01

    The gdaA gene encoding S12 family glycine-D-alanine aminopeptidase (GdaA) was found in the industrial fungus Aspergillus oryzae. GdaA shares 43% amino acid sequence identity with the D-aminopeptidase of the Gram-negative bacterium Ochrobactrum anthropi. GdaA purified from an A. oryzae gdaA-overexpressing strain exhibited high D-stereospecificity and efficiently released N-terminal glycine and D-alanine of substrates in a highly specific manner. The optimum pH and temperature were 8 to 9 and 40°C, respectively. This enzyme was stable under alkaline conditions at pH 8 to 11 and relatively resistant to acidic conditions until pH 5.0. The chelating reagent EDTA, serine protease inhibitors such as AEBSF, benzamidine, TPCK, and TLCK, and the thiol enzyme inhibitor PCMB inhibited the enzyme. The aminopeptidase inhibitor bestatin did not affect the activity. GdaA was largely responsible for intracellular glycine and D-alanine aminopeptidase activities in A. oryzae during stationary-phase growth in liquid media. In addition, the activity increased in response to the depletion of nitrogen or carbon sources in the growth media, although the GdaA-independent glycine aminopeptidase activity highly increased simultaneously. Aminopeptidases of A. oryzae attract attention because the enzymatic release of a variety of amino acids and peptides is important for the enhancement of the palatability of fermented foods. GdaA activity was found in extracts of a solid-state rice culture of A. oryzae (rice koji), which is widely used as a starter culture for Japanese traditional fermented foods, and was largely responsible for the glycine and D-alanine aminopeptidase activity detected at a pH range of 6 to 9. PMID:22005737

  8. Biodiversity of Asian rice gall midge (Orseolia oryzae Wood Mason) from five countries examined by AFLP analysis.

    Science.gov (United States)

    Katiyar, S K; Chandel, G; Tan, Y; Zhang, Y; Huang, B; Nugaliyadde, L; Fernando, K; Bentur, J S; Inthavong, S; Constantino, S; Bennett, J

    2000-04-01

    Amplified fragment length polymorphism (AFLP) analysis was used to assess the biodiversity of one of the most important dipteran pests of cereals, the Asian rice gall midge (Orseolia oryzae Wood Mason). Larvae and pupae were collected at 15 locations in five Asian countries and preserved in 95% ethanol for storage, shipment, and DNA extraction using cetyltrimethylammonium bromide (CTAB). Although only approximately 1 microg of DNA was extracted from a single pupa or larva, the use of several AFLP primers in various combinations meant that this amount of DNA was sufficient to allow many DNA fingerprints to be made per individual. Fingerprints were sufficiently reproducible, especially during selective amplification, to allow the genetic diversity within a field population to be characterized. Extraction of DNA from a pool of 20 insects yielded AFLP fingerprints in which variation among individuals was sacrificed in favor of detecting differences among populations. For each location, pooled DNA was amplified with three primer pairs. A total of 261 distinct AFLP bands were identified for the 45 fingerprints. Cluster analysis, performed by the unweighted pair-group method (UPGMA), separated the populations into two distinct groups. Group I included two populations from Guangdong province of southern China and one each from Laos and Imphal in northeastern India, while group II was comprised of eleven populations from elsewhere in India (Assam, Orissa, Madhya Pradesh, Andhra Pradesh, and Kerala) and from Nepal and Sri Lanka. AFLP analysis provided insight into the origins of gall midge biotypes. In 1992, the prevailing biotype in Imphal changed from Indian biotype 3 to a new biotype 3M. Our data show that biotype 3M belongs to group I and did not arise by a recent mutation from biotype 3, which belongs to group II. By contrast, Indian biotypes 2 and 4 are likely to have diverged through recent mutation and selection, as are Chinese biotypes 1 and 4. The almost

  9. Sensitive detection of Xanthomonas oryzae Pathovars oryzae and oryzicola by loop-mediated isothermal amplification.

    Science.gov (United States)

    Lang, Jillian M; Langlois, Paul; Nguyen, Marian Hanna R; Triplett, Lindsay R; Purdie, Laura; Holton, Timothy A; Djikeng, Appolinaire; Vera Cruz, Casiana M; Verdier, Valérie; Leach, Jan E

    2014-08-01

    Molecular diagnostics for crop diseases can enhance food security by enabling the rapid identification of threatening pathogens and providing critical information for the deployment of disease management strategies. Loop-mediated isothermal amplification (LAMP) is a PCR-based tool that allows the rapid, highly specific amplification of target DNA sequences at a single temperature and is thus ideal for field-level diagnosis of plant diseases. We developed primers highly specific for two globally important rice pathogens, Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight (BB) disease, and X. oryzae pv. oryzicola, the causal agent of bacterial leaf streak disease (BLS), for use in reliable, sensitive LAMP assays. In addition to pathovar distinction, two assays that differentiate X. oryzae pv. oryzae by African or Asian lineage were developed. Using these LAMP primer sets, the presence of each pathogen was detected from DNA and bacterial cells, as well as leaf and seed samples. Thresholds of detection for all assays were consistently 10(4) to 10(5) CFU ml(-1), while genomic DNA thresholds were between 1 pg and 10 fg. Use of the unique sequences combined with the LAMP assay provides a sensitive, accurate, rapid, simple, and inexpensive protocol to detect both BB and BLS pathogens. PMID:24837384

  10. Phylogenetic diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff), detection of polyketide synthase gene and their antagonistic activity analysis.

    Science.gov (United States)

    Wang, Ya; Gao, Bo Liang; Li, Xi Xi; Zhang, Zhi Bin; Yan, Ri Ming; Yang, Hui Lin; Zhu, Du

    2015-11-01

    The biodiversity of plant endophytic fungi is enormous, numerous competent endophytic fungi are capable of providing different forms of fitness benefits to host plants and also could produce a wide array of bioactive natural products, which make them a largely unexplored source of novel compounds with potential bioactivity. In this study, we provided a first insights into revealing the diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff.) from China using rDNA-ITS phylogenetic analysis. Here, the potential of fungi in producing bioactive natural products was estimated based on the beta-ketosynthase detected in the polyketide synthase (PKS) gene cluster and on the bioassay of antagonistic activity against two rice phytopathogens Thanatephorus cucumeris and Xanthomonas oryzae. A total of 229 endophytic fungal strains were validated in 19 genera. Among the 24 representative strains, 13 strains displayedantagonistic activity against the phytopathogens. Furthermore, PKS genes were detected in 9 strains, indicating their potential for synthesising PKS compounds. Our study confirms the phylogenetic diversity of endophytic fungi in O. rufipogon G. and highlights that endophytic fungi are not only promising resources of biocontrol agents against phytopathogens of rice plants, but also of bioactive natural products and defensive secondary metabolites. PMID:26466878

  11. A comparison of nitrate transport in four different rice(Oryza sativa L.) cultivars

    Institute of Scientific and Technical Information of China (English)

    FAN Xiaorong; SHEN Qirong; MA Zhengqiang; ZHU Huilan; YIN Xiaoming; Anthony J. Miller

    2005-01-01

    As rice can use both nitrate (NO3-) and ammonium (NH4+), we have tested the hypothesis that the shift in the pattern of cultivars grown in Jiangsu Province reflects the ability of the plants to exploit NO3- as a nitrogen (N) source. Four rice cultivars were grown in solution culture for comparison of their growth on NO3- and NH4+ nitrogen sources. All four types of rice,Xian You 63 (XY63), Yang Dao 6 (YD), Nong Keng 57 (NK) and Si You 917 (SY917), grew well and produced similar amounts of shoot biomass with 1 mmol/L NH4+ as the only N source.However, the roots of NK were significantly smaller in comparison with the other cultivars. When supplied with 1 mmol/L NO3-, YD produced the greatest biomass; while NK achieved the lowest growth among the four cultivars. Electrophysiological measurements on root rhizodermal cells showed that the NO3--elicited changes in membrane potential (ΔEm) of these four rice cultivars were significantly different when exposed to low external NO3- (<1 mmol/L); while they were very similar at high external NO3- (10 mmol/L). The root cell membrane potentials of YD and XY63 were more responsive to low external NO3- than those of NK and SY917. The ΔEm values for YD and XY63 rhizodermal cells were almost the same at both 0.1 mmol/L and 1 mmol/L NO3-;while for the NK and SY917 the values became larger as the external NO3- increased. For YD cultivar, ΔEm was measured over a range of NO3- concentrations and a Michaelis-Menten fit to the data gave a Km value of 0.17 mmol/L. Net NO3- uptake depletion kinetics were also compared and for some cultivars (YD and XY63) a single-phase uptake system with first order kinetics best fitted the data; while other cultivars (ND and SY917) showed a better fit to two uptake systems. These uptake systems had two affinity ranges: one had a similar Km in all the cultivars (0.2 mmol/L); the other much higher affinity system (0.03 mmol/L) was only present in NK and SY917. The expression pattern of twelve different

  12. Translocation and biotransformation of CuO nanoparticles in rice (Oryza sativa L.) plants

    International Nuclear Information System (INIS)

    Metal-based nanoparticles (MNPs) may be translocated and biochemically modified in vivo, which may influence the fate of MNPs in the environment. Here, synchrotron-based techniques were used to investigate the behavior of CuO NPs in rice plants exposed to 100 mg/L CuO NPs for 14 days. Micro X-ray fluorescence (μ-XRF) and micro X-ray absorption near edge structure (μ-XANES) analysis revealed that CuO NPs moved into the root epidermis, exodermis, and cortex, and they ultimately reached the endodermis but could not easily pass the Casparian strip; however, the formation of lateral roots provided a potential pathway for MNPs to enter the stele. Moreover, bulk-XANES data showed that CuO NPs were transported from the roots to the leaves, and that Cu (II) combined with cysteine, citrate, and phosphate ligands and was even reduced to Cu (I). CuO NPs and Cu-citrate were observed in the root cells using soft X-ray scanning transmission microscopy (STXM). - Highlights: • CuO NPs could not easily pass through the Casparian strip. • The formation of lateral root provides a possible pathway for CuO NPs to enter the stele. • CuO NPs can be transformed and even reduced in the rice plant. • This is the first in-depth study of the translocation pathway of CuO NPs and the presence of Cu compounds in rice plants. - The formation of the lateral root provides a potential pathway for CuO NPs to enter the stele in which Cu (II) was reduced to Cu (I)

  13. Anti-diabetic related health food properties of traditional rice (Oryza sativa L. in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Walimuni Kanchana Subhashini Mendis Abeysekera

    2015-10-01

    Full Text Available Objective: To evaluate a range of anti-diabetic related properties and some consumer preferred physicochemical properties of selected Sri Lankan traditional rice varieties. Methods: Sudu Heeneti, Goda Heeneti, Masuran and Dik Wee varieties were used in this study. Anti-diabetic related properties of bran extracts of selected varieties were studied for methylglyoxal mediated protein glycation inhibition, acetyl and butyryl-cholinesterase inhibition in vitro and anti-hyperglycemic activity in vivo. Further, selected varieties were studied for starch hydrolysis rate in vitro. Physicochemical properties including grain color, size, shape, crude protein, crude fat, ash, dietary fiber and total carbohydrate contents were studied. Results: Brans of selected varieties had significant (P < 0.05 and dose dependent methylglyoxal mediated protein glycation inhibition [IC50: (174.77 ± 6.65 to (342.87 ± 0.43 µg/mL] and acetyl [(IC50: (37.00 ± 0.68 to (291.00 ± 3.54 µg/mL] and butyryl-cholinesterase [IC50: (18.50 ± 0.60 to (96.60 ± 0.56 µg/mL] inhibitory activities. Further, Sudu Heeneti, Masuran and Dik Wee had low starch digestion rate (52.40 ± 1.44 to 53.76 ± 1.19 indicating that these varieties may be low glycemic index rices. Brans of Masuran tested in rat model showed anti-hyperglycemic activity. Physicochemical properties studied showed that selected varieties were red in color and grain size and shape were mostly medium and bold respectively. Moisture, crude protein, crude fat, ash and total carbohydrate contents varied significantly (P < 0.05 among the varieties. Conclusions: It is concluded that selected varieties could be promoted as physicochemically sound rices with a range of anti-diabetic related properties in the management of diabetes and its complications.

  14. Molecular dissection of developmental behavior of plant height in rice (Oryza sativa L.).

    OpenAIRE

    Yan, J; Zhu, J.; C. He; Benmoussa, M; P. Wu

    1998-01-01

    A doubled haploid population of 123 lines from IR64/Azucena was used to dissect the developmental behavior and genotype by environment interaction for plant height by conditional and unconditional quantitative trait loci (QTL) mapping methods in rice. It was shown that the number of QTL detected was different at various measuring stages. Some QTL could be detected at all stages and some only at one or several stages. More QTL could be found on the basis of time-dependent measures of different...

  15. Natural variation of the rice blast resistance gene Pi-ta in Oryza species and its corresponding avirulence gene AVR-Pita in Magnaporthe oryzae

    Science.gov (United States)

    The Pi-ta gene prevents the infections of M. oryzae races containing the corresponding avirulence gene AVR-Pita in a gene-for-gene manner. Pi-ta is a putative NBS type major resistance gene, and can directly recognize the AVR-Pita putative metalloprotease in triggering effective resistance. We hav...

  16. Rice RING protein OSBBI1 with E3 ligase activity confers broad-spectrum resistance against Magnaporthe oryzae by modifying the cell wall defence

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Zuhua He; Sihui Zhong; Guojun Li; Qun Li; Bizeng Mao; Yiwen Deng; Huijuan Zhang; Longjun Zeng; Fengming Song

    2011-01-01

    Emerging evidence suggests that E3 ligases play critical roles in diverse biological processes, including innate immune responses in plants. However, the mechanism of the E3 ligase involvement in plant innate immunity is unclear.We report that a rice gene, OsBBI1, encoding a RING finger protein with E3 ligase activity, mediates broad-spectrum disease resistance. The expression of OSBBI1 was induced by rice blast fungus Magnaporthe oryzae, as well as chemical inducers, benzothiadiazole and salicylic acid. Biochemical analysis revealed that OsBBI1 protein possesses E3ubiquitin ligase activity in vitro. Genetic analysis revealed that the loss of OsBBI1 function in a Tos17-insertion line increased susceptibility, while the overexpression of OsBBI1 in transgenic plants conferred enhanced resistance to multiple races of M.oryzae. This indicates that OsBBI1 modulates broad-spectrum resistance against the blast fungus. The OsBBII-overexpressing plants showed higher levels of H,O, accumulation in cells and higher levels of phenolic compounds and cross-linking of proteins in cell walls at infection sites by M. Oryzae compared with wild-type(WT)plants. The cell walls were thicker in the OsBB11-overexpressing plants and thinner in the mutant plants than in the WT plants. Our results suggest that OsBBH modulates broad-spectrum resistance to blast fungus by modifying cell wall defence responses. The functional characterization of OsBBI1 provides insight into the E3 ligase-mediated innate immunity, and a practical tool for constructing broad-spectrum resistance against the most destructive disease in rice.

  17. Somaclonal variation and comparison to mutation induced by X-rays in rice (Oryza sativa L.) by using rice landmarker

    International Nuclear Information System (INIS)

    By using rice DNA clones of landmarker set 1, set 2 and new set, RFLP analysis was carried out in plants of cv. Tsugaruotome and cv. Mutsuhomare which were derived from 300 Gy of X-ray-irradiated seeds. In the three landmarker sets were consisted of 106 genomic DNA clones and 235 cDNA clones. Each cultivar has five plants which showed polymorphism. It is considered that the occurrence of some mutation of gene concerned with DNA repairing because certain plants showed polymorphism by many landmarkers as probes. Activity of retrotransposon such as Tos17 and alteration of methylation pattern were not observed on any plants derived from X-ray-irradiated seeds. On the other hand, in plants regenerated from cultured calli, it was found the movement of Tos17 to certain area of hot spot and alteration of methylation pattern. Furthermore, it has been reported that amplification of repeated DNA segment which was not observed in the mutation induced by X-rays. Thus, on plant breeding the somaclonal variation may be more useful than the mutation induced by X-rays

  18. Control of brown spot pathogen of rice (Bipolaris oryzae using some phenolic antioxidants Controle da macha-parda do arroz (Bipolaris oryzae pelo emprego de antioxidantes fenólicos

    Directory of Open Access Journals (Sweden)

    Y.M. Shabana

    2008-09-01

    Full Text Available Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone. The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS and disease incidence (DI on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids in rice leaves and in the total carbohydrate and protein contents of the yielded grains.Bipolaris oryzae é o agente causador da doença mancha-parda do arroz e é responsável por significativas perdas econômicas. Três antioxidantes fenólicos (ácido salicílico, ácido benzóico e hidroquinona foram avaliados para o controle dessa doença do arroz. A atividade antifúngica destes compostos foi avaliada in vitro contra B. oryzae em diferentes concentrações e a eficiência de sua aplicação exógena no controle da mancha-parda foi avaliada em condições de campo. Nos ensaios in vitro, os ácidos benzóico e salicílico a 9 mM inibiram completamente a multiplicação de B. oryzae. Em condições de campo, a aspersão de ácido benzóico a 20 mM causou uma redução significativa na gravidade e incidência da doença na folhas da planta, além de aumentar significativamente o rendimento dos grãos e seus componentes. Algumas respostas bioqu

  19. Genetic diversity analysis aiding in selection of parents by RAPD markers in rice (Oryza sativa L

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    Immanuel Selvaraj. C, Pothiraj Nagarajan, K. Thiyagarajan, M Bharathi, and R Rabindran

    2011-06-01

    Full Text Available Genetic diversity among 26 rice genotypes was investigated using RAPD markers. The genotypes were screened for the leaf blastdisease reaction at two different environments. The average number of alleles amplified per primer was 9.03. Average number ofpolymorphic bands per primer was 6.80 with average polymorphism information content (PIC of 0.264. Clustering based ondendrogram revealed two major clusters and 5 sub clusters. Principal Coordinate Analysis (PCoA revealed three major groups.The first coordinate does not discriminate any of the genotypes based on the geographical origin, but the second and thirdcoordinates differentiated South East Asian and South Asian genotypes clearly. Genetic diversity analysis of rice genotypes withRAPD marker system and phenotypic screening for blast resistance revealed that White Ponni (susceptible and Moroberekan(resistant were one among the genetically distant and contrasting parents for leaf blast resistance. There is no cleardiscrimination of the markers to distinguish leaf blast resistant and susceptible genotypes into separate clusters by the principalcoordinate analysis.

  20. Morphology and mapping analysis of rice (Oryza sativa L.) clustered spikelets (Cl) mutant

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The rice clustered spikelets (Cl) mutant exhibits a phenotype that most of branch apical have 2-3 spikelets clustered together. SEM (scanning electron microscope) observation suggested that the Cl gene controlled branch apical development, and influenced the terminal spikelets elongation. The spikelet number was reduced in mutant, indicating that Cl may also have an effect on spikelet number. To map Cl locus, two F2 mapping populations derived from the crosses between the Cl and ZhongHua11, and Cl and ZheFu802 were constructed, respectively. The Cl locus was roughly mapped between two CAPS markers, CK0214 and SS0324. A further fine mapping analysis showed that the Cl locus was mapped between makers R0674E and Cl2560, with genetic distances of 0.2 and 2.1 cM, respectively. Then we found a PAC contig spanning Cl locus, the region was delimited to 196 kb. This result was useful for cloning of the Cl gene. Allelism test demonstrated that Cl was allelic to Cl2, another rice clustered spikelets mutant.

  1. Response difference of transgenic and conventional rice (Oryza sativa) to nanoparticles (γFe₂O₃).

    Science.gov (United States)

    Gui, Xin; Deng, Yingqing; Rui, Yukui; Gao, Binbin; Luo, Wenhe; Chen, Shili; Nhan, Le Van; Li, Xuguang; Liu, Shutong; Han, Yaning; Liu, Liming; Xing, Baoshan

    2015-11-01

    Nanoparticles (NPs) are an increasingly common contaminant in agro-environments, and their potential effect on genetically modified (GM) crops has been largely unexplored. GM crop exposure to NPs is likely to increase as both technologies develop. To better understand the implications of nanoparticles on GM plants in agriculture, we performed a glasshouse study to quantify the uptake of Fe2O3 NPs on transgenic and non-transgenic rice plants. We measured nutrient concentrations, biomass, enzyme activity, and the concentration of two phytohormones, abscisic acid (ABA) and indole-3-acetic acid (IAA), and malondialdehyde (MDA). Root phytohormone inhibition was positively correlated with Fe2O3 NP concentrations, indicating that Fe2O3 had a significant influence on the production of these hormones. The activities of antioxidant enzymes were significantly higher as a factor of low Fe2O3 NP treatment concentration and significantly lower at high NP concentrations, but only among transgenic plants. There was also a positive correlation between the treatment concentration of Fe2O3 and iron accumulation, and the magnitude of this effect was greatest among non-transgenic plants. The differences in root phytohormone production and antioxidant enzyme activity between transgenic and non-transgenic rice plants in vivo suggests that GM crops may react to NP exposure differently than conventional crops. It is the first study of NPs that may have an impact on GM crops, and a realistic significance for food security and food safety. PMID:26154040

  2. Effect of ureaformaldehyde on the agronomic efficiency of nitrogen fertilization in rice (Oryza sativa lin. flooded.

    Directory of Open Access Journals (Sweden)

    Pedro Meneses Dartayet

    2013-12-01

    Full Text Available The work was carried out during the years 2004 - 2011 in the international Center of Tsukuba, belonging to the International Agency of Cooperation of Japan and in the Territorial Station of Investigations of Grains "Sur del Jíbaro" in Sancti Spíritus with the objective value the employment of the nitrogenous fertilizer of Slow Liberation Ureaformaldehído on the index of agronomic efficiency in the use of the nitrogen and the increment of the agricultural yield for the production of rice; in the first one you study the speed of liberation of the nitrogen of the Ureaformaldehído and the conventional Urea to three temperatures (10; 17.5 and 25 ºC; in the second one studies effect of the fertilizer Ureaformaldehído on the agricultural yield and the index of agronomic efficiency in the use of the nitrogen, in the cultivation of the flooded rice. The main results showed the Ureaformaldehído reacted in a significant way in the measure the temperature was incremented, ending up being mineralized a percentage from 82 to the 100 days; on the other hand, the best yield was reached statistically, with the dose of 120 kg of N/ha, for the fertilizer Ureaformaldehído.

  3. Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

    International Nuclear Information System (INIS)

    To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha-1 versus 6.6 t ha-1. These mutants show lodging and shattering resistance. (Author)

  4. Quantitative proteomic analysis of the rice (Oryza sativa L. salt response.

    Directory of Open Access Journals (Sweden)

    Jianwen Xu

    Full Text Available Salt stress is one of most serious limiting factors for crop growth and production. An isobaric Tags for Relative and Absolute Quantitation (iTRAQ approach was used to analyze proteomic changes in rice shoots under salt stress in this study. A total of 56 proteins were significantly altered and 16 of them were enriched in the pathways of photosynthesis, antioxidant and oxidative phosphorylation. Among these 16 proteins, peroxiredoxin Q and photosystem I subunit D were up-regulated, while thioredoxin M-like, thioredoxin x, thioredoxin peroxidase, glutathione S-transferase F3, PSI subunit H, light-harvesting antenna complex I subunits, chloroplast chaperonin, vacuolar ATP synthase subunit H, and ATP synthase delta chain were down-regulated. Moreover, physiological data including total antioxidant capacity, peroxiredoxin activity, chlorophyll a/b content, glutathione S-transferase activity, reduced glutathione content and ATPase activity were consistent with changes in the levels of these proteins. The levels of the mRNAs encoding these proteins were also analyzed by real-time quantitative reverse transcription PCR, and approximately 86% of the results were consistent with the iTRAQ data. Importantly, our data suggest the important role of PSI in balancing energy supply and ROS generation under salt stress. This study provides information for an improved understanding of the function of photosynthesis and PSI in the salt-stress response of rice.

  5. Genotypic Difference in the Responses of Seedling Growth and Cd Toxicity in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    WU Fei-bo; DONG Jing; JIA Guo-xia; ZHENG Shan-jiu; ZHANG Guo-ping

    2006-01-01

    The experiment was carried out to study the genotypic difference in the responses of seed germination, growth and physiological characters of rice seedlings to Cd toxicity. The result showed that the germination was slightly stimulated under low Cd concentration (0.01-1.5 mM Cd), while severely depressed under higher Cd concentration (2.0 mM). Rice seedlings exposed to 0.01 mM Cd showed slight increases in plant height, root volume, biomass and chlorophyll concentration. These parameters were significantly reduced when Cd level in the medium was increased to 0.5 mM, and meanwhile corresponding increase in superoxide dismutase (SOD) and peroxidase (POD) activities, and MDA (malondialdehyde) content was observed. However, SOD and POD activities declined when plants were exposed to 1 mM Cd when compared with those under 0.5 mM Cd. Cadmium addition lowered Fe, Cu and Mn concentrations in roots and shoots. There was significant genotypic difference in the response of these parameters to Cd stress. Under Cd stress, Xiushui 110 had the least inhibition of growth and increase in MDA content, higher shoot Cd concentration, and greatest increase in POD and SOD activities, indicating its higher tolerance to Cd toxicity, while Bing 9914 had the greatest reduction of growth, and Zn, Cu, Fe, and Mn contents, but greatest increase in MDA content, and least increase in activities of antioxidative enzymes, indicating its sensitivity to Cd toxicity.

  6. In-vitro screening and field validation of rice (Oryza sativa L. genotypes for drought tolerance

    Directory of Open Access Journals (Sweden)

    S. Utharasu1* and C. R. Anandakumar1

    2014-03-01

    Full Text Available In vitro screening using polyethylene glycol (PEG was performed with matured seed-derived callus from six elite rice varieties and eight advanced cultures to understand the response to drought stress. Murashige and Skoog medium supplemented with 2 mg l-1 of 1-napthaleneacetic acid and 5, 10, 15 and 20 g l-1 of PEG 6000 were used to induce drought stress in callus. Significant differences were observed among the genotypes, treatments and their interactions for callus morphology and fresh weight. The genotypes PMK3, RMD(R1, ARB6 , ARB7 and ARB8 were identified as the most tolerant to drought stress using principal component analysis (PCA. A total of 48 crosses made from these genotypes showed significant yield increase over their respective parents. The hybrids RMD(R1/ARB7, PMK3/ARB7 and PMK3/ARB8 were identified as drought tolerant using PCA analysis. From the study it is proved that in vitro screening method can be used to identify drought tolerant rice genotypes.

  7. Genetic behaviour of some rice (Oryza sativa L. genotypes under different treatments of nitrogen levels

    Directory of Open Access Journals (Sweden)

    Metwally, T.F., S.E.M. Sedeek., A.F.Abdelkhalik., I.M. El-Rewiny and Ehab. M.R. Metwali

    2010-09-01

    Full Text Available The present investigation was carried out at the experimental farm of Rice Research and Training Center, Sakha, Kafer El-Sheikh, Egypt during 2008 and 2009 seasons to study the physio-morphological behaviour of some rice genotypes under lowand high nitrogen application. Twenty one genotypes were tested under three different nitrogen levels viz, 0, 75 and 150 kgN/ha for ten traits viz, flag leaf area, chlorophyll content, days to heading, panicle weight, , no. of filled grains/panicle, no. ofpanicles/plant ,1000-grain weight, grain yield t ha-1, grain yield efficiency index (GYEI and agronomic nitrogen use efficiency(ANUE. The genotypes were divided into three groups i.e., japonica/japonica (J/J, japonica/indica japonica (J/IJ and indicajaponica/indica japonica (IJ/IJ. GZ6296 x Giza178-1 and GZ6296 x Giza 178-3 gave the highest values of no. of filledgrain/panicle and no. of panicles/hill under low input of nitrogen. Giza177/Sakha101 and Giza176/GZ6944 (J/J gave thehighest grain yield under low input of nitrogen followed by the genotypes derived from Giza178/GZ6296 (IJ/IJ.

  8. Endophytic bacterial and fungal microbiota in sprouts, roots and stems of rice (Oryza sativa L.).

    Science.gov (United States)

    Wang, Wenfeng; Zhai, Yanyan; Cao, Lixiang; Tan, Hongming; Zhang, Renduo

    2016-01-01

    The objective of this study was to elucidate the endophytic microbiota in rice sprouts, roots, and stems, and their transmission in the plant development. Prior to DNA extraction, roots and stems were treated with 36% formaldehyde and 0.1M NaOH solutions to remove epiphytic bacterial whole 16S rRNA genes. Bacterial and fungal taxa in the sprout, root, and stem samples were analyzed using Illumina-based sequencing of the V3-V4 hyper variable regions of bacterial 16S rRNA genes and the ITS2 regions of fungal rRNA genes, respectively. Results showed that more diverse bacterial OTUs were detected in roots than in stems, while more diverse fungal OTUs were detected in stems than in roots. Compared with the endophytic microbiota in sprouts, the bacterial OTUs increased in roots but decreased in stems, whereas the fungal OTUs in both stems and roots decreased. Sprout-borne bacterial genera Sphingomonas and Pseudomonus, and fungal genera Fusarium, Pestalotiopsis, and Penicillium were detected in stems and roots. The coexistence of these indigenous bacterial and fungal taxa in sprouts, roots, and stems indicated their transmission during the development from sprouts to mature plants. The results from this study should be useful to better understand the plant-microbe interactions and to select suitable microbial taxa for rice production. PMID:27296957

  9. Isolation and genetic charac-terization of a fragile plantmutant in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The fragile rice mutant was isolated from an M2 population of indica variety Shuang Ke Zao (SKZ) treated with (-rays, and designated as fp1 (fragile plant 1) because of its fragile leaves and culms. To map FP1 locus, an F2 mapping population was derived from a cross between the fp1 and C-bao, a polymorphic japonic variety. The primary mapping result places the FP1 locus in an interval between two molecular markers, microsatellite marker RM16 (3.1 cM proximal to FP1) and STS marker G144a (9.1 cM distal to FP1) in the centromere region of chromosome 3. A CAPS marker C524a was further developed between RM16 and G144a, with 0.4 cM genetic distances to the FP1 locus, providing a practical starting point for constructing a BAC contig spanning the FP1 locus and cloning the fp1 gene. Allelism test demonstrated that fp1 is allelic to bc1, a fragile rice mutant reported previously.

  10. Physiochemical properties and cooking quality of long and short rice (Oryza sativa) grains

    International Nuclear Information System (INIS)

    Five rice grain samples namely long (American (Parboiled rice), A; Pakistan, P and Thailand, T) and short (Egyptian, E and Sudanese, S) types were investigated for their physicochemical and cooking quality characteristics. Investigations showed that rice grain of the two types had a length of 6.73 mm (A), 7.49 mm (P), 7.05 mm (T), 5.46 mm (E) and 5.64 mm (S); width of 2.08 mm (A), 1.73 mm (P), 2.06 mm (T), 2.66 mm (E) and 2.73 mm (S); thickness of 1.59 mm (A), 1.50 mm (P), 1.67 mm (T), 1.93 mm (E) and 1.83 mm (S) and length/width (L/w) ratio 3.24 (A), 4.35(P), 3.43 (T), 2.06 (E) and 2.07 (S). The L/W ratios obtained were used for determination of grain shapes. The shapes determined were slender for the long type samples and bold for the short type samples. Density values were 1.43 g/ml (A), 1.48 g/ml (P), 1.45 g/ml (T), 1.46 g/ml (E) and 1.46 g/ml (S). Paste viscosity increased from out of scale (A), 12 cm (P), 11.5 cm (T), 5.50 cm (S) to 4.50 cm (E).1000 kernel weight values were 16.67 g (A), 14.53 g (P), 18.89 g (T), 18.47 g (E) and 18.32 (S). Broken ratios obtained were 3.62 (A), 0.31 (P), 1.58 (T), 6.39 (E) and 6.54 (S). Also investigations showed that rice grains contained 8.6%-10.9% moisture, 0.3%-0.6%, ash, 0.22-0.48% fiber, 6.2%- 8.0% protein, and 0.5%-1.0 % oil. Cooking reduced the starch percentages from 59.82%-64.27% to the range of 43.97%-55.47% for both types. For all types of rice amylose seems to be lower (24.00%-31.50%) than amylopectin (31.66%-39.57%). Cooking reduced both amylose (13.83%-18.67%) and amylopectin (26.30%-34.32%) content, however, it increased the amylopectin content (39.64%) of the Sudanese, S sample. Alkali spreading values were 3 (A), 1-2 (P), 1-2 (T), 6-7(E) and 6-7 for (S) and their gelatinization temperature (G T) was classified as high - intermediate (70-74 C degree) for A, high G T (75-79 C degree) for P and T, while E and S were classified as having low G T (55-69 C degree). Gel consistency (GC) values were 86.00 mm, 41

  11. Risk assessment of potentially toxic element pollution in soils and rice (Oryza sativa) in a typical area of the Yangtze River Delta

    International Nuclear Information System (INIS)

    Soil pollution with potentially toxic elements (PTEs) resulting from rapid industrial development has caused major concerns. Selected PTEs and their accumulation and distribution in soils and rice (Oryza sativa) collected from Changshu, east China, were analyzed to evaluate the potential health risk to the local population. The soils were primarily contaminated with Hg, followed by Cu, Cd, Pb, and Zn. The concentrations of Pb, Hg, and Cd of 46, 32, and 1 rice samples exceeded their national maximum allowable levels in foods, respectively. Spatial distributions of total Cr, Cu, Pb, Zn, and Cd in soils shared similar geographical trends. The risk assessment of PTEs through rice consumption suggests that the concentrations of Cu, Pb, and Cd in some rice samples exceed their reference oral dose for adults and children. In general, there was no target hazard quotient value of any individual element that was greater than 1, but hazard index values for adults and children were 1.726 and 1.523, respectively. - Industrial development has led to increased risk from potentially toxic elements in soils and rice.

  12. Effect of Gamma Radiation on In Vitro Multiple Shoot Formation of Aromatic Rice Seeds (oryza sativa L.)

    International Nuclear Information System (INIS)

    The effect of exposure dose of gamma radiation on multiple shoot formation of aromatic rice seeds (Oryza sativa L.c v. Khao Dawk Mali 105) was investigated. The seeds were irradiated by gamma radiation with varying exposure doses of 0,4,8,12,16,20,24,28,32,36,40 and 44 krad. After irradiation, the seeds were surface sterilized and cultured on Murashige and Skoog medium supplemented with benzyl adenine 25 mg/1 to induce multiple shoot formation. After 5 weeks cultured the number of multiple shoot-forming seeds and the number of shoots per seed were counted. It was found that the number of multiple shoot-forming seeds was increased from 45.9 per mille in the control to 83.3 per mille in seeds irradiated at 24 krad. At the exposure dose of 28 krad the number of multiple shoot-forming seeds was decreased to 80 per mille and was lowest (11.4 per mille) at 40 krad. Multiple shoots formation was completely inhibited at the highest exposure dose of 44 krad. The exposure dose required to reduce the number of multiple shoot-forming seeds by 50 percent (R D50) was 38 krad. Similarly, the number of shoots per multiple shoot-forming seed was increasing as the exposure dose increased from 5.7 shoots in the control to 21.3 shoots in seeds irradiated at 40 krad. The number of shoots per seed was zero at the exposure dose of 44 krad. The multiple shoots regenerated from irradiated seeds were rooted. Then the M1 R1 plant lets were transplanted into pots grown under greenhouse conditions

  13. Identification of Novel and Conserved miRNAs from Extreme Halophyte, Oryza coarctata, a Wild Relative of Rice.

    Science.gov (United States)

    Mondal, Tapan Kumar; Ganie, Showkat Ahmad; Debnath, Ananda Bhusan

    2015-01-01

    Oryza coarctata, a halophyte and wild relative of rice, is grown normally in saline water. MicroRNAs (miRNAs) are non-coding RNAs that play pivotal roles in every domain of life including stress response. There are very few reports on the discovery of salt-responsive miRNAs from halophytes. In this study, two small RNA libraries, one each from the control and salt-treated (450 mM NaCl for 24 h) leaves of O. coarctata were sequenced, which yielded 338 known and 95 novel miRNAs. Additionally, we used publicly available transcriptomics data of O. coarctata which led to the discovery of additional 48 conserved miRNAs along with their pre-miRNA sequences through in silico analysis. In total, 36 known and 7 novel miRNAs were up-regulated whereas, 12 known and 7 novel miRNAs were down-regulated under salinity stress. Further, 233 and 154 target genes were predicted for 48 known and 14 novel differentially regulated miRNAs respectively. These targets with the help of gene ontology analysis were found to be involved in several important biological processes that could be involved in salinity tolerance. Relative expression trends of majority of the miRNAs as detected by real time-PCR as well as predicted by Illumina sequencing were found to be coherent. Additionally, expression of most of the target genes was negatively correlated with their corresponding miRNAs. Thus, the present study provides an account of miRNA-target networking that is involved in salinity adaption of O. coarctata. PMID:26506249

  14. Identification of Novel and Conserved miRNAs from Extreme Halophyte, Oryza coarctata, a Wild Relative of Rice.

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    Tapan Kumar Mondal

    Full Text Available Oryza coarctata, a halophyte and wild relative of rice, is grown normally in saline water. MicroRNAs (miRNAs are non-coding RNAs that play pivotal roles in every domain of life including stress response. There are very few reports on the discovery of salt-responsive miRNAs from halophytes. In this study, two small RNA libraries, one each from the control and salt-treated (450 mM NaCl for 24 h leaves of O. coarctata were sequenced, which yielded 338 known and 95 novel miRNAs. Additionally, we used publicly available transcriptomics data of O. coarctata which led to the discovery of additional 48 conserved miRNAs along with their pre-miRNA sequences through in silico analysis. In total, 36 known and 7 novel miRNAs were up-regulated whereas, 12 known and 7 novel miRNAs were down-regulated under salinity stress. Further, 233 and 154 target genes were predicted for 48 known and 14 novel differentially regulated miRNAs respectively. These targets with the help of gene ontology analysis were found to be involved in several important biological processes that could be involved in salinity tolerance. Relative expression trends of majority of the miRNAs as detected by real time-PCR as well as predicted by Illumina sequencing were found to be coherent. Additionally, expression of most of the target genes was negatively correlated with their corresponding miRNAs. Thus, the present study provides an account of miRNA-target networking that is involved in salinity adaption of O. coarctata.

  15. microRNAs targeting DEAD-box helicases are involved in salinity stress response in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Macovei Anca

    2012-10-01

    Full Text Available Abstract Background Rice (Oryza sativa L., one of the most important food crop in the world, is considered to be a salt-sensitive crop. Excess levels of salt adversely affect all the major metabolic activities, including cell wall damage, cytoplasmic lysis and genomic stability. In order to cope with salt stress, plants have evolved high degrees of developmental plasticity, including adaptation via cascades of molecular networks and changes in gene expression profiles. Posttranscriptional regulation, through the activity of microRNAs, also plays an important role in the plant response to salinity conditions. MicroRNAs are small endogenous RNAs that modulate gene expression and are involved in the most essential physiological processes, including plant development and adaptation to environmental changes. Results In the present study, we investigated the expression profiles of osa-MIR414, osa-MIR408 and osa-MIR164e along with their targeted genes, under salinity stress conditions in wild type and transgenic rice plants ectopically expressing the PDH45 (Pea DNA Helicase gene. The present miRNAs were predicted to target the OsABP (ATP-Binding Protein, OsDSHCT (DOB1/SK12/helY-like DEAD-box Helicase and OsDBH (DEAD-Box Helicase genes, included in the DEAD-box helicase family. An in silico characterization of the proteins was performed and the miRNAs predicted targets were validated by RLM-5′RACE. The qRT-PCR analysis showed that the OsABP, OsDBH and OsDSHCT genes were up-regulated in response to 100 and 200 mM NaCl treatments. The present study also highlighted an increased accumulation of the gene transcripts in wild type plants, with the exception of the OsABP mRNA which showed the highest level (15.1-fold change compared to control in the transgenic plants treated with 200 mM NaCl. Salinity treatments also affected the expression of osa-MIR414, osa-MIR164e and osa-MIR408, found to be significantly down-regulated, although the changes in mi

  16. Biochemical and molecular changes in rice seedlings (Oryza sativa L.) to cope with chromium stress.

    Science.gov (United States)

    Kabir, A H

    2016-07-01

    Chromium (Cr) is very toxic to both humans and plants. This investigation aimed to understand the physiological and molecular responses of rice seedlings to Cr stress. Cr toxicity did not significantly affect morphological features and Cr accumulation in roots and shoots in Pokkali but not in BRRI 51, although there was a reduction in chlorophyll concentration in leaves of both genotypes. These results imply that Pokkali has mechanisms to cope with Cr supplementation. We therefore performed quantitative real-time PCR on the expression pattern of two chelator genes, OsPCS1 and OsMT1, but there were no significant changes in expression in roots and shoots of Pokkali and BRRI 51 following Cr stress. This suggests that there was no metal sequestration following heavy metal stress in roots of these genotypes. Moreover, no expression of two heavy metal transporter genes, OsHMA3 and OsNRAMP1, was induced after Cr stress in roots and shoots, suggesting that these transporter genes are not induced by Cr stress or might not be involved in Cr uptake in rice. We also performed a targeted study on the effect of Cr on Fe uptake mechanisms. Our studies showed a consistent reduction in Fe uptake, Fe reductase activity and expression of Fe-related genes (OsFRO1 and OsIRT1) under Cr stress in both roots and leaves of Pokkali. In contrast, these parameters and genes were significantly increased in Cr-sensitive BRRI 51 under Cr stress. The results confirm that limiting Fe uptake through the down-regulation of Fe reductase and Fe transporter genes is the main strategy of Cr-tolerant Pokkali to cope with Cr stress. Finally, increased CAT, POD and GR activity and elevated glutathione and proline synthesis might provide strong antioxidant defence against Cr stress in Pokkali. Taken together, our findings reveal that Cr stress tolerance in rice (Pokkali) is not related to metal sequestration but is associated with reduced Fe transport and increased antioxidant defence. PMID:26804776

  17. Genetic divergence of jesso-balam rice (Oryza sativa L. of Bangladesh

    Directory of Open Access Journals (Sweden)

    MS Ahmed

    2015-06-01

    Full Text Available In total 27 genotypes of Jesso-Balam pure line rice germplasm were studied for fourteen morpho-physiological and four physico-chemical characters at Bangladesh Rice Research Institute, during T. Aman 2009 and T. Aman 2011 seasons. According to principal component scores, the two-dimensional scatter diagram (Z1-Z2 has apparently distributed the genotypes into seven clusters. According to Mahalanobis’ D2 statistic for the studied characters, the genotypes were clubbed into seven groups. The highest number of genotypes (6 were included in clusters I and III and the lowest two (2 in cluster V and VII. It was also revealed that no duplicate was existed among the genotypes. The intra-cluster distance was maximum (0.77 in cluster III and minimum (0.28 in cluster VII, while the maximum intercluster distance (28.37 was observed between the clusters III and IV and the minimum (2.49 between the clusters I and VII. The cluster V has produced the highest means for plant height (148.18 cm, straw yield per hill (39.97 g, panicle length (28.14 cm and protein content (9.61%. But, the cluster IV has showed the highest means for seedling height (69.5 cm, flag and penultimate leaf area (1059.5 cm2, culm diameter (5.8 cm, filled grain number per panicle (3.64, grain length (8.63 mm and 1000-grain weight (21.78 g, while the cluster VII had the highest means for grain yield per hill (31.27 g and effective tiller number per hill (13.5 and the lowest mean for days to maturity (144. Therefore, the genotypes of cluster V need to be crossed with the genotypes of cluster IV or cluster VII, for developing new Balam rice with maximum other good characters. Finally, it could be concluded that the studied Jesso-Balam pure lines germplasm is a good source of valuable genes.

  18. Mutagenic effects of β-rays on rice (oryza sativa L.)

    International Nuclear Information System (INIS)

    The mutagenic effects of 14C and some other mutagenic factors were compared, and the relationships between mutagenic effects of 14C and treated stages, doses and methods were studied with different rice varieties as test materials. The mutation rates of heading date and plant height were observed in M2. The results showed that the mutagenic effects of 14C were better than those of other mutagenic factors tested. It is most effective for inducing early-maturing mutation to treat plants with the doses of 333 x 104 Bq/plant at the stage of pollen mother cell formation; but for dwarf mutation , they were treated with 74 x 104 Bq/plant at the stage of pistil and stamen formation to pollen mother cell formation. As a best treating method, Na214CO3 solution was injected to plant bases

  19. Extraction And Stability Of Natural Colorant From Red Glutinous Rice Bran (Oryza Sativa Glutinosa

    Directory of Open Access Journals (Sweden)

    Tirza Hanum

    2001-04-01

    Full Text Available Three extraction methods were studied to isolate natural colorant from red glutinous rice bran. Stability of extracts in relation to processing conditions and in the model beverages was determined at room temperature. Identifications of anthocyanidins was performed using reversed phase HPLC. Extraction method using acidified methanol solvent showed the highest yield (260,24+28,64 mg/100g. HPLC patern indicated the presence of six major anthocyanidins, two of them were identified as apigenidin and apigenin. Stability of anthocyanin colorant was higher in a lower acid condition and was reduced to the lowest value of 49,4, 65,4, 40,8 and 36,6% by high temperature, UV light, sunlight, and the presence of oxidator agent. respectively. Retention of antocyanin in tanin and ascorbic acid added into the model beverages was lower than in protein containing beverage or control.

  20. Biochemical characterization of plant Rad52 protein from rice (Oryza sativa).

    Science.gov (United States)

    Nair, Anuradha; Agarwal, Rachna; Chittela, Rajani Kant

    2016-09-01

    DNA damage in living cells is repaired by two main pathways, homologous recombination (HR) and non-homologous end joining (NHEJ). Of all the genes promoting HR, Rad52 (Radiation sensitive 52) is an important gene which is found to be highly conserved across different species. It was believed that RAD52 is absent in plant systems until lately. However, recent genetic studies have shown the presence of RAD52 homologues in plants. Rad52 homologues in plant systems have not yet been characterized biochemically. In the current study, we bring out the biochemical properties of rice Rad52-2a protein. OsRad52-2a was over-expressed in Escherichia coli BL21 (DE3) cells and the protein was purified. The identity of purified OsRad52-2a protein was confirmed via peptide mass fingerprinting. Gel filtration and native PAGE analysis indicated that the OsRad52-2a protein in its native state probably formed an undecameric structure. Purified OsRad52-2a protein showed binding to single stranded DNA, double stranded DNA. Protein also mediated the renaturation of complementary single strands into duplex DNA in both agarose gel and FRET based assays. Put together, OsRad52-2a forms oligomeric structures and binds to ssDNA/dsDNA for mediating an important function like renaturation during homologous recombination. This study represents the first report on biochemical properties of OsRad52-2a protein from important crop like rice. This information will help in dissecting the recombination and repair machinery in plant systems. PMID:27156135

  1. Si,Fe and Mn Distributions in RiceOryza sativa L.) Rhizosphere of Red Earths and Paddy Soils

    Institute of Scientific and Technical Information of China (English)

    LIAOZHONG-WEN; WANGJIAN-LIN; 等

    1993-01-01

    An experiment using rhizobox was conducted to study Si,Fe and Mn distributions in rice rhizosphere of red earths and paddy soils.It was found that Si,Fe and Mn diftributions in rhizosphere of the paddy soils were characterized by a depleted zone around root suface,beyond which the concentrations gradually rost.From lmm layer to 2mm layer the concentrations dropped and then rose again.Whereas Si and Fe in red earths showed no depleted zone but even accumulated zone around root surface.Mn showed an approximately even distribution in each layer and no depletion was found in root surface layers.This indicated that during rice (Oryza sativa L.)plantation,depletion and accumulation of Si,Fe and Mn in rhizosphere were important features of matured red earths by water culture.The distribution changes of Si,Fe and Mn in relation to soil-root interaction are also discussed.

  2. Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae) in the Brazilian Amazon.

    Science.gov (United States)

    Júnior, Paulo Ivan Fernandes; Pereira, Gilmara Maria Duarte; Perin, Liamara; da Silva, Luana Mesquita; Baraúna, Alexandre Cardoso; Alvess, Francilene Muniz; Passos, Samuel Ribeiro; Zilli, Jerri Edson

    2013-06-01

    The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg's medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fifty-one bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360 bp nifH gene fragment. Among the 38 nifH+ isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus. The growth

  3. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Mahadtanapuk, S. [School of Agriculture and Natural Resources, University of Phayao, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Phayao 56000 (Thailand); Phanchaisri, B. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@frnf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S., E-mail: burinka@hotmail.com [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-15

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10{sup 16}–2 × 10{sup 17} ions/cm{sup 2}. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10{sup 6} spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  4. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    International Nuclear Information System (INIS)

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 1016–2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  5. Fertility alteration behaviour of Thermosensitive Genic Male Sterile lines in Rice Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    R.Latha and K.Thiyagarajan

    2010-07-01

    Full Text Available The utilization of thermosensitive genic male sterility system (TGMS has great potential for revolutionizing hybrid riceproduction in tropical countries through simple, less expensive and efficient seed production technology without anylimitation in fertility restoration which have been the hindrance for commercial exploitation of heterosis in rice usingcytoplasmic genic male sterility system (CMS. However for successful utilization of this novel male sterility system inhybrid rice breeding, knowledge on the fertility behaviour of TGMS lines, critical fertility and sterility temperatures andcritical stages of thermosensitivity are highly essential. In this study six TGMS lines viz., TS 6, TS 16, TS 18, TS 29, TS46 and TS 47 were characterized for their fertility behaviour. The lines were screened for pollen and spikelet fertility byraising the plants at fortnightly interval. All the lines had stable sterile phase with 100 per cent pollen sterility for morethan 50 consecutive days during high temperature condition (>30/20oC max/min and they reverted to fertile with morethan 60 per cent pollen and spikelet fertility during low temperature condition (<30/20oC max/min. All the lines exceptTS 29 showed one distinct sterile phase from March to June, whereas TS 29 had two sterile phases from mid February tomid June and from second week of September to first week of November. Since all the lines were completely sterile formore than 30 consecutive days during sterile phase, hybrid seed production utilising these lines can be taken up by raisingthe lines in such a way that flowering coincides with sterile phase. All the lines reverted into fertile in two phases. Thefirst fertile phase was short (13-17 days during July for all the lines except TS 29, for which it was observed duringAugust. The second fertile phase was longer in duration from late November to early February for more than 30 days inall the lines except TS 29, in which it was only for 16 days

  6. Identification of Cell Wall Synthesis Regulatory Genes Controlling Biomass Characteristics and Yield in Rice (Oryza Sativa)

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Zhaohua PEng [Mississippi State University; Ronald, Palmela [UC-Davis; Wang, Guo-Liang [The Ohio State University

    2013-04-26

    This project aims to identify the regulatory genes of rice cell wall synthesis pathways using a cell wall removal and regeneration system. We completed the gene expression profiling studies following the time course from cell wall removal to cell wall regeneration in rice suspension cells. We also completed, total proteome, nuclear subproteome and histone modification studies following the course from cell wall removal and cell wall regeneration process. A large number of differentially expressed regulatory genes and proteins were identified. Meanwhile, we generated RNAi and over-expression transgenic rice for 45 genes with at least 10 independent transgenic lines for each gene. In addition, we ordered T-DNA and transposon insertion mutants for 60 genes from Korea, Japan, and France and characterized the mutants. Overall, we have mutants and transgenic lines for over 90 genes, exceeded our proposed goal of generating mutants for 50 genes. Interesting Discoveries a) Cell wall re-synthesis in protoplasts may involve a novel cell wall synthesis mechanism. The synthesis of the primary cell wall is initiated in late cytokinesis with further modification during cell expansion. Phragmoplast plays an essential role in cell wall synthesis. It services as a scaffold for building the cell plate and formation of a new cell wall. Only one phragmoplast and one new cell wall is produced for each dividing cell. When the cell wall was removed enzymatically, we found that cell wall re-synthesis started from multiple locations simultaneously, suggesting that a novel mechanism is involved in cell wall re-synthesis. This observation raised many interesting questions, such as how the starting sites of cell wall synthesis are determined, whether phragmoplast and cell plate like structures are involved in cell wall re-synthesis, and more importantly whether the same set of enzymes and apparatus are used in cell wall re-synthesis as during cytokinesis. Given that many known cell wall

  7. Selection of rice mutants Oryza Sativa L. with tolerance to saline grounds

    International Nuclear Information System (INIS)

    A selection of rice mutants with tolerance to salinity, took place in the Escuela de Ciencias Agrarias de la Universidad Nacional de Heredia, in conditions of hothouse starting from a population of M2 segregative seed, coming from commercial seed radiated with Co 60 gamma rays. The studied segregatives were: Setesa-9, Experimental II and Experimental I. For making this selection, the seed M2 was planted in plastic trays with saline soil with electrical conductivity values from 8 to 10 mmhos/cm. In each case, non-radiated original seed was used as control. After 22 days the seedling germinated, an evaluation was made and it was seen that any of the controls had resisted to the saline stress, and only those segregatives resistent to salinity survived. These were the next ones: 9 individuals of Setesa, 10 of the Experimental II, and 9 of Experimental I. The index of selection obtained was: 3.6, 4.0 y 3.6 respectively. In a second phase of the experiment, the seedling selected as salinity resistant, were taken to the ground were they were developed for getting the M3 mutant seed tolerant to salinity. The plants were individually harvested in the ground and each one had a specific identification. Then, weight and number data, fertile grain and ineffectives of the M3 seed were taken. After, for corroborating the capacity of tolerance to salinity, M3 seed was planted in flowerpots with saline soil with a value of electrical conductivity between 8 and 10 mmhos/cm. After data were analyzed, it was proved that some rice mutants had a profit of even 28 grams for 1000 grams as: ExpI-17, ExpI-15, ExpI-08, ExpII-22, ExpII-08, ExpII-30 and Se-9-14, Se-9-39 and Se-9-10. Therefore, the methodology utilized showed being effective and efficient for the objectives of the work

  8. Patterns of sequence divergence and evolution of the S orthologous regions between Asian and African cultivated rice species.

    Science.gov (United States)

    Guyot, Romain; Garavito, Andrea; Gavory, Frédérick; Samain, Sylvie; Tohme, Joe; Ghesquière, Alain; Lorieux, Mathias

    2011-01-01

    A strong postzygotic reproductive barrier separates the recently diverged Asian and African cultivated rice species, Oryza sativa and O. glaberrima. Recently a model of genetic incompatibilities between three adjacent loci: S(1)A, S(1) and S(1)B (called together the S(1) regions) interacting epistatically, was postulated to cause the allelic elimination of female gametes in interspecific hybrids. Two candidate factors for the S(1) locus (including a putative F-box gene) were proposed, but candidates for S(1)A and S(1)B remained undetermined. Here, to better understand the basis of the evolution of regions involved in reproductive isolation, we studied the genic and structural changes accumulated in the S(1) regions between orthologous sequences. First, we established an 813 kb genomic sequence in O. glaberrima, covering completely the S(1)A, S(1) and the majority of the S(1)B regions, and compared it with the orthologous regions of O. sativa. An overall strong structural conservation was observed, with the exception of three isolated regions of disturbed collinearity: (1) a local invasion of transposable elements around a putative F-box gene within S(1), (2) the multiple duplication and subsequent divergence of the same F-box gene within S(1)A, (3) an interspecific chromosomal inversion in S(1)B, which restricts recombination in our O. sativa×O. glaberrima crosses. Beside these few structural variations, a uniform conservative pattern of coding sequence divergence was found all along the S(1) regions. Hence, the S(1) regions have undergone no drastic variation in their recent divergence and evolution between O. sativa and O. glaberrima, suggesting that a small accumulation of genic changes, following a Bateson-Dobzhansky-Muller (BDM) model, might be involved in the establishment of the sterility barrier. In this context, genetic incompatibilities involving the duplicated F-box genes as putative candidates, and a possible strengthening step involving the

  9. Patterns of Sequence Divergence and Evolution of the S1 Orthologous Regions between Asian and African Cultivated Rice Species

    Science.gov (United States)

    Gavory, Frédérick; Samain, Sylvie; Tohme, Joe; Ghesquière, Alain; Lorieux, Mathias

    2011-01-01

    A strong postzygotic reproductive barrier separates the recently diverged Asian and African cultivated rice species, Oryza sativa and O. glaberrima. Recently a model of genetic incompatibilities between three adjacent loci: S1A, S1 and S1B (called together the S1 regions) interacting epistatically, was postulated to cause the allelic elimination of female gametes in interspecific hybrids. Two candidate factors for the S1 locus (including a putative F-box gene) were proposed, but candidates for S1A and S1B remained undetermined. Here, to better understand the basis of the evolution of regions involved in reproductive isolation, we studied the genic and structural changes accumulated in the S1 regions between orthologous sequences. First, we established an 813 kb genomic sequence in O. glaberrima, covering completely the S1A, S1 and the majority of the S1B regions, and compared it with the orthologous regions of O. sativa. An overall strong structural conservation was observed, with the exception of three isolated regions of disturbed collinearity: (1) a local invasion of transposable elements around a putative F-box gene within S1, (2) the multiple duplication and subsequent divergence of the same F-box gene within S1A, (3) an interspecific chromosomal inversion in S1B, which restricts recombination in our O. sativa×O. glaberrima crosses. Beside these few structural variations, a uniform conservative pattern of coding sequence divergence was found all along the S1 regions. Hence, the S1 regions have undergone no drastic variation in their recent divergence and evolution between O. sativa and O. glaberrima, suggesting that a small accumulation of genic changes, following a Bateson-Dobzhansky-Muller (BDM) model, might be involved in the establishment of the sterility barrier. In this context, genetic incompatibilities involving the duplicated F-box genes as putative candidates, and a possible strengthening step involving the chromosomal inversion might participate to

  10. Patterns of sequence divergence and evolution of the S orthologous regions between Asian and African cultivated rice species.

    Directory of Open Access Journals (Sweden)

    Romain Guyot

    Full Text Available A strong postzygotic reproductive barrier separates the recently diverged Asian and African cultivated rice species, Oryza sativa and O. glaberrima. Recently a model of genetic incompatibilities between three adjacent loci: S(1A, S(1 and S(1B (called together the S(1 regions interacting epistatically, was postulated to cause the allelic elimination of female gametes in interspecific hybrids. Two candidate factors for the S(1 locus (including a putative F-box gene were proposed, but candidates for S(1A and S(1B remained undetermined. Here, to better understand the basis of the evolution of regions involved in reproductive isolation, we studied the genic and structural changes accumulated in the S(1 regions between orthologous sequences. First, we established an 813 kb genomic sequence in O. glaberrima, covering completely the S(1A, S(1 and the majority of the S(1B regions, and compared it with the orthologous regions of O. sativa. An overall strong structural conservation was observed, with the exception of three isolated regions of disturbed collinearity: (1 a local invasion of transposable elements around a putative F-box gene within S(1, (2 the multiple duplication and subsequent divergence of the same F-box gene within S(1A, (3 an interspecific chromosomal inversion in S(1B, which restricts recombination in our O. sativa×O. glaberrima crosses. Beside these few structural variations, a uniform conservative pattern of coding sequence divergence was found all along the S(1 regions. Hence, the S(1 regions have undergone no drastic variation in their recent divergence and evolution between O. sativa and O. glaberrima, suggesting that a small accumulation of genic changes, following a Bateson-Dobzhansky-Muller (BDM model, might be involved in the establishment of the sterility barrier. In this context, genetic incompatibilities involving the duplicated F-box genes as putative candidates, and a possible strengthening step involving the chromosomal

  11. Hydroxylamine and triethanolamine pre-irradiation treatments to induce mutation in rice (Oryza Sativa L.)

    International Nuclear Information System (INIS)

    Seeds of Padma variety of rice were at first treated with HA and TEA in the concentration of 0.3 % aqueous solution for 24 hours and were then exposed to 10 and 20 kR of x-rays. The control was kept for 24 hours in distilled water and then exposed to the same doses of x-rays. No set pattern of effect could always be seen as regards data taken for a number of characters in the M1, M2 and M3 generations. In the M1 generation, variants observed were : dwarf plant, spikelet sterility, violet coloration at base of leaf, spreading habit and inverted spikelet. In the M2 generation, the mutants observed were slender grain, compact tiller, tipped grain, dwarf bushy, bushy lodging, spikelet sterile, open spikelet with fully formed grain, early mature plant, narrow leaf, disproportionate length of lemma and palea and triangular opening of the hull. In the M3 generation, inverted spikelet and dwarf types were seen. The increase in M2 and M3 mutants was not always observed with the increase in the meiotic irregularities. In most of the cases, pollen sterility increased with the increase in meiotic irregularities in the M2 and M3 generations. (author)

  12. Expression of PIN Genes in Rice (Oryza sativa L.):Tissue Specificity and Regulation by Hormones

    Institute of Scientific and Technical Information of China (English)

    Ji-Rong Wang; Han Hu; Gao-Hang Wang; Jing Li; Jie-Yu Chen; Ping Wu

    2009-01-01

    Twelve genes of the PIN family in rice were analyzed for gene and protein structures and an evolutionary relationship with reported AtPINs in Arabidopsis.Four members of PIN1 (designated as OsPIN1a-d),one gene paired with AtPIN2 (OsPIN2),three members of PIN5 (OsPIN5a-c),one gene paired with AtPIN8 (OsPIN8),and three monocot-specific PiNs (OsPINg,OsPIN10a,and b) were identified from the phylogenetic analysis.Tissue-specific expression patterns of nine PIN genes among them were investigated using RT-PCR and GUS reporter.The wide variations in the expression domain in different tissues of the PIN genes were observed.In general,PIN genes are up-regulated by exogenous auxin,while different responses of different PIN genes to other hormones were found.

  13. [Applicability of multivariate statistics for nutritional studies: bioassay rice weevil (Sitophilus oryzae L)].

    Science.gov (United States)

    Lugo Gonázlez, Dennis Alexander; Aguilar, Víctor Hugo; Casotto, Meris; Laurentin, Alexander; Gómez, Ana

    2013-09-01

    The principal component analysis (PCA), non-metric multidimensional scaling (MDS) and analysis of similarity (ANOSIM) are multivariate statistical techniques that graphically represent numerical measures of several factors and display multiple relationships that may exist between them. In this study, we evaluated the applicability of these techniques to analyze the nutritional quality of diet, using as model, the bioassay rice weevil. The diets tested were: corn starch, potato starch, 5% glucose, peas, starved and starved with water supply. The variables studied were: survival, weight change and body composition. The PCA and MDS showed positive relationships of survival and weight change with body fat and carbohydrate parameters. Fat and carbohydrates were greater in starches diets, similar to the positive control. The PCA showed differences between populations fed with different diets, whereas the MDS showed similarity between diets. Both studies defined a gradient of the nutritive value of diets in the x-axis. The ANOSIM indicate significant (p interaction of differents variables to measure the nutritional quality of diets. PMID:25362823

  14. Characterization of four RecQ homologues from rice (Oryza sativa L. cv. Nipponbare)

    International Nuclear Information System (INIS)

    The RecQ family of DNA helicases is conserved throughout the biological kingdoms. In this report, we have characterized four RecQ homologues clearly expressed in rice. OsRecQ1, OsRecQ886, and OsRecQsim expressions were strongly detected in meristematic tissues. Transcription of the OsRecQ homologues was differentially induced by several types of DNA-damaging agents. The expression of four OsRecQ homologues was induced by MMS and bleomycin. OsRecQ1 and OsRecQ886 were induced by H2O2, and MitomycinC strongly induced the expression of OsRecQ1. Transient expression of OsRecQ/GFP fusion proteins demonstrated that OsRecQ2 and OsRecQ886 are found in nuclei, whereas OsRecQ1 and OsRecQsim are found in plastids. Neither OsRecQ1 nor OsRecQsim are induced by light. These results indicate that four of the RecQ homologues have different and specific functions in DNA repair pathways, and that OsRecQ1 and OsRecQsim may not involve in plastid differentiation but different aspects of a plastid-specific DNA repair system

  15. Radiation effect in another culture rice (Oryza Sativa L.) variety Krispo-38

    International Nuclear Information System (INIS)

    Seeds of the rice variety Krispo-38 were irradiated with 0, 100, 200, 300 and 400 Gray (Gy) and sown in the greenhouse. From each treatment, others containing uninucleate pollen grains were collected and cultured on a N6 agar medium with 5% sucrose concentration and supplemented with mg/l naphthalene acetic acid (NAA), 1 mg/l kinetin and 1 mg/l 2,4 dichlorophenoxyacetic acid (2,4-D). The pollen grains were induced to develop callus. The percentage of others that produced calli varied from 0.8 for the 400-Gy treatment to 3.3% for the control. The calli were transferred to N6 medium with 3% sucrose concentration, supplemented with 0.5 mg/l NAA and 1 mg/l kinetin. The percentage of calli that produced green plants varied from 1.9 for the 300-Gy treatment to 10.5 for the 200 Gy treatment. Plants developed in 2-5 weeks after callus transplant. A total of 101 green plants was obtained

  16. Dependence of solar radiation transport in rice [Oryza sativa] canopies on developmental stage

    International Nuclear Information System (INIS)

    Solar radiation in a rice canopy plays an important role in the energy balance on both the plant leaves and soil/water surface. A simple model was derived from the two-stream model to estimate two important factors characterizing radiation in a plant canopy, namely, transmissivity of the canopy (tausub(c)) and the albedo of the canopy (ref), from the absorption coefficient of leaves (alpha) and leaf inclination factor (F). To clarify the seasonal variation in alpha and F with growth, season-long observations were conducted in paddy fields during three different cropping seasons. Values of alpha were almost constant throughout the growing period; however, values of F tended to increase with growth. Values of F were larger than 0.5 (the theoretical value for random leaf distribution) in the late growth stage mainly due to the alterations in leaf geometry with the change in leaf inclination angle along a more horizontal axis after flowering, while in contrast, values of F were less than 0.5 in the early growth stage mainly due to the distribution bias of leaves after transplanting. Seasonal variation in F during different cropping seasons could commonly be expressed as a function of developmental stage (DVS). Using this function, tausub(c) and ref could be estimated with more accuracy. The proposed radiation model and function is expected to be applicable in more accurate evaluation of solar radiation, dry matter production and soil/water temperature in paddy fields

  17. Molecular evaluation of genetic diversity and association studies in rice (Oryza sativa L.)

    Indian Academy of Sciences (India)

    C. Vanniarajan; K. K. Vinod; Andy Pereira

    2011-04-01

    In the present study, we tested rice genotypes that included un(der)exploited landraces of Tamil Nadu along with indica and japonica test cultivars to ascertain their genetic diversity structure. Highly polymorphic microsatellite markers were used for generating marker segregation data. A novel measure, allele discrimination index, was used to determine subpopulation differentiation power of each marker. Phenotypic data were collected for yield and component traits. Pattern of molecular differentiation separated indica and japonica genotypes; indica genotypes had two subpopulations within. Landraces were found to have indica genome, but formed a separate subgroup with low linkage disequilibrium. The landraces further separated into distinct group in both hierarchical clustering analysis using neighbour-joining method as well as in the model based population structure analysis. Japonica and the remaining indica cultivars formed two other distinct groups. Linkage disequilibrium observed in the whole population was considerably reduced in subpopulations. Low linkage disequilibrium of landforms suggests their narrow adaptation in local geographical niche. Many population specific alleles could be identified particularly for japonica cultivars and landraces. Association analysis revealed nine marker–trait associations with three agronomic traits, of which 67% were previously reported. Although the testing landraces together with known cultivars had permitted genomewide association mapping, the experiment offers scope to study more landraces collected from the entire geographical region for drawing more reliable information.

  18. Aluminium localization and toxicity symptoms related to root growth inhibition in rice (Oryza sativa L.) seedlings

    Indian Academy of Sciences (India)

    M N Alvim; F T Ramos; D C Oliveira; R M S Isaias; M G C França

    2012-12-01

    We correlated root growth inhibition with aluminium (Al3+) localization and toxicity symptoms in rice roots using seedlings of two genotypes (tolerant and sensitive) that were exposed to different AlCl3 concentrations. Al3+ localization was evaluated by hematoxylin in primary roots and by morin in cross-sections of the root tips. Neutral invertase enzyme activity and callose (1$\\to$3, -D-glucan) accumulation were observed and compared with Al3+ accumulation sites. Root growth was inhibited by Al3+ in a concentration-specific manner and proportional to the increase of hematoxylin staining, being more pronounced in the sensitive genotype. Morin staining showed the presence of Al3+ deep within the roots of the sensitive genotype, indicating that the metal was able to penetrate beyond the first few cell layers. In the tolerant genotype, Al3+ penetration was restricted to the first two cell layers. Ruptures in exodermis and epidermis layers by lateral root protrusions in both genotypes allowed Al3+ to enter into the roots. More intense activity of invertase in roots of the tolerant genotype was also observed, which could be related to greater root growth of this cultivar when submitted to Al3+ stress. Moreover, Al3+-induced callose accumulation was a late response occurring in the same areas where Al3+ was present.

  19. Live-cell imaging of rice cytological changes reveals the importance of host vacuole maintenance for biotrophic invasion by blast fungus, Magnaporthe oryzae.

    Science.gov (United States)

    Mochizuki, Susumu; Minami, Eiichi; Nishizawa, Yoko

    2015-12-01

    The rice blast fungus Magnaporthe oryzae grows inside living host cells. Cytological analyses by live-cell imaging have revealed characteristics of the biotrophic invasion, particularly the extrainvasive hyphal membrane (EIHM) originating from the host plasma membrane and a host membrane-rich structure, biotrophic interfacial complex (BIC). Here, we observed rice subcellular changes associated with invasive hyphal growth using various transformants expressing specifically localized fluorescent proteins. The invasive hyphae did not penetrate across but were surrounded by the host vacuolar membrane together with EIHM even after branching. High-resolution imaging of BICs revealed that the host cytosol was accumulated at BIC with aggregated EIHM and a symplastic effector, Pwl2, in a punctate form. The vacuolar membrane did not aggregate in but closely surrounded the BIC. A good correlation was observed between the early collapse of vacuoles and damage of invasive hyphae in the first-invaded cell. Furthermore, a newly developed, long-term imaging method has revealed that the central vacuole gradually shrank until collapse, which was caused by the hyphal invasion occurring earlier in the neighboring cells than in the first-invaded cells. These data suggest that M. oryzae may suppress host vacuole collapse during early infection stages for successful infection. PMID:26472068

  20. Genetic variability and character association studies in rainfed upland rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    J. R. Patel, M. R. Saiyad, K. N. Prajapati, R. A. Patel, R. T. Bhavani

    2014-09-01

    Full Text Available A study to obtain information on genetic variability and inter-relationship of grain yield and associated characters under rainfed upland conditions was carried out using 44 diverse genotypes. The analysis of variance revealed the significant differences among the genotypes for all the traits indicating presence of sufficient variability among the genotypes for various traits. High estimate of genotypic and phenotypic coefficient of variation were observed for number of grains per panicle, grain yield per plant, straw yield per plant and harvest index indicated wider genetic variation for these traits.. High value of heritability coupled with high expected genetic advance as per cent of mean were observed for the characters number of grains per panicle, grain yield per plant, straw yield per plant, harvest index, 1000-grain weight, grain L/B ratio and amylose content indicated that selection may be effective for this character. The results of correlation studies indicated that genotypic correlation coefficients were higher in magnitude than their corresponding phenotypic correlation coefficients for most of the traits. Grain yield per plant was found positively and significantly associated with plant height, panicle length, number of total tillers per plant, number of effective tillers per plant, number of grains per panicle, harvest index and 1000-grain weight at both genotypic and phenotypic levels indicating that these traits were main yield attributing traits. Path analysis revealed that straw yield per plant had the highest positive direct effect on grain yield followed by grain length, harvest index, days to maturity, protein content, number of total tillers per plant and number of grain per panicle. For maximizing the grain yield per plant emphasis should be given in selection of characters such as number of grains per panicle, straw yield per plant, harvest index and 1000 grain weight for further improvement of upland rice.

  1. Heavy Metals in Brown Rice (Oryza sativa L.) and Soil After Long-Term Irrigation of Wastewater Discharged from Domestic Sewage Treatment Plants

    Institute of Scientific and Technical Information of China (English)

    B. Y. CHUNG; C. H. SONG; B. J. PARK; J. Y. CHO

    2011-01-01

    A pot experiment was conducted in a plastic film house to evaluate the translocation and uptake of heavy metals (Pb,Cd,Cu,and Zn) into brown rice (Oryza sativa L.) and the heavy metals residues in soils which had previously been irrigated with domestic wastewater for a long time (3 years).The range of Pb,Cd,Cu,and Zn was 5.10 ± 0.01,0.105 ± 0.017,5.76 ± 0.42,and 23.56 ± 1.40 mg kg-1,respectively in the domestic wastewater-irrigated soil,and 0.370 ± 0.006,0.011 ±0.001,0.340 ± 0.04,and 2.05 ± 0.18 mg kg-1,respectively,in the domestic wastewater-irrigated brown rice.The results indicated that application of domestic wastewater to arable land slightly increased the levels of Pb,Cd,Cu,and Zn in soil and brown rice (P < 0.01).The concentrations of heavy metals in brown rice were lower than the recommended tolerable levels proposed by the Joint FAO/WHO Expert Committee on Food Additives.However,the continuous monitoring and pollution control of hazardous materials from domestic wastewater are needed in order to prevent excessive build-up of heavy metals in the food chain.

  2. Determination of Optimal Harvest Time of Chuchung Variety Green Rice® (Oryza sativa L.) with High Contents of GABA, γ-Oryzanol, and α-Tocopherol

    Science.gov (United States)

    Kim, Hoon; Kim, Oui-Woung; Ha, Ae Wha; Park, Soojin

    2016-01-01

    In our previous study, an early-maturing variety of rice (Oryza sativa L.), Jinbu can have feature with unique green color, various phytochemicals as well as nutritive components by the optimal early harvesting, called Green Rice® (GR). The aims of the present field experiments were to evaluate the changes in the weight of 1,000 kernels, yield, and contents of proximate and bioactive compounds in Chuchung, a mid-late maturing variety, during the pre-harvest maturation of rough rice and to research the appropriate harvest time and potent bioactivity of Chuchung GR. The weights of 1,000 kernels of Chuchung GR dramatically increased until 27 days after heading (DAH). The yields of Chuchung GR declined after 27 DAH and significantly declined to 0.0% after 45 DAH. The caloric value and total mineral contents were higher in the GR than in the full ripe stage, the brown rice (BR). In the GR, the contents of bioactive compounds, such as γ-aminobutyric acid, γ-oryzanol, and α-tocopherol, were much higher (P<0.05) than those in the BR, specifically during 24~27 DAH. Therefore, bioactive Chuchung GR can be produced with a reasonable yield at 24~27 DAH and it could be useful for applications in various nutritive and functional food products. PMID:27390725

  3. Molecular dynamics of interactions of rice with rice blast and sheath blight pathogens

    Science.gov (United States)

    In an effort to develop the molecular strategies to control rice (Oryzae sativa) diseases, molecular interactions of rice with rice blast [Magnaporthe oryzae, formerly (Magnaporthe grisea] and sheath blight (Rhizoctonia solani) fungi were analyzed. The interaction of rice with M. oryzae follows a b...

  4. Studies in tissue culture of some indigenous rice (Oryza glaberrima Steud.) accessions in Ghana

    International Nuclear Information System (INIS)

    A study was conducted with the aim of developing separate protocols for callus induction and plant regeneration from different parts of three O. glaberrima accessions indigenous to Ghana. The three O. glaberrima accessions, Guame, N/4 and SARI 1 were assessed for their callus induction and plant regeneration ability from leaf segments, mature dehusked seeds and anthers on different concentrations of plant growth regulators, incorporated into Murashige and Skoog, (1962) (MS) basal medium. For leaf segments, callus was induced on MS supplemented with (0-10) mg/l 2,4-D. Callus induction frequency was significantly (p≤0.05) different among accessions, as well as among the 2,4-dichlorophenoxyacetic acid (2,4-D) levels tested. Highest callus induction frequency was exhibited at a concentration of 6 mg/l 2,4-D for all accessions tested. Callus obtained was sub-cultured on regeneration medium consisting of MS supplemented with (1:0-5) mg.l NAA:BAP. Plant regeneration was nil. Instead, prolific root formation was observed. For mature dehusked seeds, callus induction medium consisted of MS supplemented with (0-6) mg/l 2,4-D. All tested accessions exhibited highest callus frequency at 4 mg/l 2,4-D. Similarly callus induction frequency was significantly (p≤0.05) different among accessions, as well as among concentrations of 2,4-D tested. Calli obtained were sub-cultured on MS medium supplemented with (0-2.5) mg/l 6-benzylaminopurine (BAP) and exhibited the highest regeneration frequency on medium containing 2.0 mg/l BAP. However, callus induced on a concentration of 3 mg/l 2,4-D and sub-cultured on a concentration of 2 mg/l BAP gave the best response n terms of shoot proliferation, growth and root development and therefore were considered to be the optimum concentrations for callus induction and plant regeneration respectively. Plantlet regeneration was achieved only in accession N/4 while Guame and SARI 1 exhibited poor regeneration response. Among the three rice

  5. The Population Structure of African Cultivated Rice Oryza glaberrima (Steud.)

    DEFF Research Database (Denmark)

    Semon, Mande; Nielsen, Rasmus; Jones, Monty P.; McCouch, Susan R.

    2005-01-01

    (1) by a lack of decay in LD among markers on the same chromosome and (2) by a strictly increasing composite likelihood function for the recombination parameter. This suggested that the elevation in LD was due not to physical linkage but to other factors, such as population structure. A Bayesian...

  6. Drought responses of rice (Oryza sativa) under various drought severity levels and durations in biotron and field

    OpenAIRE

    Mukamuhirwa, Alphonsine

    2015-01-01

    Rice is an important staple food in human nutrition. Due to its semi-aquatic phylogenetic origin, rice is mainly produced in water intensive system. However, because of climate change, competition for water with other crops and modernization, rice production is becoming threatened by water shortage. Since drought is predicted to increase in the future, efforts have been made to develop drought adapted rice varieties. However genetic improvement has been slowed by the complex nature of drought...

  7. Mapping QTLs Linked to Physio-Morphological and Plant Production Traits under Drought Stress in Rice (Oryza sativa L. in the Target Environment

    Directory of Open Access Journals (Sweden)

    S. M. Gomez

    2006-01-01

    Full Text Available Drought stress is a major constraint for rice (Oryza sativa L. production and yield stability in rainfed ecosystems. Identifying genomic regions (QTLs contributing in drought resistance will help to develop rice cultivars suitable for water-limiting environments through marker-assisted breeding. QTLs linked to physio-morphological and plant production traits under drought stress in the field were mapped by evaluating 177 F6 recombinant inbred (RI lines of Bala × Azucena under rainfed conditions in the target environment (TE. The rice lines were subjected to severe drought stress during reproductive phase due to a natural rainfall failure event. The RI lines showed significant variation in physio-morphological and plant production traits under stress. A total of 24 QTLs were identified for various traits under stress, which individually explained 4.6 to 22.3% phenotypic variation. Composite interval mapping detected three markers viz., RM3894, RG409 and G1073 on chromosomes 3 and 8 linked to grain yield under drought stress in TE, respectively explaining 22..3, 17.1 and 10.9% of phenotypic variation. QTLs for leaf drying, days to 50% flowering and number of productive tillers under drought stress co-located at certain of these regions. Further, QTLs for several root traits overlapped with QTLs for grain yield under stress in these RI lines, indicating the pleiotropic effects of root trait QTLs on rice performance under stress. Correlation coefficients between potential root traits determined in another study and plant production under stress in this study were not significant in these RI lines. Consistent QTLs for drought resistance traits and yield under drought stress in TE were detected and might be useful for rainfed rice improvement.

  8. Studies on the Mechanism of Single Basal Application of Controlled-Release Fertilizers for Increasing Yield of Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    TANG Shuan-hu; YANG Shao-hai; CHEN Jian-sheng; XU Pei-zhi; ZHANG Fa-bao; AI Shao-ying; HUANG Xu

    2007-01-01

    This paper was to explore the mechanism of single basal application of controlled-release fertilizers for increasing yield of rice (Oryza sativa L.). Pot trials and cylinder trials were carried out from 2002 to 2005 to study the influences of single basal application of 3 controlled-release fertilizers on the changes of soil available N, root development, senescence and lodging resistance at late growth stages. Results showed that at 30 days after fertilization, single basal application of controlled-release fertilizers coated with vegetal-substance (CRF1) and polymer materials (CRF3) increased soil available N to 12.0 and 147.9%, respectively, in comparison to split fertilization of rice-specific fertilizer (RSF1). Treatments of the two CRFs obviously benefited the development of root system, resulting in greater rice root weights with extensive distribution and higher root activity. In addition, the two CRF treatments, in comparison to RSF1, enhanced chlorophyll consents of the flag leaves to 9.5 and 15.5%, and soluble protein up to 89.7 and 108.0% respectively. Application of the two CRFs also made the base of rice stems strong and large, declined the proportion of shoot and root, increased root depth index. Though relatively low K rate, single basal application of the CRF3 coated with NH4MgPO4 could also promote the development of root system, enhance root activity and some physiological functions of flag leaves. Based on these results, it was concluded that major mechanisms for increasing rice yield by single basal application of the CRFs should be attributed to grater soil available N supply, superior development of root systems, better nutrient absorption capacity, slower senescence and enhancement of lodging resistance at late stages.

  9. Monitoring and Management of Imidazolinone-Resistant Red Rice (Oryza sativa L., var. sylvatica) in Clearfield® Italian Paddy Rice

    OpenAIRE

    Laura Scarabel; Cesare Cenghialta; Dario Manuello; Maurizio Sattin

    2012-01-01

    The introduction in Italy of Clearfield® rice cultivars carrying imidazolinone-resistant traits provides an efficient option to control red rice, a conspecific weed of cultivated rice. However, despite the promulgation of specific guidelines for Clearfield® technology management, imazamox red rice survivors have been reported by farmers. Forty-two fields were monitored in 2010 and 2011 throughout the Piedmont and Lombardy regions and field cases were recorded of herbicides use and agronomic p...

  10. Kinetic and equilibrium studies on the removal of Cd2+ ions from water using polyacrylamide grafted rice (Oryza sativa) husk and (Tectona grandis) saw dust

    International Nuclear Information System (INIS)

    The increase in the use of heavy metals has resulted in an increased flux of metallic substances into the aquatic environment which poses a danger to human health. The present work relates to the removal of cadmium ions by treatment with polyacrylamide grafted rice (Oryza sativa) husk/saguan (Tectona grandis) saw dust. The drinking water guideline value recommended by WHO for cadmium is 0.005 ppm.The adsorbent has been prepared by treatment of rice husk/saw dust with acrylamide. Removal has been studied at various pH values for different times of contact and adsorbate concentrations and is found to be pH-dependent, maximum removal occurs at pH 9 and at a contact time of 180 min for both the adsorbents. The results were found to be consistent with both the Langmuir and Freundlich isotherm models. The value of n (rate constant) determined at pH 9 has been found to be 1 (within experimental limits). This is further substantiated by applying the Lagergren model. The intra-particle diffusion constants were determined by the Morris-Weber model. Continous flow column studies have also been undertaken and the breakthrough characteristics were determined. Desorption has been affected with 0.5 M HCl. The results suggest that both polyacrylamide grafted rice husk/saw dust can be used as efficient and cost effective adsorbents for cadmium ion removal

  11. EKSTRAKSI DAN STABILITAS ZAT PEWARNA ALAM DARI KATUL BERAS KETAN HITAM (Oryza sativa glutinosa)*) EXTRACTION AND STABILITY OF NATURAL COLORANT FROM RED GLUTINOUS RICE BRAN (Oryza sativa glutinosa)*)

    OpenAIRE

    Tirza Hanum

    2000-01-01

    Three extraction methods were studied to isolate natural colorant from red glutinous rice bran. Stability of extracts in relation to processing conditions and in the model beverages was determined at room temperature. Identifications of anthocyanidins was performed using reversed phase HPLC. Extraction method using acidified methanol solvent showed the highest yield (260,24 28,64 mg/100g). HPLC patern indicated the presence of six major anthocyanidins, two of them were identified as apigenid...

  12. Selection for bacterial leaf-blight (Xanthomonas oryzae) and sheath-blight (Rhizoctonia oryzae) resistant mutants in a collection of early rice mutants

    International Nuclear Information System (INIS)

    Two of the most important and common rice diseases in Indonesia are bacterial leaf blight (BLB) and sheath blight (SB). The best rice yielding varieties in Indonesia, Pelita I/1 and IR5, were treated with gamma radiation and EMS. All the early maturing mutants which were selected from M2 and M3 generations, and afterwards in the M8 generation we tested for their reaction to bacterial leaf blight and sheath blight. Pelita I/1 is moderately resistant to BLB and moderately susceptible to SB, but IR5 is susceptible to BLB or SB. At 30 and 60 days after transplanting, 107 early maturing mutants were inoculated with BLB. The bacteria were isolated from three different rice fields, and grown into Wakimoto media. Inoculation was done by the cutting method with suspension of 10-7-10-8cell/cm3. The virulence of bacteria isolated from the three fields was different. Resistant mutants were only observed in the Pelita I/1 early mutant collection; however, moderate resistance was found in the IR5 early mutants collection. At late growth stage the plant seems relatively more resistant to BLB. Early mutants of Pelita I/1 were inoculated with fungus SB following the procedure of the International Rice Sheath Blight Nursery (IRSHBN). Of 96 mutants, 55 were susceptible and 41 were moderately susceptible. Pelita I/1 was moderately susceptible with 48% damage and, compared with this, 9 mutant lines showed less than 40% damage. Selection was also carried out by natural infection; however, owing to ecoclimatic conditions the result was not convincing. (author)

  13. Identification and QTL mapping of blast resistance in wild Oryza species

    Science.gov (United States)

    Leaf blast disease of rice (Oryza sativa L.) caused by Magnaporthe oryzae B. Couch is one of the most devastating rice fungal diseases worldwide. Wild relatives of rice (Oryza spp.) may contain novel genes for biotic and abiotic stress resistance lost during domestication. A collection of 67 wild ...

  14. In-vitro evaluation of fungicides, plant extracts and bio-control agents against rice blast pathogen magnaporthe oryzae couch

    International Nuclear Information System (INIS)

    Among 5 fungicides viz., Thiophanate-methyl, Carbendazim, Fosetyl-aluminium, Mancozeb and Copper oxychloride, used against the Magnaporthe oryzae, only Mancozeb appeared as the highly effective fungicide that completely inhibited the mycelial growth of the fungus. All other fungicides showed little effect at higher concentrations. The extracts of garlic (Allium sativum L.), neem (Azadirachta indica L.) and calatropis (Calotropis procera L.) when used against M. oryzae by food poisoning method, only higher dose of garlic completely inhibited the mycelial growth of the test fungus. Six bio-control agents viz., Trichoderma harzianum, Trichoderma polysporum, Trichoderma pseudokoningii, Gliocladium virens, Paecilomyces variotii and Paecilomyces lilacinus were used. Maximum mycelial inhibition of M. oryzae was provided by P. lilacinus followed by Trichoderma spp. (author)

  15. Calibração e avaliação do modelo ORYZA-APSIM para o arroz de terras altas no Brasil Calibration and evaluation of the ORYZA-APSIM crop model for upland rice in Brazil

    Directory of Open Access Journals (Sweden)

    Rogério Lorençoni

    2010-12-01

    Full Text Available Objetivou-se com este trabalho calibrar o modelo ORYZA-APSIM e avaliar o seu desempenho na simulação do desenvolvimento, crescimento e produtividade da variedade cultivada de arroz de terras altas BRS-Primavera para as diferentes regiões produtoras dessa cultura. Na calibração foram definidas: as unidades de calor efetivo diário (HU; as taxas de desenvolvimento fenológico para cada estádio (DVR; as frações da massa de matéria seca das folhas (MSf, colmos (MS C e órgãos armazenadores (panículas (MSp, e os parâmetros para calcular a área foliar específica (AEF simulada durante o ciclo da cultura. Na avaliação foram comparados os valores simulados com os observados do desenvolvimento fenológico (número de dias da emergência ao florescimento e do crescimento da cultura (massa de matéria seca total da parte aérea (MSt índice de área foliar (IAF e a produtividade (P. O modelo apresentou desempenho satisfatório na simulação do desenvolvimento fenológico para regiões próximas ao da calibração. Para latitudes próximas ao equador, como Teresina, PI, o desempenho fenológico foi insatisfatório. Para o crescimento, nos dois experimentos, o índice de área foliar (IAF simulado diferiu do observado, e a MSt simulada foi semelhante a observada, mas diferiu entre o florescimento e a maturidade fisiológica. A MSf simulada foi satisfatória no primeiro experimento e regular no segundo. Isso é devido ao modelo superestimar os efeitos da deficiência hídrica que ocorreram durante a condução do segundo experimento. Entretanto, o modelo ORYZA-APSIM apresentou bom desempenho na simulação da ordem de produtividade ao nível de significância de 5%.This study was carried out with the purpose of calibranting the ORYZA-APSIM crop model and evaluating its performance to simulate the development, growth and yield of upland rice variety BRS-Primavera in the production area of upland rice in Brazil. Acording to the following

  16. Skp1, a component of E3 ubiquitin ligase, is necessary for growth, sporulation, development and pathogenicity in rice blast fungus (Magnaporthe oryzae).

    Science.gov (United States)

    Prakash, Chandra; Manjrekar, Johannes; Chattoo, Bharat B

    2016-08-01

    Ubiqitination is an important process in eukaryotic cells involving E3 ubiquitin ligase, which co-ordinates with cell cycle proteins and controls various cell functions. Skp1 (S-phase kinase-associated protein 1) is a core component of the SCF (Skp1-Cullin 1-F-box) E3 ubiquitin ligase complex necessary for protein degradation by the 26S proteasomal pathway. The rice blast fungus Magnaporthe oryzae has a single MoSKP1(MGG_04978) required for viability. Skp1 has multiple functions; however, its roles in growth, sporulation and appressorial development are not understood. MoSKP1 complements Skp1 function in the fission yeast temperature-sensitive mutant skp1 A7, restoring the normal length of yeast cells at restrictive temperature. The MoSkp1 protein in M. oryzae is present in spores and germ tubes, and is abundantly expressed in appressoria. Various RNA interference (RNAi) and antisense transformants of MoSKP1 in B157 show reduced sporulation, defective spore morphology, lesser septation and diffuse nuclei. Further, they show elongated germ tubes and are unable to form appressoria. Transformants arrested in G1/S stage during initial spore germination show a similar phenotype to wild-type spores treated with hydroxyurea (HU). Reduced MoSkp1 transcript and protein levels in knockdown transformants result in atypical germ tube development. MoSkp1 interacts with the putative F-box protein (MGG_06351) revealing the ability to form protein complexes. Our investigation of the role of MoSKP1 suggests that a decrease in MoSkp1 manifests in decreased total protein ubiquitination and, consequently, defective cell cycle and appressorial development. Thus, MoSKP1 plays important roles in growth, sporulation, appressorial development and pathogenicity of M. oryzae. PMID:26575697

  17. Enhanced production of protease by mutagenized strain of aspergillus oryzae in solid substrate fermentation of rice bran

    International Nuclear Information System (INIS)

    Neutral protease activity of parent strain of Aspergellus oryzae was enhanced by UV and chemical mutagenization with ethyl methane sulphonate (EMS). After screening, a hyper producing strain was isolated and found effective for tile production of neutral protease as compared to the parent strain of Aspergellus oryzae. Solid substrate fermentation was carried out in 250ml conical flask with 45 % initial moisture contents at a temperature of 30 deg. C for 72 flours. Under the optimum conditions maximum yield of neutral protease obtained was 662.61+-0.36 U/gds, Almost all the organic nitrogen supplements favored the enzyme production while sucrose proved as a best carbon source. (author)

  18. Actividad Alelopática de las Arvenses Asociadas al Cultivo de Arroz (Oryza sativa L. en el Tolima-Colombia Allelophatic Activity of Arvenses Associated with the Cultivation of Rice (Oryza sativa l. in Tolima-Colombia

    Directory of Open Access Journals (Sweden)

    Elizabeth Murillo

    2006-01-01

    Full Text Available Se recolectaron e identificaron especies de arvense de la familia Asteraceae asociadas al cultivo de arroz (Oryza sativa L. en el Tolima-Colombia, y se caracterizaron morfológica, bromatológica y farmacognósticamente. Las fracciones orgánicas de la arvense con mayor contenido de sesquiterpenlactonas se evaluó por su actividad alelopática sobre la germinación y elongación de la radícula de semillas de O. sativa, colocadas en papel filtro a concentraciones de 200, 400 y 600 ppm e incubadas durante 120 horas. El cultivo de la gramínea se encontró asociado a 12 especies invasoras que presentaron gran variabilidad en sus características morfológicas y en los índices farmacognósticos. Las fracciones clorofórmicas mostraron diferencias significativas con el extracto etanólico crudo por el efecto sobre la división celular y el crecimiento radicular de semillas de O. sativa, actividad que parece estar asociada al contenido de sesquiterpenlactonas.Asteraceae weed species associated with rice (Oryza sativa L. in the state of Tolima-Colombia were gathered, identified and morphologic, pharmacognostic and bromatologically characterized. Allelopathic activity for those organic fractions of weed with high content of sesquiterpene lactone was evaluated on the germination and radicle length of O. sativa seeds in filter paper. Both crude extract and chromatographic fractions were incubated for 120 hours at concentrations of 200, 400 and 600 ppm. Cultivation of the grainswas associated to 12 weed species which presented great variability in its morphologic characteristics and farmacognostic index. Chloroformic fractions gave significant differences with the ethanolic extract due to the effect on the cellular division and the radicle elongation of the O. sativa seeds, activity that seems to be associated to the content of sesquiterpene lactone.

  19. A novel single-stranded RNA virus isolated from the rice-pathogenic fungus Magnaporthe oryzae with similarity to members of the family Tombusviridae.

    Science.gov (United States)

    Ai, Ye-Ping; Zhong, Jie; Chen, Chuan-Yuan; Zhu, Hong-Jian; Gao, Bi-Da

    2016-03-01

    Here, we report a novel virus isolated from rice blast fungus, Magnaporthe oryzae, an important plant pathogen. This virus has an RNA genome of 3246 nucleotides. Its genome possesses two in-frame open reading frames (ORFs). The smaller ORF1 encodes a protein with significant similarity to a protein encoded by the ssRNA mycovirus Diaporthe ambigua RNA virus 1 (DaRV1). The larger ORF2 encodes a protein with similarity to RNA-dependent RNA polymerases (RdRp) of DaRV1 and other plant viruses of the family Tombusviridae. In silico analysis and comparisons with DaRV1 genome expression suggest that ORF2 is translated via a readthrough mechanism together with ORF1. Based upon results of this study, this virus, for which the provisional name Magnaporthe oryzae virus A (MoVA) is proposed, belongs to a new virus species. Furthermore, MoVA along with DaRV1 belong to a new taxon of mycoviruses that are evolutionarily related to plant viruses belonging to the family Tombusviridae. PMID:26650038

  20. Stationary-Phase Variation Due to Transposition of Novel Insertion Elements in Xanthomonas oryzae pv. oryzae

    OpenAIRE

    Rajeshwari, R.; Sonti, R. V.

    2000-01-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. Spontaneous mutants which are deficient for virulence and extracellular polysaccharide (Eps) production accumulate in large numbers in stationary-phase cultures of this bacterium, a phenomenon which we have called stationary-phase variation. A clone (pSD1) carrying the Eps biosynthetic gene (gum) cluster of X. oryzae pv. oryzae restored Eps production and virulence to several spv (for stationary-phase varia...

  1. Detection of DNA polymerase λ activity during seed germination and enhancement after salinity stress and dehydration in the plumules of indica rice (Oryza sativa L.

    Science.gov (United States)

    Sihi, Sayantani; Bakshi, Sankar; Sengupta, Dibyendu Narayan

    2015-02-01

    DNA polymerase λ (DNA pol λ) is the only reported X-family DNA polymerases in plants and has been shown to play a significant role in dry quiescent seeds, growth, development and nuclear DNA repair. cDNA for DNA pol λ has been reported in Arabidopsis and japonica rice cultivar and has been characterized from E. coli expressed protein, but very little is known about its activity at protein level in plants. The enzymatic activity of DNA pol λ was studied in dry, imbibed and during different germination stages of indica rice IR-8 (salt sensitive) by in-gel activity assay to determine its physiological role in important stages of growth and development. The upstream sequence was also analyzed using plantCARE database and was found to contain several cis-acting elements, including light responsive elements, dehydration responsive elements, Myb binding sites, etc. Hence, 4-day-old germinating seedlings of IR29, a salt-sensitive, but high yielding indica rice cultivar and Nonabokra, a salt-tolerant, but low yielding cultivar were treated with water (control) or 250 mM NaCl or 20% polyethyleneglycol-6000 for 4 and 8 h. The protein was analyzed by in vitro DNA pol λ activity assay, in-gel activity assay and Western blot analysis. DNA pol λ was not detected in dry seeds, but enhanced after imbibition and detectable from low level to high level during subsequent germination steps. Both salinity and dehydration stress led to the enhancement of the activity and protein level of DNA pol λ, as compared to control tissues. This is the first evidence of the salinity or dehydration stress induced enhancement of DNA pol λ activity in the plumules of rice (Oryza sativa L.) cultivars. PMID:26040115

  2. Microwave radiation effects on the different stages of Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae) evolutive cycle in rice, focusing its control

    International Nuclear Information System (INIS)

    As insects increase in radio tolerance as they develop and usually several developmental stages of pest may present in grain shipped commodity, it is important to know the microwave radiation susceptibility of stages of the target insect before the establishment of microwave radiation quarantine treatments. The current research had the aim to evaluate the microwave radiation effects on several phases of the rice weevil evolution cycle (S.oryzae), focusing its control. This specie is considered as on of the most serious worldwide pests for stored grains. The tests have been done in glass vials with 250 grams of whole grain (brown) rice and the irradiation was done in a 2,450 MHz commercial microwave oven, model Carousel II (potency of 800W). It was determined the exposure time needed to each phase control for the insect evolutive cycle, concluding that the immature phases (larvae and pupae), contained inside the rice, are more sensitive, requiring only 100 seconds to obtain 100% control while the egg phase requires a longer exposure (130 seconds). Referring to the grown phase, the time required to attain the lethal dose was 160 seconds. All the exposure time have been irradiated with a low potency (240 W). It also displayed that to greater quantities of rice (1.0 kg), with egg presence and forming a 2.0-centimeter layer on the microwave plate surface, it required an exposure time of 180 seconds. Therefore, in a more effective way, we can recommend these 180 seconds exposure time to the control of all phases concerning the insect evolutive cycle. (author)

  3. Microwave radiation effects on the different stages of Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae) evolutive cycle in rice, focusing its control

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Jose G.; Franco, Suely S.H., E-mail: gilmita@uol.com.br, E-mail: zegilmar60@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Franco, Caio H.; Arthur, Paula B.; Arthur, Valter, E-mail: caiohaddadfranco@lnbio.cnpem.com.br, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radiobiologia e Ambiente

    2013-07-01

    As insects increase in radio tolerance as they develop and usually several developmental stages of pest may present in grain shipped commodity, it is important to know the microwave radiation susceptibility of stages of the target insect before the establishment of microwave radiation quarantine treatments. The current research had the aim to evaluate the microwave radiation effects on several phases of the rice weevil evolution cycle (S.oryzae), focusing its control. This specie is considered as on of the most serious worldwide pests for stored grains. The tests have been done in glass vials with 250 grams of whole grain (brown) rice and the irradiation was done in a 2,450 MHz commercial microwave oven, model Carousel II (potency of 800W). It was determined the exposure time needed to each phase control for the insect evolutive cycle, concluding that the immature phases (larvae and pupae), contained inside the rice, are more sensitive, requiring only 100 seconds to obtain 100% control while the egg phase requires a longer exposure (130 seconds). Referring to the grown phase, the time required to attain the lethal dose was 160 seconds. All the exposure time have been irradiated with a low potency (240 W). It also displayed that to greater quantities of rice (1.0 kg), with egg presence and forming a 2.0-centimeter layer on the microwave plate surface, it required an exposure time of 180 seconds. Therefore, in a more effective way, we can recommend these 180 seconds exposure time to the control of all phases concerning the insect evolutive cycle. (author)

  4. Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits

    OpenAIRE

    Mst. Tuhina-Khatun; Hanafi, Mohamed M.; Mohd Rafii Yusop; Wong, M. Y.; Salleh, Faezah M.; Jannatul Ferdous

    2015-01-01

    Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 tra...

  5. Plant regeneration from mesophyll protoplast of indica rice Qiugui'ai 11 (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    JIANYuyu; JintaanankulSuwan

    1998-01-01

    In the recent decade, plant regeneration from protoplast has been obtained through embryogenic cell suspension cultures of rice. However, not only the establishment of embryogenic call suspension cultures of rice was difficult, but also the protoplasts became less and less regenerable and the genetic change was gradu ally accumulated during the prolonged culture.Since 1976 (Deka.), extensive efforts have been made to induce sustained division and regenerate plants from rnesophyll protoplasts of rice, but not successful.

  6. Effects of hydrothermal processes on antioxidants in brown, purple and red bran whole grain rice (Oryza sativa L.)

    Science.gov (United States)

    The impacts of parboiling and wet-cooking, alone and in combination, on concentrations of lipophilic antioxidants (vitamin E homologs and '-oryzanol), soluble (including proanthocyanidins and anthocyanins) and cell wall-bound phenolics and antioxidant capacities in whole grain rice from 6 rice culti...

  7. Regulation of GAs-binding protein on dwarfism of riceOryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    SONGPing; CAOXianzu; WUYonghong; LIANGJiansheng

    1994-01-01

    The levels of endogenous hormones (GAs and ABA) in rice seedlings (7d) were measured by gas-liquid chromatography with flame ionization detoctor (GLC-FID) and the GAs-binding protein on meanbrane of young rice shoot was also analysed as dascribed by Chiharu.

  8. Functional analysis of genes involved in the regulation of development of reproductive organs in rice (Oryza sativa)

    NARCIS (Netherlands)

    Chen, Yi

    2011-01-01

    Quality of the rice grain is determined mainly by starch and protein contents of the endosperm. In this thesis, the analyses of four genes involved in the regulation of development of rice grain and floret are presented. Two CCCH type zinc finger proteins, OsGZF1 and OsGZF2, were identified as novel

  9. EKSTRAKSI DAN STABILITAS ZAT PEWARNA ALAM DARI KATUL BERAS KETAN HITAM (Oryza sativa glutinosa* EXTRACTION AND STABILITY OF NATURAL COLORANT FROM RED GLUTINOUS RICE BRAN (Oryza sativa glutinosa*

    Directory of Open Access Journals (Sweden)

    Tirza Hanum1

    2000-04-01

    Full Text Available Three extraction methods were studied to isolate natural colorant from red glutinous rice bran. Stability of extracts in relation to processing conditions and in the model beverages was determined at room temperature. Identifications of anthocyanidins was performed using reversed phase HPLC. Extraction method using acidified methanol solvent showed the highest yield (260,24 28,64 mg/100g. HPLC patern indicated the presence of six major anthocyanidins, two of them were identified as apigenidin and apigenin. Stability of anthocyanin colorant was higher in a lower acid condition and was reduced to the lowest value of 49,4, 65,4, 40,8 and 36,6% by high temperature, UV light, sunlight, and the presence of oxidator agent. respectively. Retention of antocyanin in tanin and ascorbic acid added into the model beverages was lower than in protein containing beverage or control.

  10. Varietal differences in photosynthetic characters and chlorophyll fluorescence induction kinetics parameters among intergeneric progeny derived from Oryza×Sorghum, its parents, and hybrid rice

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A comparative study on the photosynthetic parameters among intergeneric progenies derived from Oryza sativa L.×Sorghum vulgare L., its maternal parent Gui 630 and commercial 3-line hybrid rice Shanyou 63 in pot experiment in greenhouse was conducted. The morphological and photosynthetic characters of canopy leaves and chlorophyll fluorescence kinetic parameters including Fv/Fm, Fv/F0, photochemical quenching coefficient and non-photochemical coefficient of canopy leaves of 3 varieties were measured. The results showed the progeny, Yuanyou 1, derived from an intergeneric cross of rice and sorghum possesses better canopy spatial architecture with thicker, heavier and bigger canopy leaf than its maternal parent Gui 630. Higher photosynthetic rate due to higher chlorophyll content, higher primary energy transformation efficiency, potential of PSII and non-photochemical quenching coefficient (qE) were also measured in Yuanyou 1. These explain partly why the intergeneric progeny has higher biomass production, and better tolerance to adverse conditions and higher field yields even under stress conditions.

  11. An Inner Membrane Protein (Imp) of Xanthomonas oryzae pv. oryzicola Functions in Carbon Acquisition, EPS Production, Bacterial Motility and Virulence in Rice

    Institute of Scientific and Technical Information of China (English)

    CHEN Gong-you

    2014-01-01

    Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak, a devastating disease in rice-growing regions worldwide. A Tn5-insertion mutant in Xoc_3248, encoding an inner membrane protein (Imp), showed reduced virulence in rice. To explore the potential function of this gene in virulence, a deletion mutant R∆imp was constructed in the wild-type RS105. The R∆imp mutant was signiifcantly impaired for bacterial virulence and growth in planta. The mutation in imp made the pathogen insufifciently utilize glucose, fructose, mannose or pyruvate as a sole carbon source, leading to less extracellular polysaccharide (EPS) production and reduced motility. The deifciencies noted for the mutant were restored to wild-type levels when imp was introduced in trans. Transcription of imp was signiifcantly declined when hrpG and hrpX was mutated and the expression of hrpG and hrpX was also signiifcantly declined when imp was deleted. Cell sublocalization in planta showed Imp membrane-binding feature. These results suggest that Imp is a virulence factor with roles in the catabolism of sugars, EPS production, and bacterial motility.

  12. Varietal differences in photosynthetic characters and chlorophyll fluorescence induction kinetics parameters among intergeneric progeny derived from Oryza×Sorghum, its parents, and hybrid rice

    Institute of Scientific and Technical Information of China (English)

    KatsuyoshiShimizu; 唐建军; 陈欣

    2002-01-01

    A comparative study on the photosynthetic parameters among intergeneric progenies derived from Oryza sativa L.× Sorghum vulgare L. , its maternal parent Gui 630 and commercial 3-line hybrid rice Shanyou 63 in pot experiment in greenhouse was conducted. The morphological and photosynthetic characters of canopy leaves and chlorophyll fluorescence kinetic pm'mneters including Fv/Fm, Fv/F0, photochemical quenching coefficient and non-photochemical coefficient of canopy leaves of 3 varieties were measured. The results showed the progeny, Yuanyou 1, derived from an intergeneric cross of rice and sorghum possesses better canopy spatial architecture with thicker, heavier and bigger canopy leaf than its maternal parent Gui 630.Higher photosynthetic rate due to higher chlorophyll content, higher primary energy transformation efficiency,potential of PSII and non-photochemieal quenching coefficient (qE) were also measured in Yuanyou 1. These explain partly why the intergeneric progeny has higher biomass production, and better tolerance to adverse conditions and higher field yields even under stress conditions.

  13. Monitoring and Management of Imidazolinone-Resistant Red Rice (Oryza sativa L., var. sylvatica in Clearfield® Italian Paddy Rice

    Directory of Open Access Journals (Sweden)

    Laura Scarabel

    2012-12-01

    Full Text Available The introduction in Italy of Clearfield® rice cultivars carrying imidazolinone-resistant traits provides an efficient option to control red rice, a conspecific weed of cultivated rice. However, despite the promulgation of specific guidelines for Clearfield® technology management, imazamox red rice survivors have been reported by farmers. Forty-two fields were monitored in 2010 and 2011 throughout the Piedmont and Lombardy regions and field cases were recorded of herbicides use and agronomic practices. Whole-plant sensitivity to imazamox was assessed and the resistance mechanism was determined by molecular analysis. Twenty-six red rice populations out of 42 were imazamox-resistant and plants of all the resistant populations possess a Ser to Asn substitution at locus 653 of the ALS gene determining the target-site resistance. Farmers frequently grow Clearfield® varieties for more than two consecutive years so increasing the selection pressure exerted by imazamox and favoring the evolution of resistant red rice. To maintain the sustainability of this new technology, a proper management based on crop rotation, utilization of certified seeds and strict control of red rice escapes has to be implemented. More generally, all stakeholders must increase their awareness that the selection pressure exerted by ALS inhibitors in rice cropping system should be reduced.

  14. Effects of Feeding Purple Rice (Oryza sativa L. Var. Glutinosa) on the Quality of Pork and Pork Products.

    Science.gov (United States)

    Jaturasitha, Sanchai; Ratanapradit, Punnares; Piawong, Witapong; Kreuzer, Michael

    2016-04-01

    Purple rice is a strain of glutaneous rice rich in anthocyanins and γ-oryzanol. Both types of compounds are involved in antioxidant and lipid metabolism of mammals. Three experimental diet types were used which consisted approximately by half either of purple rice, white rice or corn. Diets were fed to 3×10 pigs growing from about 30 to 100 kg. Meat samples were investigated either as raw or cured loin chops or as smoked bacon produced from the belly. Various physicochemical traits were assessed and data were evaluated by analysis of variance. Traits describing water-holding capacity (drip, thaw, and cooking losses) and tenderness (sensory grading, shear force) of the meat were mostly not significantly affected by the diet type. However, purple rice feeding of pigs resulted in lower fat and cholesterol contents of loin and smoked bacon compared to white rice, but not compared to corn feeding except of the fat content of the loin. The shelf life of the raw loin chops was improved by purple rice as well. In detail, the occurrence of thiobarbituric acid reactive substances after 9 days of chilled storage was three to four times higher in the white rice and corn diets than with purple rice. The n-6:n-3 ratio in the raw loin chops was 9:1 with purple rice and clearly higher with 12:1 with the other diets, meat lipids. Level and kind of effect of purple rice found in raw meat was not always recovered in the cured loin chops and the smoked bacon. Still the impression of flavor and color, as well as overall acceptability were best in the smoked bacon from the purple-rice fed pigs, whereas this effect did not occur in the cured loin chops. These findings suggest that purple rice has a certain, useful, bioactivity in pigs concerning meat quality, but some of these effects are of low practical relevance. Further studies have to show ways how transiency and low recovery in meat products of some of the effects can be counteracted. PMID:26949957

  15. Mitigating heavy metal accumulation into rice (Oryza sativa L.) using biochar amendment--a field experiment in Hunan, China.

    Science.gov (United States)

    Zheng, Ruilun; Chen, Zheng; Cai, Chao; Tie, Baiqing; Liu, Xiaoli; Reid, Brian J; Huang, Qing; Lei, Ming; Sun, Guoxin; Baltrėnaitė, Edita

    2015-07-01

    A field experiment was conducted to investigate the effect of bean stalk (BBC) and rice straw (RBC) biochars on the bioavailability of metal(loid)s in soil and their accumulation into rice plants. Phytoavailability of Cd was most dramatically influenced by biochars addition. Both biochars significantly decreased Cd concentrations in iron plaque (35-81 %), roots (30-75 %), shoots (43-79 %) and rice grain (26-71 %). Following biochars addition, Zinc concentrations in roots and shoots decreased by 25.0-44.1 and 19.9-44.2 %, respectively, although no significant decreases were observed in iron plaque and rice grain. Only RBC significantly reduced Pb concentrations in iron plaque (65.0 %) and roots (40.7 %). However, neither biochar significantly changed Pb concentrations in rice shoots and grain. Arsenic phytoavailability was not significantly altered by biochars addition. Calculation of hazard quotients (HQ) associated with rice consumption revealed RBC to represent a promising candidate to mitigate hazards associated with metal(loid) bioaccumulation. RBC reduced Cd HQ from a 5.5 to 1.6. A dynamic factor's way was also used to evaluate the changes in metal(loid) plant uptake process after the soil amendment with two types of biochar. In conclusion, these results highlight the potential for biochar to mitigate the phytoaccumulation of metal(loid)s and to thereby reduce metal(loid) exposure associated with rice consumption. PMID:25794575

  16. Physico-chemical changes in grains of some advance lines/ varieties of rice (oryza sativa l.) after parboiling

    International Nuclear Information System (INIS)

    Some of the advance lines/varieties developed at Rice Research Institute, Kala Shah Kaku, including approved fragrant (Basmati) rice variety i.e., Basmati-2000, were used to assess interactive efficacy of parboiling on these varieties/lines and practical expediency of using standardized parboiling technique for improving nutritional, milling and cooking qualities of these lines/varieties. For this purpose, white milled and parboiled rice samples of ten lines/varieties were analyzed for nutritional quality parameters such as ash, dry matter, crude fat, crude protein, crude fiber, vitamin B6; milling quality parameters such as total milling recovery, head rice recovery, ratio of broken grains and cooking quality parameters such as curling, bursting and cooked grain length. The study showed significant variation in efficacy of parboiling to different varieties/lines. The results clearly showed average increase in mineral contents in terms of ash% increase, dry matter, longer cooked grain length and considerable rise in vitamin B6 contents, higher total milling recovery and head rice recovery in almost all the samples. While crude fiber, crude protein and crude fat decreased non-significantly. Furthermore, quality reducing factors such as number of broken grains, bursting and curling percentage of cooked rice were also reduced significantly in parboiled samples. It may, therefore, be suggested that parboiling offers a better alternative to conserve and increase nutritional, milling and cooking quality values of rice varieties/lines. Less percentage of broken, burst and curled grains may result in augmented net income. (author)

  17. Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L.) to Control Rice Weevil (Sitophilus oryzae L.) Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L.) en el gorgojo del arroz (Sitophilus oryzae L.)

    OpenAIRE

    Verónica Benzi; Natalia Stefanazzi; Adriana A. Ferrero

    2009-01-01

    Rice weevil (Sitophilus oryzae L.) is a primary insect pest of stored grain. The development of resistance resulted in the application of synthetic insecticides. In recent years many plant essential oils have provided potential alternatives to currently used insect control agents. The Brazilian pepper tree (Schinus molle L. var. areira (L.) DC.) (Anacardiaceae) has different biological properties such as insecticidal activity. In this study, repellent, fumigant activity, nutritional indices, ...

  18. Pathogenic Races of Pyricularia oryzae Isolated from Various Rice Cultivars on the Blast Nursery and Paddy Field in Different Locations

    OpenAIRE

    Hongsik Shim; Wan-Hae Yeh; Boung-Joo Yoo; Inn-Shik Myung; Sung-Kee Hong; Seungdon Lee

    2012-01-01

    This study was conducted to investigate the association of race distribution of Pyricularia oryzae with ricecultivar and location. Races present in a given location were different in cultivars, and the races from a givencultivars were different by location. For precise study of race distribution, it needs to identify isolates byconsidering cultivation ratio and collection area. There are great differences between the resistant degree inthe upland blast nursery and on the resistant degree of t...

  19. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    OpenAIRE

    Saleh Dounia; Milazzo Joëlle; Adreit Henri; Tharreau Didier; Fournier Elisabeth

    2012-01-01

    Abstract Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexuall...

  20. Enhanced UV-B radiation has little effect on growth, delta13C values and pigments of pot-grown rice (Oryza sativa) in the field

    International Nuclear Information System (INIS)

    Predicted increase in ultraviolet-B (UV-B: 280–320 mn) radiation may have adverse impacts on growth and yield of rice (Oryza sativa L.), as has been found in studies hitherto. However, most of the studies were conducted in growth chambers or greenhouses where the plants are generally more sensitive to UV-B than in the field, presumably because of the distorted balance between UV-B and ultraviolet-A as well as PAR. This study was conducted to address the effects of enhanced UV-B on growth and yield of rice under a realistic spectral balance in the field. Three cultivars, “Koshihikari”,‘IR 45’and‘IR 74’were pot-grown and irradiated with enhanced UV-B for most of the growing season in the field at Tsukuba, Japan (36°01′N, 140°07′E). The UV-B enhancement simulated ca 38% depletion of stratospheric ozone at Tsukuba. The results showed no UV-B effects on plant height, numbers of tillers and panicles, dry weight of the plant parts or the grain yield for any of the 3 cultivars. Natural abundance of 13C in the flag leaves was not altered by the UV-B enhancement either. While UV-absorbing compounds showed no response to the UV-B enhancement, chlorophyll contents decreased with enhanced UV-B. However, the decrease of chlorophyll was limited to an early growth stage with no effect later. We thus found no extraordinary impact of the nearly doubled UV-B radiation on rice in the field, and it would appear that a reliable prediction of the effects of UV-B will require experiments carried out over a number of years under various climatic and solar UV-B regimes. (author)

  1. Simulação do manejo do nitrogênio em arroz de terras altas com o modelo ORYZA/APSIM 2000 Simulation of nitrogen management in upland rice with ORYZA/APSIM 2000 model

    Directory of Open Access Journals (Sweden)

    Luís F. Stone

    2012-06-01

    Full Text Available É importante definir a estratégia de manejo da adubação nitrogenada para o arroz de terras altas, pois o nitrogênio é o nutriente mais absorvido pelas plantas dessa cultura e, devido à facilidade de lixiviação no solo, pode poluir o meio ambiente. Objetivou-se, com este trabalho simular, com o modelo ORYZA/APSIM 2000, diferentes estratégias de manejo da adubação nitrogenada visando maximizar a produtividade e minimizar a lixiviação de N. Na simulação foi considerada a aplicação da dose de 100 kg ha-1 de N em cinco modos: TP - 1/5 na semeadura, 2/5 no início do perfilhamento (IP e 2/5 na diferenciação da panícula (DP; T1 - todo na semeadura; T2 - todo aos 20 dias antes da semeadura; T3 - 1/5 na semeadura e 4/5 no IP e T4 - 1/5 na semeadura e 4/5 na DP, os quais foram combinados com cinco datas de semeadura: 01/11, 15/11, 01/12, 15/12 e 31/12. O parcelamento da adubação nitrogenada mostrou-se como a estratégia com maior probabilidade de resultar em altas produtividades do arroz de terras altas. Quando não se utiliza essa estratégia, a probabilidade de perdas de nitrogênio por lixiviação é maior. Há maior probabilidade de se obter altas produtividades em datas de semeadura precoces a partir de 01/11, apesar da semeadura tardia contribuir para redução nas perdas de nitrogênio por lixiviação.It is important to define nitrogen management strategy for upland rice crop, because nitrogen is the nutrient more absorbed by rice plants and, due to the ease of leaching in soil, it can pollute the environment. This study aimed to simulate, based on ORYZA/APSIM 2000 model, different strategies for nitrogen fertilization management to maximize the productivity and minimize the N leaching. In the simulation, five application modes with an application rate of 100 kg N ha-1 were considered: TP - 1/5 at sowing, 2/5 at the beginning of tillering (T and 2/5 at panicle differentiation (P; T1 - all at sowing; T2 - all at 20 days

  2. Use of induced mutations and tissue culture in the rice (Oryza sativa L.) improvement programme in Cuba

    International Nuclear Information System (INIS)

    In 1986, the Rice Research Institute began to use tissue culture techniques for the genetic improvement of rice. Subsequently, in 1998, the Institute, in co-operation with the applied Research Centre for Nuclear Energy Development, started a programme of improvement by mutation using radiations with different LET. In the same year, the Centre started applying molecular biology to rice improvement. The tissue culture techniques included the culture of anthers and somatic tissue, recovery of interspecific hybrid embryos and the culture of protoplasts. Work in molecular biology has focused on the isolation and purification of total DNA and subsequent restriction analysis. The preliminary results of using these technologies in the Cuban rice improvement programme are described. (author). 7 refs, 6 tabs

  3. Purification, crystallization and preliminary X-ray crystallographic analysis of rice bifunctional α-amylase/subtilisin inhibitor from Oryza sativa

    International Nuclear Information System (INIS)

    The crystallization of rice α-amylase/subtilisin bifunctional inhibitor is reported. Rice bifunctional α-amylase/subtilisin inhibitor (RASI) can inhibit both α-amylase from larvae of the red flour beetle (Tribolium castaneum) and subtilisin from Bacillus subtilis. The synthesis of RASI is up-regulated during the late milky stage in developing seeds. The 8.9 kDa molecular-weight RASI from rice has been crystallized using the hanging-drop vapour-diffusion method. According to 1.81 Å resolution X-ray diffraction data from rice RASI crystals, the crystal belongs to space group P21212, with unit-cell parameters a = 79.99, b = 62.95, c = 66.70 Å. Preliminary analysis indicates two RASI molecules in an asymmetric unit with a solvent content of 44%

  4. Roles of plant growth regulators on yield, grain qualities and antioxidant enzyme activities in super hybrid rice (Oryza sativa L.)

    OpenAIRE

    Pan, Shenggang; Rasul, Fahd; Li, Wu; Tian, Hua; Mo, Zhaowen; Duan, Meiyang; Tang, Xiangru

    2013-01-01

    Background Plant growth regulators play important roles in plant growth and development, but little is known about roles of plant growth regulators in yield, grain qualities and antioxidant enzyme activities in super hybrid rice. In this study, gibberellic acid(GA3), paclobutrazol (PBZ), 6-Benzylaminopurine(6-BA) treatments and distilled water (control) were sprayed to two hybrid rice cultivars (Peizataifeng and Huayou 86) at the heading stage in the field experiments in both early and late s...

  5. Exploration of Relationship between Fragrant Gene and Growth performances of Fragrant Rice (Oryza sativa L.) Seedlings under Salinity Stress

    OpenAIRE

    Wijerathna Y M A M; Kottearachchi N S; Gimhani D R; Sirisena D N

    2014-01-01

    Fragrant rice is associated with poor agronomic traits and low tolerability to salt stress. Present study was conducted to examine the relationship between fragrant intensity of Sri Lankan rice germplasms and their seedling growth under salt stress. It was reported that correct copy of badh2 gene is associated with more salt tolerance than the mutated version of badh2 gene. Fifteen accessions that exhibited different levels of fragrance were selected and they were categorized into...

  6. Controle de arroz-vermelho em dois genótipos de arroz (Oryza sativa) tolerantes a herbicidas do grupo das imidazolinonas Red rice control in two rice (Oryza sativa) genotypes tolerant to imidazolinone herbicides

    OpenAIRE

    S.C.C Villa; E. Marchezan; P.F.S Massoni; F.M. Santos; L.A. Avila; S.L.O. Machado; G.M. Telo

    2006-01-01

    A infestação por arroz-vermelho (Oryza spp.) constitui-se num dos principais fatores limitantes da produtividade de grãos do arroz irrigado. Este trabalho teve como objetivo avaliar o controle de arroz-vermelho e o desempenho de dois genótipos de arroz irrigado, IRGA 422 CL e Tuno CL, tolerantes a herbicidas do grupo das imidazolinonas em resposta a doses e épocas de aplicações da mistura formulada de imazethapyr (75 g L-1) + imazapic (25 g L-1) (produto comercial Only®), em áreas com alta in...

  7. Quantitative Trait Loci Associated with Pollen Fertility under High Temperature Stress at Flowering Stage in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    XIAO Ying-hui; PAN Yi; Luo Li-hua; DENG Hua-bing; ZHANG Gui-lian; TANG Wen-bang; CHEN Li-yun

    2011-01-01

    High temperature stress (HTS),an increasingly important problem in rice production,significantly reduces rice yield by reducing pollen fertility and seed setting rate.Breeding rice varieties with tolerance to HTS at the flowering stage is therefore essential for maintaining rice production as the climate continues to become warm.In this study,two quantitative trait loci (QTLs) underlying tolerance to HTS were identified using recombinant inbred lines derived from a cross between an HTS-tolerant rice cultivar 996 and a sensitive cultivar 4628.Pollen fertility was used as a heat-toleranca indicator for the lines subjected to HTS at the flowering stage in field experiments.Two QTLs that affected pollen fertility,qPF4 and qPF6,were detected between RM5687 and RM471 on chromosome 4,and between RM190 and RM225 on chromosome 6,by using the composite interval mapping (CIM) analysis.The two QTLs explained 15.1% and 9.31% of the total phenotypic variation in pollen fertility,and increased the pollen fertility of the plants subjected to HTS by 7.15% and 5.25%,respectively.The positive additive effects of the two QTLs were derived from the 996 alleles.The two major QTLs identified would be useful for further fine mapping and cloning of these genes and for molecular marker-assistant breeding of heat-tolerant rice varieties.

  8. Exploration of Relationship between Fragrant Gene and Growth performances of Fragrant Rice (Oryza sativa L. Seedlings under Salinity Stress

    Directory of Open Access Journals (Sweden)

    Wijerathna Y M A M

    2014-02-01

    Full Text Available Fragrant rice is associated with poor agronomic traits and low tolerability to salt stress. Present study was conducted to examine the relationship between fragrant intensity of Sri Lankan rice germplasms and their seedling growth under salt stress. It was reported that correct copy of badh2 gene is associated with more salt tolerance than the mutated version of badh2 gene. Fifteen accessions that exhibited different levels of fragrance were selected and they were categorized into four fragrant intensity groups. Rice seedlings were grown under three salinity levels, 0.73 dSm-1 (control, 4 dSm-1 and 8 dSm-1 and their survival percentage, root length and shoot length were measured. A novel formula of Salinity Survival Index (SSI was derived from survival percentages and analysis of variance revealed that survival index under salinity stress was significantly associated with the fragrant intensity groups of rice. As the fragrant intensity increases, SSI, root length and shoot length decreases. A fragrant accession that were exceptionally salt tolerant were also disclosed. Most of the Sri Lankan fragrant rice germplasms do not possess the predominant badh2.1 fragrant allele. These findings would be useful in rice improvement breeding programs designed for fragrance and salt tolerance

  9. Development and appraisal of economical and sustainable approach for weed management in drill seeded aerobic rice (oryza sativa l.)

    International Nuclear Information System (INIS)

    Conventional rice cultivation by puddling and transplanting is a labor intensive activity. Water scarcity is a threat for the sustain ability of transplanted rice. In many areas of Asia, rice transplantation of rice is being replaced by direct seeding as farmers tried to solve the problems of labor cost and water scarcity but weed control is one of the major constraints to direct seeding. So, to control weeds in direct seeded rice present studies were designed. A two years study was conducted to develop sustainable and economical methods for managing weeds in aerobic rice grown by dry direct-seeding at Student's Farm, Department of Agronomy, University of Agriculture, Faisalabad during the years 2008 and 2009. Experiment was laid out in RCBD with five weed management strategies: hand weeding, hoeing with kasula, inter-row cultivation with tine cultivator, inter-row cultivation with spike hoe and chemical control with Nominee 100 SC along with control (no weeding). Weed dry weight was 300 g m/sup -2/, 257 g m/sup -2/, 225 g m/sup -2/ and 157 g m/sup -2/ less in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. Paddy yield was 221%, 203%, 181% and 105% more in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. (author)

  10. Adaptación del arroz riego (Oryza sativa L. en el Caribe colombiano Adaptation of irrigated rice (Oryza sativa L. in the colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Hermes Aramendiz Tatis

    2011-01-01

    Full Text Available En Colombia, el arroz ocupa el primer lugar en seguridad alimentaria, valor económico y generación de empleo entre los cultivos anuales, siendo el sistema bajo riego más importante. El objetivo fue determinar el progreso, estabilidad y adaptabilidad del rendimiento de arroz bajo riego, en cinco departamentos del caribe colombiano. Se utilizaron datos del Ministerio de Agricultura y Desarrollo Rural, correspondiente a los Departamentos de Córdoba, Bolívar, Magdalena, Cesar y Guajira, durante el periodo 1987-2008. La estimación del progreso del rendimiento se realizó a través del análisis de regresión lineal entre los años (variable explicativa y el rendimiento de grano (variable explicada. La estabilidad se determinó a través del coeficiente de variación para tres períodos consecutivos de cinco años y el último de siete. La adaptabilidad, se realizó con el coeficiente de regresión lineal (bi. Los resultados destacan que el progreso en el rendimiento de grano en el Caribe colombiano, osciló entre 1.15% y 3.36% por año y 52.2 y 168.1 kg.ha-1, especialmente en el Departamento de Bolívar (3.36% por año y 168.1 kg.ha-1. La estabilidad, resultó en general alta (CV4.57 para el rendimiento de grano.In Colombia, the rice crop under irrigation system ranks first in food security, economic value and employment offer among annual crops, becoming the most important. The objective of this study was to quantify increasing, stability and adaptability of irrigated rice in five departments of the Colombian Caribbean area. Data from the Ministry of Agriculture and Rural Development for the departments of Cordoba, Bolivar, Magdalena, Cesar and Guajira, during the year period 1987 to 2008 were used. The increasing in yield was determined using the linear regression analysis among years (independent variable and grain yield (dependent variable in each department. The yield stability was determined by the coefficient of variation across of three

  11. The distribution and copy number of copia-like retrotransposons in rice (Oryza sativa L.) and their implications in the organization and evolution of the rice genome

    OpenAIRE

    Wang, Shiping; Liu, Nan; Peng, Kaiman; Zhang, Qifa

    1999-01-01

    We used 22 fragments corresponding to the reverse transcriptase domain of copia-like retrotransposons as representatives to study the organization and distribution of these elements in the rice genome. The loci detected by these 22 fragments were assigned to 47 locations in the molecular-linkage map involving all 12 chromosomes. The distributional features of copia-like retrotransposons found in the rice genome indicated that (i) the loci detected were located mainly in one arm of each chromo...

  12. Ethnobotanicals for Storage Pest Management: Effect of powdered leaves of Olax zeylanica in suppressing infestations of rice weevil Sitophilus oryzae (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Sachini Dinusha Fernando

    2012-05-01

    Full Text Available Abstract The rice weevil Sitophilus oryzae is considered the major problem in stored rice in Sri Lanka. Due to the adverse effects of pesticide usage, research on the re-evaluation and use of many ethnobotanicals as alternative storage pest control agents has been intensified. Although plant materials with insecticidal properties provide small-scale farmers with a locally available, eco-friendly and inexpensive method of control of storage insect pests, lack of understanding and knowledge prevent their widespread application. The present study was therefore undertaken to investigate the effectiveness of the botanical Olax zeylanica in controlling infestations of the rice weevil with the view of fulfilling this lack. In two separate bioassays, contact/feeding and fumigant toxicity of powdered leaves of O. zeylanica were tested against 1-7 days old adults under laboratory conditions. All experiments were conducted using a no-choice bioassay apparatus. Contact/feeding toxicity was tested by directly exposing weevils to 1.0, 3.0, 5.0 and 7.5g of leaf powder mixed with 100g of rice grains while fumigant toxicity was evaluated by using the same doses where weevils were exposed to fumes emitted from the leaf powders. In both bioassays 100% mortality of the weevils was observed within 18 hours of exposure to 3.0, 5.0 and 7.5g doses of leaf powder. Percentage weevil mortality in treated rice tested with three doses of leaf powder at all the time intervals (except for 1.0g was significantly higher (p No Contact/feeding toxicity was recorded when weevils were directly exposed to 1.0g leaf powder whereas only 14% weevil mortality was observed even after 24hours of exposure to fumes of leaf powder. Results also revealed that weevil mortality increased both with increasing dose and time of exposure. It is of interest to note that in both bioassays a 100% weevil mortality was obtained after 18 hours of exposure to a lower amount of leaf powder such as 3.0g

  13. Salt tolerance evaluation of rice (oryza sativa L.) genotypes based on physiological characters contributing to salinity resistance

    International Nuclear Information System (INIS)

    Seven newly developed rice cultivars i.e., KS-133, DR-83, DR-64, BR-601, Gomal, JP-5 and Gomal-6, were evaluated for salinity tolerance in a glass house along with three varieties of known salinity tolerance i.e., KS-282 (tolerant), IR-6 (medium tolerant) and Basmati-385 (susceptible). Based on the survival percentage at 50 mol/m3 sodium chloride salinity imposed at seedling stage, rice cultivars KS-133, Gomal, and DR-83 showed high survival comparable to that of salinity tolerant cultivars like KS-282, and were thus placed in tolerance range. Survival percentage of JP-5, Gomal-6 and DR-64 remained in medium tolerance range (35 to 38%) as that of IR-6. The rice cultivar BR-601 showed only 13% survival and was found to be as sensitive towards salinity as Basmati-385. The results of rice survival in saline medium showed good uniformity and the check varieties showed results corresponding to those found elsewhere. Sodium (Na/sup +/) and potassium (K/sup +/) concentrations in the third leaf showed variations among different rice cultivars under salinity. There was an inverse correlation between varietal leaf Na/sup +/ vs survival percentage (r = -0.808) and Na/sup +/ vs leaf chlorophyll (r -0.857). The correlation between K/sup +/ and final survival percentage was direct (r = 0.744) and also leaf chlorophyll vs survival (r = 0.952). The shoot fresh and dry weights were greater in the rice genotypes having higher final survival percentage under saline conditions. Therefore, in addition to final survival percentage, the higher shoot fresh and dry weight under salinity could be also used as criterion for evaluation of salinity tolerance of rice. (author)

  14. Evaluation of the ORYZA2000 Rice Growth Model under Nitrogen-Limited Conditions in an Irrigated Mediterranean Environment Evaluación del Modelo de Crecimiento de Arroz ORYZA2000 bajo Condiciones Limitadas de Nitrógeno en un Ambiente Mediterráneo Regado

    Directory of Open Access Journals (Sweden)

    Pamela Artacho

    2011-03-01

    Full Text Available ORYZA2000 is a growth model for tropical lowland rice ( Oryza sativa L. developed by the International Rice Research Institute and Wageningen University. This model has been evaluated extensively in a wide range of environments. However, reports examining japonica cultivars growing in temperate climates are scarce. In this study, ORYZA2000 was calibrated and evaluated using data from experiments carried out in the South-Central area of Chile. These experiments were performed on a japonica rice cultivar growing under an irrigated Mediterranean environment at various N rates. ORYZA2000 was then applied to explore potential yield and grain yield response to N fertilization under likely weather conditions in the major rice-producing area in Chile. ORYZA2000 was sufficiently accurate to simulate grain yield and crop N uptake at the end of the season. Final crop N uptake was simulated with a root mean squared error (RMSE of 20 kg ha-1 (15% and grain yield with a RMSE of 1666 kg ha-1 (19%. However, the prediction of biomass and N uptake of individual organs throughout the season was poor. A long-term simulation study confirmed a potential yield as high as 12 000 kg ha-1 in the Parral area, as well as the existence of a scope for yield increase. The yield response to N fertilization was predicted even at rates of 300 kg ha-1, although a significant probability of low yields was also observed. This trend supports the need to incorporate dynamic N management in Chilean rice production.ORYZA2000 es un modelo para arroz tropical regado desarrollado por el Instituto Internacional de Investigación en Arroz y Universidad de Wageningen, que ha sido evaluado en un amplio rango de ambientes. Sin embargo, los reportes para cultivares japónica creciendo en ambientes templados son escasos. En este estudio, ORYZA2000 fue calibrado y evaluado usando datos de experimentos realizados en el centro-sur de Chile, que incluyeron una variedad japónica cultivada bajo un

  15. Quantifying ATP turnover in anoxic coleoptiles of rice (Oryza sativa) demonstrates preferential allocation of energy to protein synthesis

    OpenAIRE

    Edwards, Joshua M.; Roberts, Thomas H.; Atwell, Brian J.

    2012-01-01

    Oxygen deprivation limits the energy available for cellular processes and yet no comprehensive ATP budget has been reported for any plant species under O2 deprivation, including Oryza sativa. Using 3-d-old coleoptiles of a cultivar of O. sativa tolerant to flooding at germination, (i) rates of ATP regeneration in coleoptiles grown under normoxia (aerated solution), hypoxia (3% O2), and anoxia (N2) and (ii) rates of synthesis of proteins, lipids, nucleic acids, and cell walls, as well as K+ tr...

  16. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    Directory of Open Access Journals (Sweden)

    Saleh Dounia

    2012-03-01

    Full Text Available Abstract Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i two strains of opposite mating types including (ii at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs. Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar

  17. Profitability of production and resource-use efficiency among ofada rice (Oryza sativa japonica farmers in Southwest, Nigeria

    Directory of Open Access Journals (Sweden)

    Bolarin Titus Omonona

    2012-06-01

    Full Text Available Ofada rice has recently gained prominence and it is quickly drawing international attention sinceit has revealed a strong consumer disposition and it has been perceived to be more nourishingdue to its natural taste, a value added to this kind of rice. Nigeria has potential to produce it toself-sufficiency level but due to the inefficient use of inputs and in-availability of some inputs, thishas become a mirage. Data was obtained from 180 rice farmers selected from the rice growingareas in Ogun state, with the use of well structured questionnaire. The data collected were thenanalyzed using both descriptive and inferential statistics. The descriptive analysis showed that 70%of the farmers were males, the average age and farm size was 45years and 2.9ha, respectively.The maximum likelihood estimates of the stochastic production frontier model results showed thata unit increase in farm size, labour, seeds and chemicals used will result in extra 64.587kg, 3.98kg,0.54kg, and 2.258kg of the output, respectively. Marginal value product (MVP to the unit prices forthese inputs was greater than one implying that all these resources were underutilized. The grossmargin analysis revealed that the profit from rice farming was N56, 082 (US$373.88 per hectare perfarmer. Farmers’ efficiency can be enhanced by increasing the area of land cultivated, labourused, quantity of seeds and chemicals used for production.

  18. The Effects of Cation Ratios on Root Lamella Suberization in Rice (Oryza sativa L. with Contrasting Salt Tolerance

    Directory of Open Access Journals (Sweden)

    M. R. Momayezi

    2012-01-01

    Full Text Available Rice is an important produced cereal in the world. We evaluated the effect of salt compositions including NaCl and Na2SO4 on suberin lamellae as a major barrier to radial ion and water movements in two rice genotypes representing contrasting salt tolerance levels under salinity stress. Two rice genotypes, Fajr as salt tolerant and Khazar as salt sensitive, were transplanted in sand culture under glasshouse condition. Rice seedlings were treated with five salt compositions including NaCl, Na2SO4, 1 : 1, 1 : 2, and 2 : 1 molar ratios for 40 days. It was proven that suberin lamellae in endodermis of root cell wall were thickened with Na2SO4 treatment. The results demonstrated that the number of passage cells was higher in Fajr genotype than that in Khazar genotype under saline condition. Calcium concentration in root tissue decreased as the SO42- concentration in root media increased. It can be concluded that Fajr genotype is able to keep some passage cells open to maintain Ca2+ uptake. The Ca2+/Na+ ratio in shoot tissue can be also a reliable index for the early recognition of salt stress in these rice genotypes.

  19. Production and Optimization of Oleic Acid Ethyl Ester Synthesis Using Lipase From Rice Bran (Oryza sativa L. and Germinated Jatropha Seeds (Jatropha curcas L. by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Indro Prastowo

    2015-11-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Recently, the fatty acid ethyl ester has been synthesized in place of fatty acid methyl ester since ethanol has been more renewable. In this research, oleic acid ethyl ester (OAEE was synthesized using germinated jatropha seeds (Jatropha curcas.L and rice bran (Oryza sativa as source of lipase. The objective of the research was to optimize the synthesis conditions using Response Surface Methodology. Factors, such as crude enzyme concentration, molar ratio of oleic acid to ethanol, and the reaction time, were evaluated. The results show that lipase from germinated jatropha seeds had the hydrolitic and esterifi cation activity about 6.73 U/g and 298.07 U/g, respectively. Lipase from rice bran had the hydrolitic and esterifi cation activity about 10.57 U/g and 324.03 U/g, respectively. The optimum conditions of esterifi cation reaction using germinated jatropha seed lipase as biocatalyst were crude enzyme concentration of 0.31 g/ml, molar ratio of oleic acid to ethanol of 1 : 1.81, and reaction time of 50.9 min. The optimum conditions of esterifi cation reaction using rice bran lipase were crude enzyme concentration of 0.29 g/ml, molar ratio of oleic acid to ethanol of 1 : 2.05, and reaction time of 58.61 min. The obtained amounts of OAEE were 810.77 μmole and 626.92 μmole for lipases from rice bran and germinated jatropha seed, respectively. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  20. Utilization of greenable albino mutation lines of thermosensitive genie male sterile rice (Oryza sativa L. ssp indica)

    International Nuclear Information System (INIS)

    Two greenable albino mutation lines W24 and W27 induced by 60Co gamma rays treatment on seeds of a thermosensitive genie male sterile (TGMS) rice c.v 2177S were investigated on their usefulness in two-line hybrid rice. The leaf color of W24 and W27 was similar and could be expressed in different temperature conditions. The first three leaves of W24 and W27 were ablinotic at extending, but changed into green after the fourth leaf extended. The greenable leaf area were about 40% for the first leaf and 90% for the third leaf. No significant differences were detected in morphoagronomic characters and styler extrusion rate between the mutation line and 2177S, which suggested that the mutation leaf color may be a useful marker in eliminating contamination of selfed seeds in two-line hybrid rice

  1. Inducing defence enzymes in two rice (Oryza sativa varieties by G. mosseae arbuscular mycorrhizal fungus Inducción de enzimas de defensa en dos variedades de arroz (Oryza sativa por el hongo micorrízico arbuscular G. mosseae

    Directory of Open Access Journals (Sweden)

    Fernández Félix

    2006-12-01

    Full Text Available Protecting plants against fundamentally radical pathogens is one of arbuscular mycorrhizal fungi's benefits. This work was aimed at comparing the effect of one such fungus (Glomus mosseae on inducing a defensive response in two rice (Oryza sativa varieties (LP-7 and J-104. Peroxidise, polyphenoloxidase, chitinase, (3-1,3 glucanase and phenylalanine ammonium lyase enzymatic activity and peroxidase and polyphenoloxidase isoenzymatic expression were determined in both radical and foliar tissues. Mycorrhizal colonisation and visual density percentage were also evaluated. The results revealed that the G. mosseae fungus caused variations in enzymatic activity. Differences were observed in the two varieties behaviour patterns according to evaluation time and plant área studied. The differences detected in peroxidase and polyphenoloxidase electrophoretic patterns were due to the varieties and not to mycorrhisation effect. Rice variety LP-7 generally presented a successful response to inoculation with the G. mosseae arbuscular mycorrhizal fungus, manifesting higher defence mechanism induction. The best results for protecting crops could thus be obtained by using this combination. Key words: peroxidase, polyphenoloxidase, chitinase, (3-1,3 glucanase and phenylalanine ammonium lyase.Entre los beneficios que los hongos micorrízicos arbusculares proporcionan a las plantas se encuentra la protección contra patógenos, fundamentalmente radicales. Por lo que fue objetivo de este trabajo comparar el efecto de uno de estos hongos, Glomus mosseae, en la inducción de respuestas de defensa en dos variedades de arroz (Oryza sativa, LP-7 y J-104. Para lo cual se determinaron, tanto en tejido radical como foliar, las activida­des enzimáticas de peroxidasa, polifenoloxidasa, quitinasa, (3-1,3 glucanasa y fenilalanina amonio liasa; así como la expresión isoenzimática de peroxidasas y polifenoloxidasas. También se evaluaron los porcentajes de

  2. Genetic analysis of durable resistance to Magnaporthe oryzae in the rice accession Gigante Vercelli identified two blast resistance loci.

    Science.gov (United States)

    Urso, Simona; Desiderio, Francesca; Biselli, Chiara; Bagnaresi, Paolo; Crispino, Laura; Piffanelli, Pietro; Abbruscato, Pamela; Assenza, Federica; Guarnieri, Giada; Cattivelli, Luigi; Valè, Giampiero

    2016-02-01

    Rice cultivars exhibiting durable resistance to blast, the most important rice fungal disease provoking up to 30 % of rice losses, are very rare and searching for sources of such a resistance represents a priority for rice-breeding programs. To this aim we analyzed Gigante Vercelli (GV) and Vialone Nano (VN), two temperate japonica rice cultivars in Italy displaying contrasting response to blast, with GV showing a durable and broad-spectrum resistance, whereas VN being highly susceptible. An SSR-based genetic map developed using a GV × VN population segregating for blast resistance identified two blast resistance loci, localized to the long arm of chromosomes 1 and 4 explaining more than 78 % of the observed phenotypic variation for blast resistance. The pyramiding of two blast resistance QTLs was therefore involved in the observed durable resistance in GV. Mapping data were integrated with information obtained from RNA-seq expression profiling of all classes of resistance protein genes (resistance gene analogs, RGAs) and with the map position of known cloned or mapped blast resistance genes to search candidates for the GV resistant response. A co-localization of RGAs with the LOD peak or the marker interval of the chromosome 1 QTL was highlighted and a valuable tool for selecting the resistance gene during breeding programs was developed. Comparative analysis with known blast resistance genes revealed co-positional relationships between the chromosome 1 QTL with the Pi35/Pish blast resistance alleles and showed that the chromosome 4 QTL represents a newly identified blast resistance gene. The present genetic analysis has therefore allowed the identification of two blast resistance loci in the durable blast-resistant rice cultivar GV and tools for molecular selection of these resistance genes. PMID:26141566

  3. Heavy metal contamination of paddy soils and rice (Oryza sativa L.) from Kočani Field (Macedonia)

    OpenAIRE

    Rogan, Nastja; Serafimovski, Todor; Dolenec, Matej; Tasev, Goran; Dolenec, Tadej

    2009-01-01

    This research focuses on the heavy metal contamination of the paddy soils and rice from Kočani Field (eastern Macedonia) resulting from irrigation by riverine water impacted by past and present base-metal mining activities and acid mine drainage. Very high concentrations of As, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99, 983 and 1,245 μg g-1) and the rice (0.53, 0.31, 5.8, 0.5 and 67 μg g-1) in the western part of Kočani Field, close to the Zleto...

  4. Cloning and expression of a cDNA encoding ribosomal protein S4 from Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cDNA clone, pS4, has been isolated from a cDNA library prepared from rice anthers of about 1.0 mm in length. DNA sequence analysis and database search show that the cDNA encodes a protein which is highly homologous to eukaryotic 80S ribosomal protein subunit 4 (S4). Northern hybridization indicates that this gene expresses in all tissues analyzed although the expression level varies and it cannot be induced by mechanical wounding in leaves. Southern blot analysis demonstrates that this rice S4 gene is from a multigene family.

  5. Allelopathy of weed extracts on yield and its components in four cultivars of rice (Oryza sativa L.)

    OpenAIRE

    Ali MOHADESI; Abouzar ABBASIAN; Saeed BAKHSHIPOUR; Fatemeh TAVASOLI; Salehi, Masoud; Ahad MADANI

    2011-01-01

    Weeds are enemies to the crop plants and have harmful effects on agricultural crops due to several factors such as competition for space, light and nutrients. Allelopathic effects of weed extracts were studied on grain yield and yield components of rice. The experiment was carried out in the Rice Research Institute of Chaparsar, in 2006- 2007, in Tonekabon, Iran (latitude 36°54’ N, longitude 50° 40’E, level -20 m altitude), split plot on basis of randomized completely block design (RCBD) with...

  6. Caracterização morfológica de ecótipos de arroz daninho (Oryza sativa provenientes de áreas de arroz irrigado Morphological characterization of red rice (Oryza Sativa ecotypes derived from irrigated rice areas

    Directory of Open Access Journals (Sweden)

    A.M.L. Schwanke

    2008-06-01

    Full Text Available Objetivou-se neste estudo a caracterização fenotípica de 16 ecótipos de arroz daninho provenientes de lavouras comerciais dos Estados do Rio Grande do Sul e Santa Catarina, quando comparados aos cultivares BR-IRGA 409, BR-IRGA 410, IRGA 417 e El Paso L 144, em casa de vegetação. Foram semeados 16 ecótipos de arroz daninho e os quatro cultivares de arroz irrigado. O cultivo foi realizado em vasos plásticos com capacidade para 9 litros, contendo solo, utilizando-se cinco repetições por genótipo. Foram avaliadas as seguintes variáveis: coloração das folhas, pilosidade, afilhamento efetivo, graus-dia biológico para completar o florescimento, degrane, número de afilhos férteis, área foliar da folha-bandeira, altura de planta, número de sementes por panícula e produção por planta. Os resultados obtidos evidenciam grande variabilidade morfológica entre os ecótipos estudados.Aspects related to the phenotypical characterization of red rice ecotypes collected in the states of Rio Grande do Sul and Santa Catarina were studied and compared to those of commercial rice cultivars BR-IRGA 409, BR-IRGA 410, IRGA 417, and El Paso L 144. The sixteen red rice ecotypes plus four rice cultivars were sown with five replications in plastic pails filled with 9 liters of soil. The genotypes were described according to the traits proposed by the International Rice Research Institute (IRRI, 1980. The following plant and seed parameters were evaluated: leaf color and hairiness, effective tillering, biological day-degrees to complete the flowering period, seed shattering, number of fertile tillers, flag leaf area, plant height, number of seeds per panicle and seed production. The results showed a great morphological variability among the red rice ecotypes.

  7. Changes in LIF [Laser Induced Fluerescence] spectra and photosynthetic rate of rice [Oryza sativa] leaves under background light of different intensities

    International Nuclear Information System (INIS)

    Chlorophyll fluorescence is known to be a sensitive probe of photosynthesis. Laser induced fluorescence (LIF) is useful for remotely sensing physiological information of plants by optical measurement. However, it is difficult to assess the LIF independently because of changes in background light. Background light, like sunlight, not only stimulates photosynthetic reaction but also induces fluorescence. To demonstrate the possibility of detecting changes in photosynthetic reaction according to background light from the LIF spectra, the correlation between LIF spectra and intensity of incident light on leaves was investigated. The LIF spectra from rice (Oryza sativa L.) leaves, which were illuminated with a metal halide lamp as background light, were measured. A gated CCD camera with monochrometer was synchronized to a pulsed UV-laser (Nd: YAG, 355 nm) to detect the LIF spectrum under background light of different intensities. The LIF magnitude increased linearly with the laser intensity at each intensity of background light. The slope of fluorescence against laser intensity was considered to be a measure of fluorescent efficiency. The fluorescent efficiency increased with intensity of illumination. This increase of fluorescent efficiency was mainly caused by the increase of blue-green fluorescence (BGF) but chlorophyll fluorescence was constant. These changes of LIF spectra can be explained by the interaction of the fluorescent efficiency of chlorophyll and re-absorption of BGF; these phenomena reflect the redox state of the first electron acceptor (QA) in the photosynthetic reaction. The ratio of regression coefficients of BGF to chlorophyll fluorescence against the laser intensity changed in accordance with the change of photosynthetic rate of rice leaves. Photosynthetic information of leaves was detectable by analyzing the correlation between induction intensity and LIF spectra under changing background light

  8. OsWOX3A is involved in negative feedback regulation of the gibberellic acid biosynthetic pathway in rice (Oryza sativa).

    Science.gov (United States)

    Cho, Sung-Hwan; Kang, Kiyoon; Lee, Sang-Hwa; Lee, In-Jung; Paek, Nam-Chon

    2016-04-01

    The plant-specific WUSCHEL-related homeobox (WOX) nuclear proteins have important roles in the transcriptional regulation of many developmental processes. Among the rice (Oryza sativa) WOX proteins, a loss of OsWOX3A function in narrow leaf2 (nal2) nal3 double mutants (termed nal2/3) causes pleiotropic effects, such as narrow and curly leaves, opened spikelets, narrow grains, more tillers, and fewer lateral roots, but almost normal plant height. To examine OsWOX3A function in more detail, transgenic rice overexpressing OsWOX3A (OsWOX3A-OX) were generated; unexpectedly, all of them consistently exhibited severe dwarfism with very short and wide leaves, a phenotype that resembles that of gibberellic acid (GA)-deficient or GA-insensitive mutants. Exogenous GA3 treatment fully rescued the developmental defects of OsWOX3A-OX plants, suggesting that constitutive overexpression of OsWOX3A downregulates GA biosynthesis. Quantitative analysis of GA intermediates revealed significantly reduced levels of GA20 and bioactive GA1 in OsWOX3A-OX, possibly due to downregulation of the expression of KAO, which encodes ent-kaurenoic acid oxidase, a GA biosynthetic enzyme. Yeast one-hybrid and electrophoretic mobility shift assays revealed that OsWOX3A directly interacts with the KAO promoter. OsWOX3A expression is drastically and temporarily upregulated by GA3 and downregulated by paclobutrazol, a blocker of GA biosynthesis. These data indicate that OsWOX3A is a GA-responsive gene and functions in the negative feedback regulation of the GA biosynthetic pathway for GA homeostasis to maintain the threshold levels of endogenous GA intermediates throughout development. PMID:26767749

  9. Conservation of IRE1-Regulated bZIP74 mRNA Unconventional Splicing in Rice (Oryza sativa L.) Involved in ER Stress Responses

    Institute of Scientific and Technical Information of China (English)

    Sun-Jie Lu; Zheng-Ting Yang; Ling Sun; Le Sun; Ze-Ting Song; Jian-Xiang Liu

    2012-01-01

    Protein folding in the endoplasmic reticulum (ER) is a fundamental process in plant cells that is vulnerable to many environmental stresses.When unfolded or misfolded proteins accumulate in the ER,the well-conserved unfolded protein response (UPR) is initiated to mitigate the ER stress by enhancing the protein folding capability and/or accelerating the ER-associated protein degradation.Here,we report the conservation of the activation mechanism of OsbZIP74 (also known as OsbZIP50),an important ER stress regulator in monocot plant rice (Oryza sativa L.).Under normal conditions,OsbZIP74 mRNA encodes a basic leucine-zipper transcription factor with a putative transmembrane domain.When treating with ER stress-inducing agents such as tunicamycin and DTT,the conserved double stem-loop structures of OsbZIP74 mRNA are spliced out.Thereafter,the resulting new OsbZIP74 mRNA produces the nucleus-localized form of OsbZIP74 protein,eliminating the hydrophobic region.The activated form of OsbZIP74 has transcriptional activation activity in both yeast cells and Arabidopsis leaf protoplasts.The induction of OsbZIP74 splicing is much suppressed in the OsIRE1 knockdown rice plants,indicating the involvement of OsIRE1 in OsbZIP74 splicing.We also demonstrate that the unconventional splicing of OsbZIP74 mRNA is associated with heat stress and salicylic acid,which is an important plant hormone in systemic acquired resistance against pathogen or parasite.

  10. Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits.

    Science.gov (United States)

    Tuhina-Khatun, Mst; Hanafi, Mohamed M; Rafii Yusop, Mohd; Wong, M Y; Salleh, Faezah M; Ferdous, Jannatul

    2015-01-01

    Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO₂, and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future. PMID:26258135

  11. Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L. Genotypes Based on Quantitative Traits

    Directory of Open Access Journals (Sweden)

    Mst. Tuhina-Khatun

    2015-01-01

    Full Text Available Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g. The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2, and number of filled grains/panicle and yields/plant (g. Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g, which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future.

  12. Development of pyramidal lines with two major QTLs conferring resistance to sheath blight in rice (Oryza sativa L.)

    Science.gov (United States)

    Hossain, Md Kamal; Jena, Kshirod; Bhuiyan, Md Atiqur Rahman; Ratnam, Wickneswari

    2014-09-01

    Sheath blight is an emerging threat in rice cultivation. It is animportant disease caused by the soil-borne necrotrophic pathogenic fungus, Rhizoctonia solani Kühn. However, to date neither known major genes for quantitative resistance, nor any rice lines immune to this disease has been identified. The disease resistance is quantitative in nature. Numerous genes are involved in this resistance process. There are few quantitative trait loci (QTLs) detected conferring improved resistance against the disease. Teqing and Tetepshowimproved resistance having QTLs, qSB-9 and qSBR11-1, respectively. Since, these QTLs demonstrates additive effects, pyramiding of these QTLs might be an option to increase the sheath blight resistance in rice. Nine rice cultivars were screened at greenhouse conditions. Results showed that Tetep and Teqing had the lowest disease ratings. UKMRC2a new high yielding cultivar was as recipient parent. Crosses between UKMRC2 and Teqing, and UKMRC2 and Tetep were made and confirmed. Subsequently 4-way crosses between the two F1s were performed to develop pyramidal lines.

  13. Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    CHAI Lu; LI Zhi-kang; ZHANG Jian; PAN Xiao-biao; ZHANG Fan; ZHENG Tian-qing; ZHAO Xiu-qing; WANG Wen-sheng; Ali Jauhar; XU Jian-long

    2014-01-01

    Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the whole-plant growth duration salt tolerance (ST) was genetically dissected by phenotyping two sets of BC2F5 introgression lines (ILs) for four yield traits under severe natural salt stress and non-stress ifled conditions using SSR markers and the methods of advanced backcross QTL (AB-QTL) analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and non-stress conditions were identiifed, most (>90%) of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan (HHZ) ILs with favorable donor alleles at multiple QTLs and signiifcantly improved yield traits under salt stress and non-stress conditions were identiifed, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection (MAS) or genome selection.

  14. Molecular cloning, expression analysis and chromosomal mapping of salt-responsive cDNAs in rice ( Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    李子银; 张劲松; 陈受宜

    1999-01-01

    By using differential display PCR (DD-PCR) technique, two salt-inducible and one salt-repressed cDNA fragments were isolated from rice. The three eDNA fragments were characterized respectively as partial sequence of rice S-adenosylmethionine deearboxylase (SAMDC) gene, a new member of translation elongation factor 1A gene (named REF1A ), and a novel gene whose function is unknown (named SRG1). The full-length cDNA of SAMDC gene (named SAMDC1) was further isolated by RT-PCR approach and the deduced polypeptide was found to be homologous to SAMDC proteins of other plants, yeast and human. Northern hybridization revealed that expression of SAMDC1 and REF1A was induced, while SRG1 was dramatically repressed, by salinity stress. Southern blot analysis demonstrated that SAMDC1 and SRG1 were present as a single copy gene in rice genome, whereas rice REF1A gene was organized as a gene family. The REF1A, SAMDC1, and SRG1 genes were located on chromosome 3, 4, and 6 respectively by RFLP mapping approach using ZYQ

  15. Effects of salt stress on ion balance and nitrogen metabolism of old and young leaves in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Wang Huan

    2012-10-01

    Full Text Available Abstract Background It is well known that salt stress has different effects on old and young tissues. However, it remains largely unexplored whether old and young tissues have different regulatory mechanism during adaptation of plants to salt stress. The aim of this study was to investigate whether salt stress has different effects on the ion balance and nitrogen metabolism in the old and young leaves of rice, and to compare functions of both organs in rice salt tolerance. Results Rice protected young leaves from ion harm via the large accumulation of Na+ and Cl− in old leaves. The up-regulation of OsHKT1;1, OsHAK10 and OsHAK16 might contribute to accumulation of Na+ in old leaves under salt stress. In addition, lower expression of OsHKT1;5 and OsSOS1 in old leaves may decrease frequency of retrieving Na+ from old leaf cells. Under salt stress, old leaves showed higher concentration of NO3− content than young leaves. Up-regulation of OsNRT1;2, a gene coding nitrate transporter, might contribute to the accumulation of NO3− in the old leaves of salt stressed-rice. Salt stress clearly up-regulated the expression of OsGDH2 and OsGDH3 in old leaves, while strongly down-regulated expression of OsGS2 and OsFd-GOGAT in old leaves. Conclusions The down-regulation of OsGS2 and OsFd-GOGAT in old leaves might be a harmful response to excesses of Na+ and Cl−. Under salt stress, rice might accumulate Na+ and Cl− to toxic levels in old leaves. This might influence photorespiration process, reduce NH4+ production from photorespiration, and immediately down-regulate the expression of OsGS2 and OsFd-GOGAT in old leaves of salt stressed rice. Excesses of Na+ and Cl− also might change the pathway of NH4+ assimilation in old leaves of salt stressed rice plants, weaken GOGAT/GS pathway and elevate GDH pathway.

  16. A consortium of rhizobacterial strains and biochemical growth elicitors improve cold and drought stress tolerance in rice (Oryza sativa L.).

    Science.gov (United States)

    Kakar, K U; Ren, X-L; Nawaz, Z; Cui, Z-Q; Li, B; Xie, G-L; Hassan, M A; Ali, E; Sun, G-C

    2016-05-01

    In the present study, a consortium of two rhizobacteria Bacillus amyloliquefaciens Bk7 and Brevibacillus laterosporus B4, termed 'BB', biochemical elicitors salicylic acid and β-aminobutyric acid (SB) and their mixture (BBSB) were investigated for cold and drought stress tolerance in rice plants. After withholding water for 16 days, rice plants treated with BBSB showed 100% survival, improved seedling height (35.4 cm), shoot number (6.12), and showed minimum symptoms of chlorosis (19%), wilting (4%), necrosis (6%) and rolling of leaves. Similarly, BB inoculation enhanced plant growth and reduced overall symptoms in rice seedlings subjected to 0 ± 5 °C for 24 h. Our results imply several mechanisms underlying BB- and BBSB-elicited stress tolerance. In contrast to the control, both treatments significantly decreased leaf monodehydroascorbate (MDA) content and electrolyte leakage, and increased leaf proline and cholorophyll content. Moreover, activities of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) increased 3.0- and 3.6-fold, respectively. Moreover, expression of OsMYB3R-2, OsDIL, OsDREB1A and OsCDPK13 genes was significantly up-regulated, suggesting that these genes play important roles in abiotic stress tolerance of rice. In addition, bacterial strains Bk7 and B4 were able to produce high amounts of IAA and siderophores, and colonise the plant roots, while only strain Bk7 exhibited the capability to form biofilms and solubilise inorganic phosphate. This study indicates that the BB and BBSB bio-formulations can be used to confer induced systematic tolerance and improve the health of rice plants subject to chilling and drought stress. PMID:26681628

  17. Induction of dominant male sterility by using 60Co γ-rays irradiation in rice oryza sativa L

    International Nuclear Information System (INIS)

    The fertility of M1 plants, which developed from dried rice (c.v. Zhe9248) seeds treated with γ-rays at the dosage of 300 Gy, decreased dramatically, and some of the M1 plants showed completely male sterile. There were still fertile and sterile plants in the M2F1 population of artificially emasculated high sterile Zhe9248 M1 plants crossed to normal variety G93-89, and consequently, Zhe9248 was back crossed to the sterile plants successively as recurrent parent. In all the above back cross populations, fertile and sterile plants segregated in a 1 : 1 ratio. The M4BC2 male sterile plants were crossed to various rice materials, e.g. early season indica rice (Zhefu 504, H416), middle season indica rice (Chuan-si-ran-zhan, Yu-Zhan), maintainer lines (Fu-Nan B, 351 B) and restorer lines (IR36, 20964). In all the above F1 populations, male sterile and fertile plants again segregated in a 1 : 1 ratio. In addition, sib-crossing were made in the back crosses and hybrid crosses between male sterile and fertile plants, male sterile and fertile plants appeared in a similar fashion as in test crosses. However, no male sterile plants were recovered from fertile plants either of back crosses or test crosses. The anthers of male sterile plants appeared small and poorly developed, the pollen showed typical abortion or round abortion, the seed set in bagged panicles was very low. The experimental data showed that this male sterile rice mutant was inherited in a single-gene mode

  18. Tolerance of anaerobic conditions caused by flooding during germination and early growth in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Berta eMiro

    2013-07-01

    Full Text Available Rice is semi-aquatic, adapted to a wide range of hydrologies, from aerobic soils in uplands to anaerobic and flooded fields in waterlogged lowlands, to even deeply submerged soils in flood-prone areas. Considerable diversity is present in native rice landraces selected by farmers over centuries. Our understanding of the adaptive features of these landraces to native ecosystems has improved considerably over the recent past. In some cases, major genes associated with tolerance have been cloned, such as SUB1A that confers tolerance of complete submergence and SNORKEL genes that control plant elongation to escape deepwater. Modern rice varieties are sensitive to flooding during germination and early growth, a problem commonly encountered in rainfed areas, but few landraces capable of germination under these conditions have recently been identified, enabling research into tolerance mechanisms. Major QTLs were also identified, and are being targeted for molecular breeding and for cloning. Nevertheless, limited progress have been made in identifying regulatory processes for traits that are unique to tolerant genotypes, including faster germination and coleoptile elongation, formation of roots and leaves under hypoxia, ability to catabolize starch into simple sugars for subsequent use in glycolysis and fermentative pathways to generate energy. Here we discuss the state of knowledge on the role of the PDC-ALDH-ACS bypass and the ALDH enzyme as the likely candidates effective in tolerant rice genotypes. Potential involvement of factors such as cytoplasmic pH regulation, phytohormones, reactive oxygen species scavenging and other metabolites is also discussed. Further characterization of contrasting genotypes would help in elucidating the genetic and biochemical regulatory and signaling mechanisms associated with tolerance. This could facilitate breeding rice varieties suitable for direct seeding systems and guide efforts for improving waterlogging

  19. Iron and zinc isotope fractionation during uptake and translocation in rice (Oryza sativa) grown in oxic and anoxic soils

    Science.gov (United States)

    Arnold, Tim; Markovic, Tamara; Kirk, Guy J. D.; Schönbächler, Maria; Rehkämper, Mark; Zhao, Fangjie J.; Weiss, Dominik J.

    2015-11-01

    Stable isotope fractionation is emerging quickly as a powerful novel technique to study metal uptake and translocation in plants. Fundamental to this development is a thorough understanding of the processes that lead to isotope fractionation under differing environmental conditions. In this study, we investigated Zn and Fe isotope fractionation in rice grown to maturity in anaerobic and aerobic soils under greenhouse conditions. The overall Zn isotope fractionation between the soil and above ground plant material was negligible in aerobic soil but significant in anaerobic soil with isotopically lighter Zn in the rice plant. The observed range of fractionation is in line with previously determined fractionations of Zn in rice grown in hydroponic solutions and submerged soils and emphasizes the effect of taking up different chemical forms of Zn, most likely free and organically complexed Zn. The Zn in the grain was isotopically lighter than in the rest of the above ground plant in rice grown in aerobic and anaerobic soils alike. This suggests that in the course of the grain loading and during the translocation within the plant important biochemical and/or biophysical processes occur. The isotope fractionation observed in the grains would be consistent with an unidirectional controlled transport from shoot to grain with a fractionation factor of α ≈ 0.9994. Iron isotopes showed an isotopic lighter signature in shoot and grain compared to the bulk soil or the leachate in aerobic and anaerobic soils alike. The negative direction of isotopic fractionation is consistent with possible changes in the redox state of Fe occurring during the uptake and translocation processes. The isotope fractionation pattern between shoots and grain material are different for Zn and Fe which finally suggests that different mechanisms operate during translocation and grain-loading in rice for these two key micronutrients.

  20. Influence of transplanting dates on heat-unit requirement of different phenological stages and subsequently yield and quality of scented rice (Oryza sativa) seed

    International Nuclear Information System (INIS)

    An experiment was conducted under field conditions during the rainy seasons of 2000 and 2001 at Kamal, to study the phenology, growing degree-days (GDD) and its subsequent effect on seed yield and quality of 'Pusa Basmati l' rice (Oryza sativa L.).The crop transplanted on 30 June took 109.5 calendar days and 3 125.9 growing degree-days from transplanting to maturity (total phenophases) which got reduced with delay in transplanting almost linearly. The calendar days and growing degree-days of vegetative and generative phase I and II were reduced by 7 to 9 days and 256.5, 393.5 and 427.6 growing degree-days, respectively, with delay in transplanting (4 August) compared to 30 June. However, the calendar days and growing degree-days required for physiological maturity were significantly increased in delayed transplanting (28 July and 4 August) during ripening phase. The plant traits, viz 1 ODD-seed weight, per cent germination, vigour I and vigour II, and seed yield showed a significant decline with delay in transplanting. Increasing the growing degree-days of any growth phase had differential effect on seed yield and electrical conductivity of seed. Adverse effects of late planting (28 July and 4 August) were reflected in lower yield and increased electrical conductivity values of ripening phase. Plantings made up to the middle of July were safe for higher seed yield and quality

  1. Production of oleic acid ethyl ester catalyzed by crude rice bran (Oryza sativa lipase in a modified fed-batch system: problem and its solution

    Directory of Open Access Journals (Sweden)

    Indro Prastowo

    2015-01-01

    Full Text Available A fed-batch system was modified for the enzymatic production of Oleic Acid Ethyl Ester (OAEE using rice bran (Oryza sativa lipase by retaining the substrate molar ratio (ethanol/oleic acid at 2.05: 1 during the reaction. It resulted in an increase in the ester conversion up to 76.8% in the first 6 h of the reaction, and then followed by a decrease from 76.8% to 22.9% in 6 h later. Meanwhile, the production of water in the reaction system also showed a similar trend to the trend of ester production. The water was hypothesized to lead lipase to reverse the reaction which resulted in a decrease in both (water and esters in the last 6 h of the reaction. In order to overcome the problem, zeolite powders (25 and 50 mg/ml were added into the reaction system at 5 h of the reaction. As the result, final ester conversions increased drastically up to 90 - 95.7% (1.17 – 1.24 times. The addition also proved a hypothesis that the water was involved in reducing the ester conversion in the last 6 h of the reaction. Thus, the combination was effective to produce the high final ester conversion.

  2. Application of Principal Component Analysis in Assessment of Relation Between the Parameters of Technological Quality of Wheat Grains Treated with Inert Dusts Against Rice Weevil (Sitophilus oryzae L.

    Directory of Open Access Journals (Sweden)

    Marija Bodroža-Solarov

    2011-01-01

    Full Text Available Quality parameters of several wheat grain lots (low vitreous and high vitreous grains,non-infested and infested with rice weevils, (Sitophilus oryzae L. treated with inert dusts(natural zeolite, two diatomaceous earths originating from Serbia and a commercial productProtect-It® were investigated. Principal component analysis (PCA was used to investigatethe classification of treated grain lots and to assess how attributes of technological qualitycontribute to this classification. This research showed that vitreousness (0.95 and test weight(0.93 contributed most to the first principal component whereas extensigraph area (-0.76contributed to the second component. The determined accountability of the total variabilityby the first component was around 55%, while with the second it was 18%, which meansthat those two dimensions together account for around 70% of total variability of the observedset of variables. Principal component analysis (PCA of data set was able to distinguishamong the various treatments of wheat lots. It was revealed that inert dust treatments producedifferent effects depending on the degree of endosperm vitreousness.

  3. A High Temperature-Dependent Mitochondrial Lipase EXTRA GLUME1 Promotes Floral Phenotypic Robustness against Temperature Fluctuation in Rice (Oryza sativa L.)

    Science.gov (United States)

    Zhang, Yu’e; Xu, Ting; Guo, Feifei; Tang, Huashan; Li, Xiang; Wang, Pengfei; Qian, Wenfeng; Xue, Yongbiao

    2016-01-01

    The sessile plants have evolved diverse intrinsic mechanisms to control their proper development under variable environments. In contrast to plastic vegetative development, reproductive traits like floral identity often show phenotypic robustness against environmental variations. However, it remains obscure about the molecular basis of this phenotypic robustness. In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness. Physiological and biochemical analyses showed that EG1 encodes a predominantly mitochondria-localized functional lipase and functions in a high temperature-dependent manner. Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness. Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control. PMID:27367609

  4. OsMADS6 plays an essential role in endosperm nutrient accumulation and is subject to epigenetic regulation in rice (Oryza sativa).

    Science.gov (United States)

    Zhang, Jian; Nallamilli, Babi R; Mujahid, Hana; Peng, Zhaohua

    2010-11-01

    MADS-box transcription factors are known for their roles in plant growth and development. The regulatory mechanisms of spatial and temporal specific expression of MADS-box genes and the function of MADS-box genes in other biological processes are still to be explored. Here, we report that OsMADS6 is highly expressed in flower and endosperm in Oryza sativa (rice). In addition to displaying a homeotic organ identity phenotype in all the four whorls of the flowers, the endosperm development is severely affected in its mutant. At least 32% of the seeds lacked starch filling and aborted. For seeds that have starch filling and develop to maturity, the starch content is reduced by at least 13%. In addition, the seed shape changes from elliptical to roundish, and the protein content increases from 12.1 to 15.0% (P < 0.05). Further investigation shows that ADP-glucose pyrophosphorylase genes, encoding the rate-limiting step enzyme in the starch synthesis pathway, are subject to the regulation of OsMADS6. Chromatin immunoprecipitation (ChIP)-PCR analyses on the chromatin of the OsMADS6 gene find that H3K27 is trimethylated in tissues where OsMADS6 is silenced, and that H3K36 is trimethylated in tissues where OsMADS6 is highly activated. Point mutation analysis reveals that leucine at position 83 is critical to OsMADS6 function. PMID:20822505

  5. N-glycan containing a core α1,3-fucose residue is required for basipetal auxin transport and gravitropic response in rice (Oryza sativa).

    Science.gov (United States)

    Harmoko, Rikno; Yoo, Jae Yong; Ko, Ki Seong; Ramasamy, Nirmal Kumar; Hwang, Bo Young; Lee, Eun Ji; Kim, Ho Soo; Lee, Kyung Jin; Oh, Doo-Byoung; Kim, Dool-Yi; Lee, Sanghun; Li, Yang; Lee, Sang Yeol; Lee, Kyun Oh

    2016-10-01

    In plants, α1,3-fucosyltransferase (FucT) catalyzes the transfer of fucose from GDP-fucose to asparagine-linked GlcNAc of the N-glycan core in the medial Golgi. To explore the physiological significance of this processing, we isolated two Oryza sativa (rice) mutants (fuct-1 and fuct-2) with loss of FucT function. Biochemical analyses of the N-glycan structure confirmed that α1,3-fucose is missing from the N-glycans of allelic fuct-1 and fuct-2. Compared with the wild-type cv Kitaake, fuct-1 displayed a larger tiller angle, shorter internode and panicle lengths, and decreased grain filling as well as an increase in chalky grains with abnormal shape. The mutant allele fuct-2 gave rise to similar developmental abnormalities, although they were milder than those of fuct-1. Restoration of a normal tiller angle in fuct-1 by complementation demonstrated that the phenotype is caused by the loss of FucT function. Both fuct-1 and fuct-2 plants exhibited reduced gravitropic responses. Expression of the genes involved in tiller and leaf angle control was also affected in the mutants. We demonstrate that reduced basipetal auxin transport and low auxin accumulation at the base of the shoot in fuct-1 account for both the reduced gravitropic response and the increased tiller angle. PMID:27241276

  6. Estimation of genetic divergence in rice (oryza sativa l) germplasms on the basis of paddy yield and rice stem borer's (pyralidae: lepidoptera) resistance

    International Nuclear Information System (INIS)

    Field trials were carried out to estimate resistance along with paddy yield in 55 rice germplasm lines (35 aromatic and 20 non-aromatic genotypes) for rice stem borers (Pyralidae: Lepidoptera) to expose their potential in pest management approach. The results expressed significant differences for pest damage build-up and paddy yield among the rice germplasm lines. The findings clearly portrayed that based upon the percentage of pest invasions (dead hearts and white heads damage), no genotype was exclusively resistant to stem borers damage under field conditions. Two aromatic genotypes, Jajai-15A/97 and Basmati-Cr-34, exhibited least borers prevalence and amplified paddy yield while Sonehri Sugdasi (P) and Sada Gulab (P) pointed out a peak pest invasion and declined paddy yield. The estimation of pest incidence build-up and paddy productivity within non-aromatic genotypes confirmed that IR8 (P), IR6-15-2 and IR6 (P) were mainly proficient for bearing condensed pest invasion and augmented paddy yield. IR8-2.5-4, IR6-15-10 and IR6-20-9 demonstrated elevated pest susceptibility and gave poor yield. Rest of the germplasms appeared to be least tolerant or vulnerable to pest build-up and reduced paddy production. The tolerant and high yielding genotypes should be popularised in rice borers endemic areas and can be used in varietals resistance breeding strategy. The outcome of current studies necessitates the integration of existing host plant tolerance along with other management strategies to accomplish a suitable control of rice stem borers and enhance paddy yield. (author)

  7. O-2 dynamics in the rhizosphere of young rice plants (Oryza sativa L.) as studied by planar optodes

    DEFF Research Database (Denmark)

    Larsen, Morten; Santner, Jakob; Oburger, Eva;

    2015-01-01

    Radial O-2 loss (ROL) strongly affect the O-2 availability in the rhizosphere of rice. The ROL create an oxic zone around the roots, protecting the plant from toxic reduced chemical species and regulates the redox chemistry in the soil. This study investigates the spatio-temporal variability in O-2...... dynamics in the rice rhizosphere. Applying high-resolution planar optode imaging, we investigated the O-2 dynamics of plants grown in water saturated soil, as a function of ambient O-2 level, irradiance and plant development, for submerged and emerged plants. O-2 leakage was heterogeneously distributed...... with zones of intense leakage around roots tips and young developing roots. While the majority of roots exhibited high ROL others remained surrounded by anoxic soil. ROL was affected by ambient O-2 levels around the plant, as well as irradiance, indicating a direct influence of photosynthetic activity on ROL...

  8. Multiple splicing types of OsRIX4, an RAD21 homolog in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    DONG HaiTao; LI DeBao; GUO XiaoQin; PEI YanXi; DAI ChengEn; FANG YongQi; TU QiChao; ZHUANG JieYun; ZHAO Dong; ZHENG KangLe

    2007-01-01

    The present paper describes multiple splicing types of OsRIX4, an RAD21 homolog in rice. A type of alternative splicing (AS), distinctive from all five previously known splicing types, was identified in which interior sequences of a constitutive exon could be spliced. Translation of the transcript produced with this AS type was demonstrated at the protein level. Expression of multiple transcripts was organ specific. The expression abundance of transcripts, OsRIX4-4 and OsRIX4-5, was positively correlated with fertility in rice. The splicing type identified in the present study provided the means to further understand and define different mRNA splicing types in plants and suggested that post-transcription processing of mRNA and its regulation mechanism are complex.

  9. Identification of salt-stress responsive genes in rice (Oryza sativa L.) by cDNA array

    Institute of Scientific and Technical Information of China (English)

    何新建; 陈建权; 张志刚; 张劲松; 陈受宜

    2002-01-01

    To identify salt stress-responsive genes, we constructed a cDNA library with the salt-tolerant rice cultivar, Lansheng. About 15000 plasmids were extracted and dotted on filters with Biomeck 2000 HDRT system or by hand. Thirty genes were identified to display altered expression levels responding to 150 mmol/L NaCl. Among them eighteen genes were up-regulated and the remainders down-regulated. Twenty-seven genes have their homologous genes in GenBank Databases. The expression of twelve genes was studied by Northern analysis. Based on the functions, these genes can be classified into five categories, including photosynthesis-related gene, transport-related gene, metabolism-related gene, stress- or resistance-related gene and the others with various functions. The results showed that salt stress influenced many aspects of rice growth. Some of these genes may play important roles in plant salt tolerance.

  10. Effects of Nitrogen and Cycocel Application on Soil Nitrate Pollution and Agronomic Characters of Rice (Oryza sativa L.)

    OpenAIRE

    Rezvani, M; M. Shafiezadeh

    2015-01-01

    Nowadays, due to the effective role of nitrogen fertilizer in growth, yield and crop quality, farmers apply large amount of chemical fertilizers. High application of nitrogen fertilizers has caused soil and water pollution and environmental dangers, higher nitrate accumulation in plant, and different disease risks in human and livestock. In order to investigate the effects of nitrogen and cycocel application effects on soil nitrate pollution and agronomic traits of rice, an experiment was arr...

  11. Differential gene expression in an elite hybrid rice cultivar (Oryza sativa, L and its parental lines based on SAGE data

    Directory of Open Access Journals (Sweden)

    Chen Chen

    2007-09-01

    Full Text Available Abstract Background It was proposed that differentially-expressed genes, aside from genetic variations affecting protein processing and functioning, between hybrid and its parents provide essential candidates for studying heterosis or hybrid vigor. Based our serial analysis of gene expression (SAGE data from an elite Chinese super-hybrid rice (LYP9 and its parental cultivars (93-11 and PA64s in three major tissue types (leaves, roots and panicles at different developmental stages, we analyzed the transcriptome and looked for candidate genes related to rice heterosis. Results By using an improved strategy of tag-to-gene mapping and two recently annotated genome assemblies (93-11 and PA64s, we identified 10,268 additional high-quality tags, reaching a grand total of 20,595 together with our previous result. We further detected 8.5% and 5.9% physically-mapped genes that are differentially-expressed among the triad (in at least one of the three stages with P-values less than 0.05 and 0.01, respectively. These genes distributed in 12 major gene expression patterns; among them, 406 up-regulated and 469 down-regulated genes (P Conclusion We improved tag-to-gene mapping strategy by combining information from transcript sequences and rice genome annotation, and obtained a more comprehensive view on genes that related to rice heterosis. The candidates for heterosis-related genes among different genotypes provided new avenue for exploring the molecular mechanism underlying heterosis.

  12. Preformed expression of defense is a hallmark of partial resistance to rice blast fungal pathogen Magnaporthe oryzae

    OpenAIRE

    Tharreau D; Saindrenan P; Chalvon Véronique; Ballini Elsa; Grand Xavier; Vergne Emilie; Nottéghem J-L; Morel J-B

    2010-01-01

    Abstract Background Partial resistance to plant pathogens is extensively used in breeding programs since it could contribute to resistance durability. Partial resistance often builds up during plant development and confers quantitative and usually broad-spectrum resistance. However, very little is known on the mechanisms underlying partial resistance. Partial resistance is often explained by poorly effective induction of plant defense systems. By exploring rice natural diversity, we asked whe...

  13. Comparative transcriptional profiling under drought stress between upland and lowland rice (Oryza sativa L.) using cDNA-AFLP

    Institute of Scientific and Technical Information of China (English)

    GAO FengHua; ZHANG HongLiang; WANG HaiGuang; GAO Hong; LI ZiChao

    2009-01-01

    The continuous growth of lowland rice (LR) in paddy fields supplied with enough water over the years, and of upland rice (UR) in naturally rain-fed soils, has resulted in greater resistance to drought stress in UR compared to LR. To elucidate their differential regulation mechanisms of drought-resistance, genome-wide transcript regulation under drought stress in UR and LR was investigated using cDNA-AFLP. The results indicated that over 90% of gene expression was not affected by drought stress in the two rice genotypes, more than 8% was regulated by drought stress in both, and less than 1% was specifically expressed in UR or LR. Fifty-seven genes were specifically expressed in UR and thirty-eight specifically in LR. Genes specifically expressed in UR included cell rescue and defence genes functioning in drought-resistance, signal transduction molecules, nucleotides and amino acid biosynthesis genes required for plant growth, and the regulatory genes for growth and development. In LR, genes specifically expressed were related to protein and nucleotide degradation. Some genes were upregulated earlier in UR, and downregulated genes were inclined to be downregulated earlier in UR compared to LR, implying that more rapid regulation mechanisms caused earlier responses of UR to drought stress. Expression levels of upregulated genes in UR were higher than those in LR. The differences in gene expression between UR and LR could account for stronger regulation ability, more drought-resistance and superior growth of UR under drought stress compared to LR.

  14. Identification of quantitative trait loci for four morphologic traits under water stress in rice(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Late season drought coinciding with the rice booting to heading stage affects the development of plant height,panicle exsertion,and flag leaf size,and causes significant yield loss.In this study,a recombinant inbred line population derived from a cross between paddy and upland cultivars was used for data collection of the morphologic traits under well water and drought stress conditions.bought stress was applied at the stage of panicle initiation in the field in 2002 and at the booting stage in PVC pipes in 2003.The data from stress con ditions and their ratios(tait measured under stress condition/trait measured under well water condition)or differences(trait measured under stress condition minus trait measured under well water condition)were used for OTL analysis.Totally,17 and 36 QTLs for these traits were identified in 2002 and 2003,respectively,which explained a range of 2.58%-29.82%Of the phenotypic variation.Among them,six QTLs were commonly identified in the two years,suggesting that the drought stress in the two years was different.The genetic basis of these traits will provide useful information for improving rice late season drought resistance,and their application as indirect indices in rice late season drought resistance screening was also discussed.

  15. Assessment of Relationship Between Bacterial Stripe Resistance And Leaf Protein Bands In Rice (Oryza sativa L.) Varieties.

    Science.gov (United States)

    Talei, D.; Fotokian, M. H.

    2008-01-01

    Bacterial stripe as a new rice disease in Iran is more frequent nowadays. The objective of this study was to assessment of resistance in rice varieties together with evaluating of zymogram bands resulted from SDS PAGE electrophoresis of leaf proteins. For this purpose, 30 lines were tested in a randomized complete block design with three replications. The analysis of variance showed that there was significant difference between genotypes for resistance. Mean compare based on field results revealed that Domsiyah had the lowest resistance while Nemat and 7162 demonstrated the highest resistance. Laboratory results showed that there were significant difference between protein bands resulted from sensitive and resistance verities. Twenty bands were observed through SDS PAGE electrophoresis of leaf proteins. The 9th and 12th bands were found in sensitive varieties while were not in resistance genotypes. According to the results of this study, 7162 variety can be considered as the sources of resistance in breeding programs. Meanwhile attending to existence of 9th and 12th bands in sensitive varieties, resistance against bacterial stripe of rice maybe influenced by absence of these proteins.

  16. Selection efficiencies for improving drought/salt tolerances and yield using introgression breeding in rice(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Ying; Wang; Lubiao; Zhang; Afif; Nafisah; Linghua; Zhu; Jianlong; Xu; Zhikang; Li

    2013-01-01

    The backcross(BC) breeding strategy has been increasingly used for developing high yielding varieties with improved abiotic stress tolerances in rice. In this study, 189Huang-Hua-Zhan(HHZ) introgression lines(ILs) developed from three different selection schemes were evaluated for yield related traits under drought stress and non-stress conditions in the target and off-season winter nursery environments to assess the selection efficiency of BC breeding for improving different complex traits, and led us to five important results. The first result indicated that the primary target traits should be selected first in the target environments(TEs) in order to achieve the maximum genetic gain. Secondly, BC breeding for drought tolerance(DT) in rice was almost equally effective by strong phenotypic selection in the main target environments and in the winter-season of Hainan.Thirdly, exploiting genetic diversity in the subspecific gene pools is of great importance for future genetic improvement of complex traits in rice. Fourthly, considerable genetic gain can be effectively achieved by selection for secondary target traits among the ILs with the primary traits. Finally, the developed ILs provide useful materials for future genetic/genomic dissection and molecular breeding of complex traits.

  17. EFEITO DO TRATAMENTO QUÍMICO DE SEMENTES NO CONTROLE DE BRUSONE (Pyricularia oryzae) E MANCHA PARDA (Helminthosporium oryzae) DO ARROZ EFFECT OF CHEMICAL SEED TREATMENT IN THE CONTROL OF BLAST DISEASE AND BROWN SPOT OF RICE

    OpenAIRE

    Wilson Ferreira de Oliveira; Valácia Lemes da Silva; Meire Aparecida Damaceno

    2007-01-01

    Com o objetivo de controlar brusone (Pyricularia oryzae) e mancha parda (Helminthosporium oryzae) do arroz (Oryza sativa), diferentes fungicidas foram testados, através do tratamento de sementes, a nível de campo em solo de várzea (glei pouco húmico). Os resultados mostraram, preliminarmente e de modo geral, que os fungicidas dichlofluanid e terbuconazole propiciaram aumento no “stand” superiores a 30% quando compar...

  18. QTL analysis of novel genomic regions associated with yield and yield related traits in new plant type based recombinant inbred lines of rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Marathi Balram

    2012-08-01

    Full Text Available Abstract Background Rice is staple food for more than half of the world’s population including two billion Asians, who obtain 60-70% of their energy intake from rice and its derivatives. To meet the growing demand from human population, rice varieties with higher yield potential and greater yield stability need to be developed. The favourable alleles for yield and yield contributing traits are distributed among two subspecies i.e., indica and japonica of cultivated rice (Oryza sativa L.. Identification of novel favourable alleles in indica/japonica will pave way to marker-assisted mobilization of these alleles in to a genetic background to break genetic barriers to yield. Results A new plant type (NPT based mapping population of 310 recombinant inbred lines (RILs was used to map novel genomic regions and QTL hotspots influencing yield and eleven yield component traits. We identified major quantitative trait loci (QTLs for days to 50% flowering (R2 = 25%, LOD = 14.3, panicles per plant (R2 = 19%, LOD = 9.74, flag leaf length (R2 = 22%, LOD = 3.05, flag leaf width (R2 = 53%, LOD = 46.5, spikelets per panicle (R2 = 16%, LOD = 13.8, filled grains per panicle (R2 = 22%, LOD = 15.3, percent spikelet sterility (R2 = 18%, LOD = 14.24, thousand grain weight (R2 = 25%, LOD = 12.9 and spikelet setting density (R2 = 23%, LOD = 15 expressing over two or more locations by using composite interval mapping. The phenotypic variation (R2 ranged from 8 to 53% for eleven QTLs expressing across all three locations. 19 novel QTLs were contributed by the NPT parent, Pusa1266. 15 QTL hotpots on eight chromosomes were identified for the correlated traits. Six epistatic QTLs effecting five traits at two locations were identified. A marker interval (RM3276-RM5709 on chromosome 4 harboring major QTLs for four traits was identified. Conclusions The present study reveals that favourable alleles for

  19. Endophytic colonization of rice (Oryza sativa L. by the diazotrophic bacterium Burkholderia kururiensis and its ability to enhance plant growth

    Directory of Open Access Journals (Sweden)

    Katherine A. Mattos

    2008-09-01

    Full Text Available Burkholderia kururiensis is a diazotrophic bacterium originally isolated from a polluted aquifer environment and presents a high level of similarity with the rice endophyte "B. brasilensis" species. This work assessed the ability of B. kururiensis to endophytically colonize rice plantlets by monitoring different tissues of root-inoculated plants for the presence of bacterial growth in different media, electron microscopy and by 16S rDNA analysis. Observations of roots, stems and leaves of inoculated rice plantlets by electron microscopy revealed B. kururiensis colonization predominantly on root hair zones, demonstrating endophytic colonization primarily through the endodermis, followed by spreading into xylem vessels, a possible pathway leading to aerial parts. Although indifferent for the bacterial growth itself, addition of a nitrogen source was a limiting factor for endophytic colonization. As endophytic colonization was directly associated to an enhanced plant development, production of phytohormone auxin/indole-3-acetic acid by B. kururiensis was assayed with transgenic rice plantlets containing an auxin-responsive reporter (DR5-GUS. Our findings suggest the ability of auxin production by plant-associated B. kururiensis which may have a stimulatory effect on plant development, as evidenced by activation of DR5-GUS. We hereby demonstrate, for the first time, the ability of B. kururiensis to endophytically colonize rice, promoting both plant growth and rice grain yield.Burkholderia kururiensis é uma bactéria diazotrófica, originalmente isolada de um ambiente aquático poluído e apresenta alto nível de similaridade com a espécie endofítica "B. brasilensis" encontrada na planta de arroz. Este artigo demonstrou a habilidade de B. kururiensis colonizar endofiticamente plântulas de arroz, após esta bactéria ter sido inoculada na raiz das plantas. Esta capacidade foi confirmada pelo crescimento bacteriano em diferentes tecidos da planta

  20. Recurrent parent genome recovery analysis in a marker-assisted backcrossing program of rice (Oryza sativa L.).

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

    2015-02-01

    Backcross breeding is the most commonly used method for incorporating a blast resistance gene into a rice cultivar. Linkage between the resistance gene and undesirable units can persist for many generations of backcrossing. Marker-assisted backcrossing (MABC) along with marker-assisted selection (MAS) contributes immensely to overcome the main limitation of the conventional breeding and accelerates recurrent parent genome (RPG) recovery. The MABC approach was employed to incorporate (a) blast resistance gene(s) from the donor parent Pongsu Seribu 1, the blast-resistant local variety in Malaysia, into the genetic background of MR219, a popular high-yielding rice variety that is blast susceptible, to develop a blast-resistant MR219 improved variety. In this perspective, the recurrent parent genome recovery was analyzed in early generations of backcrossing using simple sequence repeat (SSR) markers. Out of 375 SSR markers, 70 markers were found polymorphic between the parents, and these markers were used to evaluate the plants in subsequent generations. Background analysis revealed that the extent of RPG recovery ranged from 75.40% to 91.3% and from 80.40% to 96.70% in BC1F1 and BC2F1 generations, respectively. In this study, the recurrent parent genome content in the selected BC2F2 lines ranged from 92.7% to 97.7%. The average proportion of the recurrent parent in the selected improved line was 95.98%. MAS allowed identification of the plants that are more similar to the recurrent parent for the loci evaluated in backcross generations. The application of MAS with the MABC breeding program accelerated the recovery of the RP genome, reducing the number of generations and the time for incorporating resistance against rice blast. PMID:25553855

  1. Physiological and mutagenic effects of sodium azide alone and in combination with gamma-rays on rice (Oryza sativa l.)

    International Nuclear Information System (INIS)

    Physiological and mutagenic effects of sodium azide alone and in combination with gamma-rays were studied in rice under laboratory and field conditions. The physiological damage and mutagenic effect of M2 were investigated. The results are as follows: 1. Sodium azide could induce physiological damage in M1 generation and mutations of chlorophyll, plant height and heading date in M2 generation. The damage and mutation frequencies increased with increasing concentrations of sodium azide. 2. Physiological and mutagenic effects were found to be pH dependent. In comparison with treatments at pH 7.0, sodium azide caused more M1 damage and induced more mutation in M2 at pH 3.0. 3. Sensitivity of rice to sodium azide increased after presoaking treatments. 24h-presoaking, howoever, could alleviate injury by sodium azide at pH 3.0. 4. Treatments of gamma-rays together with sodium azide resulted in increased M1 damage and M2 mutation frequencies, and the combinative effect was more conspicuous when azide was used at pH 3.0. An expanded mutation spectrum was also observed in the combined treatments. 5. Number of the initial cells in the embryo of main panicles was estimated to be 2—3, according to the segregation ratio of chlorophyll mutants in M2. The combined treatments of gamma-rays(15—30kR)together with so- dium azide(0.5—1mM)at pH 3.0 were recommended for rice mutation breeding programm. (author)

  2. Assessment of genetic diversity in Indian rice germplasm (Oryza sativa L.): use of random versus trait-linked microsatellite markers

    Indian Academy of Sciences (India)

    Sheel Yadav; Ashutosh Singh; M. R. Singh; Nitika Goel; K. K. Vinod; T. Mohapatra; A. K. Singh

    2013-12-01

    Assessment of genetic diversity in a crop germplasm is a vital part of plant breeding. DNA markers such as microsatellite or simple sequence repeat markers have been widely used to estimate the genetic diversity in rice. The present study was carried out to decipher the pattern of genetic diversity in terms of both phenotypic and genotypic variability, and to assess the efficiency of random vis-à-vis QTL linked/gene based simple sequence repeat markers in diversity estimation. A set of 88 rice accessions that included landraces, farmer’s varieties and popular Basmati lines were evaluated for agronomic traits and molecular diversity. The random set of SSR markers included 50 diversity panel markers developed under IRRI’s Generation Challenge Programme (GCP) and the trait-linked/gene based markers comprised of 50 SSR markers reportedly linked to yield and related components. For agronomic traits, significant variability was observed, ranging between the maximum for grains/panicle and the minimum for panicle length. The molecular diversity based grouping indicated that varieties from a common centre were genetically similar, with few exceptions. The trait-linked markers gave an average genetic dissimilarity of 0.45 as against that of 0.37 by random markers, along with an average polymorphic information constant value of 0.48 and 0.41 respectively. The correlation between the kinship matrix generated by trait-linked markers and the phenotype based distance matrix (0.29) was higher than that of random markers (0.19). This establishes the robustness of trait-linked markers over random markers in estimating genetic diversity of rice germplasm.

  3. Evaluation of the effects of ozone on yield of Japanese rice (Oryza sativa L.) based on stomatal ozone uptake

    International Nuclear Information System (INIS)

    To evaluate the negative impact of ozone (O3) on Japanese crop plant yield based on cumulative stomatal O3 flux, a Japanese rice cultivar, Koshihikari, was exposed to O3 in O3-exposure chambers. Stomatal diffusive conductance to water vapour were measured during the experimental period. We parameterized and improved a stomatal diffusive conductance model by considering seasonal changes in stomatal diffusive conductance, as well as the acute effects of O3 on this variable. Our adjusted model accounted for 64% of the variation within the data set. Based on the results of linear regression analyses of the relationship between relative yield and cumulative O3 uptake, the negative impact of O3 on the yield of Koshihikari can be evaluated using cumulative O3 uptake with a threshold of 10 nmol O3 m−2 projected leaf area s−1 and an integration period of −300 to 100 °C days from anthesis. -- Highlights: • Stomatal conductance model for Japanese rice was parameterized and improved. • The model accounted for 64% of variation within measured stomatal conductance. • The O3-induced reduction in yield was evaluated using cumulative stomatal O3 uptake. • Flux threshold of 10 nmol O3 m−2 s−1 (POD10) was adequate for the evaluation. • POD10 from −300 to 100 °C days from anthesis was important for O3 effect on yield. -- The negative impact of O3 on yield of Japanese rice can be evaluated by cumulative stomatal O3 uptake

  4. Strategies on Sample Size Determination and Qualitative and Quantitative Traits Integration to Construct Core Collection of Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-ling; LU Yong-gen; LI Jin-quan; Xu Hai-ming; Muhammad Qasim SHAHID

    2011-01-01

    The development of a core collection could enhance the utilization of germplasm collections in crop improvement programs and simplify their management.Selection of an appropriate sampling strategy is an important prerequisite to construct a core collection with appropriate size in order to adequately represent the genetic spectrum and maximally capture the genetic diversity in available crop collections.The present study was initiated to construct nested core collections to determine the appropriate sample size to represent the genetic diversity of rice landrace collection based on 15 quantitative traits and 34 qualitative traits of 2 262 rice accessions.The results showed that 50-225 nested core collections,whose sampling rate was 2.2%-9.9%,were sufficient to maintain the maximum genetic diversity of the initial collections.Of these,150 accessions (6.6%) could capture the maximal genetic diversity of the initial collection.Three data types,i.e.qualitative traits (QT1),quantitative traits (QT2) and integrated qualitative and quantitative traits (QTT),were compared for their efficiency in constructing core collections based on the weighted pair-group average method combined with stepwise clustering and preferred sampling on adjusted Euclidean distances.Every combining scheme constructed eight rice core collections (225,200,175,150,125,100,75 and 50).The results showed that the QTT data was the best in constructing a core collection as indicated by the genetic diversity of core collections.A core collection constructed only on the information of QT1 could not represent the initial collection effectively.QTT should be used together to construct a productive core collection.

  5. Role of silicon in alleviation of iron deficiency and toxicity in hydroponically-grown rice (Oryza sativa L. plants

    Directory of Open Access Journals (Sweden)

    A Abdol Zadeh

    2013-03-01

    Full Text Available Silicon (Si nutrition may alleviate biotic and abiotic stresses including heavy metal deficiency and toxicity in plants. Iron deficiency and toxicity are important limiting factors in growth of rice. In the present study, role of Si nutrition on alleviation of iron deficiency and toxicity was investigated in rice plants. Plants were cultivated in greenhouse in hydroponics, using Yoshida solution, under different iron treatments (0, 2, 10, 20, 50, 100 and 250 mg/L as Fe- EDTA and Si nutrition (0 and 1.5 mM as sodium silicate. Results revealed that both iron deficiency and toxicity imposed significant reduction in fresh and dry weight and length of plants. The activity of catalase was decreased in shoots due to iron deficiency. Activity of catalase in roots and cell wall peroxidase in shoots increased under iron toxicity compared with control plants. Si nutrition increased Si content in plants and improved plant growth in both iron deficiency (not in the absence of iron and toxicity. Application of Si increased the activity of catalase in shoots and polyphenol oxidase in both roots and shoots under iron deficiency. Also, the activity of catalase in roots and polyphenol oxidase in shoots raised following iron toxicity. This in turn may reduce the oxidative stress in plants. In addition, increase of lignin in extreme iron toxicity due to Si nutrition may enhance sites of iron absorption in plant cell walls and decrease iron toxicity. The results indicated that Si nutrition could ameliorate harmful effects of iron deficiency and toxicity in rice plants possibly through improvement of antioxidant enzyme activity and reduction of oxidative stress.

  6. Allelopathy of weed extracts on yield and its components in four cultivars of rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Ali MOHADESI

    2011-07-01

    Full Text Available Weeds are enemies to the crop plants and have harmful effects on agricultural crops due to several factors such as competition for space, light and nutrients. Allelopathic effects of weed extracts were studied on grain yield and yield components of rice. The experiment was carried out in the Rice Research Institute of Chaparsar, in 2006- 2007, in Tonekabon, Iran (latitude 36°54’ N, longitude 50° 40’E, level -20 m altitude, split plot on basis of randomized completely block design (RCBD with 4 replications. Results showed highly significant differences suggesting substantial to moderate phenotypic variability in most parameters evaluated except number of empty grain and 1000 -grain weight. Also, most yield of single plant obtained from umbrella sedge extract (28.5 g. It seems that umbrella sedge had least minerals in water; it could be affected positively on important factors such as yield of single plant compared to other treatments. Correlation coefficient analysis revealed significant and negative correlation between number of empty grain and yield of single plant (r=-0.42***. It’s implies that grain yield magnitude of Nemat cultivar exhibiting the least number of empty grain. Although yield of single plant was not affected neither by plant height nor number of tiller. In addition, irrigation water due to existence of high mineral and chemical pesticides in upstream of station farms severely was reduced yield. Also, results of this research showed that weed extracts haven’t very allelopathic effect on rice and in end of growing season, that’s better, plant leftover return and remain in field.

  7. Comparison of physiological responses to oxidative and .heavymetal stress in seedlings of rice paddy, Oryza sativa L.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Physiological responses on the bases of activities of antioxidant enzymes: peroxidase, catalase, superoxide dismutase and glutathione reductase as well as estimation of total protein, lipid peroxidation and thiols in the form of iprotein, non-protein, glutathione and phytochelatin measured in growing seedlings of paddy, Oryza sativa L. , from day 2 to 8 were compared following treatment of seeds for 5h with oxidative agents, paraquat 5 × 10-5, 10-4, 10-3 mol/L, H2O2 10-3, 5 × 10-3, 10-2 mol/L, and CdCl2 10- 5, 10- 4, 5 × 10- 3 mol/L. A significant induction of all antioxidant enzymes along with an increase in the levels of protein, lipid peroxidation and glutathione was noted in response to oxidative stress, C dCl2 induced significant peroxidase and catalase activities but not superoxide dismutase. In a marked contrast from oxidative stress, CdCl2 decreased glutathione reductase activity as well as glutathione levels but increased phytochelatin level. The different physiological responses thus underlined the crucial involvement of glutathione and phytochelatin in the oxidative and heavy metal-linduced adaptive responses respectively.

  8. CURRENT STATUS AND POTENTIAL OF BIOTECHNOLOGICAL APPROACHES FOR RICE BLAST DISEASE IN THE RICE CULTIVATION TECHNOLOGY

    OpenAIRE

    Petenko A. I.; Volkova S. A.

    2014-01-01

    Rice blast caused by Pyricularia oryzae is a major disease affecting rice production grown in upland and wetland rice. Application of biotechnological approach to protect against the disease may be an alternative strategy to chemical control

  9. Association of Duration and Rate of Grain Filling with Grain Yield in Temperate Japonica Rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate

  10. PERFORMANCE OF TRANSPLANTED SCENTED RICE (ORYZA SATIVA L.) UNDER SRI BASED CULTIVATION PRACTICES; A SUSTAINABLE METHOD FOR CROP PRODUCTION

    OpenAIRE

    DAMINI THAWAIT; Patel, Amit K.; SAMAPTIKA KAR; MANISH KUMAR SHARMA; MAYUR R. MESHRAM

    2014-01-01

    The experiment was carried out at Raipur during season of 2012 to find out the performance of transplanted scented rice under different planting geometries and seedling densities. The treatment (T2 ) i.e. planting of 2-3 seedlings hill-1 transplanted in the spacing of 25 cm x 25 cm recorded significantly highest i.e. Plant height (129.64cm), number of tillers (15.70 tillers hill-1), dry matter accumulation (102.65 g hill-1) and yield attributing characters along with highest gr...

  11. Analysis of SSLP and Soluble Protein Contents in Leaves of Mutants Induced by High Pressure in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    HE Xiu-ying; XU Shi-ping; LIAO Yao-ping; MAO Xing-xue; WENG Ke-nan; CHEN Zhao-ming; CHEN Yue-han; XIAO Wan-sheng

    2004-01-01

    Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatellite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants,and the contents were significantly lower than those of the original variety.

  12. Root-induced changes to cadmium speciation in the rhizosphere of two rice (Oryza sativa L.) genotypes

    International Nuclear Information System (INIS)

    Our aim was to investigate rhizosphere effects on the chemical behavior of Cd. This was done in a glasshouse experiment, where two rice cultivars (Zhenong54 and Sixizhan) were grown in soil spiked with cadmium (Cd) at two levels, 3.9±0.5 and 8.3±0.5 mg kg-1 soil, placed in a rhizobox until ripening stage. Chemical forms of cadmium near the root surface were then assessed using a sequential extraction procedure (SEP). There were significant differences in Cd species, especially exchangeable Cd (EXC-Cd) between the two rice cultivars as affected by rice roots. The lowest EXC-Cd with Zhenong54 appeared in the near-rhizosphere area with little difference between tillering stage and ripening stage while Sixizhan had its lowest EXC-Cd concentration in the root compartment. Both cultivars had slight changes in the Fe/Mn oxide-bound fraction of Cd (FMO-Cd) at the grain ripening stage while the control treatments without plants had a significant increase in FMO-Cd at the same time, indicating a transformation from a less bioavailable form (FMO-Cd) to more bioavailable forms (EXC-Cd). Soil microbial biomass in the vicinity of the root surface had opposite trends to some extent with EXC-Cd, partly because of the root-induced changes to bioavailable Cd. Unlike Zhenong54, Sixizhan had a higher Cd concentration in the root, but only a small proportion of Cd translocated from the root to grain. - Research highlights: →We investigated genotypic effects on Cd speciation in the rhizosphere of rice. →Zhenong54 (ZN) and Sixizhan (SX) were grown in rhizobox to show root-induced changes. →Lowest exchangeable-Cd of ZN was in near-rhizosphere while SX in root compartment. →Soil microbial biomass had opposite trends with exchangeable-Cd in both cultivars. →Unlike ZN, SX had higher Cd content in roots, but lower Cd content in shoots.

  13. Genetic expression and effects of the rolled leaf gene Rl(t)in hybrid rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We constructed a near isogenic line of rolled leaf gene Rl(t), which expressed incompletely dominance for the character of rolled leaf(RL), with genetic background of Zhenshan 97B. Using RL Zhenshan 97B and the original Zhenshan 97B as the female parents,and Minghui 63 and Yanhui 559 as the male parents, crosses of RL Shanyou 63 (RS63) and Shanyou 63(S63), RL Shanyou 559 ( RS559) and Shanyou 559 (S559) were made. Inheritance and effects of Rl(t) in hybrid rice were studied at the flowering and at the 20 d after flowering, respectively. Results were as follows:

  14. Cupincin: A Unique Protease Purified from Rice (Oryza sativa L.) Bran Is a New Member of the Cupin Superfamily

    OpenAIRE

    Sreedhar, Roopesh; Kaul Tiku, Purnima

    2016-01-01

    Cupin superfamily is one of the most diverse super families. This study reports the purification and characterization of a novel cupin domain containing protease from rice bran for the first time. Hypothetical protein OsI_13867 was identified and named as cupincin. Cupincin was purified to 4.4 folds with a recovery of 4.9%. Cupincin had an optimum pH and temperature of pH 4.0 and 60°C respectively. Cupincin was found to be a homotrimer, consisting of three distinct subunits with apparent mole...

  15. Proteomic Identification of OsCYP2, a Rice Cyclophilin That Is Involved in Rice (Oryza sativa L.) Seedlings in Response to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    Songlin Ruan; Huasheng Ma; Shiheng Wang; Yaping Fu; Ya Xin; Wenzhen Liu; Fang Wang

    2012-01-01

    High Salinity is a major environmental stress influencing growth and development of rice.Comparative proteomic analysis of hybrid rice shoot proteins from Shanyou 10 seedlings,a salt-tolerant hybrid variety,and Liangyoupeijiu seedlings,a salt-sensitive hybrid variety,was performed to identify new components involved in salt-stress signaling.Phenotypic analysis of one protein that was upregulated during salt-induced stress,cyclophilin 2 (OsCYP2),indicated that OsCYP2 transgenic rice seedlings had better tolerance to salt stress than did wild-type seedlings.Interestingly,wild-type seedlings exhibited a marked reduction in maximal photochemical efficiency under salt stress,whereas no such change was observed for OsCYP2-transgenic seedlings.OsCYP2-transgenic seedlings had lower levels of lipid peroxidation products and higher activities of antioxidant enzymes than wild-type seedlings.Spatiotemporal expression analysis of OsCYP2 showed that it could be induced by salt stress in both Shanyou 10 and Liangyoupeijiu seedlings,but Shanyou 10 seedlings showed higher OsCYP2 expression levels.Moreover,circadian rhythm expression of OsCYP2 in Shanyou 10 seedlings occurred earlier than in Liangyoupeijiu seedlings.Treatment with PEG,heat,or ABA induced OsCYP2 expression in Shanyou 10 seedlings but inhibited its expression in Liangyoupeijiu seedlings.Cold stress inhibited OsCYP2 expression in Shanyou 10 and Liangyoupeijiu seedlings.In addition,OsCYP2 was strongly expressed in shoots but rarely in roots in two rice hybrid varieties.Together,these data suggest that OsCYP2 may act as a key regulator that controls ROS level by modulating activities of antioxidant enzymes at translation level.OsCYP2 expression is not only induced by salt stress,but also regulated by circadian rhythm.Moreover,OsCYP2 is also likely to act as a key component that is involved in signal pathways of other types of stresses-PEG,heat,cold,or ABA.

  16. Detection of epitasis, additive and dominance variation in rice (Oryza sativa L. using triple test cross analysis

    Directory of Open Access Journals (Sweden)

    N.R. Koli, Chandra Prakash, R.K. Mahawar ,B.L.Kumhar and S.S.Punia

    2014-12-01

    Full Text Available An investigation was carried out to detect the epistasis, additive and dominance components of genetic variance for yield and yield attributing traits through triple test cross analysis, involving three testers (P1, P2 and their F1 and ten lines of rice. The estimate of total epistasis was found non-significant for all the traits while partitioning of total epistasis revealed that, i type of epistasis (additive x additive were highly significant for yield per plant, plant height, number of panicle per meter square, panicle length and number of grains per panicle. The additive (D and dominance (H effects were highly significant for yield per plant, plant height, panicle length, number of grains per panicle and 1000 grain weight. The degree of dominance (H/D1/2 was less than the unity indicating, partial dominance for plant height, panicles / m2 and 1000 grain weight whereas, yield per plant, panicle length and number of grains per panicle indicating over dominance (>1 . Since, the predominance components of epistasis in autogamous crop is additive x additive (i type, we suggest that the selection may be delayed to later generation for the improvement of yield through yield components in rice.

  17. [Analysis of gene loci and epistasis for drought tolerance in seedling stage of rice (Oryza sativa L.)].

    Science.gov (United States)

    Teng, Sheng; Qian, Qian; Zeng, Da-Li; Kunihiro, Yasufumi; Fujimoto, Kan; Huang, Da-Nian; Zhu, Li-Huang

    2002-01-01

    Drought tolerance of rice is important because a considerable proportion of the world rice area is not irrigated and is prone to water deficit. In this study, an indica variety, Zhai Ye Qing 8 (ZYQ8), and a japonica variety, Jing Xi 17 (JX17), and their double haploid (DH) population were used for genetic study of drought tolerance. Water supply was stopped in seedling period for 15 days and then drought tolerance of the DH population and their parents were investigated. Mapping quantitative trait loci (QTLs) was undertaken base on the constructed molecular linkage map of this population. Two QTLs (qDR-5 and qDR-12) for drought tolerance were identified, they were in the region of GA41-GA257 on chromosome 5 and RG457-Y12817R on chromosome 12, respectively. The tolerance alleles of both QTLs were from the indica parent, ZYQ8. In the meantime two genes for drought tolerance near GA257 and Y12817R were detected too by using Epistat software, that is in accordance with the result by using Mapmaker/QTL. In addition, three loci (RG541, G318 and G192 on chromosome 1, 4 and 8, respectively) were found interacting with GA257 by Epistat software, while one locus (CT234 on chromosome 3) found interacting with Y12817R were also detected by Epistat software. PMID:12182078

  18. Mapping quantitative trait loci associated with yield and yield components under reproductive stage salinity stress in rice (Oryza sativa L.)

    Indian Academy of Sciences (India)

    Reza Mohammadi; Merlyn S. Mendioro; Genaleen Q. Diaz; Glenn B. Gregorio; Rakesh K. Singh

    2013-12-01

    Salinity tolerance in rice is critical at reproductive stage because it ultimately determines grain yield. An F2 mapping population derived from a Sadri/FL478 cross was exposed to saline field conditions (6–8 dS m-1) after the active tillering stage to identify reproductive stage specific QTLs for salinity tolerance. Genetic linkage map was constructed using 123 microsatellite markers on 232 F2 progenies. Totally 35 QTLs for 11 traits under salinity stress were detected with LOD >3, out of which 28 QTLs that explained from 5.9 to 30.0% phenotypic variation were found to be significant based on permutation test. Three major QTL clusters were found on chromosomes 2 (RM423–RM174), 4 (RM551–RM518) and 6 (RM20224–RM528) for multiple traits under salinity stress. Both parental lines contributed additively for QTLs identified for the yield components. A majority of the QTLs detected in our study are reported for the first time for reproductive stage salinity stress. Fine-mapping of selected putative QTLs will be the next step to facilitate marker-assisted backcrossing and to detect useful genes for salinity tolerance at the reproductive stage in rice.

  19. Grain Quality and Genetic Analysis of Hybrids Derived from Different Ecological Types in Japonica Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    LENG Yan; HONG De-lin

    2004-01-01

    The performance and inheritance of 7 quality traits were studied using F2 rice grain derived from 8×8 diallel crossing made by employing 8 parents of different ecological japonica rice types. Differences in each trait among 8 parents were not obvious, but in F2 generation, transgressive phenomena were found in all the traits studied, indicating that the genes controlling these traits among parents were segregated. The inheritance of grain width, grain weight, chalkiness score (CS), gelatinization temperature (GT) and gel consistency (GC) were suitable to additive-dominant model, and dominant effect contributed mainly for the 5 traits. The inheritance of grain length (GL) and amylose content (AC) did not fit into additive-dominant model, existing epistatic interactions. Dominant genes for grain width and grain weight had the efficiency of decreasing effect, and dominant genes for CS, GT and GC had the efficiency of enhancing effect. Koshihikari contained more recessive genes for gelatinization temperature than other varieties. Zhendao 88 had more dominant genes in grain width and grain weight than other varieties.Xiushui 04 possessed more dominant genes for GL and GC, and more recessive genes for CS than other varieties.

  20. Natural Homologous Triploidization and DNA Methylation in SARII-628, a Twin-seedling Line of Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    PENG Hai; ZHANG Hong-yu; LI Yun; XU Pei-zhou; WANG Xu-dong; WU Xian-jun

    2007-01-01

    A total of five pairs of diploid-triploid twin-seedlings (a diploid seedling and a triploid seedling emerged from a grain)were selected out from 4500 pairs of seedlings from SARII-628, a twin-seedling rice line. SSR analysis indicated that no difference between the diploid seedling and corresponding triploid seedling in a twin-seedling was found at the 310 loci,(methylation-sensitive AFLP)'was used to analyze methylation mutation. Although no methylation mutation was noted among the five diploids, 29 methylation mutation loci were found from the corresponding triploids. This suggested that methylation mutation happened rapidly on M0 generation after natural homologous triploidization. The mutations were classified into 10 types, including 3 increased types, 3 decreased types and 4 undecided types of methylation-degrees. The bands of 22 loci were sequenced and then those sequences were searched through website. The result showed that the methylation mutation involved into the whole rice genome and the 12 pairs of chromosomes. The mutation trend was site-related and there were different mutation loci for different triploids, which foretold that SARII-628 would have different evolution fates after natural homologous triploidization.