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Sample records for model plant oryza

  1. 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.

  2. Practical Utilization of OryzaExpress and Plant Omics Data Center Databases to Explore Gene Expression Networks in Oryza Sativa and Other Plant Species.

    Science.gov (United States)

    Kudo, Toru; Terashima, Shin; Takaki, Yuno; Nakamura, Yukino; Kobayashi, Masaaki; Yano, Kentaro

    2017-01-01

    Analysis of a gene expression network (GEN), which is constructed based on similarity of gene expression profiles, is a widely used approach to gain clues for new biological insights. The recent abundant availability of transcriptome data in public databases is enabling GEN analysis under various experimental conditions, and even comparative GEN analysis across species. To provide a platform to gain biological insights from public transcriptome data, valuable databases have been created and maintained. This chapter introduces the web database OryzaExpress, providing omics information on Oryza sativa (rice). The integrated database Plant Omics Data Center, supporting a wide variety of plant species, is also described to compare omics information among multiple plant species.

  3. Genome information of Methylobacterium oryzae, a plant-probiotic methylotroph in the phyllosphere.

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    Min-Jung Kwak

    Full Text Available Pink-pigmented facultative methylotrophs in the Rhizobiales are widespread in the environment, and many Methylobacterium species associated with plants produce plant growth-promoting substances. To gain insights into the life style at the phyllosphere and the genetic bases of plant growth promotion, we determined and analyzed the complete genome sequence of Methylobacterium oryzae CBMB20T, a strain isolated from rice stem. The genome consists of a 6.29-Mb chromosome and four plasmids, designated as pMOC1 to pMOC4. Among the 6,274 coding sequences in the chromosome, the bacterium has, besides most of the genes for the central metabolism, all of the essential genes for the assimilation and dissimilation of methanol that are either located in methylotrophy islands or dispersed. M. oryzae is equipped with several kinds of genes for adaptation to plant surfaces such as defense against UV radiation, oxidative stress, desiccation, or nutrient deficiency, as well as high proportion of genes related to motility and signaling. Moreover, it has an array of genes involved in metabolic pathways that may contribute to promotion of plant growth; they include auxin biosynthesis, cytokine biosynthesis, vitamin B12 biosynthesis, urea metabolism, biosorption of heavy metals or decrease of metal toxicity, pyrroloquinoline quinone biosynthesis, 1-aminocyclopropane-1-carboxylate deamination, phosphate solubilization, and thiosulfate oxidation. Through the genome analysis of M. oryzae, we provide information on the full gene complement of M. oryzae that resides in the aerial parts of plants and enhances plant growth. The plant-associated lifestyle of M. oryzae pertaining to methylotrophy and plant growth promotion, and its potential as a candidate for a bioinoculant targeted to the phyllosphere and focused on phytostimulation are illuminated.

  4. Phylogeny of Plant CAMTAs and Role of AtCAMTAs in Nonhost Resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Rahman, Hafizur; Yang, Juan; Xu, You-Ping; Munyampundu, Jean-Pierre; Cai, Xin-Zhong

    2016-01-01

    Calmodulin-binding transcription activator (CAMTA) constitutes one of the most important Ca(2+)/CaM-regulated transcription factor families in plants. Nevertheless, the phylogeny, protein interaction network, and role in nonhost resistance of plant CAMTAs are not well understood. In this study, 200 CAMTA genes were identified from 35 species representing four major plant lineages. The CAMTA genes were conserved in multicellular land plants but absent in unicellular eukaryotes, and were likely to emerge from the fusion of two separate genes encoding a CAMTA-like protein and an IQ/CaM binding motif containing protein, respectively, in the embryophyta lineage ancestor. Approximately one fourth of plant CAMTAs did not contain a TIG domain. This non-TIG class of CAMTAs seems to have newly evolved through mutation of some key amino acids in the TIG domain of flowering land plants after divergence from the non-flowering plants. Phylogenetic analysis classified CAMTA proteins into three major groups and nine distinct subgroups, a result supported by protein domain and motif conservation analyses. Most (59.0 and 21.5%) of the identified CAMTA genes contained 12 or 11 introns, respectively. Gene duplication, intron invasion, enlargement and turnover, as well as exon rearrangements and skipping have apparently occurred during evolution of the CAMTA family. Moreover, 38 potential interactors of six Arabidopsis CAMTAs were predicted and 10 predicted target genes of AtCAMTA3 exhibited changes in expression between Atcamta3 mutants and wild-type plants. The majority of predicted interactors are transcription factors and/or Ca(2+)/CaM-regulated proteins, suggesting that transcriptional regulation of the target genes might be the dominant functional mechanism of AtCAMTAs, and AtCAMTAs might act together with other Ca(2+) signaling components to regulate Ca(2+)-related biological processes. Furthermore, functional analyses employing Atcamta mutants revealed that AtCAMTA3 negatively

  5. Phylogeny of plant CAMTAs and role of AtCAMTAs in nonhost resistance to Xanthomonas oryzae pv. oryzae

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    Hafizur eRahman

    2016-02-01

    Full Text Available Calmodulin-binding transcription activator (CAMTA constitutes one of the most important Ca2+/CaM-regulated transcription factor families in plants. Nevertheless, the phylogeny, protein interaction network and role in nonhost resistance of plant CAMTAs are not well understood. In this study, 200 CAMTA genes were identified from 35 species representing four major plant lineages. The CAMTA genes were conserved in multicellular land plants but absent in unicellular eukaryotes, and were likely to emerge from the fusion of two separate genes encoding a CAMTA-like protein and an IQ/CaM binding motif containing protein, respectively, in the embryophyta lineage ancestor. Approximately one fourth of plant CAMTAs did not contain a TIG domain. This non-TIG class of CAMTAs seems to have newly evolved through mutation of some key amino acids in the TIG domain of flowering land plants after divergence from the non-flowering plants. Phylogenetic analysis classified CAMTA proteins into three major groups and nine distinct subgroups, a result supported by protein domain and motif conservation analyses. Most (59.0% and 21.5% of the identified CAMTA genes contained 12 or 11 introns, respectively. Gene duplication, intron invasion, enlargement and turnover, as well as exon rearrangements and skipping have apparently occurred during evolution of the CAMTA family. Moreover, 38 potential interactors of six Arabidopsis CAMTAs were predicted and 10 predicted target genes of AtCAMTA3 exhibited changes in expression between Atcamta3 mutants and wild-type plants. The majority of predicted interactors are transcription factors and/or Ca2+/CaM-regulated proteins, suggesting that transcriptional regulation of the target genes might be the dominant functional mechanism of AtCAMTAs, and AtCAMTAs might act together with other Ca2+ signaling components to regulate Ca2+-related biological processes. Furthermore, functional analyses employing Atcamta mutants revealed that AtCAMTA3

  6. Esterase as molecular marker for salt tolerance in regenerated plants of rice, Oryza sativa L.

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    Swapna, T S

    2002-09-01

    Esterase variation was studied in plants regenerated from callus cultures of four rice (Oryza sativa) varieties, viz. pokkali, which is a moderately salt tolerant variety and three salt sensitive varieties MI 48, annapoorna and jyothi. Variation was studied at tillering stage of plants regenerated from callus culture and germinated from seeds. Somaclonal variants for salt tolerance could be detected using variation in esterase banding pattern and activity.

  7. Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae

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    Andréa Roveré Franz

    2011-03-01

    Full Text Available Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae. Stored grains are subject to losses in quality nutritional value and in sanitation from the time they are stored to the time they are consumed. Botanical insecticides may offer an alternative solution for pest control. The objective was to test the insecticidal properties of the essential oils of Cymbopogon citratus (leaf, Zingiber officinale (root and Mentha sp. (leaf. The efficacy of these oils was tested to control the rice weevil, S. oryzae, using hydrodistillation. Chemical analysis of the essential oils was carried out by gas chromatography. Major components of C. citratus were geranial (48% and neral (31%, of Z. officinale were α-zingibereno (13%, geranial (16%, neral (10% and α-farneseno (5% and of Mentha sp. was menthol (92%. Bioassays were carried out by fumigation and topical application. In topical application assays, the essential oil of C. citratus had greater toxicity (LC50 0.027 µL mL-1 and shorter exposure time than the oils of the other two plants. After 24 h and 48 h, 70% and 100% mortality of S. oryzae occurred, respectively. In fumigation assays, essential oil of Z. officinale had a lower LC50 (1.18 µL cm-2 and 70% mortality after 24 h exposure. Therefore, we recommend the use of essential oils of C. citratus and Z. officinale to control the rice weevil S. oryzae.

  8. Genome evolution of Oryza

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    Tieyan Liu

    2014-01-01

    Full Text Available The genus Oryza is composed of approximately 24 species. Wild species of Oryza contain a largely untapped resource of agronomically important genes. As an increasing number of genomes of wild rice species have been or will be sequenced, Oryza is becoming a model system for plant comparative, functional and evolutionary genomics studies. Comparative analyses of large genomic regions and whole-genome sequences have revealed molecular mechanisms involved in genome size variation, gene movement, genome evolution of polyploids, transition of euchromatin to heterochromatin and centromere evolution in the genus Oryza. Transposon activity and removal of transposable elements by unequal recombination or illegitimate recombination are two important factors contributing to expansion or contraction of Oryza genomes. Double-strand break repair mediated gene movement, especially non-homologous end joining, is an important source of non-colinear genes. Transition of euchromatin to heterochromatin is accompanied by transposable element amplification, segmental and tandem duplication of genic segments, and acquisition of heterochromatic genes from other genomic locations. Comparative analyses of multiple genomes dramatically improve the precision and sensitivity of evolutionary inference than single-genome analyses can provide. Further investigations on the impact of structural variation, lineage-specific genes and evolution of agriculturally important genes on phenotype diversity and adaptation in the genus Oryza should facilitate molecular breeding and genetic improvement of rice.

  9. Genetic evidence for natural product-mediated plant-plant allelopathy in rice (Oryza sativa).

    Science.gov (United States)

    Xu, Meimei; Galhano, Rita; Wiemann, Philipp; Bueno, Emilio; Tiernan, Mollie; Wu, William; Chung, Ill-Min; Gershenzon, Jonathan; Tudzynski, Bettina; Sesma, Ane; Peters, Reuben J

    2012-02-01

    • There is controversy as to whether specific natural products play a role in directly mediating antagonistic plant-plant interactions - that is, allelopathy. If proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza sativa). • However, while substantiated by the presence of phytotoxic compounds at potentially relevant concentrations, demonstrating a direct role for specific natural products in allelopathy has been difficult because of the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied. • The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock-outs of the relevant diterpene synthases (copalyl diphosphate synthase 4 (OsCPS4) and kaurene synthase-like 4 (OsKSL4)), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (Echinochloa crus-galli). • Thus, our results not only provide novel genetic evidence for natural product-mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Bioremoval of heavy metals and nutrients from sewage plant by Anabaena oryzae and Cyanosarcina fontana.

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    Fawzy, Mustafa A; Issa, Ahmed A

    2016-01-01

    The present study demonstrated the growth of two species of cyanobacteria on wastewater isolated from sewage plant in Aswan, Egypt. We evaluated their efficiency for eliminating nitrogen, phosphorus, chemical oxygen demand (COD) and heavy metals (Fe(2+), Pb(2+), Cu(2+), and Mn(2+)). The growth of Cyanosarcina fontana has supported wastewater as a growth medium than Anabaena oryzae compared to standard medium. The nutrients concentration such as COD, NO3-N and PO4-P were decreased by the growth of A. oryzae and C. fontana in the wastewater after primary settling and centrate. However, the reduction of COD was less efficient than the other nutrients. The reduction percentage of COD, NO3-N and PO4-P reached 39.3, 84.1 and 90.7% as well as 54.6, 83.1, and 89.8%, in cultures of A. oryzae and C. fontana grown in the wastewater after primary settling, respectively. The reduction amounted to 10.1, 76.8, and 63.0% by A. oryzae and 43.2, 62.1, and 74.8% by C. fontana, grown in the centrate, respectively. Cyanobacteria species have the ability to accumulate the heavy metals from the wastewater to level far than the exceeding metal level in the water. Whereas, the heavy metals biosorption performance of C. fontana was higher in accumulating Fe(2+) (93.95%), Pb(2+) (81.21%), Cu(2+) (63.9%), and Mn(2+) (48.49%) compared to A. oryzae. The biosorption ability is dependent on the nature of the adsorbent studied and the type of wastewater treated. Therefore, removal of heavy metals and nutrients by the tested algae is strongly recommended as a powerful technique for the removal of pollutants from wastewater.

  11. Optimal Estimation of Phenological Crop Model Parameters for Rice (Oryza sativa)

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    Sharifi, H.; Hijmans, R. J.; Espe, M.; Hill, J. E.; Linquist, B.

    2015-12-01

    Crop phenology models are important components of crop growth models. In the case of phenology models, generally only a few parameters are calibrated and default cardinal temperatures are used which can lead to a temperature-dependent systematic phenology prediction error. Our objective was to evaluate different optimization approaches in the Oryza2000 and CERES-Rice phenology sub-models to assess the importance of optimizing cardinal temperatures on model performance and systematic error. We used two optimization approaches: the typical single-stage (planting to heading) and three-stage model optimization (for planting to panicle initiation (PI), PI to heading (HD), and HD to physiological maturity (MT)) to simultaneously optimize all model parameters. Data for this study was collected over three years and six locations on seven California rice cultivars. A temperature-dependent systematic error was found for all cultivars and stages, however it was generally small (systematic error changes in cardinal temperature relative to the default values and thus optimization of cardinal temperatures did not affect systematic error or model performance. Compared to single stage optimization, three-stage optimization had little effect on determining time to PI or HD but significantly improved the precision in determining the time from HD to MT: the RMSE reduced from an average of 6 to 3.3 in Oryza2000 and from 6.6 to 3.8 in CERES-Rice. With regards to systematic error, we found a trade-off between RMSE and systematic error when optimization objective set to minimize RMSE or systematic error. Therefore, it is important to find the limits within which the trade-offs between RMSE and systematic error are acceptable, especially in climate change studies where this can prevent erroneous conclusions.

  12. Enhanced disease resistance and drought tolerance in transgenic rice plants overexpressing protein elicitors from Magnaporthe oryzae.

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    Wang, Zhenzhen; Han, Qiang; Zi, Qian; Lv, Shun; Qiu, Dewen; Zeng, Hongmei

    2017-01-01

    Exogenous application of the protein elicitors MoHrip1 and MoHrip2, which were isolated from the pathogenic fungus Magnaporthe oryzae (M. oryzae), was previously shown to induce a hypersensitive response in tobacco and to enhance resistance to rice blast. In this work, we successfully transformed rice with the mohrip1 and mohrip2 genes separately. The MoHrip1 and MoHrip2 transgenic rice plants displayed higher resistance to rice blast and stronger tolerance to drought stress than wild-type (WT) rice and the vector-control pCXUN rice. The expression of salicylic acid (SA)- and abscisic acid (ABA)-related genes was also increased, suggesting that these two elicitors may trigger SA signaling to protect the rice from damage during pathogen infection and regulate the ABA content to increase drought tolerance in transgenic rice. Trypan blue staining indicated that expressing MoHrip1 and MoHrip2 in rice plants inhibited hyphal growth of the rice blast fungus. Relative water content (RWC), water usage efficiency (WUE) and water loss rate (WLR) were measured to confirm the high capacity for water retention in transgenic rice. The MoHrip1 and MoHrip2 transgenic rice also exhibited enhanced agronomic traits such as increased plant height and tiller number.

  13. Improved annotation through genome-scale metabolic modeling of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Vongsangnak, Wanwipa; Olsen, Peter; Hansen, Kim;

    2008-01-01

    to a genome scale metabolic model of A. oryzae. Results: Our assembled EST sequences we identified 1,046 newly predicted genes in the A. oryzae genome. Furthermore, it was possible to assign putative protein functions to 398 of the newly predicted genes. Noteworthy, our annotation strategy resulted......Background: Since ancient times the filamentous fungus Aspergillus oryzae has been used in the fermentation industry for the production of fermented sauces and the production of industrial enzymes. Recently, the genome sequence of A. oryzae with 12,074 annotated genes was released but the number...... of hypothetical proteins accounted for more than 50% of the annotated genes. Considering the industrial importance of this fungus, it is therefore valuable to improve the annotation and further integrate genomic information with biochemical and physiological information available for this microorganism and other...

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

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    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

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

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    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.

  16. Biotoxic efficacy of two horticultural plants against infestation of Sitophilus oryzae on stored maize

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    Mercy Olayinka ONI

    2016-06-01

    Full Text Available Since botanicals still remained the most promising tool that could obviate the use of chemical insecticides, this study investigated the biotoxic effect of Acacia auriculiformis and Acalypha goddsefiana powder and oil against Sitophilus oryzae. The powder of the plants were tested at 0.0g (control, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0g dosages while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations per 20g of maize seeds. Solvent control was also prepared for the oil extracts bioassay. Mortality, adult emergence, % inhibition rate and % weight loss were observed. LD50 and LC50 of the powders and oils of the two botanicals were calculated at 48 hours of application. The powders of both plants achieved complete weevil mortality within 72h of application at 2.0g and their effect was significantly (p<0.05 different from other dosages except 1.0g dosage. Also, the extracts of both plant achieved 100% insect mortality within 48h hours of application at 5%. However the powder and oil of A. auriculiformis appeared more effective than that of A. goddsefiana in term of mortality as reflected by their lethal dosage and concentration. However, A. goddsefiana powder and extract appeared more effective than that of A. auriculiformis in term of protectability as they greatly reduced the emergence of the adult weevil and their ability to cause weight loss of the maize grains. Only the higher dosages and concentrations of the plants were able to achieve 100% inhibition rate.

  17. The ability on hydraulic-lift from deeper rooted plants with a phytoassay of rice (Oryza sativa L.)

    OpenAIRE

    2009-01-01

    Hydraulic lift(HL), the exudation of water from root system of deeper rooted plants under soil desiccated conditions is considered as a potential irrigation system in drought areas. The ability of HL in sorghum(Sorghum bicolor(L.)Moench)was evaluated by a split root experiment with mixed-cropped rice(Oryza sativa L.)as an indicator plant for phytoassay. Growth parameters of rice and soil water conditions are measured after withholding irrigation with or without sorghum root connection between...

  18. Modeling enzyme production with Aspergillus oryzae in pilot scale vessels with different agitation, aeration, and agitator types

    DEFF Research Database (Denmark)

    Albæk, Mads Orla; Gernaey, Krist; Hansen, Morten S.;

    2011-01-01

    The purpose of this article is to demonstrate how a model can be constructed such that the progress of a submerged fed‐batch fermentation of a filamentous fungus can be predicted with acceptable accuracy. The studied process was enzyme production with Aspergillus oryzae in 550 L pilot plant stirred...... tank reactors. Different conditions of agitation and aeration were employed as well as two different impeller geometries. The limiting factor for the productivity was oxygen supply to the fermentation broth, and the carbon substrate feed flow rate was controlled by the dissolved oxygen tension....... In order to predict the available oxygen transfer in the system, the stoichiometry of the reaction equation including maintenance substrate consumption was first determined. Mainly based on the biomass concentration a viscosity prediction model was constructed, because rising viscosity of the fermentation...

  19. OsPIN5b modulates rice (Oryza sativa) plant architecture and yield by changing auxin homeostasis, transport and distribution.

    Science.gov (United States)

    Lu, Guangwen; Coneva, Viktoriya; Casaretto, José A; Ying, Shan; Mahmood, Kashif; Liu, Fang; Nambara, Eiji; Bi, Yong-Mei; Rothstein, Steven J

    2015-09-01

    Plant architecture attributes such as tillering, plant height and panicle size are important agronomic traits that determine rice (Oryza sativa) productivity. Here, we report that altered auxin content, transport and distribution affect these traits, and hence rice yield. Overexpression of the auxin efflux carrier-like gene OsPIN5b causes pleiotropic effects, mainly reducing plant height, leaf and tiller number, shoot and root biomass, seed-setting rate, panicle length and yield parameters. Conversely, reduced expression of OsPIN5b results in higher tiller number, more vigorous root system, longer panicles and increased yield. We show that OsPIN5b is an endoplasmic reticulum (ER) -localized protein that participates in auxin homeostasis, transport and distribution in vivo. This work describes an example of an auxin-related gene where modulating its expression can simultaneously improve plant architecture and yield potential in rice, and reveals an important effect of hormonal signaling on these traits.

  20. Two independent S-phase checkpoints regulate appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae

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    Osés-Ruiz, Míriam; Sakulkoo, Wasin; Littlejohn, George R.; Martin-Urdiroz, Magdalena

    2017-01-01

    To cause rice blast disease, the fungal pathogen Magnaporthe oryzae develops a specialized infection structure called an appressorium. This dome-shaped, melanin-pigmented cell generates enormous turgor and applies physical force to rupture the rice leaf cuticle using a rigid penetration peg. Appressorium-mediated infection requires septin-dependent reorientation of the F-actin cytoskeleton at the base of the infection cell, which organizes polarity determinants necessary for plant cell invasion. Here, we show that plant infection by M. oryzae requires two independent S-phase cell-cycle checkpoints. Initial formation of appressoria on the rice leaf surface requires an S-phase checkpoint that acts through the DNA damage response (DDR) pathway, involving the Cds1 kinase. By contrast, appressorium repolarization involves a novel, DDR-independent S-phase checkpoint, triggered by appressorium turgor generation and melanization. This second checkpoint specifically regulates septin-dependent, NADPH oxidase-regulated F-actin dynamics to organize the appressorium pore and facilitate entry of the fungus into host tissue. PMID:28028232

  1. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    NARCIS (Netherlands)

    Coutinho, Pedro M; Andersen, Mikael R; Kolenova, Katarina; vanKuyk, Patricia A; Benoit, Isabelle; Gruben, Birgit S; Trejo-Aguilar, Blanca; Visser, Hans; van Solingen, Piet; Pakula, Tiina; Seiboth, Bernard; Battaglia, Evy; Aguilar-Osorio, Guillermo; de Jong, Jan F; Ohm, Robin A; Aguilar, Mariana; Henrissat, Bernard; Nielsen, Jens; Stålbrand, Henrik; de Vries, Ronald P

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs

  2. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    DEFF Research Database (Denmark)

    Coutinho, Pedro M.; Andersen, Mikael Rørdam; Kolenova, Katarina

    2009-01-01

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs an...

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

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    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.

  4. Risk Assessment of Heavy Metals Contamination in Paddy Soil, Plants, and Grains (Oryza sativa L.) at the East Coast of India

    OpenAIRE

    Deepmala Satpathy; M. Vikram Reddy; Soumya Prakash Dhal

    2014-01-01

    Heavy metals known to be accumulated in plants adversely affect human health. This study aims to assess the effects of agrochemicals especially chemical fertilizers applied in paddy fields, which release potential toxic heavy metals into soil. Those heavy metals get accumulated in different parts of paddy plant (Oryza sativa L.) including the grains. Concentrations of nonessential toxic heavy metals (Cd, Cr, and Pb) and the micronutrients (Cu, Mn, and Zn) were measured in the paddy field soil...

  5. Experimental infection of Fusarium proliferatum in Oryza sativa plants; fumonisin B1 production and survival rate in grains.

    Science.gov (United States)

    Kushiro, Masayo; Saitoh, Hatsuo; Sugiura, Yoshitsugu; Aoki, Takayuki; Kawamoto, Shin-ichi; Sato, Toyozo

    2012-06-01

    Fusarium proliferatum is a plant pathogenic fungus associated with crops such as asparagus and corn, and it possesses the ability to produce a range of mycotoxins, including fumonisins. In Asia, rice (Oryza sativa) is a staple cereal and is occasionally colonized by this fungus without obvious physiological changes. F. proliferatum is closely related to Gibberella fujikuroi (anamorph F. fujikuroi) responsible for Bakanae disease in rice; however there are few reports of F. proliferatum as a rice pathogen. In this study, we examined the pathogenic potential of F. proliferatum in rice plants with respect to browning, fumonisin production, and survival rates in rice grains. Fungal inoculation was conducted by spraying a conidial suspension of F. proliferatum onto rice plants during the flowering period. Browning was found on the stalk, leaf, and ear of rice. Fumonisin B(1) was detected at levels from trace to 21 ng/g grains, using tandem mass spectrometry. Fungal recovery after 6 months indicated that F. proliferatum had high affinity to rice plants being still viable in grains. From this study, it can be concluded that F. proliferatum is a possible pathogen of rice and possesses a potential to produce fumonisin B(1) in rice grains in the field. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Aerial mycelia of Aspergillus oryzae accelerate alpha-amalyse production in a model solid-state fermentation system

    NARCIS (Netherlands)

    Rahardjo, Y.S.P.; Weber, F.J.; Haemers, S.; Tramper, J.; Rinzema, A.

    2005-01-01

    Aspergillus oryzae is commonly used in solid-state fermentation (SSF) and forms abundant aerial mycelia. Previously, we have shown that aerial mycelia are extremely important for the respiration of this fungus during growth on a wheat-flour model substrate. In this paper, we show that aerial mycelia

  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. Genome-wide profiling of DNA methylation provides insights into epigenetic regulation of fungal development in a plant pathogenic fungus, Magnaporthe oryzae.

    Science.gov (United States)

    Jeon, Junhyun; Choi, Jaeyoung; Lee, Gir-Won; Park, Sook-Young; Huh, Aram; Dean, Ralph A; Lee, Yong-Hwan

    2015-02-24

    DNA methylation is an important epigenetic modification that regulates development of plants and mammals. To investigate the roles of DNA methylation in fungal development, we profiled genome-wide methylation patterns at single-nucleotide resolution during vegetative growth, asexual reproduction, and infection-related morphogenesis in a model plant pathogenic fungus, Magnaporthe oryzae. We found that DNA methylation occurs in and around genes as well as transposable elements and undergoes global reprogramming during fungal development. Such reprogramming of DNA methylation suggests that it may have acquired new roles other than controlling the proliferation of TEs. Genetic analysis of DNA methyltransferase deletion mutants also indicated that proper reprogramming in methylomes is required for asexual reproduction in the fungus. Furthermore, RNA-seq analysis showed that DNA methylation is associated with transcriptional silencing of transposable elements and transcript abundance of genes in context-dependent manner, reinforcing the role of DNA methylation as a genome defense mechanism. This comprehensive approach suggests that DNA methylation in fungi can be a dynamic epigenetic entity contributing to fungal development and genome defense. Furthermore, our DNA methylomes provide a foundation for future studies exploring this key epigenetic modification in fungal development and pathogenesis.

  9. Constitutive expression of a plant ferredoxin-like protein (pflp) enhances capacity of photosynthetic carbon assimilation in rice (Oryza sativa).

    Science.gov (United States)

    Chang, Hsiang; Huang, Hsiang-En; Cheng, Chin-Fu; Ho, Mei-Hsuan; Ger, Mang-Jye

    2017-04-01

    The plant ferredoxin-like protein (PFLP) gene, cloned from sweet peppers predicted as an electron carrier in photosynthesis, shows high homology to the Fd-I sequence of Arabidopsis thaliana, Lycopersicon esculentum, Oryza sativa and Spinacia oleracea. Most of pflp related studies focused on anti-pathogenic effects, while less understanding for the effects in photosynthesis with physiological aspects, such as photosynthesis rate, and levels of carbohydrate metabolites. This project focuses on the effects of pflp overexpression on photosynthesis by physiological evaluations of carbon assimilation with significant higher levels of carbohydrates with higher photosynthesis efficiency. In this report, two independent transgenic lines of rice plants (designated as pflp-1 and pflp-2) were generated from non-transgenic TNG67 rice plant (WT). Both transgenic pflp rice plants exhibited enhanced photosynthesis efficiency, and gas exchange rates of photosynthesis were 1.3- and 1.2-fold higher for pflp-1 and pflp-2 than WT respectively. Significantly higher electron transport rates of pflp rice plants were observed. Moreover, photosynthetic products, such as fructose, glucose, sucrose and starch contents of pflp transgenic lines were increased accordingly. Molecular evidences of carbohydrate metabolism related genes activities (osHXK5, osHXK6, osAGPL3, osAGPS2α, osSPS, ospFBPase, oscFBPase, and osSBPase) in transgenic lines were higher than those of WT. For performance of crop production, 1000-grain weight for pflp-1 and pflp-2 rice plants were 52.9 and 41.1 g that were both significantly higher than 31.6 g for WT, and panicles weights were 1.4- and 1.2-fold higher than WT. Panicle number, tiller number per plants for pflp rice plants were all significantly higher compared with those of WT where there was no significant difference observed between two pflp rice plants. Taken altogether; this study demonstrated that constitutive pflp expression can improve rice production by

  10. Root aquaporins contribute to whole plant water fluxes under drought stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Grondin, Alexandre; Mauleon, Ramil; Vadez, Vincent; Henry, Amelia

    2016-02-01

    Aquaporin activity and root anatomy may affect root hydraulic properties under drought stress. To better understand the function of aquaporins in rice root water fluxes under drought, we studied the root hydraulic conductivity (Lpr) and root sap exudation rate (Sr) in the presence or absence of an aquaporin inhibitor (azide) under well-watered conditions and following drought stress in six diverse rice varieties. Varieties varied in Lpr and Sr under both conditions. The contribution of aquaporins to Lpr was generally high (up to 79% under well-watered conditions and 85% under drought stress) and differentially regulated under drought. Aquaporin contribution to Sr increased in most varieties after drought, suggesting a crucial role for aquaporins in osmotic water fluxes during drought and recovery. Furthermore, root plasma membrane aquaporin (PIP) expression and root anatomical properties were correlated with hydraulic traits. Three chromosome regions highly correlated with hydraulic traits of the OryzaSNP panel were identified, but did not co-locate with known aquaporins. These results therefore highlight the importance of aquaporins in the rice root radial water pathway, but emphasize the complex range of additional mechanisms related to root water fluxes and drought response.

  11. Traditional and modern plant breeding methods with examples in rice (Oryza sativa L.).

    Science.gov (United States)

    Breseghello, Flavio; Coelho, Alexandre Siqueira Guedes

    2013-09-01

    Plant breeding can be broadly defined as alterations caused in plants as a result of their use by humans, ranging from unintentional changes resulting from the advent of agriculture to the application of molecular tools for precision breeding. The vast diversity of breeding methods can be simplified into three categories: (i) plant breeding based on observed variation by selection of plants based on natural variants appearing in nature or within traditional varieties; (ii) plant breeding based on controlled mating by selection of plants presenting recombination of desirable genes from different parents; and (iii) plant breeding based on monitored recombination by selection of specific genes or marker profiles, using molecular tools for tracking within-genome variation. The continuous application of traditional breeding methods in a given species could lead to the narrowing of the gene pool from which cultivars are drawn, rendering crops vulnerable to biotic and abiotic stresses and hampering future progress. Several methods have been devised for introducing exotic variation into elite germplasm without undesirable effects. Cases in rice are given to illustrate the potential and limitations of different breeding approaches.

  12. Plant development models

    NARCIS (Netherlands)

    Chuine, I.; Garcia de Cortazar-Atauri, I.; Kramer, K.; Hänninen, H.

    2013-01-01

    In this chapter we provide a brief overview of plant phenology modeling, focusing on mechanistic phenological models. After a brief history of plant phenology modeling, we present the different models which have been described in the literature so far and highlight the main differences between them,

  13. Growth responses of NaCl stressed rice (Oryza sativa L.) plants ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-27

    Sep 27, 2010 ... Effect of salinity (NaCl) in the presence of proline was assessed .... factors, with salinity being considered as a major constraint. (Ashraf, 2004 ... conditions) to increase the plant growth rate than saline ..... Photosynthetic.

  14. Enhancement and modeling of microparticle-added Rhizopus oryzae lactic acid production.

    Science.gov (United States)

    Coban, Hasan Bugra; Demirci, Ali

    2016-02-01

    Lactic acid has a wide industrial application area and can be produced by fungal strains. However, excessive bulk growth form of fungi during the fermentations is a major problem, which limits the fermentation performance. Microparticles are excellent tools to prevent bulk fungal growth and provide homogenized fermentation broth to increase uniformity and the prediction performance of the models. Therefore, in this study, addition of aluminum oxide and talcum microparticles into fermentations was evaluated to enhance the production of lactic acid by Rhizopus oryzae. The results showed that the bulk fungal growth was prevented and the lactic acid concentration increased from 6.02 to 13.88 and 24.01 g/L, when 15 g/L of aluminum oxide or 10 g/L of talcum was used, respectively, in the shake-flask fermentations. Additionally, substrate concentration, pH, and agitation were optimized in the bioreactors using response surface methodology, and optimum values were determined as 126 g/L of glucose, 6.22 pH, and 387 rpm, respectively. Under these conditions, lactic acid production further increased to 75.1 ± 1.5 g/L with 10 g/L of talcum addition. Also, lactic acid production and glucose consumption in the batch fermentation were successfully modeled with modified Gompertz model and modified logistic model. RMSE and MAE values for lactic acid production were calculated as 2.279 and 1.498 for the modified Gompertz model; 3.6 and 4.056 for the modified logistic model. Additionally, modified logistic model predicted glucose consumption with -2.088 MAE and 2.868 RMSE, whereas these values were calculated as 2.035 and 3.946 for the modified Gompertz model.

  15. Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants.

    Science.gov (United States)

    Doni, Febri; Isahak, Anizan; Che Mohd Zain, Che Radziah; Wan Yusoff, Wan Mohtar

    2014-01-01

    Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO2 concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO2 m(-2) s(-1)), internal CO2 concentration (336.97 ppm), water use efficiency (1.15 μmoCO2/mmoH2O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation.

  16. Open-pit coal-mining effects on rice paddy soil composition and metal bioavailability to Oryza sativa L. plants in Cam Pha, northeastern Vietnam.

    Science.gov (United States)

    Martinez, Raul E; Marquez, J Eduardo; Hòa, Hoàng Thị Bích; Gieré, Reto

    2013-11-01

    This study quantified Cd, Pb, and Cu content, and the soil-plant transfer factors of these elements in rice paddies within Cam Pha, Quang Ninh province, northeastern Vietnam. The rice paddies are located at a distance of 2 km from the large Coc Sau open-pit coal mine. Electron microprobe analysis combined with backscattered electron imaging and energy-dispersive spectroscopy revealed a relatively high proportion of carbon particles rimmed by an iron sulfide mineral (probably pyrite) in the quartz-clay matrix of rice paddy soils at 20-30 cm depth. Bulk chemical analysis of these soils revealed the presence of Cd, Cu, and Pb at concentrations of 0.146±0.004, 23.3±0.1, and 23.5±0.1 mg/kg which exceeded calculated background concentrations of 0.006±0.004, 1.9±0.5, and 2.4±1.5 mg/kg respectively at one of the sites. Metals and metalloids in Cam Pha rice paddy soils, including As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn, were found in concentrations ranging from 0.2±0.1 to 140±3 mg/kg, which were in close agreement with toxic metal contents in mine tailings and Coc Sau coal samples, suggesting mining operations as a major cause of paddy soil contamination. Native and model Oryza sativa L. rice plants were grown in the laboratory in a growth medium to which up to 1.5 mg/kg of paddy soil from Cam Pha was added to investigate the effects on plant growth. A decrease in growth by up to 60% with respect to a control sample was found for model plants, whereas a decrease of only 10% was observed for native (Nep cai hoa vang variety) rice plants. This result suggests an adaptation of native Cam Pha rice plants to toxic metals in the agricultural lands. The Cd, Cu, and Pb contents of the native rice plants from Cam Pha paddies exceeded permitted levels in foods. Cadmium and Pb were highest in the rice plant roots with concentrations of 0.84±0.02 and 7.7±0.3 mg/kg, suggesting an intake of these metals into the rice plant as shown, for example, by Cd and Pb concentrations of 0

  17. 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

  18. Ethanol and Protein from Ethanol Plant By-Products Using Edible Fungi Neurospora intermedia and Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Veronika Bátori

    2015-01-01

    Full Text Available Feasible biorefineries for production of second-generation ethanol are difficult to establish due to the process complexity. An alternative is to partially include the process in the first-generation plants. Whole stillage, a by-product from dry-mill ethanol processes from grains, is mostly composed of undegraded bran and lignocelluloses can be used as a potential substrate for production of ethanol and feed proteins. Ethanol production and the proteins from the stillage were investigated using the edible fungi Neurospora intermedia and Aspergillus oryzae, respectively. N. intermedia produced 4.7 g/L ethanol from the stillage and increased to 8.7 g/L by adding 1 FPU of cellulase/g suspended solids. Saccharomyces cerevisiae produced 0.4 and 5.1 g/L ethanol, respectively. Under a two-stage cultivation with both fungi, up to 7.6 g/L of ethanol and 5.8 g/L of biomass containing 42% (w/w crude protein were obtained. Both fungi degraded complex substrates including arabinan, glucan, mannan, and xylan where reductions of 91, 73, 38, and 89% (w/v were achieved, respectively. The inclusion of the current process can lead to the production of 44,000 m3 of ethanol (22% improvement, around 12,000 tons of protein-rich biomass for animal feed, and energy savings considering a typical facility producing 200,000 m3 ethanol/year.

  19. Deciphering the signaling mechanisms of the plant cell wall degradation machinery in Aspergillus oryzae

    DEFF Research Database (Denmark)

    Udatha, D. B. R. K. Gupta; Topakas, Evangelos; Salazar, Margarita Pena;

    2015-01-01

    . oryzae genome were only partially explained by the chemical similarity of the enzyme inducers. Genes encoding enzymes that have attracted considerable interest such as cellobiose dehydrogenases and copper-dependent polysaccharide mono-oxygenases presented a substrate-specific induction. Several homology...... in 2360 reactions in the genome scale metabolic network of A. oryzae, was performed through a two-step molecular docking against the binding pockets of the transcription factors AoXlnR and AoAmyR. A total of six metabolites viz., sulfite (H2SO3), sulfate (SLF), uroporphyrinogen III (UPGIII), ethanolamine...

  20. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Nor’Aishah, E-mail: aishahnh@ns.uitm.edu.my [Faculty of Applied Science, UniversitiTeknologi MARA (UiTM), Kuala Pilah, Negeri Sembilan (Malaysia); Rafii, Mohd Y., E-mail: mrafii@upm.edu.my [Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Department of Crop Science, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Rahim, Harun A. [Agrotechnology & Bioscience Division, Malaysian Nuclear Agency, Bangi, Kajang, Selangor (Malaysia); Ali, Nusaibah Syd [Department of Plant Protection, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Mazlan, Norida [Department of Agriculture Technology, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Abdullah, Shamsiah [Faculty of Plantation and Agrotechnology, UniversitiTeknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)

    2016-02-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

  1. Identification of Intergeneric Hybrid Plants Between Oryza sativa and O. minuta via GISH and RAPD

    Institute of Scientific and Technical Information of China (English)

    YU Shun-wu; CHEN Bao-tang; TAO Ai-lin; ZHANG Duan-pin

    2003-01-01

    To transfer desirable resistance traits from O. minuta to O. sativa, intergeneric hybrid plants between O. sativa (AA, 2n=2X=24) and O. minuta (BBCC, 2n=4X=48) were produced by embryo rescue after sexual cross. Morphological observation and chromosome counts indicated their hybrid status (ABC, 2n =3X=36). Genomic in situ hybridization (GISH) was further applied to confirm the parentage of the chromosomes of F1 hybrids. Chromosomes of O. minuta and O. sativa were distinguishable in the hybrids in different fluorescence colors. GISH indicated that A and BC chromosomes were not randomly assembled in a cell.RAPD profiles unequivocally revealed their hybrids with double parent patterns. The results of blast tests showed that the hybrids had obtained disease resistance from O. minuta, and had a level of susceptibility between the parents.

  2. 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.

  3. 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

    2016-03-16

    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.

  4. Translocation and biotransformation of CuO nanoparticles in rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Peng, Cheng; Duan, Dechao; Xu, Chen; Chen, Yongsheng; Sun, Lijuan; Zhang, Hai; Yuan, Xiaofeng; Zheng, Lirong; Yang, Yuanqiang; Yang, Jianjun; Zhen, Xiangjun; Chen, Yingxu; Shi, Jiyan

    2015-02-01

    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).

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

    Institute of Scientific and Technical Information of China (English)

    Wen; Lu; Luqi; Pan; Haijun; Zhao; Yulin; Jia; Yanli; Wang; Xiaoping; Yu; Xueyan; Wang

    2014-01-01

    The 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 the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.

  6. Adsorption of polycyclic aromatic hydrocarbons (PAHs) on Rhizopus oryzae cell walls: application of cosolvent models for validating the cell wall-water partition coefficient.

    Science.gov (United States)

    Ma, Bin; Xu, Minmin; Wang, Jiaojiao; Chen, Huaihai; He, Yan; Wu, Laosheng; Wang, Haizhen; Xu, Jianming

    2011-11-01

    The cell wall-cosolvent partition coefficients (Km) of polycyclic aromatic hydrocarbons (PAHs) were determined for Rhizopus oryzae cell walls by controlling the volume fraction of methanol (f) ranging from 0.1 to 0.5. Five cosolvent models were employed for extrapolating the cell wall-water partition coefficients (Kw) in pure water. The extrapolated Kw values of four PAHs on R. oryzae cell walls were ranged from 2.9 to 5.1. Comparison of various Kw values of pyrene generated from extrapolation and the QSPR model, together with predicted different (PD), mean percentage deviations (MPD), and root mean square errors (RSE), revealed that the performance of the LL and Bayesian models were the best among all five tested cosolvent models. This study suggests that R. oryzae cell walls play an important role in the partitioning of PAHs during bioremediation because of the high Kw of fungal cell walls.

  7. Modelado del Efecto de la Temperatura, Actividad de Agua y pH sobre el Crecimiento de Rhizopus oryzae Modeling the Effects of Temperature, Water Activity and pH on the Growth of Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    M.L Carrillo

    2007-01-01

    Full Text Available El objetivo de este trabajo fue modelar el crecimiento de Rhizopus oryzae, hongo deteriorativo de alimentos, en función de la temperatura, la actividad de agua (a w y el pH. Las curvas de crecimiento de Rhizopus oryzae se generaron a las condiciones de temperatura (20 y 30 °C, a w (0.895 y 0.99 y pH (3 y 5 dadas por un diseño factorial completo. Dichas curvas se obtuvieron al graficar el diámetro de las colonias contra el tiempo y se ajustaron con el modelo de Baranyi para obtener los parámetros de crecimiento (velocidad específica de crecimiento, tiempo de latencia y crecimiento máximo, a partir de los cuales se generó un modelo polinomial. El análisis estadístico indicó que todos los factores ejercen un efecto significativo (p The proposal of this work was modeling the growth of Rhizopus oryzae- fungus deteriorative food- in function of temperature, water activity (a w and pH. Growth curves of R. oryzae were generated at conditions of temperature (20 and 30°C, a w (0.895 and 0.99 and pH (3 and 5 giving in factorial full design. Such curves were obtained to graphic the colony diameter versus time and were adjusted with the Baranyi model in order to obtain the growth parameters - specific growth rate, latency of time and maximal growth-, to left was generated a polynomial model. The three factors were statistically significant (p<0.001 on the fungi growth.

  8. Impact of Engineered Nanoparticles on Virulence of Xanthomonas oryzae pv oryzae and on Rice Sensitivity at its Infection

    Directory of Open Access Journals (Sweden)

    Giuliano Degrassi

    2014-12-01

    Full Text Available The present work of nanocotoxicity wants to propose a new plant model starting from the rice plant. The model takes into consideration the impact of engineered nanoparticles (Ag, Co, Ni, CeO2, Fe3O4, TiO2 on rice plants that were weakened by infections of Xanthomonas oryzae pv oryzae bacteria. The results indicate that some NPs increase the rice sensitivity to the pathogen while others decrease the virulence of the pathogen towards rice. No-enrichment in component metal concentration is detected in above organs of rice, with exception of Ni-NPs treatment. An imbalance of major elements in infected rice crops treated with NPs was investigated.

  9. Influence of nutrient composition and plant growth regulators on callus induction and plant regeneration in glutinous rice (Oryza sativa L.).

    Science.gov (United States)

    Duangsee, K; Bunnag, S

    2014-01-01

    The potential for callus induction and regeneration depends on nutrient composition and plant growth regulators. The aim of the present study was to investigate the effect of nutrient composition and plant growth regulators on callus induction and plant regeneration in the glutinous rice cultivar Khunvang. The effect of 2,4-D concentrations (1, 2, 3, 4 and 5 mg L(-1)) on callus induction and growth were investigated. The results revealed that the highest percentage of callus induction (97%) was observed in MS medium supplemented with 5 mg L(-1) 2,4-D under 16 h Photoperiod. The effects of casein hydrolysate concentrations of casein hydrolysate (0, 300, 500, 700 and 900 mg L(-1)) and proline (0, 300, 500, 700 and 900 mg L(-1)) on callus induction and growth of Khunvang were also observed. The results indicated that the increasing casein hydrolysate and proline concentrations did not show a significant effect on callus growth. However, proline concentration of 900 mg L(-1) yielded 85.67% of callus growth.

  10. OryzaGenome: Genome Diversity Database of Wild Oryza Species

    KAUST Repository

    Ohyanagi, Hajime

    2015-11-18

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a textbased browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tabdelimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/ scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

  11. OryzaGenome: Genome Diversity Database of Wild Oryza Species.

    Science.gov (United States)

    Ohyanagi, Hajime; Ebata, Toshinobu; Huang, Xuehui; Gong, Hao; Fujita, Masahiro; Mochizuki, Takako; Toyoda, Atsushi; Fujiyama, Asao; Kaminuma, Eli; Nakamura, Yasukazu; Feng, Qi; Wang, Zi-Xuan; Han, Bin; Kurata, Nori

    2016-01-01

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a text-based browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tab-delimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

  12. 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

  13. Assessing adsorption of polycyclic aromatic hydrocarbons on Rhizopus oryzae cell wall components with water-methanol cosolvent model.

    Science.gov (United States)

    Ma, Bin; Lv, Xiaofei; He, Yan; Xu, Jianming

    2016-03-01

    The contribution of different fungal cell wall components in adsorption of polycyclic aromatic hydrocarbons (PAHs) is still unclear. We isolated Rhizopus oryzae cell walls components with sequential extraction, characterized functional groups with NEXAFS spectra, and determined partition coefficients of PAHs on cell walls and cell wall components with cosolvent model. Spectra of NEXAFS indicated that isolated cell walls components were featured with peaks at ~532.7 and ~534.5eV energy. The lipid cosolvent partition coefficients were approximately one order of magnitude higher than the corresponding carbohydrate cosolvent partition coefficients. The partition coefficients for four tested carbohydrates varied at approximate 0.5 logarithmic units. Partition coefficients between biosorbents and water calculated based cosolvent models ranged from 0.8 to 4.2. The present study proved the importance of fungal cell wall components in adsorption of PAHs, and consequently the role of fungi in PAHs bioremediation.

  14. Risk Assessment of Heavy Metals Contamination in Paddy Soil, Plants, and Grains (Oryza sativa L. at the East Coast of India

    Directory of Open Access Journals (Sweden)

    Deepmala Satpathy

    2014-01-01

    Full Text Available Heavy metals known to be accumulated in plants adversely affect human health. This study aims to assess the effects of agrochemicals especially chemical fertilizers applied in paddy fields, which release potential toxic heavy metals into soil. Those heavy metals get accumulated in different parts of paddy plant (Oryza sativa L. including the grains. Concentrations of nonessential toxic heavy metals (Cd, Cr, and Pb and the micronutrients (Cu, Mn, and Zn were measured in the paddy field soil and plant parts. Mn and Cd are found to be accumulated more in shoot than in root. The metal transfer factors from soil to rice plant were significant for Pb, Cd, Cu, Cr, Mn, and Zn. The ranking order of bioaccumulation factor (BAF for heavy metals was Zn > Mn > Cd > Cu > Cr > Pb indicating that the accumulation of micronutrients was more than that of nonessential toxic heavy metals. The concentrations of heavy metals were found to be higher in paddy field soils than that of the nearby control soil but below permissible limits. The higher Health Index (HI values of rice consuming adults (1.561 and children (1.360 suggest their adverse health effects in the near future.

  15. 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 (Panthocyanins, 520.17mg 100g(-1) of phenolics and 46.50% inhibition of the DPPH radical. A decrease in the color intensity was observed when pH values were changed while anthocyanins were reversible in the process of protonation/deprotonation. The addition of glucose, phytic 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.

  16. Comparison of power output by rice (Oryza sativa) and an associated weed (Echinochloa glabrescens) in vascular plant bio-photovoltaic (VP-BPV) systems.

    Science.gov (United States)

    Bombelli, Paolo; Iyer, Durgaprasad Madras Rajaraman; Covshoff, Sarah; McCormick, Alistair J; Yunus, Kamran; Hibberd, Julian M; Fisher, Adrian C; Howe, Christopher J

    2013-01-01

    Vascular plant bio-photovoltaics (VP-BPV) is a recently developed technology that uses higher plants to harvest solar energy and the metabolic activity of heterotrophic microorganisms in the plant rhizosphere to generate electrical power. In the present study, electrical output and maximum power output variations were investigated in a novel VP-BPV configuration using the crop plant rice (Oryza sativa L.) or an associated weed, Echinochloa glabrescens (Munro ex Hook. f.). In order to compare directly the physiological performances of these two species in VP-BPV systems, plants were grown in the same soil and glasshouse conditions, while the bio-electrochemical systems were operated in the absence of additional energy inputs (e.g. bias potential, injection of organic substrate and/or bacterial pre-inoculum). Diurnal oscillations were clearly observed in the electrical outputs of VP-BPV systems containing the two species over an 8-day growth period. During this 8-day period, O. sativa generated charge ∼6 times faster than E. glabrescens. This greater electrogenic activity generated a total charge accumulation of 6.75 ± 0.87 Coulombs for O. sativa compared to 1.12 ± 0.16 for E. glabrescens. The average power output observed over a period of about 30 days for O. sativa was significantly higher (0.980 ± 0.059 GJ ha(-1) year(-1)) than for E. glabrescens (0.088 ± 0.008 GJ ha(-1) year(-1)). This work indicates that electrical power can be generated in both VP-BPV systems (O. sativa and E. glabrescens) when bacterial populations are self-forming. Possible reasons for the differences in power outputs between the two plant species are discussed.

  17. Investigation of the biological roles of autophagy in appressorium morphogenesis in Magnaporthe oryzae

    Institute of Scientific and Technical Information of China (English)

    Xiao-hong LIU; Fu-cheng LIN

    2008-01-01

    Magnaporthe oryzae has been used as a primary model organism for investigating fungus-plant interaction. Many researches focused on molecular mechanisms of appressorium formation to restrain this fungal pathogen. Autophagy is a very high conserved process in eukaryotic cells. Recently, autophagy has been considered as a key process in development and differentiation in M. oryzae. In this report, we present and discuss the current state of our knowledge on gene expression in appressorium formation and the progress in autophagy of rice blast fungi.

  18. Production of biodiesel from plant oil hydrolysates using an Aspergillus oryzae whole-cell biocatalyst highly expressing Candida antarctica lipase B.

    Science.gov (United States)

    Adachi, Daisuke; Hama, Shinji; Nakashima, Kazunori; Bogaki, Takayuki; Ogino, Chiaki; Kondo, Akihiko

    2013-05-01

    For enzymatic biodiesel production from plant oil hydrolysates, an Aspergillus oryzae whole-cell biocatalyst that expresses Candida antarctica lipase B (r-CALB) with high esterification activity was developed. Each of soybean and palm oils was hydrolyzed using Candida rugosa lipase, and the resultant hydrolysates were subjected to esterification where immobilized r-CALB was used as a catalyst. In esterification, r-CALB afforded a methyl ester content of more than 90% after 6 h with the addition of 1.5 M equivalents of methanol. Favorably, stepwise additions of methanol and a little water were unnecessary for maintaining the lipase stability of r-CALB during esterification. During long-term esterification in a rotator, r-CALB can be recycled for 20 cycles without a significant loss of lipase activity, resulting in a methyl ester content of more than 90% even after the 20th batch. Therefore, the presented reaction system using r-CALB shows promise for biodiesel production from plant oil hydrolysates.

  19. Role of blue green algae biofertilizer in ameliorating the nitrogen demand and fly-ash stress to the growth and yield of rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Tripathi, R D; Dwivedi, S; Shukla, M K; Mishra, S; Srivastava, S; Singh, R; Rai, U N; Gupta, D K

    2008-02-01

    Rice is a major food crop throughout the world; however, accumulation of toxic metals and metalloids in grains in contaminated environments is a matter of growing concern. Field experiments were conducted to analyze the growth performance, elemental composition (Fe, Si, Zn, Mn, Cu, Ni, Cd and As) and yield of the rice plants (Oryza sativa L. cv. Saryu-52) grown under different doses of fly-ash (FA; applied @ 10 and 100 tha(-1) denoted as FA(10) and FA(100), respectively) mixed with garden soil (GS) in combination with nitrogen fertilizer (NF; applied @ 90 and 120 kg ha(-1) denoted as NF(90) and NF(120), respectively) and blue green algae biofertilizer (BGA; applied @ 12.5 kg ha(-1) denoted as BGA(12.5)). Significant enhancement of growth was observed in the plants growing on amended soils as compared to GS and best response was obtained in amendment of FA(10)+NF(90)+BGA(12.5). Accumulation of Si, Fe, Zn and Mn was higher than Cu, Cd, Ni and As. Arsenic accumulation was detected only in FA(100) and its amendments. Inoculation of BGA(12.5) caused slight reduction in Cd, Ni and As content of plants as compared to NF(120) amendment. The high levels of stress inducible non-protein thiols (NP-SH) and cysteine in FA(100) were decreased by application of NF and BGA indicating stress amelioration. Study suggests integrated use of FA, BGA and NF for improved growth, yield and mineral composition of the rice plants besides reducing the high demand of nitrogen fertilizers.

  20. Action of Multiple Cell Wall-Degrading Enzymes Is Required for Elicitation of Innate Immune Responses During Xanthomonas oryzae pv. oryzae Infection in Rice.

    Science.gov (United States)

    Tayi, Lavanya; Maku, Roshan; Patel, Hitendra Kumar; Sonti, Ramesh V

    2016-08-01

    Xanthomonas oryzae pv. oryzae secretes a number of plant cell wall-degrading enzymes (CWDEs) whose purified preparations induce defense responses in rice. These defense responses are suppressed by X. oryzae pv. oryzae using type 3 secretion system (T3SS) effectors and a type 3 secretion system mutant (T3SS(-)) of X. oryzae pv. oryzae is an inducer of rice defense responses. We assessed the role of individual CWDEs in induction of rice defense responses during infection, by mutating them in the genetic background of a T3SS(-). We mutated the genes for five different plant CWDEs secreted by X. oryzae pv. oryzae, including two cellulases (clsA and cbsA), one xylanase (xyn), one pectinase (pglA), and an esterase (lipA), singly in a T3SS(-) background. We have demonstrated that, as compared with a T3SS(-) of X. oryzae pv. oryzae, a cbsA(-)T3SS(-), a clsA(-)T3SS(-), and a xyn(-)T3SS(-) are deficient in induction of rice immune responses such as callose deposits and programmed cell death. In comparison, a lipA(-) T3SS(-) and a pglA(-)T3SS(-) is as efficient in induction of host defense responses as a T3SS(-). Overall, these results indicate that the collective action of X. oryzae pv. oryzae-secreted ClsA, CbsA, and Xyn proteins is required for induction of rice defense responses during infection.

  1. 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.

  2. Domain analysis of 3 Keto Acyl-CoA synthase for structural variations in Vitis vinifera and Oryza brachyantha using comparative modelling.

    Science.gov (United States)

    Sagar, Mamta; Pandey, Neetesh; Qamar, Naseha; Singh, Brijendra; Shukla, Akanksha

    2015-03-01

    The long chain fatty acids incorporated into plant lipids are derived from the iterative addition of C2 units which is provided by malonyl-CoA to an acyl-CoA after interactions with 3-ketoacyl-CoA synthase (KCS), found in several plants. This study provides functional characterization of three 3 ketoacyl CoA synthase like proteins in Vitis vinifera (one) and Oryza brachyantha (two proteins). Sequence analysis reveals that protein of Oryza brachyantha shows 96% similarity to a hypothetical protein in Sorghum bicolor; total 11 homologs were predicted in Sorghum bicolor. Conserved domain prediction confirm the presence of FAE1/Type III polyketide synthase-like protein, Thiolase-like, subgroup; Thiolase-like and 3-Oxoacyl-ACP synthase III, C-terminal and chalcone synthase like domain but very long chain 3-keto acyl CoA domain is absent. All three proteins were found to have Chalcone and stilbene synthases C terminal domain which is similar to domain of thiolase and β keto acyl synthase. Its N terminal domain is absent in J3M9Z7 protein of Oryza brachyantha and F6HH63 protein of Vitis vinifera. Differences in N-terminal domain is responsible for distinguish activity. The J3MF16 protein of Oryza brachyantha contains N terminal domain and C terminal domain and characterized using annotation of these domains. Domains Gcs (streptomyces coelicolor) and Chalcone-stilbene synthases (KAS) in 2-pyrone synthase (Gerbera hybrid) and chalcone synthase 2 (Medicago sativa) were found to be present in three proteins. This similarity points toward anthocyanin biosynthetic process. Similarity to chalcone synthase 2 reveals its possible role in Naringenine and Chalcone synthase like activity. In 3 keto acyl CoA synthase of Oryza brachyantha. Active site residues C-240, H-407, N-447 are present in J3MF16 protein that are common in these three protein at different positions. Structural variations among dimer interface, product binding site, malonyl-CoA binding sites, were predicted in

  3. Emerging Importance of Helicases in Plant Stress Tolerance: Characterization of Oryza sativa Repair Helicase XPB2 Promoter and Its Functional Validation in Tobacco under Multiple Stresses.

    Science.gov (United States)

    Raikwar, Shailendra; Srivastava, Vineet K; Gill, Sarvajeet S; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. Helicases, the unique molecular motors, are emerged as prospective molecules to engineer stress tolerance in plants and are involved in nucleic acid metabolism including DNA repair. The repair helicase, XPB is an evolutionary conserved protein present in different organisms, including plants. Availability of few efficient promoters for gene expression in plants provoked us to study the promoter of XPB for better understanding of gene regulation under stress conditions. Here, we report the in silico analysis of novel stress inducible promoter of Oryza sativa XPB2 (OsXPB2). The in vivo validation of functionality/activity of OsXPB2 promoter under abiotic and hormonal stress conditions was performed by Agrobacterium-mediated transient assay in tobacco leaves using OsXPB2::GUS chimeric construct. The present research revealed that OsXPB2 promoter contains cis-elements accounting for various abiotic stresses (salt, dehydration, or cold) and hormone (Auxin, ABA, or MeJA) induced GUS expression/activity in the promoter-reporter assay. The promoter region of OsXPB2 contains CACG, GTAACG, CACGTG, CGTCA CCGCCGCGCT cis acting-elements which are reported to be salt, dehydration, cold, MeJA, or ABA responsive, respectively. Functional analysis was done by Agrobacterium-mediated transient assay using agroinfiltration in tobacco leaves, followed by GUS staining and fluorescence quantitative analyses. The results revealed high induction of GUS activity under multiple abiotic stresses as compared to mock treated control. The present findings suggest that OsXPB2 promoter is a multi-stress inducible promoter and has potential applications in sustainable crop production under abiotic stresses by regulating desirable pattern of gene expression.

  4. 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.

  5. Characterization of N2-fixing plant growth promoting endophytic and epiphytic bacterial community of Indian cultivated and wild rice (Oryza spp.) genotypes.

    Science.gov (United States)

    Banik, Avishek; Mukhopadhaya, Subhra Kanti; Dangar, Tushar Kanti

    2016-03-01

    The diversity of endophytic and epiphytic diazotrophs in different parts of rice plants has specificity to the niche (i.e. leaf, stem and root) of different genotypes and nutrient availability of the organ. Inoculation of the indigenous, polyvalent diazotrophs can facilitate and sustain production of non-leguminous crops like rice. Therefore, N2-fixing plant growth promoting bacteria (PGPB) were isolated from different parts of three Indian cultivated [Oryza sativa L. var. Sabita (semi deep/deep water)/Swarna (rain fed shallow lowland)/Swarna-Sub1(submergence tolerant)] and a wild (O. eichingeri) rice genotypes which respond differentially to nitrogenous fertilizers. Thirty-five isolates from four rice genotypes were categorized based on acetylene reduction assay on nitrogenase activity, biochemical tests, BIOLOG and 16S rRNA gene sequencing. The bacteria produced 9.36-155.83 nmole C2H4 mg(-1) dry bacteria h(-1) and among them nitrogenase activity of 11 potent isolates was complemented by nifH-sequence analysis. Phylogenetic analysis based on 16S rDNA sequencing divided them into five groups (shared 95-100 % sequence homology with type strains) belonging to five classes-alpha (Ancylobacter, Azorhizobium, Azospirillum, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium, spp.), beta (Burkholderia sp.), gamma (Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas spp.) Proteobacteria, Bacilli (Bacillus, Paenibacillus spp.) and Actinobacteria (Microbacterium sp.). Besides, all bacterial strains possessed the intrinsic PGP traits of like indole (0.44-7.4 µg ml(-1)), ammonia (0.18-6 mmol ml(-1)), nitrite (0.01-3.4 mol ml(-1)), and siderophore (from 0.16-0.57 μmol ml(-1)) production. Inoculation of rice (cv. Swarna) seedlings with selected isolates had a positive impact on plant growth parameters like shoot and root elongation which was correlated with in vitro PGP attributes. The results indicated that the

  6. Relationship between xanthophyll cycle and non-photochemical quenching in rice (Oryza sativa L.) plants in response to light stress.

    Science.gov (United States)

    Vaz, Janet; Sharma, Prabhat K

    2011-01-01

    Thirty days old rice plants grown under low and moderate light conditions were transferred to full sunlight to observe the extent of photoinhibitory damage and protective mechanism, and the relationship between xanthophyll cycle and nonphotochemical quenching (qN) under changing light environment. Control plants (low, moderate and sun grown) exhibited similar Fv/Fm ratio, indicating similar photosynthetic efficiency prior to light stress. On exposure to the high light treatment, low light grown plants exhibited faster and higher degree of photoinhibition compared to moderate and high light grown plants. Moderate and high light grown plants showed relatively less photoinhibition and also showed higher qN, indicating better capacity of energy dissipation. Increase in qN in moderate light and sun grown plants was accompanied by conversion of violaxanthin (V) to antheraxanthin (A) and zeaxanthin (Z) indicating operation of Z-dependent thermal dissipation. Rice plants fed with ascorbate (AsA), a stimulator of the de-epoxidation state of V to Z, showed higher Fv/Fm ratio and qN than the plants fed with dithiothreitol (DTT) an inhibitor of xanthophyll cycle. This indicated that an increased amount of energy reached PS II reaction centre, due to absence of A and Z formation, thereby causing greater damage to photosynthesis in DTT fed rice plants. The present data confirmed the relationship between qN and Z in dissipating the excess light energy, thereby protecting plants against photodamage.

  7. Studies on the bioactivity of marine microorganisms using Pyricularia oryzae model

    Institute of Scientific and Technical Information of China (English)

    WEN Zhanbo; PEI Yuehu; TIAN Li; GAO Aiguo; HONG Xuguang; LI Xianchun

    2006-01-01

    A total of 2 088 marine microorganisms including 1 392 strains of bacteria and 696 strains of fungi were isolated from diverse marine environment such as the South Pole, the North Pole, and Qingdao tideland, etc. Through a systematic screening process involving the use of Pyricularia oryzae mode, 90 bacteria and 31 fungi strains demonstrating positive bioactivities were identified. The rates of active strains of marine bacteria and marine fungi were 6.5% and 4.5%, respectively. The relationships between the active strains and the sampling locations and hosts were studied. For marine bacteria, the three locations showing the highest rates of active strains were 8.4% in the Zhujiang Estuary, 7.2% at the North Pole and 6.3% in the Bohai Sea. For marine fungi, the highest rates observed were 7.8% at the South Pole, 7.4% in the South China Sea and 6.8% at the Qingdao tideland. An analysis of the host showed that the three highest rates of active strain for marine bacteria were 8.2% for seawater from the Zhujiang Estuary, 8% for alga from the Qingdao tideland and 7.6% for sea mud from the North Pole. For marine fungi, the highest rates observed were 8.3% for Qingdao actiniae, 7.4% for South China Sea poriferan and 4.5% for soil of Qingdao Suaeda salsa. Four fungi and two bacteria samples were selected for further study because of their high bioactivity. They were found to be active towards several pathogenic microorganisms, and demonstrated stable genetic and thermal characteristics and conservation activities.

  8. Structure-function analysis of a CVNH-LysM lectin expressed during plant infection by the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Koharudin, Leonardus M I; Viscomi, Arturo R; Montanini, Barbara; Kershaw, Michael J; Talbot, Nicholas J; Ottonello, Simone; Gronenborn, Angela M

    2011-05-11

    The rice blast fungus Magnaporthe oryzae's genome encodes a hypothetical protein (MGG_03307) containing a type III CVNH lectin, in which a LysM domain is inserted between individual repeats of a single CVNH domain. At present, no structural or ligand binding data are available for any type III CVNH and functional studies in natural source organisms are scarce. Here, we report NMR solution structure and functional data on MGG_03307. The structure of the CVNH/LysM module revealed that intact and functionally competent CVNH and LysM domains are present. Using NMR titrations, carbohydrate specificities for both domains were determined, and it was found that each domain behaves as an isolated unit without any interdomain communication. Furthermore, live-cell imaging revealed a predominant localization of MGG_03307 within the appressorium, the specialized fungal cell for gaining entry into rice tissue. Our results suggest that MGG_03307 plays a role in the early stages of plant infection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Role of silicon in alleviation of iron deficiency and toxicity in hydroponically-grown rice (Oryza sativa L.) plants

    OpenAIRE

    A Abdol Zadeh; z Kiani Chalmardi

    2013-01-01

    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 nutritio...

  10. 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

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

    Institute of Scientific and Technical Information of China (English)

    Jingting; Zhang; Liping; Feng; Haiping; Zou; De; Li; Liu

    2015-01-01

    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 western region of

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

    Institute of Scientific and Technical Information of China (English)

    Jingting Zhang; Liping Feng; Haiping Zou; De Li Liu

    2015-01-01

    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 western region of Songnen

  13. Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis

    Directory of Open Access Journals (Sweden)

    Abdjad Asih Nawangsih

    2011-04-01

    Full Text Available Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis. X. oryzae pv. oryzae (Xoo causes bacterial leaf blight (BLB of rice (Oryza sativa L., a major disease that constrains production of the staple crop in many countries of the world. Identification of X. oryzae pv. oryzae (Xoo was conducted based on the disease symptoms, pathogenicity, morphological, physiological, and genetic characteristics of bacterial cultures isolated from the infected plants. Fifty bacterial isolates predicted as Xoo have been successfully isolated. They are aerobic, rod shaped, and Gram negative bacteria. The isolates were evaluated for their hypersensitivity in tobacco and pathogenicity in rice plant. Fifty isolates induced hypersensitive reaction in tobacco and showed pathogenicity symptom in rice in different length. Based on physiological test, hypersensitivity and pathogenicity reactions, three bacterial isolates strongly predicted as Xoo, i.e. STG21, STG42, and STG46, were non indole formation, non pigment fluorescent, hydrolyzed casein, catalase activity positive, but negative oxidase. Partial sequencing of 16S rRNA genes of STG21 and STG42 showed 80% and 82% homology with X. oryzae, respectively, while STG46 showed 84% homology with X. campestris. Mini-Tn5 transposon mutagenesis of STG21 generated one of the mutants (M5 lossed it’s ability to induce hypersensitive reaction in tobacco plant and deficient in pathogenicity on rice. The lesion length of rice leaf caused by the mutant M5 decreased up to 80%.

  14. Introduction of cecropin B gene into rice (Oryza sativa L.) by particle bombardment and analysis of transgenic plants

    Institute of Scientific and Technical Information of China (English)

    黄大年; 朱冰; 杨炜; 薛锐; 肖晗; 田文忠; 李良材; 戴顺洪

    1996-01-01

    An expression vector pCBl suitable for rice transformation, harboring a synthesized cecropin B gene and a selectable marker gene (bar), was constructed. It was introduced into immature embryos of two japonica varieties by particle bombardment, and several transgenic plants were obtained. The results from Basta treatment, PCR analysis, dot and Southern blot analysis of cecropin B gene in transgenic plants indicated that both bar and cecropin B gene were integrated into the genome of transformed plants. Northern blot analysis of transgenic plants showed the expression of cecropin B gene at transcriptional level. Some of transgenic plants revealed improved resistances to two types of bacterial diseases, rice bacterial blight and rice bacterial streak to different extent.

  15. 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.

  16. Functional identiifcation of phenazine biosynthesis genes in plant pathogenic bacteriaPseudomonas syringae pv.tomato and Xanthomonas oryzaepv.oryzae

    Institute of Scientific and Technical Information of China (English)

    LI Wen; XU You-ping; Jean-Pierre Munyampundu; XU Xin; QI Xian-fei; GU Yuan; CAI Xin-zhong

    2016-01-01

    Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identiifed phenazine biosynthesis (phz) genes in two genome-completed plant pathogenic bacteriaPseudomonas syringae pv.tomato(Pst) DC3000 andXanthomonas oryzaepv.oryzae(Xoo) PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads,phz homologs inPst DC3000 andXoo PXO99A consisted of phzC/D/E/F/G andphzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-1-carboxylic acid (PCA) ofPst DC3000 accumulated to 13.4 μg L–1, while that ofXoo PXO99A was almost undetectable. Moreover,Pst DC3000 was resistant to 1 mg mL–1 PCA, whileXoo PXO99A was sensitive to 50 μg mL–1 PCA. Furthermore, mutation ofphzF blocked the PCA production and signiifcantly reduced the pathogenicity ofPst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed thatPst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologicaly controled by phenazines. Additionaly,phz-mediated PCA production is required for ful pathogenicity ofPst DC3000. To our knowledge, this is the ifrst report of PCA production and its function in pathogenicity of a plant pathogenicP. syringaestrain.

  17. Uncovering a Nuisance Influence of a Phenological Trait of Plants Using a Nonlinear Structural Equation: Application to Days to Heading and Culm Length in Asian Cultivated Rice (Oryza Sativa L.).

    Science.gov (United States)

    Onogi, Akio; Ideta, Osamu; Yoshioka, Takuma; Ebana, Kaworu; Yamasaki, Masanori; Iwata, Hiroyoshi

    2016-01-01

    Phenological traits of plants, such as flowering time, are linked to growth phase transition. Thus, phenological traits often influence other traits through the modification of the duration of growth period. This influence is a nuisance in plant breeding because it hampers genetic evaluation of the influenced traits. Genetic effects on the influenced traits have two components, one that directly affects the traits and one that indirectly affects the traits via the phenological trait. These cannot be distinguished by phenotypic evaluation and ordinary linear regression models. Consequently, if a phenological trait is modified by introgression or editing of the responsible genes, the phenotypes of the influenced traits can change unexpectedly. To uncover the influence of the phenological trait and evaluate the direct genetic effects on the influenced traits, we developed a nonlinear structural equation (NSE) incorporating a nonlinear influence of the phenological trait. We applied the NSE to real data for cultivated rice (Oryza sativa L.): days to heading (DH) as a phenological trait and culm length (CL) as the influenced trait. This showed that CL of the cultivars that showed extremely early heading was shortened by the strong influence of DH. In a simulation study, it was shown that the NSE was able to infer the nonlinear influence and direct genetic effects with reasonable accuracy. However, the NSE failed to infer the linear influence in this study. When no influence was simulated, an ordinary bi-trait linear model (OLM) tended to infer the genetic effects more accurately. In such cases, however, by comparing the NSE and OLM using an information criterion, we could assess whether the nonlinear assumption of the NSE was appropriate for the data analyzed. This study demonstrates the usefulness of the NSE in revealing the phenotypic influence of phenological traits.

  18. 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.

  19. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  20. The influence of plant spacing in the early stages of selection of rice (Oryza sativa L.) varieties

    Energy Technology Data Exchange (ETDEWEB)

    Torró, I.; Bretó, P.; García-Yzaguirre, A.

    2016-11-01

    The cultural practices of the early generations in a pedigree breeding programme may influence its success. The main objective of this study was to compare two selection environments in rice: Widely spaced planting in the field and dense planting in concrete basins. Both methods had yielded commercial varieties in the past. Two F2 populations (J and MS), derived from two crosses sharing the same female parent, were transplanted to both environments. Phenotypic traits were evaluated and their narrow sense heritabilities (h2) estimated in the F3 and in the F4 progenies of selected plants, all grown in the field. Growth potential was more apparent in the field for most traits, especially those related to yield, but broad sense heritabilities were higher in the basins for ten traits, being higher in the field for the other five. In population F2MS, field selection resulted in F3 plants which retained a higher tillering ability than those derived from basins selection. Most traits showed low h2 values: Additive variance was only relevant in panicle length (in both populations), plant height and mean panicle weight (in the J population). However, response to one generation of selection (from F3 to F4) also showed fixable variation in panicle number. In addition, this selection reduced plant height, increased culm diameter and internode length (in both populations), and improved pulling resistance (against lodging) in population J. It may be concluded that both practices can be used for selection in the F2, although different responses might be expected in yield related traits. (Author)

  1. The influence of plant spacing in the early stages of selection of rice (Oryza sativa L. varieties

    Directory of Open Access Journals (Sweden)

    Isabel Torró

    2016-06-01

    Full Text Available The cultural practices of the early generations in a pedigree breeding programme may influence its success. The main objective of this study was to compare two selection environments in rice: Widely spaced planting in the field and dense planting in concrete basins. Both methods had yielded commercial varieties in the past. Two F2 populations (J and MS, derived from two crosses sharing the same female parent, were transplanted to both environments. Phenotypic traits were evaluated and their narrow sense heritabilities (h2 estimated in the F3 and in the F4 progenies of selected plants, all grown in the field. Growth potential was more apparent in the field for most traits, especially those related to yield, but broad sense heritabilities were higher in the basins for ten traits, being higher in the field for the other five. In population F2MS, field selection resulted in F3 plants which retained a higher tillering ability than those derived from basins selection. Most traits showed low h2 values: Additive variance was only relevant in panicle length (in both populations, plant height and mean panicle weight (in the J population. However, response to one generation of selection (from F3 to F4 also showed fixable variation in panicle number. In addition, this selection reduced plant height, increased culm diameter and internode length (in both populations, and improved pulling resistance (against lodging in population J. It may be concluded that both practices can be used for selection in the F2, although different responses might be expected in yield related traits.

  2. Zinc Concentration in Rice (Oryza sativa L.) Grains and Allocation in Plants as Affected by Different Zinc Fertilization Strategies

    NARCIS (Netherlands)

    Yin, Hong Juan; Gao, Xiao Peng; Stomph, Tjeerd Jan; Li, Lu Jiu; Zhang, Fu Suo; Zou, Chun Qin

    2016-01-01

    Concern over the food chain transfer of zinc (Zn) is increasing because of its importance in human health. A field experiment was conducted on a low Zn soil to determine the effect of different Zn fertilization strategies on grain Zn concentration and Zn allocation in different plant tissues of r

  3. Modeling plants with sensor data

    Institute of Scientific and Technical Information of China (English)

    MA Wei; XIANG Bo; ZHA HongBin; LIU Jia; ZHANG XiaoPeng

    2009-01-01

    Sensor data,typically images and laser data,are essential to modeling real plants.However,due to the complex geometry of the plants,the measurement data are generally limited,thereby bringing great difficulties in classifying and constructing plant organs,comprising leaves and branches.The paper presents an approach to modeling plants with the sensor data by detecting reliable sharp features,i.e.the leaf apexes of the plants with leaves and the branch tips of the plants without leaves,on volumes recovered from the raw data.The extracted features provide good estimations of correct positions of the organs.Thereafter,the leaves are reconstructed separately by simply fitting and optimizing a generic leaf model.One advantage of the method is that it involves limited manual intervention.For plants without leaves,we develop an efficient strategy for decomposition-based skeletonization by using the tip features to reconstruct the 3D models from noisy laser data.Experiments show that the sharp feature detection algorithm is effective,and the proposed plant modeling approach is competent in constructing realistic models with sensor data.

  4. Cloning of a putative monogalactosyldiacylglycerol synthase gene from rice (Oryza sativa L.) plants and its expression in response to submergence and other stresses.

    Science.gov (United States)

    Qi, Yanhua; Yamauchi, Yasuo; Ling, Jianqun; Kawano, Naoyoshi; Li, Debao; Tanaka, Kiyoshi

    2004-07-01

    Suppression subtractive hybridization was used to construct a subtractive cDNA library from plants of non-submerged and 7-day-submerged rice (Oryza sativa L., FR13A, a submergence-tolerant cultivar). One clone of the subtractive cDNA library, S23, was expressed abundantly during submergence. The full length of S23 was amplified using 5'- and 3'-rapid amplification of cDNA ends, and found to consist of 1,671 bp with an open reading frame of 1,077 bp (181-1257) encoding 358 amino acids. Its deduced amino acid sequence showed a high homology with monogalactosyldiacylglycerol synthase (UDPgalactose: 1,2-diacylglycerol 3-beta-D-galactosyl transferase; EC 2.4.1.46, MGDG synthase) from Arabidopsis thaliana; therefore, we named the gene OsMGD. Time-course studies showed that the expression of OsMGD in the rice cultivars FR13A and IR42 (submergence-susceptive cultivar) during submergence was gradually increased and that expression in FR13A was higher than in IR42. The expression of OsMGD in FR13A was influenced by benzyladenine and illumination. The accumulation of OsMGD mRNA in both FR13A and IR42 was also increased by ethephon, gibberellin, drought and salt treatment, but cold stress had no effect on the expression of the gene. These results suggest that the expression of OsMGD mRNA requires benzyladenine or illumination, and that the process is also mediated by ethephon and gibberellin. Salt and drought stress have an effect similar to that of submergence. Furthermore, the enhanced expression of OsMGD may relate to photosynthesis, and play an important role during submergence.

  5. Identification of QTLs for Plant Height and Its Components by Using Single Segment Substitution Lines in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    HE Feng-hua; XI Zhang-ying; ZENG Rui-zhen; Akshay TALUKDAR; ZHANG Gui-quan

    2005-01-01

    QTLs for plant height and its components on the substituted segments of fifty-two single segment substitution lines (SSSLs)in rice were identified through t-test (P≤0.001) for comparison between each SSSL and recipient parent Huajingxian 74. On the 14 substituted segments, 24 QTLs were detected, 10 for plant height, 2 for panicle length, 4 for length of thefirst internode from the top,5 for length of the second internode from the top and 3 for length of the third internode from the top, respectively. All these QTLs were distributed on nine rice chromosomes except chromosomes 5, 9 and 11. The additive effect ranged from -4.08 to 3.98 cm, and the additive effect percentages varied from -19.35% to 10.43%.

  6. Endophytic colonization of rice (Oryza sativa L.) by the diazotrophic bacterium Burkholderia kururiensis and its ability to enhance plant growth

    OpenAIRE

    Mattos, Katherine A; Vania L.M. Pádua; Alexandre Romeiro; Hallack,Leticia F.; Bianca C. Neves; Tecia M.U. Ulisses; Claudia F. Barros; Adriane R Todeschini; Previato, José O.; Lucia Mendonça-Previato

    2008-01-01

    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 ino...

  7. Indoleacetic acid production and plant growth promoting potential of bacterial endophytes isolated from rice (Oryza sativa L.) seeds.

    Science.gov (United States)

    Shahzad, Raheem; Waqas, Muhammad; Khan, Abdul Latif; Al-Hosni, Khadija; Kang, Sang-Mo; Seo, Chang-Woo; Lee, In-Jung

    2017-06-01

    Bacterial endophytes from the phyllosphere and rhizosphere have been used to produce bioactive metabolites and to promote plant growth. However, little is known about the endophytes residing in seeds. This study aimed to isolate and identify seed-borne bacterial endophytes from rice and elucidate their potential for phytohormone production and growth enhancement. The isolated endophytes included Micrococcus yunnanensis RWL-2, Micrococcus luteus RWL-3, Enterobacter soli RWL-4, Leclercia adecarboxylata RWL-5, Pantoea dispersa RWL-6, and Staphylococcus epidermidis RWL-7, which were identified using 16S rRNA sequencing and phylogenetic analysis. These strains were analyzed for indoleacetic acid (IAA) production by using GC-MS and IAA was found in the range of 11.50 ± 0.77 μg ml(-1) to 38.80 ± 1.35 μg ml(-1). We also assessed the strains for plant growth promoting potential because these isolates were able to produce IAA in pure culture. Most of the growth attributes of rice plants (shoot and root length, fresh and dry biomass, and chlorophyll content) were significantly increased by bacterial endophytes compared to the controls. These results show that IAA producing bacterial endophytes can improve hostplant growth traits and can be used as bio-fertilizers.

  8. Plant innate immunity multicomponent model

    Directory of Open Access Journals (Sweden)

    Giuseppe eAndolfo

    2015-11-01

    Full Text Available Our understanding of plant–pathogen interactions is making rapid advances in order to address issues of global importance such as improving agricultural productivity and sustainable food security. Innate immunity has evolved in plants, resulting in a wide diversity of defence mechanisms adapted to specific threats. The postulated PTI/ETI model describes two perception layers of plant innate immune system, which belong to a first immunity component of defence response activation. To better describe the sophisticated defence system of plants, we propose a new model of plant immunity. This model considers the plant’s ability to distinguish the feeding behaviour of their many foes, such as a second component that modulates innate immunity. This hypothesis provides a new viewpoint highlighting the relevance of hormone crosstalk and primary metabolism in regulating plant defence against the different behaviours of pathogens with the intention to stimulate further interest in this research area.

  9. 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

  10. Rice blast fungus (Magnaporthe oryzae) infects Arabidopsis via a mechanism distinct from that required for the infection of rice.

    Science.gov (United States)

    Park, Ju-Young; Jin, Jianming; Lee, Yin-Won; Kang, Seogchan; Lee, Yong-Hwan

    2009-01-01

    Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice (Oryza sativa) blast. Although M. oryzae as a whole infects a wide variety of monocotyledonous hosts, no dicotyledonous plant has been reported as a host. We found that two rice pathogenic strains of M. oryzae, KJ201 and 70-15, interacted differentially with 16 ecotypes of Arabidopsis (Arabidopsis thaliana). Strain KJ201 infected all ecotypes with varying degrees of virulence, whereas strain 70-15 caused no symptoms in certain ecotypes. In highly susceptible ecotypes, small chlorotic lesions appeared on infected leaves within 3 d after inoculation and subsequently expanded across the affected leaves. The fungus produced spores in susceptible ecotypes but not in resistant ecotypes. Fungal cultures recovered from necrotic lesions caused the same symptoms in healthy plants, satisfying Koch's postulates. Histochemical analyses showed that infection by the fungus caused an accumulation of reactive oxygen species and eventual cell death. Similar to the infection process in rice, the fungus differentiated to form appressorium and directly penetrated the leaf surface in Arabidopsis. However, the pathogenic mechanism in Arabidopsis appears distinct from that in rice; three fungal genes essential for pathogenicity in rice played only limited roles in causing disease symptoms in Arabidopsis, and the fungus seems to colonize Arabidopsis as a necrotroph through the secretion of phytotoxic compounds, including 9,12-octadecadienoic acid. Expression of PR-1 and PDF1.2 was induced in response to infection by the fungus, suggesting the activation of salicylic acid- and jasmonic acid/ethylene-dependent signaling pathways. However, the roles of these signaling pathways in defense against M. oryzae remain unclear. In combination with the wealth of genetic and genomic resources available for M. oryzae, this newly established pathosystem allows comparison of the molecular and cellular mechanisms underlying

  11. Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

    NARCIS (Netherlands)

    Heinemann, A.B.; Oort, van P.A.J.; Simoes Fernandes, D.; Maia, A.H.N.

    2012-01-01

    Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs) data severely limits site-specific crop modelling. The objective of this

  12. Influence of sulfur on the accumulation of mercury in rice plant (Oryza sativa L.) growing in mercury contaminated soils.

    Science.gov (United States)

    Li, Yunyun; Zhao, Jiating; Guo, Jingxia; Liu, Mengjiao; Xu, Qinlei; Li, Hong; Li, Yu-Feng; Zheng, Lei; Zhang, Zhiyong; Gao, Yuxi

    2017-09-01

    Sulfur (S) is an essential element for plant growth and its biogeochemical cycling is strongly linked to the species of heavy metals in soil. In this work, the effects of S (sulfate and elemental sulfur) treatment on the accumulation, distribution and chemical forms of Hg in rice growing in Hg contaminated soil were investigated. It was found that S could promote the formation of iron plaque on the root surface and decrease total mercury (T-Hg) and methylmercury (MeHg) accumulation in rice grains, straw, and roots. Hg in the root was dominated in the form of RS-Hg-SR. Sulfate treatment increased the percentage of RS-Hg-SR to T-Hg in the rice root and changed the Hg species in soil. The dominant Hg species (70%) in soil was organic substance bound fractions. Sulfur treatment decreased Hg motility in the rhizosphere soils by promoting the conversion of RS-Hg-SR to HgS. This study is significant since it suggests that low dose sulfur treatment in Hg-containing water irrigated soil can decrease both T-Hg and MeHg accumulation in rice via inactivating Hg in the soil and promoting the formation of iron plaque in rice root, which may reduce health risk for people consuming those crops. Copyright © 2017. Published by Elsevier Ltd.

  13. Nitrogen can improve the rapid response of photosynthesis to changing irradiance in rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Sun, Jiali; Ye, Miao; Peng, Shaobing; Li, Yong

    2016-08-10

    To identify the effect of nitrogen (N) nutrition on the dynamic photosynthesis of rice plants, a pot experiment was conducted under two N conditions. The leaf N and chlorophyll levels, as well as steady-state photosynthesis, were significantly increased under high N. After the transition from saturating to low light levels, decreases in the induction state (IS%) of leaf photosynthesis (A) and stomatal conductance (gs) were more severe under low than under high N supply. After the transition from low to flecked irradiance, the times to 90% of maximum A (T90%A) were significantly longer under low than under high N supply. Under flecked irradiance, the maximum A under saturating light (Amax-fleck) and the steady-state A under low light (Amin-fleck) were both lower than those under uniform irradiance (Asat and Ainitial). Under high N supply, Amax-fleck was 14.12% lower than Asat, while it was 22.80% lower under low N supply. The higher IS%, shorter T90%A, and the lower depression of Amax-fleck from Asat under high N supply led to a less carbon loss compared with under a low N supply. Therefore, we concluded that N can improve the rapid response of photosynthesis to changing irradiance.

  14. Silicate mineral impacts on the uptake and storage of arsenic and plant nutrients in rice ( Oryza sativa L.).

    Science.gov (United States)

    Seyfferth, Angelia L; Fendorf, Scott

    2012-12-18

    Arsenic-contaminated rice grain may threaten human health globally. Since H₃AsO₃⁰ is the predominant As species found in paddy pore-waters, and H₄SiO₄⁰ and H₃AsO₃⁰ share an uptake pathway, silica amendments have been proposed to decrease As uptake and consequent As concentrations in grains. Here, we evaluated the impact of two silicate mineral additions differing in solubility (+Si(L), diatomaceous earth, 0.29 mM Si; +Si(H), Si-gel, 1.1 mM Si) to soils differing in mineralogy on arsenic concentration in rice. The +Si(L) addition either did not change or decreased As concentration in pore-water but did not change or increased grain-As levels relative to the (+As--Si) control. The +Si(H) addition increased As in pore-water, but it significantly decreased grain-As relative to the (+As--Si) control. Only the +Si(H) addition resulted in significant increases in straw- and husk-Si. Total grain- and straw-As was negatively correlated with pore-water Si, and the relationship differed between two soils exhibiting different mineralogy. These differing results are a consequence of competition between H₄SiO₄⁰ and H₃AsO₃⁰ for adsorption sites on soil solids and subsequent plant-uptake, and illustrate the importance of Si mineralogy on arsenic uptake.

  15. Linear and Nonlinear Regression Methods for Equilibrium Modelling of p-Nitrophenol Biosorption by Rhizopus oryzae: Comparison of Error Analysis Criteria

    Directory of Open Access Journals (Sweden)

    Zvezdelina Lyubenova Yaneva

    2013-01-01

    Full Text Available The study assessed the applicability of Rhizopus oryzae dead fungi as a biosorbent medium for p-nitrophenol (p-NP removal from aqueous phase. The extent of biosorption was measured through five equilibrium sorption isotherms represented by the Langmuir, Freundlich, Redlich-Peterson, multilayer and Fritz-Schlunder models. Linear and nonlinear regression methods were compared to determine the best-fitting equilibrium model to the experimental data. A detailed error analysis was undertaken to investigate the effect of applying seven error criteria for the determination of the single-component isotherm parameters. According to the comparison of the error functions and to the estimation of the corrected Akaike information criterion (, the Freundlich equation was ranked as the first and the Fritz-Schlunder as the second best-fitting models describing the experimental data. The present investigations proved the high efficiency (94% of Rhizopus Oryzae as an alternative adsorbent for p-NP removal from aqueous phase and revealed the mechanism of the separation process.

  16. Modelling and controlling hydropower plants

    CERN Document Server

    Munoz-Hernandez, German Ardul; Jones, Dewi Ieuan

    2013-01-01

    Hydroelectric power stations are a major source of electricity around the world; understanding their dynamics is crucial to achieving good performance.  Modelling and Controlling Hydropower Plants discusses practical and well-documented cases of modelling and controlling hydropower station modelling and control, focussing on a pumped storage scheme based in Dinorwig, North Wales.  Single-input-single-output and multiple-input-multiple-output models, which cover the linear and nonlinear characteristics of pump-storage hydroelectric power stations, are reviewed. The most important dynamic features are discussed, and the verification of these models by hardware in the loop simulation is described. To show how the performance of a pump-storage hydroelectric power station can be improved, classical and modern controllers are applied to simulated models of the Dinorwig power plant. These include PID, fuzzy approximation, feed-forward and model-based predictive control with linear and hybrid prediction models. Mod...

  17. Modeling golden section in plants

    Institute of Scientific and Technical Information of China (English)

    Lanling Zeng; Guozhao Wang

    2009-01-01

    Plants are complex structures, changing their shapes in response to environmental factors such as sunlight, water and neighboring plants. However, some mathematical rules can be found in their growth patterns, one of which is the golden section. The golden section can be observed in branching systems, phyllotaxis, flowers and seeds, and often the spiral arrangement of plant organs. In this study, tree, flower and fruit models have been generated by using the corresponding golden section characteristics, resulting in more natural patterns. Furthermore, the golden section can be found in the bifurcate angles of trees and lobed leaves, extending the golden section theory.

  18. Study on the Repellent Activity of Plant Essectial Oils Against Latheticus oryzae Waterhouse%5种植物精油对长头谷盗的控制作用研究

    Institute of Scientific and Technical Information of China (English)

    郭钰; 曾玲; 梁广文

    2013-01-01

    选取小茴香、肉桂、丁香、辣椒和生姜精油,研究其对长头谷盗的控制作用.结果表明:(1)5种精油对长头谷盗均具有显著的驱避活性,其中丁香和生姜精油的5个试验浓度(1∶1、1∶10、1∶15、1∶20和1∶50)对长头谷盗的驱避效果最好,处理60h后,其驱避活性均达到Ⅴ级,72 h后,其驱避活性分别仍达到Ⅲ级和Ⅳ级;(2)小茴香、肉桂和丁香精油对长头谷盗有明显的触杀作用,其中处理最低浓度(1∶50)的肉桂时,长头谷盗的死亡率仍在60%以上;辣椒和生姜精油的触杀活性较弱,5个试验浓度对长头谷盗的死亡率几乎为零;(3)5种精油对长头谷盗均无明显的熏蒸作用.%Five plant essential oils of Foeniculum vulgare,Cinnamomum cassia,Syzygium aromaticum,Capsicum annuum and Zingiber officinale were used to investigate their repellent action,contact action and fumigation against Latheticas oryzae Waterhouse in this paper.The results showed that:(1) Five plant essential oils significantly repelled L.oryzae,and Syzygium aromaticum and Zingiber officinale with 5 tests concentration(1∶1,1 ∶ 10,1∶15,1∶20 and 1 ∶ 50) had the best repellent effects.60 h later,the repellency percentages was Ⅴ level,and 72 h later,the percentages were Ⅲ level and Ⅳ level,respectively.(2)Foeniculum vulgare,Cinnamomum cassia and Syzygium aromaticum essential oils could effectivelf kill L.oryzae adults.The contact toxicity of Foeniculum vulgare essential oil at 1∶ 50 concentration had no contact effect to L.oryzae,but the mortality of 1 ∶ 50 concentration was over 60%.However,the contact activity of Capsicum annuum and Zingiber officinale essential oils were weak,and the mortality of L.oryzae of five test concentrations were nearly zero.(3) In a word,all of the five kinds of essential oils couldn' t effectively fumigate L.oryzae adults.

  19. PENGARUH RHIZOPUS ORYZAE DAN ASPERGILLUS ORYZAE TERHADAP KUALITAS KECAP

    Directory of Open Access Journals (Sweden)

    Dewi Sabita Slamet

    2012-11-01

    Full Text Available Telah diteliti pengganti fermentasi mikroorganisme Aspergillus oryzae Rhyzopus oryzae dan campuran Aspergillus dan Rhyzopus oryzae, dengan perendaman dalam larutan garam 20% dalam waktu yang berbeda terhadap kualitas kecap.Lamanya perendaman dalam larutan garam 20% yang berbeda menghasilkan kadar protein kecap yang berbeda. Aspergillus oryzae lebih baik dalam menghasilkan enzima protease dari pada Rhyzopus oryzae.Uji organoleptik menunjukkan perbedaan tidak bermakna dalam hal rasa maupun aroma antar kecap yang dibuat dengan strain jamur yang berlainan serta waktu perendaman yang berbeda. Untuk membuat kecap, sebaiknya dilakukan perendaman dalam larutan garam 20% selama 14 hari.

  20. Modeling of solar polygeneration plant

    Science.gov (United States)

    Leiva, Roberto; Escobar, Rodrigo; Cardemil, José

    2017-06-01

    In this work, a exergoeconomic analysis of the joint production of electricity, fresh water, cooling and process heat for a simulated concentrated solar power (CSP) based on parabolic trough collector (PTC) with thermal energy storage (TES) and backup energy system (BS), a multi-effect distillation (MED) module, a refrigeration absorption module, and process heat module is carried out. Polygeneration plant is simulated in northern Chile in Crucero with a yearly total DNI of 3,389 kWh/m2/year. The methodology includes designing and modeling a polygeneration plant and applying exergoeconomic evaluations and calculating levelized cost. Solar polygeneration plant is simulated hourly, in a typical meteorological year, for different solar multiple and hour of storage. This study reveals that the total exergy cost rate of products (sum of exergy cost rate of electricity, water, cooling and heat process) is an alternative method to optimize a solar polygeneration plant.

  1. OsSERK1 regulates rice development but not immunity to Xanthomonas oryzae pv. oryzae or Magnaporthe oryzae

    Institute of Scientific and Technical Information of China (English)

    Shimin Zuo; and Pamela C Ronald; Xiaogang Zhou; Mawsheng Chen; Shilu Zhang; Benjamin Schwessinger; Deling Ruan; Can Yuan; Jing Wang; Xuewei Chen

    2014-01-01

    Somatic embryogenesis receptor kinase (SERK) proteins play pivotal roles in regulation of plant development and immunity. The rice genome contains two SERK genes, OsSerk1 and OsSerk2. We previously demonstrated that OsSerk2 is required for rice Xa21‐mediated resistance to Xanthomonas oryzae pv. oryzae (Xoo) and for normal development. Here we report the molecular characterization of OsSerk1. Overexpres-sion of OsSerk1 results in a semi‐dwarf phenotype whereas silencing of OsSerk1 results in a reduced angle of the lamina joint. OsSerk1 is not required for rice resistance to Xoo or Magnaporthe oryzae. Overexpression of OsSerk1 in OsSerk2‐silenced lines complements phenotypes associated with brassinosteroid (BR) signaling defects, but not the disease resistance phenotype mediated by Xa21. In yeast, OsSERK1 interacts with itself forming homodimers, and also interacts with the kinase domains of OsSERK2 and BRI1, respectively. OsSERK1 is a functional protein kinase capable of auto‐phosphorylation in vitro. We conclude that, whereas OsSERK2 regulates both rice development and immunity, OsSERK1 functions in rice development but not immunity to Xoo and M. oryzae.

  2. 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

  3. 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

  4. Isolation and identification of plant growth promoting rhizobacteria from maize (Zea mays L. rhizosphere and their plant growth promoting effect on rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Karnwal Arun

    2017-06-01

    Full Text Available The use of plant growth promoting rhizobacteria is increasing in agriculture and gives an appealing manner to replace chemical fertilizers, pesticides, and dietary supplements. The objective of our research was to access the plant growth promotion traits of Pseudomonas aeruginosa, P. fluorescens and Bacillus subtilis isolated from the maize (Zea mays L. rhizosphere. In vitro studies showed that isolates have the potential to produce indole acetic acid (IAA, hydrogen cyanide, phosphate solubilisation, and siderophore. RNA analysis revealed that two isolates were 97% identical to P. aeruginosa strain DSM 50071 and P. aeruginosa strain NBRC 12689 (AK20 and AK31, while two others were 98% identical to P. fluorescens strain ATCC 13525, P. fluorescens strain IAM 12022 (AK18 and AK45 and one other was 99% identical to B. subtilis strain NCDO 1769 (AK38. Our gnotobiotic study showed significant differences in plant growth variables under control and inoculated conditions. In the present research, it was observed that the isolated strains had good plant growth promoting effects on rice.

  5. Zinco, chumbo e cádmio em plantas de arroz (Oryza Sativa L. cultivadas em solo após adição de resíduo siderúrgico Zinc, lead and cadmium influence in rice plants (Oryza Sativa L. cultivated in soil with addition of siderurgical residue

    Directory of Open Access Journals (Sweden)

    André Fernão Martins de Andrade

    2008-10-01

    Full Text Available Os efeitos da aplicação de resíduo siderúrgico, proveniente da concentração de zinco em lama de altos-fornos siderúrgicos, como fonte de zinco para plantas de arroz (Oryza Sativa L. BRS Curinga e a toxicidade devida ao cádmio e ao chumbo no resíduo, foram estudados em experimento de casa de vegetação. O material de solo usado foi proveniente do horizonte A e B de um Latossolo Vermelho-Amarelo e do horizonte A de um Neossolo Flúvico, coletados no município de Pinheiral, Estado do Rio de Janeiro. Foram aplicadas quatro doses de resíduo (94; 281; 844 e 2531kg ha-1. Foi determinado o teor de zinco, cádmio e chumbo na raiz e na parte aérea das plantas de arroz. As plantas crescidas no horizonte A do Neossolo Flúvico apresentaram a maior produção de matéria seca e a maior acumulação de zinco e a menor de cádmio. As plantas de arroz desenvolvidas no horizonte B do Latossolo apresentaram a menor produção de matéria seca, menor acumulação de zinco e a maior de chumbo, enquanto que as cultivadas no horizonte A do Latossolo apresentaram a mais elevada produção de matéria seca dos três substratos utilizados. O zinco e o chumbo concentraram-se, principalmente, nas raízes das plantas, e o cádmio se concentrou na parte aérea. Pelas características apresentadas nos solos estudados e pelas concentrações fitotóxicas do chumbo e do cádmio encontradas nas plantas desenvolvidas sobre o horizonte B do Latossolo, não é recomendável a utilização desse resíduo como fonte de zinco para a cultura do arroz.The effects of application of siderurgical residue, originated from the zinc concentration in siderurgical high-ovens mud, as supply of zinc for rice plants (Oryza Sativa L. and the toxicity due to cadmium and lead from the residue, were studied in a greenhouse experiment.The period of the experiment was from April of 2005 to March of 2006. The soil materials were from the A and B horizons of a Yellow - Red Oxisol, and the A

  6. 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...

  7. Empirical Modeling of Plant Gas Fluxes in Controlled Environments

    Science.gov (United States)

    Cornett, Jessie David

    1994-01-01

    As humans extend their reach beyond the earth, bioregenerative life support systems must replace the resupply and physical/chemical systems now used. The Controlled Ecological Life Support System (CELSS) will utilize plants to recycle the carbon dioxide (CO2) and excrement produced by humans and return oxygen (O2), purified water and food. CELSS design requires knowledge of gas flux levels for net photosynthesis (PS(sub n)), dark respiration (R(sub d)) and evapotranspiration (ET). Full season gas flux data regarding these processes for wheat (Triticum aestivum), soybean (Glycine max) and rice (Oryza sativa) from published sources were used to develop empirical models. Univariate models relating crop age (days after planting) and gas flux were fit by simple regression. Models are either high order (5th to 8th) or more complex polynomials whose curves describe crop development characteristics. The models provide good estimates of gas flux maxima, but are of limited utility. To broaden the applicability, data were transformed to dimensionless or correlation formats and, again, fit by regression. Polynomials, similar to those in the initial effort, were selected as the most appropriate models. These models indicate that, within a cultivar, gas flux patterns appear remarkably similar prior to maximum flux, but exhibit considerable variation beyond this point. This suggests that more broadly applicable models of plant gas flux are feasible, but univariate models defining gas flux as a function of crop age are too simplistic. Multivariate models using CO2 and crop age were fit for PS(sub n), and R(sub d) by multiple regression. In each case, the selected model is a subset of a full third order model with all possible interactions. These models are improvements over the univariate models because they incorporate more than the single factor, crop age, as the primary variable governing gas flux. They are still limited, however, by their reliance on the other environmental

  8. Mathematical Modelling Plant Signalling Networks

    KAUST Repository

    Muraro, D.

    2013-01-01

    During the last two decades, molecular genetic studies and the completion of the sequencing of the Arabidopsis thaliana genome have increased knowledge of hormonal regulation in plants. These signal transduction pathways act in concert through gene regulatory and signalling networks whose main components have begun to be elucidated. Our understanding of the resulting cellular processes is hindered by the complex, and sometimes counter-intuitive, dynamics of the networks, which may be interconnected through feedback controls and cross-regulation. Mathematical modelling provides a valuable tool to investigate such dynamics and to perform in silico experiments that may not be easily carried out in a laboratory. In this article, we firstly review general methods for modelling gene and signalling networks and their application in plants. We then describe specific models of hormonal perception and cross-talk in plants. This mathematical analysis of sub-cellular molecular mechanisms paves the way for more comprehensive modelling studies of hormonal transport and signalling in a multi-scale setting. © EDP Sciences, 2013.

  9. Celebrating Plant Cells: A Special Issue on Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ A special issue on plant cell biology is long overdue for JIPB! In the last two decades or so, the plant biology community has been thrilled by explosive discoveries regarding the molecular and genetic basis of plant growth, development, and responses to the environment, largely owing to recent maturation of model systems like Arabidopsis thaliana and the rice Oryza sativa, as well as the rapid development of high throughput technologies associated with genomics and proteomics.

  10. Modeling and dynamic behaviour of hydropower plants

    CERN Document Server

    Kishor, Nand

    2017-01-01

    This book presents a systematic approach to mathematical modeling of different configurations of hydropower plants over four sections - modeling and simulation approaches; control of hydropower plants; operation and scheduling of hydropower plants, including pumped storage; and special features of small hydropower plants.

  11. Modelling meristem development in plants

    OpenAIRE

    Heisler, Marcus G.; Jönsson, Henrik

    2007-01-01

    Meristems continually supply new cells for post-embryonic plant development and coordinate the initiation of new organs, such as leaves and flowers. Meristem function is regulated by a large and interconnected dynamic system that includes transcription networks, intercellular protein signalling, polarized transport of hormones and a constantly changing cellular topology. Mathematical modelling, in which the dynamics of a system are simulated using explicitly defined interactions, can serve as...

  12. Field Guide to Plant Model Systems.

    Science.gov (United States)

    Chang, Caren; Bowman, John L; Meyerowitz, Elliot M

    2016-10-06

    For the past several decades, advances in plant development, physiology, cell biology, and genetics have relied heavily on the model (or reference) plant Arabidopsis thaliana. Arabidopsis resembles other plants, including crop plants, in many but by no means all respects. Study of Arabidopsis alone provides little information on the evolutionary history of plants, evolutionary differences between species, plants that survive in different environments, or plants that access nutrients and photosynthesize differently. Empowered by the availability of large-scale sequencing and new technologies for investigating gene function, many new plant models are being proposed and studied. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Polyploid evolution in Oryza officinalis complex of the genus Oryza

    Directory of Open Access Journals (Sweden)

    Li Changbao

    2009-10-01

    Full Text Available Abstract Background Polyploidization is a prominent process in plant evolution, whereas the mechanism and tempo-spatial process remained poorly understood. Oryza officinalis complex, a polyploid complex in the genus Oryza, could exemplify the issues not only for it covering a variety of ploidy levels, but also for the pantropical geographic pattern of its polyploids in Asia, Africa, Australia and Americas, in which a pivotal genome, the C-genome, witnessed all the polyploidization process. Results Tracing the C-genome evolutionary history in Oryza officinalis complex, this study revealed the genomic relationships, polyploid forming and diverging times, and diploidization process, based on phylogeny, molecular-clock analyses and fluorescent in situ hybridization using genome-specific probes. Results showed that C-genome split with B-genome at ca. 4.8 Mya, followed by a series of speciation of C-genome diploids (ca. 1.8-0.9 Mya, which then partook in successive polyploidization events, forming CCDD tetraploids in ca. 0.9 Mya, and stepwise forming BBCC tetraploids between ca. 0.3-0.6 Mya. Inter-genomic translocations between B- and C-genomes were identified in BBCC tetraploid, O. punctata. Distinct FISH (fluorescent in situ hybridization patterns among three CCDD species were visualized by C-genome-specific probes. B-genome was modified before forming the BBCC tetraploid, O. malampuzhaensis. Conclusion C-genome, shared by all polyploid species in the complex, had experienced different evolutionary history particularly after polyploidization, e.g., inter-genomic exchange in BBCC and genomic invasion in CCDD tetraploids. It diverged from B-genome at 4.8 Mya, then participated in the tetraploid formation spanning from 0.9 to 0.3 Mya, and spread into tropics of the disjunct continents by transcontinentally long-distance dispersal, instead of vicariance, as proposed by this study, given that the continental splitting was much earlier than the C

  14. A Study on Combination of Multi-plant-extract with Activity Resisting Magnaporthe oryzae%抗稻瘟病菌活性多植物提取物组方研究

    Institute of Scientific and Technical Information of China (English)

    霍光华; 严伟; 符金华; 陈明辉; 叶亚建

    2012-01-01

      To strengthen the activity resisting the rice blast of natural products from plants and lessen their use doses, inhibition of the mycelium growth and pore Germination were determined and a prescription pharmacodynamic model was adopted for the combination of fractions from the multi-plant-extract with the activity. Results showed the ethanol extracts of Schima superba leaves, Sapindus mukorossi mesocarp, Magnolia grandiflora leaves, Camellia oleifera leaves, Castanopsis sclerophylla leaves, and Cedrus deodara leaves were of strong activities resisting Magnaporthe oryza. 50% effective concentration (EC 50) / minimum inhibitting concentration (MIC) of inhibitting mycelium growth were 0.08/0.60, 0.08/0.80, 0.17/1.00, 0.22/0.60, 0.35/1.50, and 0.16/1.00 ㎎/mL respectively. MIC of the inhibiting spore germination were 1.6, 1.7, 2.9, 3.1, 2.9, and 4.6㎎/mL respectively. Antifungal effects of 70% ethanol extract combination showed there were strong synergic effects of the combination between Sapindus mukorossi and Magnolia grandiflora, antagonistic effects of the combination between Schima superba and Cedrus deodara, but the maximum inhibiting effect of higher doses combination was among Schima superba, Sapindus mukorossi and Magnolia grandiflora on Mycelial growth inhibition. Any combination of two plant materials could strengthen the inhibition effects on the spore germination of Magnaporthe oryzae, and the multiple combination of Schima superba, Sapindus mukorossi, Magnolia grandiflora, Camellia oleifera, Castanopsis sclerophylla could get the best effects. The prescription pharmacodynamic model selected was of good correlation between measured values and forecast values, with strong predictable features, which was suitable for screening the multi-component groups in the development of botanical fungicides.%  为了强化植物天然产物抗稻瘟活性和减少使用剂量,进行了菌丝生长和孢子萌发抑制活性测定、配伍药效模型多植

  15. Crystallization and preliminary crystallographic studies of LipA, a secretory lipase/esterase from Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Aparna, Gudlur; Chatterjee, Avradip; Jha, Gopaljee; Sonti, Ramesh V.; Sankaranarayanan, Rajan, E-mail: sankar@ccmb.res.in [Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007 (India)

    2007-08-01

    The crystallization and preliminary crystallographic studies of LipA, a lipase/esterase secreted by X. oryzae pv. oryzae during its infection of rice plants, are reported. Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight, a serious disease of rice. Several enzymes that are secreted through the type II secretion system of this bacterium play an important role in the plant–microbe interaction, being important for virulence and also being able to induce potent host defence responses. One of these enzymes is a secretory lipase/esterase, LipA, which shows a very weak homology to other bacterial lipases and gives a positive tributyrin plate assay. In this study, LipA was purified from the culture supernatant of an overexpressing clone of X. oryzae pv. oryzae and two types of crystals belonging to space group C2 but with two different unit-cell parameters were obtained using the hanging-drop vapour-diffusion method. Type I crystals diffract to a maximum resolution of 1.89 Å and have unit-cell parameters a = 93.1, b = 62.3, c = 66.1 Å, β = 90.8°. Type II crystals have unit-cell parameters a = 103.6, b = 54.6, c = 66.3 Å, β = 92.6° and diffract to 1.86 Å. Solvent-content analysis shows one monomer in the asymmetric unit in both the crystal forms.

  16. Identification and molecular characterization of twin-arginine translocation system (Tat) in Xanthomonas oryzae pv. oryzae strain PXO99.

    Science.gov (United States)

    Chen, Lei; Hu, Baishi; Qian, Guoliang; Wang, Chen; Yang, Wanfeng; Han, Zhicheng; Liu, Fengquan

    2009-02-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, one of the most widespread and destructive bacterial diseases in rice. This study identified and characterized the contribution of the twin-arginine translocation (Tat) pathway to motility, chemotaxis, extracellular polysaccharide (EPS) production and virulence in X. oryzae pv. oryzae strain PXO99. The tatC disruption mutant (strain TCM) of strain PXO99 were generated, and confirmed both by PCR and Southern blotting. Strain PXO99 cells were highly motile in NYGB 0.3% soft agar plate. In contrast, the tatC mutation impaired motility. Furthermore, strain TCM cells lacked detectable flagella and exhibited almost no chemotaxis toward glucose under aerobic conditions, indicating that the Tat secretion pathway contributed to flagellar biogenesis and chemotactic responses. It was also observed that strain TCM exhibited a reductive production of extracellular polysaccharide (EPS) and a significant reduction of virulence on rice plants when compared with the wild type PXO99. However, the tatC mutation in strain PXO99 did not affect growth rate and the ability to induce hypersensitive response (HR) in nonhost tobacco (Nicotiana tabacum L. cv. Samsun). Our findings indicated that the Tat system of X. oryzae pv. oryzae played an important role in the pathogen's virulence.

  17. Plant memory: a tentative model.

    Science.gov (United States)

    Thellier, M; Lüttge, U

    2013-01-01

    All memory functions have molecular bases, namely in signal reception and transduction, and in storage and recall of information. Thus, at all levels of organisation living organisms have some kind of memory. In plants one may distinguish two types. There are linear pathways from reception of signals and propagation of effectors to a type of memory that may be described by terms such as learning, habituation or priming. There is a storage and recall memory based on a complex network of elements with a high degree of integration and feedback. The most important elements envisaged are calcium waves, epigenetic modifications of DNA and histones, and regulation of timing via a biological clock. Experiments are described that document the occurrence of the two sorts of memory and which show how they can be distinguished. A schematic model of plant memory is derived as emergent from integration of the various modules. Possessing the two forms of memory supports the fitness of plants in response to environmental stimuli and stress.

  18. Identification and analysis of in planta expressed genes of Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Mitchell Thomas K

    2010-02-01

    Full Text Available Abstract Background Infection of plants by pathogens and the subsequent disease development involves substantial changes in the biochemistry and physiology of both partners. Analysis of genes that are expressed during these interactions represents a powerful strategy to obtain insights into the molecular events underlying these changes. We have employed expressed sequence tag (EST analysis to identify rice genes involved in defense responses against infection by the blast fungus Magnaporthe oryzae and fungal genes involved in infectious growth within the host during a compatible interaction. Results A cDNA library was constructed with RNA from rice leaves (Oryza sativa cv. Hwacheong infected with M. oryzae strain KJ201. To enrich for fungal genes, subtraction library using PCR-based suppression subtractive hybridization was constructed with RNA from infected rice leaves as a tester and that from uninfected rice leaves as the driver. A total of 4,148 clones from two libraries were sequenced to generate 2,302 non-redundant ESTs. Of these, 712 and 1,562 ESTs could be identified to encode fungal and rice genes, respectively. To predict gene function, Gene Ontology (GO analysis was applied, with 31% and 32% of rice and fungal ESTs being assigned to GO terms, respectively. One hundred uniESTs were found to be specific to fungal infection EST. More than 80 full-length fungal cDNA sequences were used to validate ab initio annotated gene model of M. oryzae genome sequence. Conclusion This study shows the power of ESTs to refine genome annotation and functional characterization. Results of this work have advanced our understanding of the molecular mechanisms underpinning fungal-plant interactions and formed the basis for new hypothesis.

  19. Cell wall degrading enzyme induced rice innate immune responses are suppressed by the type 3 secretion system effectors XopN, XopQ, XopX and XopZ of Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Sinha, Dipanwita; Gupta, Mahesh Kumar; Patel, Hitendra Kumar; Ranjan, Ashish; Sonti, Ramesh V

    2013-01-01

    Innate immune responses are induced in plants and animals through perception of Damage Associated Molecular Patterns. These immune responses are suppressed by pathogens during infection. A number of studies have focussed on identifying functions of plant pathogenic bacteria that are involved in suppression of Pathogen Associated Molecular Pattern induced immune responses. In comparison, there is very little information on functions used by plant pathogens to suppress Damage Associated Molecular Pattern induced immune responses. Xanthomonasoryzae pv. oryzae, a gram negative bacterial pathogen of rice, secretes hydrolytic enzymes such as LipA (Lipase/Esterase) that damage rice cell walls and induce innate immune responses. Here, we show that Agrobacterium mediated transient transfer of the gene for XopN, a X. oryzae pv. oryzae type 3 secretion (T3S) system effector, results in suppression of rice innate immune responses induced by LipA. A xopN (-) mutant of X. oryzae pv. oryzae retains the ability to suppress these innate immune responses indicating the presence of other functionally redundant proteins. In transient transfer assays, we have assessed the ability of 15 other X. oryzae pv. oryzae T3S secreted effectors to suppress rice innate immune responses. Amongst these proteins, XopQ, XopX and XopZ are suppressors of LipA induced innate immune responses. A mutation in any one of the xopN, xopQ, xopX or xopZ genes causes partial virulence deficiency while a xopN (-) xopX (-) double mutant exhibits a greater virulence deficiency. A xopN (-) xopQ (-) xopX (-) xopZ (-) quadruple mutant of X. oryzae pv. oryzae induces callose deposition, an innate immune response, similar to a X. oryzae pv. oryzae T3S(-) mutant in rice leaves. Overall, these results indicate that multiple T3S secreted proteins of X. oryzae pv. oryzae can suppress cell wall damage induced rice innate immune responses.

  20. 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.

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

    Science.gov (United States)

    Su, Zhen-Zhu; Mao, Li-Juan; Li, Na; Feng, Xiao-Xiao; Yuan, Zhi-Lin; Wang, Li-Wei; Lin, Fu-Cheng; Zhang, Chu-Long

    2013-01-01

    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.

  2. ZINC-INDUCED FACILITATOR-LIKE family in plants: lineage-specific expansion in monocotyledons and conserved genomic and expression features among rice (Oryza sativa paralogs

    Directory of Open Access Journals (Sweden)

    Lopes Karina L

    2011-01-01

    Full Text Available Abstract Background Duplications are very common in the evolution of plant genomes, explaining the high number of members in plant gene families. New genes born after duplication can undergo pseudogenization, neofunctionalization or subfunctionalization. Rice is a model for functional genomics research, an important crop for human nutrition and a target for biofortification. Increased zinc and iron content in the rice grain could be achieved by manipulation of metal transporters. Here, we describe the ZINC-INDUCED FACILITATOR-LIKE (ZIFL gene family in plants, and characterize the genomic structure and expression of rice paralogs, which are highly affected by segmental duplication. Results Sequences of sixty-eight ZIFL genes, from nine plant species, were comparatively analyzed. Although related to MSF_1 proteins, ZIFL protein sequences consistently grouped separately. Specific ZIFL sequence signatures were identified. Monocots harbor a larger number of ZIFL genes in their genomes than dicots, probably a result of a lineage-specific expansion. The rice ZIFL paralogs were named OsZIFL1 to OsZIFL13 and characterized. The genomic organization of the rice ZIFL genes seems to be highly influenced by segmental and tandem duplications and concerted evolution, as rice genome contains five highly similar ZIFL gene pairs. Most rice ZIFL promoters are enriched for the core sequence of the Fe-deficiency-related box IDE1. Gene expression analyses of different plant organs, growth stages and treatments, both from our qPCR data and from microarray databases, revealed that the duplicated ZIFL gene pairs are mostly co-expressed. Transcripts of OsZIFL4, OsZIFL5, OsZIFL7, and OsZIFL12 accumulate in response to Zn-excess and Fe-deficiency in roots, two stresses with partially overlapping responses. Conclusions We suggest that ZIFL genes have different evolutionary histories in monocot and dicot lineages. In rice, concerted evolution affected ZIFL duplicated genes

  3. Mathematical models for plant-herbivore interactions

    Science.gov (United States)

    Feng, Zhilan; DeAngelis, Donald L.

    2017-01-01

    Mathematical Models of Plant-Herbivore Interactions addresses mathematical models in the study of practical questions in ecology, particularly factors that affect herbivory, including plant defense, herbivore natural enemies, and adaptive herbivory, as well as the effects of these on plant community dynamics. The result of extensive research on the use of mathematical modeling to investigate the effects of plant defenses on plant-herbivore dynamics, this book describes a toxin-determined functional response model (TDFRM) that helps explains field observations of these interactions. This book is intended for graduate students and researchers interested in mathematical biology and ecology.

  4. Structural determination of elicitors in Sogatella furcifera (Horváth) that induce Japonica rice plant varieties (Oryza sativa L.) to produce an ovicidal substance against S. furcifera eggs.

    Science.gov (United States)

    Yang, Jeong-Oh; Nakayama, Naoya; Toda, Kyohei; Tebayashi, Shinichi; Kim, Chul-Sa

    2014-01-01

    Certain Japonica rice plant varieties (Oryza sativa L.) show resistance to the eggs of the white backed planthopper (Sogatella furcifera Horváth) by the formation of watery lesions and production of benzyl benzoate, an active ovicidal compound. Benzyl benzoate results in high ovicidal activity of S. furcifera eggs and reduces egg hatchability. The production of benzyl benzoate by the rice plants is only induced by an unknown elicitor(s) from the female S. furcifera. Therefore, we tried to isolate and identify these elicitors. An active 80% MeOH extract of S. furcifera was separated on a reverse-phase ODS MPLC, and the elicitor(s) was eluted in 100% MeOH and 100% EtOH fractions. Further separation of the active 100% MeOH fraction using a HPLC led to the isolation of four active compounds. The structures of each compound were determined by using NMR, LC-MS, and GC-MS spectra. The compounds were 1,2-dilinoleoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, 1-palmitoyl-2-oleoyl-X-glycero-3-phosphoethanolamine, and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine.

  5. The Potential of Streptomyces as Biocontrol Agents against the Rice Blast Fungus, Magnaporthe oryzae (Pyricularia oryzae)

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ser, Hooi-Leng; Khan, Tahir M.; Chuah, Lay-Hong; Pusparajah, Priyia; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Rice is a staple food source for more than three billion people worldwide. However, rice is vulnerable to diseases, the most destructive among them being rice blast, which is caused by the fungus Magnaporthe oryzae (anamorph Pyricularia oryzae). This fungus attacks rice plants at all stages of development, causing annual losses of approximately 10–30% in various rice producing regions. Synthetic fungicides are often able to effectively control plant diseases, but some fungicides result in serious environmental and health problems. Therefore, there is growing interest in discovering and developing new, improved fungicides based on natural products as well as introducing alternative measures such as biocontrol agents to manage plant diseases. Streptomyces bacteria appear to be promising biocontrol agents against a wide range of phytopathogenic fungi, which is not surprising given their ability to produce various bioactive compounds. This review provides insight into the biocontrol potential of Streptomyces against the rice blast fungus, M. oryzae. The ability of various Streptomyces spp. to act as biocontrol agents of rice blast disease has been studied by researchers under both laboratory and greenhouse/growth chamber conditions. Laboratory studies have shown that Streptomyces exhibit inhibitory activity against M. oryzae. In greenhouse studies, infected rice seedlings treated with Streptomyces resulted in up to 88.3% disease reduction of rice blast. Studies clearly show that Streptomyces spp. have the potential to be used as highly effective biocontrol agents against rice blast disease; however, the efficacy of any biocontrol agent may be affected by several factors including environmental conditions and methods of application. In order to fully exploit their potential, further studies on the isolation, formulation and application methods of Streptomyces along with field experiments are required to establish them as effective biocontrol agents. PMID:28144236

  6. The Potential of Streptomyces as Biocontrol Agents against the Rice Blast Fungus, Magnaporthe oryzae (Pyricularia oryzae).

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ser, Hooi-Leng; Khan, Tahir M; Chuah, Lay-Hong; Pusparajah, Priyia; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Rice is a staple food source for more than three billion people worldwide. However, rice is vulnerable to diseases, the most destructive among them being rice blast, which is caused by the fungus Magnaporthe oryzae (anamorph Pyricularia oryzae). This fungus attacks rice plants at all stages of development, causing annual losses of approximately 10-30% in various rice producing regions. Synthetic fungicides are often able to effectively control plant diseases, but some fungicides result in serious environmental and health problems. Therefore, there is growing interest in discovering and developing new, improved fungicides based on natural products as well as introducing alternative measures such as biocontrol agents to manage plant diseases. Streptomyces bacteria appear to be promising biocontrol agents against a wide range of phytopathogenic fungi, which is not surprising given their ability to produce various bioactive compounds. This review provides insight into the biocontrol potential of Streptomyces against the rice blast fungus, M. oryzae. The ability of various Streptomyces spp. to act as biocontrol agents of rice blast disease has been studied by researchers under both laboratory and greenhouse/growth chamber conditions. Laboratory studies have shown that Streptomyces exhibit inhibitory activity against M. oryzae. In greenhouse studies, infected rice seedlings treated with Streptomyces resulted in up to 88.3% disease reduction of rice blast. Studies clearly show that Streptomyces spp. have the potential to be used as highly effective biocontrol agents against rice blast disease; however, the efficacy of any biocontrol agent may be affected by several factors including environmental conditions and methods of application. In order to fully exploit their potential, further studies on the isolation, formulation and application methods of Streptomyces along with field experiments are required to establish them as effective biocontrol agents.

  7. 基因枪法转化水稻(Oryza sativa L.)获得可育的转抗虫基因水稻再生植株%Obtaining Fertile Transgenic Plants of Resistant-insect Rice (Oryza sativa L.) via Particle Bombardment

    Institute of Scientific and Technical Information of China (English)

    安韩冰; 朱祯; 李慧芬; 吴茜; 周兆澜; 徐鸿林; 徐军望; 安利佳; 李向辉

    2001-01-01

    应用基因枪(particle bombardment)转化技术成功地将豇豆胰蛋白酶抑制剂(c owpea trypsin inhibitor, CpTI)基因分别导入三个水稻粳稻栽培品种(Oryza sativa L. , japonica)中花8、中花10和中作321的幼胚和胚性愈伤组织中,并由此获得了可育的再生植 株,抗性植株的筛选频率为6.1%~12.24%。经PCR、Southern blot分子检测和ELISA检测等 证实 所获得的潮霉素抗性植株为转基因植株。抗虫性分析结果表明,部分转基因水稻植株对玉米 螟虫(Ostrinia nubilalis)有较好的抗性。%A cowpea trypsin inhibitor (CpTI) gene was successfully transferred into imm atur e embryos and embryogenic calli of three varieties of rice, Zhonghua 8 , Zhonghu a 10 and Zhongzuo 321 via the particle bombardment. Fertile transgenic rice plan ts were obtained, and confirmed by assay of PCR, Southern blot and ELISA. Select ive frequencies of HygB resistance plants were among 6.1%~12.4%. Resistant-in sect bioassay indicated that some of transgenic rice plants shown good resistance to corn borer (Ostrinia nubilalis).

  8. Effect of Preexposure to Triazoles on Susceptibility and Virulence of Rhizopus oryzae.

    Science.gov (United States)

    Bellanger, Anne-Pauline; Albert, Nathaniel D; Lewis, Russell E; Walsh, Thomas J; Kontoyiannis, Dimitrios P

    2015-12-01

    Triazole prophylaxis has become the norm in patients with hematological malignancies. Breakthrough infections caused by Mucorales during triazole prophylaxis remain a challenging problem. We found that preexposure of Rhizopus oryzae to antifungal triazoles (fluconazole, voriconazole, posaconazole, and itraconazole) did not modify the in vitro susceptibility of Rhizopus oryzae to posaconazole. In contrast, preexposure of Rhizopus to triazoles was associated with the enhanced in vitro susceptibility of R. oryzae to amphotericin B. Preexposure to posaconazole did not alter the virulence of R. oryzae in the fly model of mucormycosis.

  9. Automated recovery of three-dimensional models of plant shoots from multiple color images.

    Science.gov (United States)

    Pound, Michael P; French, Andrew P; Murchie, Erik H; Pridmore, Tony P

    2014-12-01

    Increased adoption of the systems approach to biological research has focused attention on the use of quantitative models of biological objects. This includes a need for realistic three-dimensional (3D) representations of plant shoots for quantification and modeling. Previous limitations in single-view or multiple-view stereo algorithms have led to a reliance on volumetric methods or expensive hardware to record plant structure. We present a fully automatic approach to image-based 3D plant reconstruction that can be achieved using a single low-cost camera. The reconstructed plants are represented as a series of small planar sections that together model the more complex architecture of the leaf surfaces. The boundary of each leaf patch is refined using the level-set method, optimizing the model based on image information, curvature constraints, and the position of neighboring surfaces. The reconstruction process makes few assumptions about the nature of the plant material being reconstructed and, as such, is applicable to a wide variety of plant species and topologies and can be extended to canopy-scale imaging. We demonstrate the effectiveness of our approach on data sets of wheat (Triticum aestivum) and rice (Oryza sativa) plants as well as a unique virtual data set that allows us to compute quantitative measures of reconstruction accuracy. The output is a 3D mesh structure that is suitable for modeling applications in a format that can be imported in the majority of 3D graphics and software packages. © 2014 American Society of Plant Biologists. All Rights Reserved.

  10. Mathematical Models Light Up Plant Signaling

    NARCIS (Netherlands)

    Chew, Y.H.; Smith, R.W.; Jones, H.J.; Seaton, D.D.; Grima, R.; Halliday, K.J.

    2014-01-01

    Plants respond to changes in the environment by triggering a suite of regulatory networks that control and synchronize molecular signaling in different tissues, organs, and the whole plant. Molecular studies through genetic and environmental perturbations, particularly in the model plant Arabidopsis

  11. Mathematical Models Light Up Plant Signaling

    NARCIS (Netherlands)

    Chew, Y.H.; Smith, R.W.; Jones, H.J.; Seaton, D.D.; Grima, R.; Halliday, K.J.

    2014-01-01

    Plants respond to changes in the environment by triggering a suite of regulatory networks that control and synchronize molecular signaling in different tissues, organs, and the whole plant. Molecular studies through genetic and environmental perturbations, particularly in the model plant Arabidopsis

  12. 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.

  13. Level of detail technique for plant models

    Institute of Scientific and Technical Information of China (English)

    Xiaopeng ZHANG; Qingqiong DENG; Marc JAEGER

    2006-01-01

    Realistic modelling and interactive rendering of forestry and landscape is a challenge in computer graphics and virtual reality. Recent new developments in plant growth modelling and simulation lead to plant models faithful to botanical structure and development, not only representing the complex architecture of a real plant but also its functioning in interaction with its environment. Complex geometry and material of a large group of plants is a big burden even for high performances computers, and they often overwhelm the numerical calculation power and graphic rendering power. Thus, in order to accelerate the rendering speed of a group of plants, software techniques are often developed. In this paper, we focus on plant organs, i.e. leaves, flowers, fruits and inter-nodes. Our approach is a simplification process of all sparse organs at the same time, i. e. , Level of Detail (LOD) , and multi-resolution models for plants. We do explain here the principle and construction of plant simplification. They are used to construct LOD and multi-resolution models of sparse organs and branches of big trees. These approaches take benefit from basic knowledge of plant architecture, clustering tree organs according to biological structures. We illustrate the potential of our approach on several big virtual plants for geometrical compression or LOD model definition. Finally we prove the efficiency of the proposed LOD models for realistic rendering with a virtual scene composed by 184 mature trees.

  14. 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.

  15. Genomic affinity between Oryza sativa and Oryza brachyantha as ...

    African Journals Online (AJOL)

    USER

    2010-05-24

    May 24, 2010 ... brachyantha as revealed by in situ hybridization and ... Department of Genetics, Hazara University, Garden Campus Mansehra, Pakistan. Accepted 26 April ..... Oryza complex identified on the basis of molecular divergence.

  16. Characterization and mapping of a spotted leaf mutant in rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Xue Xu

    2014-06-01

    Full Text Available Spotted leaf mutant belongs to a class of mutants that can produce necrotic lesions spontaneously in plants without any attack by pathogens. These mutants have no beneficial effect on plant productivity but provide a unique opportunity to study programmed cell death in plant defense responses. A novel rice spotted leaf mutant (spl30 was isolated through low-energy heavy ion irradiation. Lesion expression was sensitive to light and humidity. The spl30 mutant caused a decrease in chlorophyll and soluble protein content, with marked accumulation of reactive oxygen species (ROS around the lesions. In addition, the spl30 mutant significantly enhanced resistance to rice bacterial blight (X. oryzae pv. oryzae from China (C1-C7. The use of SSR markers showed that the spl30 gene was located between markers XSN2 and XSN4. The genetic distance between the spl30 gene and XSN2 and between spl30 and XSN4 was 1.7 cM and 0.2 cM, respectively. The spl30 gene is a new gene involved in lesion production and may be related to programmed cell death in rice. The ability of this mutant to confer broad resistance to bacterial blight provides a model for studying the interaction between plants and pathogenic bacteria.

  17. Assessment of genetic diversity of Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Bacterial blight of rice, caused by Xanthomonas oryzae pv. Oryzae(Xoo. ), is one of the major rice diseases in China. Making clear the shift of genetic diversity of the pathogen will provide important information for rice breeding. Strains collected from 11 provinces located in Southern region of the Changjiang River in China were assessed by using inoculation method and IS-PCR(Insertion Sequence-Based Polymerase Chain Reaction) analysis.

  18. Diversity of the Ty-1 copia retrotransposon Tos17 in rice (Oryza sativa L.) and the AA genome of the Oryza genus

    OpenAIRE

    Petit, J.; Bourgeois, E; Stenger, W.; Bes, M.; Droc, G.; Meynard, D.; Courtois, B.; Ghesquière, Alain; Sabot, François; Panaud, O.; Guiderdoni, E.

    2009-01-01

    Retrotransposons are mobile genetic elements, ubiquitous in Eukaryotic genomes, which have proven to be major genetic tools in determining phylogeny and structuring genetic diversity, notably in plants. We investigate here the diversity of the Ty1-copia retrotransposon Tos17 in the cultivated rice of Asian origin (Oryza sativa L.) and related AA genome species of the Oryza genus, to contribute understanding of the complex evolutionary history in this group of species through that of the eleme...

  19. DIMO, a plant dispersal model

    NARCIS (Netherlands)

    Wamelink, G.W.W.; Jochem, R.; Greft, van der J.G.M.; Franke, J.; Malinowska, A.H.; Geertsema, W.; Prins, A.H.; Ozinga, W.A.; Hoek, van der D.C.J.; Grashof-Bokdam, C.J.

    2014-01-01

    Due to human activities many natural habitats have become isolated. As a result the dispersal of many plant species is hampered. Isolated populations may become extinct and have a lower probability to become reestablished in a natural way. Moreover, plant species may be forced to migrate to new area

  20. Model-based explanation of plant knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Huuskonen, P.J. [VTT Electronics, Oulu (Finland). Embedded Software

    1997-12-31

    This thesis deals with computer explanation of knowledge related to design and operation of industrial plants. The needs for explanation are motivated through case studies and literature reviews. A general framework for analysing plant explanations is presented. Prototypes demonstrate key mechanisms for implementing parts of the framework. Power plants, steel mills, paper factories, and high energy physics control systems are studied to set requirements for explanation. The main problems are seen to be either lack or abundance of information. Design knowledge in particular is found missing at plants. Support systems and automation should be enhanced with ways to explain plant knowledge to the plant staff. A framework is formulated for analysing explanations of plant knowledge. It consists of three parts: 1. a typology of explanation, organised by the class of knowledge (factual, functional, or strategic) and by the target of explanation (processes, automation, or support systems), 2. an identification of explanation tasks generic for the plant domain, and 3. an identification of essential model types for explanation (structural, behavioural, functional, and teleological). The tasks use the models to create the explanations of the given classes. Key mechanisms are discussed to implement the generic explanation tasks. Knowledge representations based on objects and their relations form a vocabulary to model and present plant knowledge. A particular class of models, means-end models, are used to explain plant knowledge. Explanations are generated through searches in the models. Hypertext is adopted to communicate explanations over dialogue based on context. The results are demonstrated in prototypes. The VICE prototype explains the reasoning of an expert system for diagnosis of rotating machines at power plants. The Justifier prototype explains design knowledge obtained from an object-oriented plant design tool. Enhanced access mechanisms into on-line documentation are

  1. Validation and Characterization of Ghd7.1, a Major Quantitative Trait Locus with Pleiotropic Effects on Spikelets per Panicle, Plant Height, and Heading Date in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Touming Liu; Haiyang Liu; Huang Zhan; Yongzhong Xing

    2013-01-01

    A quantitative trait locus (QTL) that affects heading date (HD) and the number of spikelets per panicle (SPP) was previously identified in a small region on chromosome 7 in rice (Oryza sativa L.). In order to further characterize the QTL region, near isogenic lines (NILs) were quickly obtained by self-crossing recombinant inbred line 189, which is heterozygous in the vicinity of the target region. The pleiotropic effects of QTL Ghd7.1 on plant height (PH), SPP, and HD, were validated using an NIL-F2 population. Ghd7.1 explained 50.2%, 45.3%, and 76.9%of phenotypic variation in PH, SPP, and HD, respectively. Ghd7.1 was precisely mapped to a 357-kb region on the basis of analysis of the progeny of the NIL-F2 population. Day-length treatment confirmed that Ghd7.1 is sensitive to photoperiod, with long days delaying heading up to 12.5 d. Identification of panicle initiation and development for the pair of NILs showed that Ghd7.1 elongated the photoperiod-sensitive phase more than 10 d, but did not change the basic vegetative phase and the reproductive growth phase. These findings indicated that Ghd7.1 regulates SPP by controlling the rate of panicle differentiation rather than the duration of panicle development.

  2. Plant Growth Models Using Artificial Neural Networks

    Science.gov (United States)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  3. High Affinity Iron Permease is Required for Virulence of Rhizopus oryzae

    Science.gov (United States)

    Rhizopus oryzae is the most common cause of mucormycosis. Clinical and animal model data clearly demonstrate that the presence of elevated available serum iron predisposes the host to develop mucormycosis. The high affinity iron permease gene (rFTR1) is required for R. oryzae iron transport in iro...

  4. ANTAGONISTIC ACTIVITY OF SERRATIA MARCESCENS AGAINST PYRICULARIA ORYZAE

    Directory of Open Access Journals (Sweden)

    V. JAIGANESH

    2007-08-01

    Full Text Available Rice is an important crop, widely affected by quite a number of diseases that results in higher yield losses. Among the fungal diseases, blast incited by Pyricularia oryzae is a major disease. The biological method of plant disease management seems to be an alternative to chemical fungicides in managing the blast disease. A new bio control agent viz., Serratia marcescens appears to be an ideal agent for the control of P. oryzae, because it produces chitinolytic enzymes which causes degradation of the fungal cell walls, induction of plant defence reaction and certain antifungal low molecular weight molecules. A study was undertaken to investigate the effect of a new bio control agent like S. marcescens against P. oryzae. The talc based formulation of S. marcescens (@ 1.0, 1.5, 2.0 and 2.5 kg/ha was sprayed on old IR 50 rice plants in fields. Out of the six-bio protectants tested, S. marcescens was found very effective against P. oryzae under in vitro conditions. S. marcescens could be isolated from shoots as well as roots emerging from the treated seeds and the plant parts from treated seeds inhibited P. oryzae. The antagonist S. marcescens survived in the phyllosphere even 80 days after spray. The results revealed that rice blast control was achieved by spraying S. marcescens @ 1.0 kg/ha. The increasing dose of talc-based inoculum when applied on foliage increased the phyllosphere population of S. marcescens and controlled rice blast. The maximum disease control was achieved when inoculum was applied at 2.5 kg/ha.

  5. Effect of external iron and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake in rice (Oryza sativa L.)

    OpenAIRE

    Azizur Rahman, Mohammad; Mamunur, Rahman, Mohammad; Kadohashi, K.; Maki, Teruya; Hasegawa, Hiroshi

    2011-01-01

    This study was conducted to investigate the effect of external iron status and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake. Rice seedlings (Oryza sativa L.) were used as model plant, and were grown in artificially contaminated sandy soils irrigated with Murashige and Skoog (MS) culture solution. Arsenate uptake in roots and shoots of rice seedlings were affected significantly (p > 0.05) while dimethylarsinic acid (DMAA) was not by the additional iron and chelat...

  6. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L.and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O. sativa and O. meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice bfeeding program for the improvement of bacterial blight resistance.

  7. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L. and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.

  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. Thirteen challenges in modelling plant diseases

    Science.gov (United States)

    The underlying structure of epidemiological models, and the questions that models can be used to address, do not necessarily depend on the identity of the host. This means that certain preoccupations of plant disease modelers are similar to those of modelers of diseases in animals and humans. Howeve...

  10. Zinc absorption from low phytic acid genotypes of maize (Zea mays L.), Barley (Hordeum vulgare L.), and Rice (Oryza sativa L.) assessed in a suckling rat pup model.

    Science.gov (United States)

    Lönnerdal, Bo; Mendoza, Concepcion; Brown, Kenneth H; Rutger, J Neil; Raboy, Victor

    2011-05-11

    Dietary phytic acid is a major causative factor for low Zn bioavailability in many cereal- and legume-based diets. The bioavailability of Zn in seed of low phytic acid (lpa) variants of maize ( Zea mays L.), rice ( Oryza sativa L.), and barley ( Hordeum vulgare L.) was evaluated using a suckling rat pup model. Suckling rat pups (14 days old, n = 6-8/treatment) were fasted for 6 h and intubated with (65)Zn-radiolabeled suspensions prepared using seed produced by either wild-type (normal phytic acid) or lpa genotypes of each cereal. Test solutions were radiolabeled overnight (all genotypes) or immediately prior to intubation (barley genotypes). Pups were killed 6 h postintubation and tissues removed and counted in a gamma counter. Zn absorption was low from wild-type genotypes of maize (21, 33%) and rice (26%), and phytic acid reduction resulted in significantly higher Zn absorption, 47-52 and 35-52%, respectively. Zn absorption from wild-type barley incubated overnight was high (86-91%), and phytate reduction did not improve Zn absorption (84-90%), which is likely due to endogenous phytase activity. When the wild-type barley solutions were prepared immediately before intubation, Zn absorption was significantly lower (63, 78%) than from the lpa cultivars (92, 96%). Variation in seed or flour phenolic acid levels did not affect Zn absorption. Differences in seed Zn levels did not substantially affect Zn absorption. Thus, when phytic acid is abundant in a diet, it has a larger effect on Zn absorption than the level of Zn. Therefore, reducing the phytic acid content of staple cereal grains may contribute to enhancing Zn nutrition of populations consuming these staple foods.

  11. Modeling Operating Modes during Plant Life Cycle

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lind, Morten

    2012-01-01

    Modelling process plants during normal operation requires a set a basic assumptions to define the desired functionalities which lead to fullfillment of the operational goal(-s) for the plant. However during during start-up and shut down as well as during batch operation an ensemble of interrelate...

  12. Plant aquaporins: structure meets function as associating with sensing of Xanthomonas oryzae Hpa1 and subsequent signal transduction%植物水通道蛋白结构与功能及其识别与转导水稻黄单胞菌Hpa1信号的机制

    Institute of Scientific and Technical Information of China (English)

    尤真真; 高蓉; 田珊; 董汉松

    2013-01-01

    Plant aquaporin proteins basically mediate water transport through cell membranes,and also affect plant-microbe interactions and plant defense responses.Molecular mechanisms that underlie the dual function are unclear.Recently,the rice and Arabidopsis aquaporins OsPIP1; 2 and AtPIP1 ; 4 interact with Hpa1,a protein secreted by type Ⅲ pathway in Xanthomonas oryzae pathovars oryzae and oryzicola,which cause bacterial blight disaese and bacterial leaf streak disease of rice,respectively have been determined.When applied to plants or produced in transgenic plants,Hpa1 localizes to the apoplast and induces hydrogen peroxide generation in the same cellular location.The generation of hydrogen peroxide is dependent on the NADPH oxidase located at the plasma membrane.In response to Hpa1,moreover,the apoplastic hydrogen peroxide translocates to the cytoplasm with subcequent effects of enhancing plant defense responses to bacterial pathogens.According to established models in regard to the topological structure of aquaporins,the performance of bacterial type Ⅲ secretion,and subcellular trafficking of hydrogen peroxide in plants,it is necessary to identify the functional domain for OsPIP1 ; 2 interacting with Hpa1,and elucidate molecular features and structural basis of the OsPIP1 ; 2-Hpa1 interaction.Signal transduction triggered by the molecular interaction may be linked with the role of OsPIP1 ; 2 Hpa1 interaction in modulating translocation of apoplastic hydrogen peroxide to the cytoplasm,thus connecting the signal translocation with defense responses in rice.The OsPIP1 ; 2-Hpa1 interaction may also play a role in facilitating the translocation of X.oryzae type Ⅲ effector proteins from the bacterial cell to the plant cell because Hpa1 has been suggested as a candidate of tyep-Ⅲ effector translocators.With this hypothesis,studies are to further reveal regulatory mechanisms of plant-pathogen interactions,offerring a significant extension of aquaporins' functions over

  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. Common and distant structural characteristics of feruloyl esterase families from Aspergillus oryzae.

    Directory of Open Access Journals (Sweden)

    D B R K Gupta Udatha

    Full Text Available BACKGROUND: Feruloyl esterases (FAEs are important biomass degrading accessory enzymes due to their capability of cleaving the ester links between hemicellulose and pectin to aromatic compounds of lignin, thus enhancing the accessibility of plant tissues to cellulolytic and hemicellulolytic enzymes. FAEs have gained increased attention in the area of biocatalytic transformations for the synthesis of value added compounds with medicinal and nutritional applications. Following the increasing attention on these enzymes, a novel descriptor based classification system has been proposed for FAEs resulting into 12 distinct families and pharmacophore models for three FAE sub-families have been developed. METHODOLOGY/PRINCIPAL FINDINGS: The feruloylome of Aspergillus oryzae contains 13 predicted FAEs belonging to six sub-families based on our recently developed descriptor-based classification system. The three-dimensional structures of the 13 FAEs were modeled for structural analysis of the feruloylome. The three genes coding for three enzymes, viz., A.O.2, A.O.8 and A.O.10 from the feruloylome of A. oryzae, representing sub-families with unknown functional features, were heterologously expressed in Pichia pastoris, characterized for substrate specificity and structural characterization through CD spectroscopy. Common feature-based pharamacophore models were developed according to substrate specificity characteristics of the three enzymes. The active site residues were identified for the three expressed FAEs by determining the titration curves of amino acid residues as a function of the pH by applying molecular simulations. CONCLUSIONS/SIGNIFICANCE: Our findings on the structure-function relationships and substrate specificity of the FAEs of A. oryzae will be instrumental for further understanding of the FAE families in the novel classification system. The developed pharmacophore models could be applied for virtual screening of compound databases for

  15. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas

    2010-08-15

    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  16. Bioaccumulation and translocation of polyhalogenated compounds in rice (Oryza sativa L.) planted in paddy soil collected from an electronic waste recycling site, South China.

    Science.gov (United States)

    Zhang, Yun; Luo, Xiao-Jun; Mo, Ling; Wu, Jiang-Ping; Mai, Bi-Xian; Peng, Yong-Hong

    2015-10-01

    The bioaccumulation and translocation of polyhalogenated compounds (PHCs) in rice planted in the paddy soils of an electronic waste (e-waste) recycling site were investigated, along with the effect of contaminated soils on rice growth. The PHCs included polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and dechlorane plus (DPs). The morphological development and all measured physiological parameters of rice plants except for peroxidase were significantly inhibited by e-waste contaminated soils. Specifically, soil-root bioaccumulation factors (RCFs) increased with increasing logarithm of octanol-water partition coefficient (logKow) for PCBs, but decreased for PBDEs. During translocation from root to stem, translocation factors (TFs) and logKow were positively correlated. However, the accumulation mechanism in the leaf was concentration-dependent. In the high concentration exposure group, translocation play more important role in determination PHCs burden in leaf than atmospheric uptake, with logTF (from stem to leaf) being positively correlated with logKow. In contrast, in the low exposure and control groups, logTF (from stem to leaf) was negatively correlated with logKow. In addition, Syn-DP was selectively accumulated in plant tissues. In conclusion, this study demonstrates that e-waste contaminated soils affect rice growth, revealed the rule of the bioaccumulation and translocation of PHCs in rice plants.

  17. The local impact of a coal-fired power plant on inorganic mercury and methyl-mercury distribution in rice (Oryza sativa L.).

    Science.gov (United States)

    Xu, Xiaohang; Meng, Bo; Zhang, Chao; Feng, Xinbin; Gu, Chunhao; Guo, Jianyang; Bishop, Kevin; Xu, Zhidong; Zhang, Sensen; Qiu, Guangle

    2017-04-01

    Emission from coal-fired power plants is one of the major anthropogenic sources of mercury (Hg) in the environment, because emitted Hg can be quickly deposited nearby the source, attention is paid to the effects of coal-burning facilities on levels of toxic methyl-mercury (MeHg) in biota near such sources. Since rice is an agricultural crop that can bio-accumulate MeHg, the potential effects of a large Hg-emitting coal-fired power plant in Hunan Province, China on both inorganic Hg (Hg(II)) and MeHg distributions in rice was investigated. Relatively high MeHg (up to 3.8 μg kg(-1)) and Hg(II) (up to 22 μg kg(-1)) concentrations were observed in rice samples collected adjacent to the plant, suggesting a potential impact of Hg emission from the coal fired power plant on the accumulation of Hg in rice in the area. Concentrations of MeHg in rice were positively correlated with soil MeHg, soil S, and gaseous elemental Hg (GEM) in ambient air. Soil MeHg was the most important factor controlling MeHg concentrations in rice. The methylation of Hg in soils may be controlled by factors such as the chemical speciation of inorganic Hg, soil S, and ambient GEM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Actant model of an extraction plant

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, Helle

    1999-05-01

    Facing a growing complexity of industrial plants, we recognise the need for qualitative modelling methods capturing functional and causal complexity in a human-centred way. The present paper presents actant modelling as a functional modelling method rooted in linguistics and semiotics. Actant modelling combines actant models from linguistics with multilevel flow modelling (MFM). Thus the semantics of MFM functions is developed further and given an interpretation in terms of actant functions. The present challenge is to provide coherence between seemingly different categories of knowledge. Yet the gap between functional and causal modelling methods can be bridged. Actant modelling provides an open and provisional, but in no way exhaustive or final answer as to how teleological concepts like goals and functions relate to causal concepts. As the main focus of the paper an actant model of an extraction plant is presented. It is shown how the actant model merges functional and causal knowledge in a natural way.

  19. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size-asymmetric ......A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size...

  20. Models of plant populations and communities

    Energy Technology Data Exchange (ETDEWEB)

    Huston, M.

    1990-01-01

    This document is the overview of the plant section in the book, {und Individual-Based Models and Approaches in Ecology}. A brief description of each of the chapters is provided, as well as a comparison of the models presented in each chapter. Four of the six chapters deal with single species interactions, one dealt with a two species system (plants and pollinators) and one deals with multispecies interactions. Both i-state distribution models and i-state configuration models are discussed. (MHB)

  1. The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).

    Science.gov (United States)

    Wang, Kai; Wambugu, Peterson W; Zhang, Bin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

    2015-09-20

    The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Analysis of the Peroxidase Activity of Rice (Oryza Sativa) Recombinant Hemoglobin 1: Implications for the In Vivo Function of Hexacoordinate Non-Symbiotic Hemoglobins in Plants

    Science.gov (United States)

    In plants, it has been proposed that hexacoordinate (class 1) non-symbiotic Hbs (nsHb-1) function in vivo as peroxidases. However, little is known about the peroxidase activity of nsHb-1. We evaluated the peroxidase activity of rice recombinant Hb1 (a nsHb-1) by using the guaiacol/H2O2 system at pH ...

  3. A collection of cytochrome P450 monooxygenase genes involved in modification and detoxification of herbicide atrazine in rice (Oryza sativa) plants.

    Science.gov (United States)

    Rong Tan, Li; Chen Lu, Yi; Jing Zhang, Jing; Luo, Fang; Yang, Hong

    2015-09-01

    Plant cytochrome P450 monooxygenases constitute one of the largest families of protein genes involved in plant growth, development and acclimation to biotic and abiotic stresses. However, whether these genes respond to organic toxic compounds and their biological functions for detoxifying toxic compounds such as herbicides in rice are poorly understood. The present study identified 201 genes encoding cytochrome P450s from an atrazine-exposed rice transcriptome through high-throughput sequencing. Of these, 69 cytochrome P450 genes were validated by microarray and some of them were confirmed by real time PCR. Activities of NADPH-cytochrome P450 reductase (CPR) and p-nitroanisole O-demethylase (PNOD) related to toxicity were determined and significantly induced by atrazine exposure. To dissect the mechanism underlying atrazine modification and detoxification by P450, metabolites (or derivatives) of atrazine in plants were analyzed by ultra performance liquid chromatography mass spectrometry (UPLC/MS). Major metabolites comprised desmethylatrazine (DMA), desethylatrazine (DEA), desisopropylatrazine (DIA), hydroxyatrazine (HA), hydroxyethylatrazine (HEA) and hydroxyisopropylatrazine (HIA). All of them were chemically modified by P450s. Furthermore, two specific inhibitors of piperonyl butoxide (PBO) and malathion (MAL) were used to assess the correlation between the P450s activity and rice responses including accumulation of atrazine in tissues, shoot and root growth and detoxification. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Two Rab5 Homologs Are Essential for the Development and Pathogenicity of the Rice Blast Fungus Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Cheng D. Yang

    2017-05-01

    Full Text Available The rice blast fungus, Magnaporthe oryzae, infects many economically important cereal crops, particularly rice. It has emerged as an important model organism for studying the growth, development, and pathogenesis of filamentous fungi. RabGTPases are important molecular switches in regulation of intracellular membrane trafficking in all eukaryotes. MoRab5A and MoRab5B are Rab5 homologs in M. oryzae, but their functions in the fungal development and pathogenicity are unknown. In this study, we have employed a genetic approach and demonstrated that both MoRab5A and MoRab5B are crucial for vegetative growth and development, conidiogenesis, melanin synthesis, vacuole fusion, endocytosis, sexual reproduction, and plant pathogenesis in M. oryzae. Moreover, both MoRab5A and MoRab5B show similar localization in hyphae and conidia. To further investigate possible functional redundancy between MoRab5A and MoRab5B, we overexpressed MoRAB5A and MoRAB5B, respectively, in MoRab5B:RNAi and MoRab5A:RNAi strains, but neither could rescue each other’s defects caused by the RNAi. Taken together, we conclude that both MoRab5A and MoRab5B are necessary for the development and pathogenesis of the rice blast fungus, while they may function independently.

  5. Growth and product formation of Aspergillus oryzae during submerged cultivations: Verification of a morphologically structured model using fluorescent probes

    DEFF Research Database (Denmark)

    Agger, Teit; Spohr, Anders Bendsen; Carlsen, Morten

    1998-01-01

    and automated image analysis, has been developed for measuring the fraction of active cells. The method employs the fluorescent dye 3,3'-dihexyloxocarbocyanin to stain organelles inside the hyphae and Calcoflour White to stain the cell wall. The ratio between the projected areas of the organelles...... and of the entire hyphal element is then taken to be proportional to the fraction of active cells. When applied to chemostat and fed-batch experiments, the double-staining method seemed to confirm the basic morphological structure of the model. The model is able to produce accurate simulations of steady......-state and transient conditions in chemostats, of batch cultivations, and even the formation of a single hyphal element from a spore, all with the same values of the model parameters. (C) 1998 John Wiley & Sons, Inc....

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

    Directory of Open Access Journals (Sweden)

    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

  7. An analytical model of memristors in plants.

    Science.gov (United States)

    Markin, Vladislav S; Volkov, Alexander G; Chua, Leon

    2014-01-01

    The memristor, a resistor with memory, was postulated by Chua in 1971 and the first solid-state memristor was built in 2008. Recently, we found memristors in vivo in plants. Here we propose a simple analytical model of 2 types of memristors that can be found within plants. The electrostimulation of plants by bipolar periodic waves induces electrical responses in the Aloe vera and Mimosa pudica with fingerprints of memristors. Memristive properties of the Aloe vera and Mimosa pudica are linked to the properties of voltage gated K(+) ion channels. The potassium channel blocker TEACl transform plant memristors to conventional resistors. The analytical model of a memristor with a capacitor connected in parallel exhibits different characteristic behavior at low and high frequency of applied voltage, which is the same as experimental data obtained by cyclic voltammetry in vivo.

  8. Plant STAND P-loop NTPases: a current perspective of genome distribution, evolution, and function : Plant STAND P-loop NTPases: genomic organization, evolution, and molecular mechanism models contribute broadly to plant pathogen defense.

    Science.gov (United States)

    Arya, Preeti; Acharya, Vishal

    2017-09-12

    STAND P-loop NTPase is the common weapon used by plant and other organisms from all three kingdoms of life to defend themselves against pathogen invasion. The purpose of this study is to review comprehensively the latest finding of plant STAND P-loop NTPase related to their genomic distribution, evolution, and their mechanism of action. Earlier, the plant STAND P-loop NTPase known to be comprised of only NBS-LRRs/AP-ATPase/NB-ARC ATPase. However, recent finding suggests that genome of early green plants comprised of two types of STAND P-loop NTPases: (1) mammalian NACHT NTPases and (2) NBS-LRRs. Moreover, YchF (unconventional G protein and members of P-loop NTPase) subfamily has been reported to be exceptionally involved in biotic stress (in case of Oryza sativa), thereby a novel member of STAND P-loop NTPase in green plants. The lineage-specific expansion and genome duplication events are responsible for abundance of plant STAND P-loop NTPases; where "moderate tandem and low segmental duplication" trajectory followed in majority of plant species with few exception (equal contribution of tandem and segmental duplication). Since the past decades, systematic research is being investigated into NBS-LRR function supported the direct recognition of pathogen or pathogen effectors by the latest models proposed via 'integrated decoy' or 'sensor domains' model. Here, we integrate the recently published findings together with the previous literature on the genomic distribution, evolution, and distinct models proposed for functional molecular mechanism of plant STAND P-loop NTPases.

  9. Plant Modeling for Human Supervisory Control

    DEFF Research Database (Denmark)

    Lind, Morten

    1999-01-01

    This paper provides an overview of multilevel flow modelling (MFM) and its application for design of displays for the supervisory control of industrial plant. The problem of designing the inforrrzatian content of sacpervisory displays is discussed and plant representations like MFM using levels...... is also provided by an analysis of the relations between levels of abstraction. It is also described how MFM supparts reazsonin about control actions by defining levels of intervention and by modal distinctions between function enablement and initiation....

  10. Plant Growth Modelling and Applications: The Increasing Importance of Plant Architecture in Growth Models

    Science.gov (United States)

    Fourcaud, Thierry; Zhang, Xiaopeng; Stokes, Alexia; Lambers, Hans; Körner, Christian

    2008-01-01

    Background Modelling plant growth allows us to test hypotheses and carry out virtual experiments concerning plant growth processes that could otherwise take years in field conditions. The visualization of growth simulations allows us to see directly and vividly the outcome of a given model and provides us with an instructive tool useful for agronomists and foresters, as well as for teaching. Functional–structural (FS) plant growth models are nowadays particularly important for integrating biological processes with environmental conditions in 3-D virtual plants, and provide the basis for more advanced research in plant sciences. Scope In this viewpoint paper, we ask the following questions. Are we modelling the correct processes that drive plant growth, and is growth driven mostly by sink or source activity? In current models, is the importance of soil resources (nutrients, water, temperature and their interaction with meristematic activity) considered adequately? Do classic models account for architectural adjustment as well as integrating the fundamental principles of development? Whilst answering these questions with the available data in the literature, we put forward the opinion that plant architecture and sink activity must be pushed to the centre of plant growth models. In natural conditions, sinks will more often drive growth than source activity, because sink activity is often controlled by finite soil resources or developmental constraints. PMA06 This viewpoint paper also serves as an introduction to this Special Issue devoted to plant growth modelling, which includes new research covering areas stretching from cell growth to biomechanics. All papers were presented at the Second International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA06), held in Beijing, China, from 13–17 November, 2006. Although a large number of papers are devoted to FS models of agricultural and forest crop species, physiological and genetic

  11. STANDARDIZING THE EXTRACTION AND EVALUATION OF ANTIMICROBIAL FRACTION FROM STREPTOMYCES SP. TC1 AGAINST XANTHOMONAS ORYZAE PV. ORYZAE

    Directory of Open Access Journals (Sweden)

    NANJUNDAN JAIVEL*, RAMASAMY RAJESH AND PONNUSAMY MARIMUTHU

    2014-08-01

    Full Text Available Streptomyces are prokaryotic microorganisms capable of producing a wide range of secondary metabolites has the capacity to fight with the competing plant pathogens and suppress the growth of them. A promising Streptomyces sp. TC1 isolate exhibited antimicrobial activity against bacterial leaf blight pathogen Xanthomonas oryzae pv. oryzae under in vitro conditions. The antimicrobial activity of TC1 culture filtrate was found to be higher at seven days of incubation. The optimized extraction of antimicrobial fractions from the culture filtrate was obtained with ethyl acetate solvent. Adjusting the pH of the culture filtrate to 3 prior to extraction process resulted in increased recovery of antimicrobial fractions. The crude antimicrobial fraction obtained from the TC1 fermentation broth exhibited a minimum inhibitory concentration value of 300 µg/ml against the test pathogen Xanthomonas oryzae pv. oryzae. The antimicrobial activity results including agar well diffusion assay and MIC experiments strongly recommend that the Streptomyces sp. TC1 can be explored for antimicrobial metabolites for bacterial blight disease control in rice.

  12. Plant microRNA-target interaction identification model based on the integration of prediction tools and support vector machine.

    Directory of Open Access Journals (Sweden)

    Jun Meng

    Full Text Available Confident identification of microRNA-target interactions is significant for studying the function of microRNA (miRNA. Although some computational miRNA target prediction methods have been proposed for plants, results of various methods tend to be inconsistent and usually lead to more false positive. To address these issues, we developed an integrated model for identifying plant miRNA-target interactions.Three online miRNA target prediction toolkits and machine learning algorithms were integrated to identify and analyze Arabidopsis thaliana miRNA-target interactions. Principle component analysis (PCA feature extraction and self-training technology were introduced to improve the performance. Results showed that the proposed model outperformed the previously existing methods. The results were validated by using degradome sequencing supported Arabidopsis thaliana miRNA-target interactions. The proposed model constructed on Arabidopsis thaliana was run over Oryza sativa and Vitis vinifera to demonstrate that our model is effective for other plant species.The integrated model of online predictors and local PCA-SVM classifier gained credible and high quality miRNA-target interactions. The supervised learning algorithm of PCA-SVM classifier was employed in plant miRNA target identification for the first time. Its performance can be substantially improved if more experimentally proved training samples are provided.

  13. Modeling Performance of Plant Growth Regulators

    Directory of Open Access Journals (Sweden)

    W. C. Kreuser

    2017-03-01

    Full Text Available Growing degree day (GDD models can predict the performance of plant growth regulators (PGRs applied to creeping bentgrass ( L.. The goal of this letter is to describe experimental design strategies and modeling approaches to create PGR models for different PGRs, application rates, and turf species. Results from testing the models indicate that clipping yield should be measured until the growth response has diminished. This is in contrast to reapplication of a PGR at preselected intervals. During modeling, inclusion of an amplitude-dampening coefficient in the sinewave model allows the PGR effect to dissipate with time.

  14. Screening for Nemaicidal Activity of Some Chinese Plant Extracts against Plant Parasitic Nematodes, Bursaphelenchus xylophilus, Meloidogyne arenaria and Hirschmanniella oryzae%植物抽提物对几种植物病原线虫的杀线活性筛选

    Institute of Scientific and Technical Information of China (English)

    文艳华; 冯志新; 徐汉虹; 陈立

    2001-01-01

    Extracts of 14 Chinese plants (belong to 10 fami lies in Hubei,Shanxi and Guangdong Provinces, China) were assessed f or nematicidal activity against Bursaphelenchus xylophilus using a fungal-f eedin g method in vitro. Some of 14 plant extracts were also assessed for nematicidal activity against Meloidogyne arenaria and Hirschmanniella oryzae. Five p lant ext racts(Cephalotaxus fortunei, Cephalotaxus sinensis, Paeonia suffrutccosa, Soph or a viciifolia and Derris elliptica) showed strong nematicidal activity against B ursaphelenchus xylophilus; 3 plant extracts (Cephalotaxus fortunei, Paeonia suf frutccosa, Sophora viciifolia) also showed strong nematicidal activity agains t M. arenaria and H.oryzae. While 4 plant extracts (Sargentodoxus argota enia, Mang lietia patungensis, Liriope spicata, and Liriodendron chinese) demonstrated no nematicidal activity against B. xylophilus and M. arenaria.%测定了中国湖北、陕西及广东省的10科14种植物抽提物对几种植物病原线虫的杀线活性,结果表明:对松材线虫,毛鱼藤(Derris elliptica)根有极强杀线活性,三尖杉( Cephalotaxus fortunei)茎叶、粗榧(Cephalotaxus sinensis)叶、狼牙刺( Sophora vi ciifolia)种子、紫斑牡丹(Paeonia suffrutccosa)茎有强杀线活性,神农香菊( Dendra nthema indicum)全株有中等杀线活性,瓜叶乌头(Aconitum hemsleyanum)全株、香果树(Emmenopterys henryi)叶、东方荚果蕨(Matteuccia orientalis)茎叶、大叶醉鱼草( Buddleja davidii)叶均无杀线活性;对花生根结线虫及水稻潜根线虫,三尖杉茎叶、狼牙刺种子、紫斑牡丹茎有极强杀线活性,神农香菊全株有中等杀线活性;大血藤(Sargento do xus argotaenia)茎、巴东木莲(Manglietia patungensis)叶、土麦冬(Liriop e spicat a)全株及鹅掌揪(Liriodendron chinese)叶对松材线虫、花生根结线虫均无杀线活性。

  15. Model feedstock supply processing plants

    Directory of Open Access Journals (Sweden)

    V. M. Bautin

    2013-01-01

    Full Text Available The model of raw providing the processing enterprises entering into vertically integrated structure on production and processing of dairy raw materials, differing by an orientation on achievement of cumulative effect by the integrated structure acting as criterion function which maximizing is reached by optimization of capacities, volumes of deliveries of raw materials and its qualitative characteristics, costs of industrial processing of raw materials and demand for dairy production is developed.

  16. Flux balance analysis of genome-scale metabolic model of rice (Oryza sativa): Aiming to increase biomass

    Indian Academy of Sciences (India)

    Rahul Shaw; Sudip Kundu

    2015-10-01

    Due to socio-economic reasons, it is essential to design efficient stress-tolerant, more nutritious, high yielding rice varieties. A systematic understanding of the rice cellular metabolism is essential for this purpose. Here, we analyse a genome-scale metabolic model of rice leaf using Flux Balance Analysis to investigate whether it has potential metabolic flexibility to increase the biosynthesis of any of the biomass components. We initially simulate the metabolic responses under an objective to maximize the biomass components. Using the estimated maximum value of biomass synthesis as a constraint, we further simulate the metabolic responses optimizing the cellular economy. Depending on the physiological conditions of a cell, the transport capacities of intracellular transporters (ICTs) can vary. To mimic this physiological state, we randomly vary the ICTs’ transport capacities and investigate their effects. The results show that the rice leaf has the potential to increase glycine and starch in a wide range depending on the ICTs’ transport capacities. The predicted biosynthesis pathways vary slightly at the two different optimization conditions. With the constraint of biomass composition, the cell also has the metabolic plasticity to fix a wide range of carbon-nitrogen ratio.

  17. Model of how plants sense zinc deficiency

    DEFF Research Database (Denmark)

    Assuncao, Ana G.L.; Persson, Daniel Olof; Husted, Søren;

    2013-01-01

    to develop plant-based solutions addressing nutrient-use-efficiency and adaptation to nutrient-limited or -toxic soils. Recently two transcription factors of the bZIP family (basic-region leucine zipper) have been identified in Arabidopsis and shown to be pivotal in the adaptation response to zinc deficiency....... They represent not only the first regulators of zinc homeostasis identified in plants, but also a very promising starting-point that can provide new insights into the molecular basis of how plants sense and adapt to the stress of zinc deficiency. Considering the available information thus far we propose...... in this review a putative model of how plants sense zinc deficiency....

  18. Modelling and simulation of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Eborn, J.

    1998-02-01

    Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Integrated production and recycling of materials are trends that give rise to heterogenous systems, which are difficult to handle within one area of expertise. Model libraries are an excellent way to package engineering knowledge of systems and units to be reused by those who are not experts in modelling. Many commercial packages provide good model libraries, but they are usually domain-specific and closed. Heterogenous, multi-domain systems requires open model libraries written in general purpose modelling languages. This thesis describes a model database for thermal power plants written in the object-oriented modelling language OMOLA. The models are based on first principles. Subunits describe volumes with pressure and enthalpy dynamics and flows of heat or different media. The subunits are used to build basic units such as pumps, valves and heat exchangers which can be used to build system models. Several applications are described; a heat recovery steam generator, equipment for juice blending, steam generation in a sulphuric acid plant and a condensing steam plate heat exchanger. Model libraries for industrial use must be validated against measured data. The thesis describes how parameter estimation methods can be used for model validation. Results from a case-study on parameter optimization of a non-linear drum boiler model show how the technique can be used 32 refs, 21 figs

  19. A continuous growth model for plant tissue

    Science.gov (United States)

    Bozorg, Behruz; Krupinski, Pawel; Jönsson, Henrik

    2016-12-01

    Morphogenesis in plants and animals involves large irreversible deformations. In plants, the response of the cell wall material to internal and external forces is determined by its mechanical properties. An appropriate model for plant tissue growth must include key features such as anisotropic and heterogeneous elasticity and cell dependent evaluation of mechanical variables such as turgor pressure, stress and strain. In addition, a growth model needs to cope with cell divisions as a necessary part of the growth process. Here we develop such a growth model, which is capable of employing not only mechanical signals but also morphogen signals for regulating growth. The model is based on a continuous equation for updating the resting configuration of the tissue. Simultaneously, material properties can be updated at a different time scale. We test the stability of our model by measuring convergence of growth results for a tissue under the same mechanical and material conditions but with different spatial discretization. The model is able to maintain a strain field in the tissue during re-meshing, which is of particular importance for modeling cell division. We confirm the accuracy of our estimations in two and three-dimensional simulations, and show that residual stresses are less prominent if strain or stress is included as input signal to growth. The approach results in a model implementation that can be used to compare different growth hypotheses, while keeping residual stresses and other mechanical variables updated and available for feeding back to the growth and material properties.

  20. Interannual variability of plant phenology in tussock tundra: modelling interactions of plant productivity, plant phenology, snowmelt and soil thaw

    NARCIS (Netherlands)

    Wijk, van M.T.; Williams, M.; Laundre, J.A.; Shaver, G.R.

    2003-01-01

    We present a linked model of plant productivity, plant phenology, snowmelt and soil thaw in order to estimate interannual variability of arctic plant phenology and its effects on plant productivity. The model is tested using 8 years of soil temperature data, and three years of bud break data of Betu

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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. Assessment of the Phytotoxicity of Metal Oxide Nanoparticles on Two Crop Plants, Maize (Zea mays L.) and Rice (Oryza sativa L.).

    Science.gov (United States)

    Yang, Zhongzhou; Chen, Jing; Dou, Runzhi; Gao, Xiang; Mao, Chuanbin; Wang, Li

    2015-11-30

    In this study, the phytotoxicity of seven metal oxide nanoparticles(NPs)-titanium dioxide (nTiO₂), silicon dioxide (nSiO₂), cerium dioxide (nCeO₂), magnetite (nFe₃O₄), aluminum oxide (nAl₂O₃), zinc oxide (nZnO) and copper oxide (nCuO)-was assessed on two agriculturally significant crop plants (maize and rice). The results showed that seed germination was not affected by any of the seven metal oxide NPs. However, at the concentration of 2000 mg·L(-1), the root elongation was significantly inhibited by nCuO (95.73% for maize and 97.28% for rice), nZnO (50.45% for maize and 66.75% for rice). On the contrary, minor phytotoxicity of nAl₂O₃ was only observed in maize, and no obvious toxic effects were found in the other four metal oxide NPs. By further study we found that the phytotoxic effects of nZnO, nAl₂O₃ and nCuO (25 to 2000 mg·L(-)¹) were concentration dependent, and were not caused by the corresponding Cu(2+), Zn(2+) and Al(3+) ions (0.11 mg·L(-)¹, 1.27 mg·L(-)¹ and 0.74 mg·L(-)¹, respectively). Furthermore, ZnO NPs (<50 nm) showed greater toxicity than ZnO microparticles(MPs)(<5 μm) to root elongation of both maize and rice. Overall, this study provided valuable information for the application of engineered NPs in agriculture and the assessment of the potential environmental risks.

  4. Assessment of the Phytotoxicity of Metal Oxide Nanoparticles on Two Crop Plants, Maize (Zea mays L. and Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Zhongzhou Yang

    2015-11-01

    Full Text Available In this study, the phytotoxicity of seven metal oxide nanoparticles(NPs—titanium dioxide (nTiO2, silicon dioxide (nSiO2, cerium dioxide (nCeO2, magnetite (nFe3O4, aluminum oxide (nAl2O3, zinc oxide (nZnO and copper oxide (nCuO—was assessed on two agriculturally significant crop plants (maize and rice. The results showed that seed germination was not affected by any of the seven metal oxide NPs. However, at the concentration of 2000 mg·L−1, the root elongation was significantly inhibited by nCuO (95.73% for maize and 97.28% for rice, nZnO (50.45% for maize and 66.75% for rice. On the contrary, minor phytotoxicity of nAl2O3 was only observed in maize, and no obvious toxic effects were found in the other four metal oxide NPs. By further study we found that the phytotoxic effects of nZnO, nAl2O3 and nCuO (25 to 2000 mg·L−1 were concentration dependent, and were not caused by the corresponding Cu2+, Zn2+ and Al3+ ions (0.11 mg·L−1, 1.27 mg·L−1 and 0.74 mg·L−1, respectively. Furthermore, ZnO NPs (<50 nm showed greater toxicity than ZnO microparticles(MPs(<5 μm to root elongation of both maize and rice. Overall, this study provided valuable information for the application of engineered NPs in agriculture and the assessment of the potential environmental risks.

  5. Nonhost resistance of barley is successfully manifested against Magnaporthe grisea and a closely related Pennisetum-infecting lineage but is overcome by Magnaporthe oryzae

    NARCIS (Netherlands)

    Zellerhoff, N.; Jarosch, B.; Groenewald, J.Z.; Crous, P.W.; Schaffrath, U.

    2006-01-01

    Magnaporthe oryzae is a major pathogen of rice (Oryza sativa L.) but is also able to infect other grasses, including barley (Hordeum vulgare L.). Here, we report a study using Magnaporthe isolates collected from other host plant species to evaluate their capacity to infect barley. A nonhost type of

  6. New concepts for dynamic plant uptake models

    DEFF Research Database (Denmark)

    Rein, Arno; Legind, Charlotte Nielsen; Trapp, Stefan

    2011-01-01

    Models for the prediction of chemical uptake into plants are widely applied tools for human and wildlife exposure assessment, pesticide design and for environmental biotechnology such as phytoremediation. Steady-state considerations are often applied, because they are simple and have a small data...

  7. Epigenetic regulation of development and pathogenesis in fungal plant pathogens.

    Science.gov (United States)

    Dubey, Akanksha; Jeon, Junhyun

    2017-08-01

    Evidently, epigenetics is at forefront in explaining the mechanisms underlying the success of human pathogens and in the identification of pathogen-induced modifications within host plants. However, there is a lack of studies highlighting the role of epigenetics in the modulation of the growth and pathogenicity of fungal plant pathogens. In this review, we attempt to highlight and discuss the role of epigenetics in the regulation of the growth and pathogenicity of fungal phytopathogens using Magnaporthe oryzae, a devastating fungal plant pathogen, as a model system. With the perspective of wide application in the understanding of the development, pathogenesis and control of other fungal pathogens, we attempt to provide a synthesized view of the epigenetic studies conducted on M. oryzae to date. First, we discuss the mechanisms of epigenetic modifications in M. oryzae and their impact on fungal development and pathogenicity. Second, we highlight the unexplored epigenetic mechanisms and areas of research that should be considered in the near future to construct a holistic view of epigenetic functioning in M. oryzae and other fungal plant pathogens. Importantly, the development of a complete understanding of the modulation of epigenetic regulation in fungal pathogens can help in the identification of target points to combat fungal pathogenesis. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  8. Compound leaf development in model plant species.

    Science.gov (United States)

    Bar, Maya; Ori, Naomi

    2015-02-01

    Plant leaves develop in accordance with a common basic program, which is flexibly adjusted to the species, developmental stage and environment. Two key stages of leaf development are morphogenesis and differentiation. In the case of compound leaves, the morphogenesis stage is prolonged as compared to simple leaves, allowing for the initiation of leaflets. Here, we review recent advances in the understanding of how plant hormones and transcriptional regulators modulate compound leaf development, yielding a substantial diversity of leaf forms, focusing on four model compound leaf organisms: cardamine (Cardamine hirsuta), tomato (Solanum lycopersicum), medicago (Medicago truncatula) and pea (Pisum sativum).

  9. Identification of genes required for nonhost resistance to Xanthomonas oryzae pv. oryzae reveals novel signaling components.

    Directory of Open Access Journals (Sweden)

    Wen Li

    Full Text Available BACKGROUND: Nonhost resistance is a generalized, durable, broad-spectrum resistance exhibited by plant species to a wide variety of microbial pathogens. Although nonhost resistance is an attractive breeding strategy, the molecular basis of this form of resistance remains unclear for many plant-microbe pathosystems, including interactions with the bacterial pathogen of rice, Xanthomonas oryzae pv. oryzae (Xoo. METHODS AND FINDINGS: Virus-induced gene silencing (VIGS and an assay to detect the hypersensitive response (HR were used to screen for genes required for nonhost resistance to Xoo in N. benthamiana. When infiltrated with Xoo strain YN-1, N. benthamiana plants exhibited a strong necrosis within 24 h and produced a large amount of H(2O(2 in the infiltrated area. Expression of HR- and defense-related genes was induced, whereas bacterial numbers dramatically decreased during necrosis. VIGS of 45 ACE (Avr/Cf-elicited genes revealed identified seven genes required for nonhost resistance to Xoo in N. benthamiana. The seven genes encoded a calreticulin protein (ACE35, an ERF transcriptional factor (ACE43, a novel Solanaceous protein (ACE80, a hydrolase (ACE117, a peroxidase (ACE175 and two proteins with unknown function (ACE95 and ACE112. The results indicate that oxidative burst and calcium-dependent signaling pathways play an important role in nonhost resistance to Xoo. VIGS analysis further revealed that ACE35, ACE80, ACE95 and ACE175, but not the other three ACE genes, interfered with the Cf-4/Avr4-dependent HR. CONCLUSIONS/SIGNIFICANCE: N. benthamiana plants inoculated with Xoo respond by rapidly eliciting an HR and nonhost resistance. The oxidative burst and other signaling pathways are pivotal in Xoo-N. benthamiana nonhost resistance, and genes involved in this response partially overlap with those involved in Cf/Avr4-dependent HR. The seven genes required for N. benthamiana-mediated resistance to Xoo provide a basis for further dissecting

  10. 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.

  11. The rice bacterial pathogen Xanthomonas oryzae pv. oryzae produces 3-hydroxybenzoic acid and 4-hydroxybenzoic acid via XanB2 for use in xanthomonadin, ubiquinone, and exopolysaccharide biosynthesis.

    Science.gov (United States)

    Zhou, Lian; Huang, Tin-Wei; Wang, Jia-Yuan; Sun, Shuang; Chen, Gongyou; Poplawsky, Alan; He, Ya-Wen

    2013-10-01

    Xanthomonas oryzae pv. oryzae, the causal agent of rice bacterial blight, produces membrane-bound yellow pigments, referred to as xanthomonadins. Xanthomonadins protect the pathogen from photodamage and host-induced perioxidation damage. They are also required for epiphytic survival and successful host plant infection. Here, we show that XanB2 encoded by PXO_3739 plays a key role in xanthomonadin and coenzyme Q8 biosynthesis in X. oryzae pv. oryzae PXO99A. A xanB2 deletion mutant exhibits a pleiotropic phenotype, including xanthomonadin deficiency, producing less exopolysaccharide (EPS), lower viability and H2O2 resistance, and lower virulence. We further demonstrate that X. oryzae pv. oryzae produces 3-hydroxybenzoic acid (3-HBA) and 4-hydroxybenzoic acid (4-HBA) via XanB2. 3-HBA is associated with xanthomonadin biosynthesis while 4-HBA is mainly used as a precursor for coenzyme Q (CoQ)8 biosynthesis. XanB2 is the alternative source of 4-HBA for CoQ8 biosynthesis in PXO99A. These findings suggest that the roles of XanB2 in PXO99A are generally consistent with those in X. campestris pv. campestris. The present study also demonstrated that X. oryzae pv. oryzae PXO99A has evolved several specific features in 3-HBA and 4-HBA signaling. First, our results showed that PXO99A produces less 3-HBA and 4-HBA than X. campestris pv. campestris and this is partially due to a degenerated 4-HBA efflux pump. Second, PXO99A has evolved unique xanthomonadin induction patterns via 3-HBA and 4-HBA. Third, our results showed that 3-HBA or 4-HBA positively regulates the expression of gum cluster to promote EPS production in PXO99A. Taken together, the results of this study indicate that XanB2 is a key metabolic enzyme linking xanthomonadin, CoQ, and EPS biosynthesis, which are collectively essential for X. oryzae pv. oryzae pathogenesis.

  12. Plant adaptive behaviour in hydrological models (Invited)

    Science.gov (United States)

    van der Ploeg, M. J.; Teuling, R.

    2013-12-01

    Models that will be able to cope with future precipitation and evaporation regimes need a solid base that describes the essence of the processes involved [1]. Micro-behaviour in the soil-vegetation-atmosphere system may have a large impact on patterns emerging at larger scales. A complicating factor in the micro-behaviour is the constant interaction between vegetation and geology in which water plays a key role. The resilience of the coupled vegetation-soil system critically depends on its sensitivity to environmental changes. As a result of environmental changes vegetation may wither and die, but such environmental changes may also trigger gene adaptation. Constant exposure to environmental stresses, biotic or abiotic, influences plant physiology, gene adaptations, and flexibility in gene adaptation [2-6]. Gene expression as a result of different environmental conditions may profoundly impact drought responses across the same plant species. Differences in response to an environmental stress, has consequences for the way species are currently being treated in models (single plant to global scale). In particular, model parameters that control root water uptake and plant transpiration are generally assumed to be a property of the plant functional type. Assigning plant functional types does not allow for local plant adaptation to be reflected in the model parameters, nor does it allow for correlations that might exist between root parameters and soil type. Models potentially provide a means to link root water uptake and transport to large scale processes (e.g. Rosnay and Polcher 1998, Feddes et al. 2001, Jung 2010), especially when powered with an integrated hydrological, ecological and physiological base. We explore the experimental evidence from natural vegetation to formulate possible alternative modeling concepts. [1] Seibert, J. 2000. Multi-criteria calibration of a conceptual runoff model using a genetic algorithm. Hydrology and Earth System Sciences 4(2): 215

  13. Stochastic spatial models of plant diseases

    CERN Document Server

    Brown, D H

    2001-01-01

    I present three models of plant--pathogen interactions. The models are stochastic and spatially explicit at the scale of individual plants. For each model, I use a version of pair approximation or moment closure along with a separation of timescales argument to determine the effects of spatial clustering on threshold structure. By computing the spatial structure early in an invasion, I find explicit corrections to mean field theory. In the first chapter, I present a lattice model of a disease that is not directly lethal to its host, but affects its ability to compete with neighbors. I use a type of pair approximation to determine conditions for invasions and coexistence. In the second chapter, I study a basic SIR epidemic point process in continuous space. I implement a multiplicative moment closure scheme to compute the threshold transmission rate as a function of spatial parameters. In the final chapter, I model the evolution of pathogen resistance when two plant species share a pathogen. Evolution may lead...

  14. The Oryza map alignment project: Construction, alignment and analysis of 12 BAC fingerprint/end sequence framework physical maps that represent the 10 genome types of genus Oryza

    Science.gov (United States)

    The Oryza Map Alignment Project (OMAP) provides the first comprehensive experimental system for understanding the evolution, physiology and biochemistry of a full genus in plants or animals. We have constructed twelve deep-coverage BAC libraries that are representative of both diploid and tetraploid...

  15. Whole-plant dynamic system of nitrogen use for vegetative growth and grain filling in rice plants (Oryza sativa L. as revealed through the production of 350 grains from a germinated seed over 150 days: a review and synthesis

    Directory of Open Access Journals (Sweden)

    Tadakatsu Yoneyama

    2016-08-01

    Full Text Available A single germinated rice (Oryza sativa L seed can produce 350 grains with the sequential development of 15 leaves on the main stem and 7 ‒ 10 leaves on 4 productive tillers (forming 5 panicles in total, using nitrogen (N taken up from the environment over a 150-day growing season. Nitrogen travels from uptake sites to the grain through growing organ-directed cycling among sequentially developed organs. Over the past 40 years, the dynamic system for N allocation during vegetative growth and grain filling has been elucidated through studies on N and 15N transport as well as enzymes and transporters involved. In this review, we synthesize the information obtained in these studies along the following main points: (1 During vegetative growth before grain-filling, about half of the total N in the growing organs, including young leaves, tillers, root tips and differentiating panicles is supplied via phloem from mature source organs such as leaves and roots, after turnover and remobilization of proteins, whereas the other half is newly taken up and supplied via xylem, with an efficient xylem-to-phloem transfer at stem nodes. Thus, the growth of new organs depends equally on both N sources. (2 A large fraction (as much as 80% of the grain N is derived largely from mature organs such as leaves and stems by degradation, including the autophagy pathway of chloroplast proteins (e.g., Rubisco. (3 Mobilized proteinogenic amino acids, including arginine, lysine, proline and valine, are derived mainly from protein degradation, with amino acid transporters playing a role in transferring these amino acids across cell membranes of source and sink organs, and enabling their efficient reutilization in the latter. On the other hand, amino acids such as glutamine, glutamic acid, γ-amino butyric acid, aspartic acid, and alanine are produced by assimilation of newly taken up N by roots and transported via xylem and phloem. The formation of 350 filled grains over 50

  16. Whole-Plant Dynamic System of Nitrogen Use for Vegetative Growth and Grain Filling in Rice Plants (Oryza sativa L.) as Revealed through the Production of 350 Grains from a Germinated Seed Over 150 Days: A Review and Synthesis.

    Science.gov (United States)

    Yoneyama, Tadakatsu; Tanno, Fumio; Tatsumi, Jiro; Mae, Tadahiko

    2016-01-01

    A single germinated rice (Oryza sativa L) seed can produce 350 grains with the sequential development of 15 leaves on the main stem and 7-10 leaves on four productive tillers (forming five panicles in total), using nitrogen (N) taken up from the environment over a 150-day growing season. Nitrogen travels from uptake sites to the grain through growing organ-directed cycling among sequentially developed organs. Over the past 40 years, the dynamic system for N allocation during vegetative growth and grain filling has been elucidated through studies on N and (15)N transport as well as enzymes and transporters involved. In this review, we synthesize the information obtained in these studies along the following main points: (1) During vegetative growth before grain-filling, about half of the total N in the growing organs, including young leaves, tillers, root tips and differentiating panicles is supplied via phloem from mature source organs such as leaves and roots, after turnover and remobilization of proteins, whereas the other half is newly taken up and supplied via xylem, with an efficient xylem-to-phloem transfer at stem nodes. Thus, the growth of new organs depends equally on both N sources. (2) A large fraction (as much as 80%) of the grain N is derived largely from mature organs such as leaves and stems by degradation, including the autophagy pathway of chloroplast proteins (e.g., Rubisco). (3) Mobilized proteinogenic amino acids (AA), including arginine, lysine, proline and valine, are derived mainly from protein degradation, with AA transporters playing a role in transferring these AAs across cell membranes of source and sink organs, and enabling their efficient reutilization in the latter. On the other hand, AAs such as glutamine, glutamic acid, γ-amino butyric acid, aspartic acid, and alanine are produced by assimilation of newly taken up N by roots and and transported via xylem and phloem. The formation of 350 filled grains over 50 days during the

  17. Biochemical and structural properties of cyanases from Arabidopsis thaliana and Oryza sativa.

    Science.gov (United States)

    Qian, Dan; Jiang, Lin; Lu, Lu; Wei, Chunhong; Li, Yi

    2011-01-01

    Cyanate is toxic to all organisms. Cyanase converts cyanate to CO₂ and NH₃ in a bicarbonate-dependent reaction. The biophysical functions and biochemical characteristics of plant cyanases are poorly studied, although it has been investigated in a variety of proteobacteria, cyanobacteria and fungi. In this study, we characterised plant cyanases from Arabidopsis thaliana and Oryza sativa (AtCYN and OsCYN). Prokaryotic-expressed AtCYN and OsCYN both showed cyanase activity in vitro. Temperature had a similar influence on the activity of both cyanases, but pH had a differential impact on AtCYN and OsCYN activity. Homology modelling provided models of monomers of AtCYN and OsCYN, and a coimmunoprecipitation assay and gel filtration indicated that AtCYN and OsCYN formed homodecamers. The analysis of single-residue mutants of AtCYN indicated that the conserved catalytic residues also contributed to the stability of the homodecamer. KCNO treatment inhibited Arabidopsis germination and early seedling growth. Plants containing AtCYN or OsCYN exhibited resistance to KCNO stress, which demonstrated that one role of cyanases in plants is detoxification. Transcription level of AtCYN was higher in the flower than in other organs of Arabidopsis. AtCYN transcription was not significantly affected by KCNO treatment in Arabidopsis, but was induced by salt stress. This research broadens our knowledge on plant detoxification of cyanate via cyanase.

  18. Biochemical and structural properties of cyanases from Arabidopsis thaliana and Oryza sativa.

    Directory of Open Access Journals (Sweden)

    Dan Qian

    Full Text Available Cyanate is toxic to all organisms. Cyanase converts cyanate to CO₂ and NH₃ in a bicarbonate-dependent reaction. The biophysical functions and biochemical characteristics of plant cyanases are poorly studied, although it has been investigated in a variety of proteobacteria, cyanobacteria and fungi. In this study, we characterised plant cyanases from Arabidopsis thaliana and Oryza sativa (AtCYN and OsCYN. Prokaryotic-expressed AtCYN and OsCYN both showed cyanase activity in vitro. Temperature had a similar influence on the activity of both cyanases, but pH had a differential impact on AtCYN and OsCYN activity. Homology modelling provided models of monomers of AtCYN and OsCYN, and a coimmunoprecipitation assay and gel filtration indicated that AtCYN and OsCYN formed homodecamers. The analysis of single-residue mutants of AtCYN indicated that the conserved catalytic residues also contributed to the stability of the homodecamer. KCNO treatment inhibited Arabidopsis germination and early seedling growth. Plants containing AtCYN or OsCYN exhibited resistance to KCNO stress, which demonstrated that one role of cyanases in plants is detoxification. Transcription level of AtCYN was higher in the flower than in other organs of Arabidopsis. AtCYN transcription was not significantly affected by KCNO treatment in Arabidopsis, but was induced by salt stress. This research broadens our knowledge on plant detoxification of cyanate via cyanase.

  19. Genome-wide identification of lineage-specific genes in Arabidopsis, Oryza and Populus

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaohan [ORNL; Jawdy, Sara [ORNL; Tschaplinski, Timothy J [ORNL; Tuskan, Gerald A [ORNL

    2009-01-01

    Protein sequences were compared among Arabidopsis, Oryza and Populus to identify differential gene (DG) sets that are in one but not the other two genomes. The DG sets were screened against a plant transcript database, the NR protein database and six newly-sequenced genomes (Carica, Glycine, Medicago, Sorghum, Vitis and Zea) to identify a set of species-specific genes (SS). Gene expression, protein motif and intron number were examined. 192, 641 and 109 SS genes were identified in Arabidopsis, Oryza and Populus, respectively. Some SS genes were preferentially expressed in flowers, roots, xylem and cambium or up-regulated by stress. Six conserved motifs in Arabidopsis and Oryza SS proteins were found in other distant lineages. The SS gene sets were enriched with intronless genes. The results reflect functional and/or anatomical differences between monocots and eudicots or between herbaceous and woody plants. The Populus-specific genes are candidates for carbon sequestration and biofuel research.

  20. Combination Patterns of Major R Genes Determine the Level of Resistance to the M. oryzae in Rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Yunyu Wu

    Full Text Available Rice blast caused by Magnaporthe oryzae is the most devastating disease of rice and poses a serious threat to world food security. In this study, the distribution and effectiveness of 18 R genes in 277 accessions were investigated based on pathogenicity assays and molecular markers. The results showed that most of the accessions exhibited some degree of resistance (resistance frequency, RF >50%. Accordingly, most of the accessions were observed to harbor two or more R genes, and the number of R genes harbored in accessions was significantly positively correlated with RF. Some R genes were demonstrated to be specifically distributed in the genomes of rice sub-species, such as Pigm, Pi9, Pi5 and Pi1, which were only detected in indica-type accessions, and Pik and Piz, which were just harbored in japonica-type accessions. By analyzing the relationship between R genes and RF using a multiple stepwise regression model, the R genes Pid3, Pi5, Pi9, Pi54, Pigm and Pit were found to show the main effects against M. oryzae in indica-type accessions, while Pita, Pb1, Pik, Pizt and Pia were indicated to exhibit the main effects against M. oryzae in japonica-type accessions. Principal component analysis (PCA and cluster analysis revealed that combination patterns of major R genes were the main factors determining the resistance of rice varieties to M. oryzae, such as 'Pi9+Pi54', 'Pid3+Pigm', 'Pi5+Pid3+Pigm', 'Pi5+Pi54+Pid3+Pigm', 'Pi5+Pid3' and 'Pi5+Pit+Pid3' in indica-type accessions and 'Pik+Pib', 'Pik+Pita', 'Pik+Pb1', 'Pizt+Pia' and 'Pizt+Pita' in japonica-type accessions, which were able to confer effective resistance against M. oryzae. The above results provide good theoretical support for the rational utilization of combinations of major R genes in developing rice cultivars with broad-spectrum resistance.

  1. Crucial roles of abscisic acid biogenesis in virulence of rice blast fungus Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Carla eSpence

    2015-12-01

    Full Text Available 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 JA- and ETH-mediated ISR. ABA acts antagonistically towards SA, JA, and ETH signaling, to impede plant defense responses. EA105 may be reducing the virulence of M. oryzae by preventing the pathogen from up-regulating the key ABA biosynthetic gene NCED3 in rice roots, as well as a β-glucosidase likely involved in activating conjugated inactive forms of ABA. However, changes in total ABA concentrations were not apparent, provoking the question of whether ABA concentration is an indicator of ABA signaling and response. In the rice-M. oryzae interaction, ABA plays a dual role in disease severity by increasing plant susceptibility and accelerating pathogenesis in the fungus itself. ABA is biosynthesized by M. oryzae. Further, exogenous ABA increased spore germination and appressoria formation, distinct from other plant growth regulators. EA105, which inhibits appressoria formation, counteracted the virulence-promoting effects of ABA on M. oryzae. The role of endogenous fungal ABA in blast disease was confirmed through the inability of a knockout mutant impaired in ABA biosynthesis to form lesions on rice. Therefore, it appears that EA105 is invoking multiple strategies in its protection of rice from blast including direct mechanisms as well as those mediated through plant signaling. ABA is a molecule that is likely implicated in both tactics.

  2. Transcriptome Analysis of Oryza sativa Calli Under Microgravity

    Science.gov (United States)

    Jin, Jing; Chen, Haiying; Cai, Weiming

    2015-11-01

    The transcriptome of Oryza sativacalli was analyzed on board the Chinese spaceship "Shenzhou 8" to study the effects of microgravity on plant signal transduction and secondary metabolism (as one of the experiments with SIMBOX on Shenzhou 8). Calli of Oryza sativa were pre-cultured for 4 days on ground and then loaded into the stationary platform or the rotating platform of a biological incubator, called SIMBOX, to grow in space under microgravity conditions or 1g-conditions, respectively. The calli were fixed by RNAlater after grew 324 h under microgravity. After 17 days, Shenzhou 8 returned to Earth carrying SIMBOX. Oryza sativa calli were recovered, and the RNA was extracted for transcriptome analysis. After comparing 1 gspaceflight controls-inflight controls with 1 g-ground controls, 157 probe sets with different expression levels (fold change ≥2, p<0.05) were identified. When comparing spaceflight controls to 1 g-ground controls and to 1 g-inflight controls, 678 probe sets with different expression levels (fold change ≥2, p<0.05) were identified. The fact that the same 678 probe sets were identified in these two comparisons suggests that transcription was affected under microgravity conditions. MapMan analysis was used to classify 627 microgravity responsive (MR) transcripts. The MR transcripts were mainly involved in cell wall structure, the TCA cycle, primary metabolism, transcription, protein modification and degradation, hormone metabolism, calcium regulation, receptor like kinase activity and transport.

  3. Towards a reference plant trait ontology for modeling knowledge of plant traits and phenotypes

    Science.gov (United States)

    Ontology engineering and knowledge modeling for the plant sciences is expected to contribute to the understanding of the basis of plant traits that determine phenotypic expression in a given environment. Several crop- or clade-specific plant trait ontologies have been developed to describe plant tr...

  4. Plant parameters for plant functional groups of western rangelands to enable process-based simulation modeling

    Science.gov (United States)

    Regional environmental assessments with process-based models require realistic estimates of plant parameters for the primary plant functional groups in the region. “Functional group” in this context is an operational term, based on similarities in plant type and in plant parameter values. Likewise...

  5. Molecular Cytogenetic Analysis of Spontaneous Interspecific Hybrid Between Oryza sativa and Oryza minuta

    Institute of Scientific and Technical Information of China (English)

    YI Chuan-deng; CHENG Xu; WANG Bei-bei; LIANG Guo-hua; GONG Zhi-yun; TANG Shu-zhu; GU Ming-hong

    2008-01-01

    Genomic in situ hybridization (GISH) is a powerful tool to characterize parental chromosomes in interspecific hybrids, including the behaviour of autosynapsis and chromosome paidng. It was used to distinguish the chromosomes of Oryza sativa from wild species in a spontaneous interspecific hybdd and to investigate the chromosome pairing at metaphase I in meiosis of the hybdd in this study. The hybrid was a triploid with 36 chromosomes according to the chromosome nurnber investigated in mitosis of root tips. During metaphase I of meiosis in the hybrid, less chromosome pairing was observed and most of the chromosomes existed as univalent. Based on GISH and FISH (Fluorescent in situ hybridization) analyses, the chromosomes of the hybrid were composed of genomes A, B and C. Thus, it was believed that the hybrid was the result of natural hybridization between cultivated rice and wild species O. minuta which was planted in experimental fields.

  6. Molecular Cytogenetic Analysis of Spontaneous Interspecific Hybrid Between Oryza sativa and Oryza minuta

    Directory of Open Access Journals (Sweden)

    Chuan-deng YI

    2008-12-01

    Full Text Available Genomic in situ hybridization (GISH is a powerful tool to characterize parental chromosomes in interspecific hybrids, including the behaviour of autosynapsis and chromosome pairing. It was used to distinguish the chromosomes of Oryza sativa from wild species in a spontaneous interspecific hybrid and to investigate the chromosome pairing at metaphase I in meiosis of the hybrid in this study. The hybrid was a triploid with 36 chromosomes according to the chromosome number investigated in mitosis of root tips. During metaphase I of meiosis in the hybrid, less chromosome pairing was observed and most of the chromosomes existed as univalent. Based on GISH and FISH (Fluorescent in situ hybridization analyses, the chromosomes of the hybrid were composed of genomes A, B and C. Thus, it was believed that the hybrid was the result of natural hybridization between cultivated rice and wild species O. minuta which was planted in experimental fields.

  7. 与栽培密度相关的水稻形态基因研究进展%RESEARCH PROGRESS ON PLANT MORPHOLOGICAL GENES RELATED TO PLANTING DENSITY IN RICE(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    王寅; 徐建伟; 张丹丹; 舒小丽; 吴殿星

    2011-01-01

    The yield of rice is closely related with the density of planting.Compared with traditional hand transplanting,high-density cultivation is more convenient for efficient agricultural production by the novel cultivation methods such as direct seeding,throwing rice seedlings and machine transplanting.In this paper,the relationship of planting density with grain yield was briefly summarized,and the research progress on plant morphological genes related to planting density,i.e.ideal plant architecture,tiller controlling,tiller angle,erected leaves,rolled leaves and narrow leaves were reviewed.%水稻产量与栽培密度密切相关,在直播、抛秧和机插秧等有别于传统手插秧的新型栽培模式下,高密度栽培更加便于农业的高效生产。本文简述了水稻不同栽培密度与产量间的关系,综述了与水稻栽培密度相关的理想株型、分蘖角度控制、分蘖数控制、直立叶、卷叶及窄叶等形态基因的研究及其进展。

  8. Representing plant hydraulics in a global Earth system model.

    Science.gov (United States)

    Kennedy, D.; Gentine, P.

    2015-12-01

    Earth system models need improvement to reproduce observed seasonal and diurnal cycles of photosynthesis and respiration. Model water stress parameterizations lag behind the plant physiology literature. A plant hydraulics model is developed and deployed in a global Earth system model (NCAR CESM 1.2.2 with CLM 4.5). Assimilation and transpiration are attenuated according to literature cavitation curves. Water stress is evaluated based on plant functional type hydraulic parameters forced by soil moisture and atmospheric conditions. Resolving the plant water status allows for modelling divergent strategies for water stress. The case of isohydric versus anisohydric species is presented, showing that including plant hydraulic traits alter modelled photosynthesis and transpiration.

  9. Mass balance-based plant-wide wastewater treatment plant models ...

    African Journals Online (AJOL)

    2006-07-03

    Jul 3, 2006 ... Mass balance-based plant-wide wastewater treatment plant models – Part ... organics under anaerobic conditions .... which limit the capacity of the WWTP. ..... Thermophilic Heat Treatment on the Anaerobic Digestibility of Pri-.

  10. Functional–structural plant models: a growing paradigm for plant studies

    Science.gov (United States)

    Sievänen, Risto; Godin, Christophe; DeJong, Theodore M.; Nikinmaa, Eero

    2014-01-01

    A number of research groups in various areas of plant biology as well as computer science and applied mathematics have addressed modelling the spatiotemporal dynamics of growth and development of plants. This has resulted in development of functional–structural plant models (FSPMs). In FSPMs, the plant structure is always explicitly represented in terms of a network of elementary units. In this respect, FSPMs are different from more abstract models in which a simplified representation of the plant structure is frequently used (e.g. spatial density of leaves, total biomass, etc.). This key feature makes it possible to build modular models and creates avenues for efficient exchange of model components and experimental data. They are being used to deal with the complex 3-D structure of plants and to simulate growth and development occurring at spatial scales from cells to forest areas, and temporal scales from seconds to decades and many plant generations. The plant types studied also cover a broad spectrum, from algae to trees. This special issue of Annals of Botany features selected papers on FSPM topics such as models of morphological development, models of physical and biological processes, integrated models predicting dynamics of plants and plant communities, modelling platforms, methods for acquiring the 3-D structures of plants using automated measurements, and practical applications for agronomic purposes. PMID:25469374

  11. Functional-structural plant models: a growing paradigm for plant studies.

    Science.gov (United States)

    Sievänen, Risto; Godin, Christophe; DeJong, Theodore M; Nikinmaa, Eero

    2014-09-01

    A number of research groups in various areas of plant biology as well as computer science and applied mathematics have addressed modelling the spatiotemporal dynamics of growth and development of plants. This has resulted in development of functional-structural plant models (FSPMs). In FSPMs, the plant structure is always explicitly represented in terms of a network of elementary units. In this respect, FSPMs are different from more abstract models in which a simplified representation of the plant structure is frequently used (e.g. spatial density of leaves, total biomass, etc.). This key feature makes it possible to build modular models and creates avenues for efficient exchange of model components and experimental data. They are being used to deal with the complex 3-D structure of plants and to simulate growth and development occurring at spatial scales from cells to forest areas, and temporal scales from seconds to decades and many plant generations. The plant types studied also cover a broad spectrum, from algae to trees. This special issue of Annals of Botany features selected papers on FSPM topics such as models of morphological development, models of physical and biological processes, integrated models predicting dynamics of plants and plant communities, modelling platforms, methods for acquiring the 3-D structures of plants using automated measurements, and practical applications for agronomic purposes.

  12. A New Eudesmane Sesquiterpene from Nigrospora oryzae, an Endophytic Fungus of Aquilaria sinensis

    Directory of Open Access Journals (Sweden)

    Dongli Li

    2014-07-01

    Full Text Available A new eudesmane-type sesquiterpene, 11 -hydroxy capitulatin B (1 , along with a known related sesquiterpene, capitulatin B (2, was isolated from the endophytic fungus Nigrospora oryzae A8 from Aquilaria sinensis, the only plant resource for agarwood production in China. This research demonstrates that the endophytic fungi from A. sinensis might play a role in the formation of agarwood.

  13. Organic anion exudation by lowland rice (Oryza sativa L.) at zinc and phosphorus deficiency

    NARCIS (Netherlands)

    Hoffland, E.; Wei, C.Z.; Wissuwa, M.

    2006-01-01

    The objectives of this paper were to determine (1) if lowland rice (Oryza sativa L.) plants respond similarly to low zinc (Zn) and phosphorus (P) availability by increased root exudation of low-molecular weight organic anions (LMWOAs) and (2) if genotypic variation in tolerance to low soil supply of

  14. Ketoglutarate transport protein KgtP is secreted through the type III secretion system and contributes to virulence in Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Guo, Wei; Cai, Lu-Lu; Zou, Hua-Song; Ma, Wen-Xiu; Liu, Xi-Ling; Zou, Li-Fang; Li, Yu-Rong; Chen, Xiao-Bin; Chen, Gong-You

    2012-08-01

    The phytopathogenic prokaryote Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight (BB) of rice and utilizes a type III secretion system (T3SS) to deliver T3SS effectors into rice cells. In this report, we show that the ketoglutarate transport protein (KgtP) is secreted in an HpaB-independent manner through the T3SS of X. oryzae pv. oryzae PXO99(A) and localizes to the host cell membrane for α-ketoglutaric acid export. kgtP contained an imperfect PIP box (plant-inducible promoter) in the promoter region and was positively regulated by HrpX and HrpG. A kgtP deletion mutant was impaired in bacterial virulence and growth in planta; furthermore, the mutant showed reduced growth in minimal media containing α-ketoglutaric acid or sodium succinate as the sole carbon source. The reduced virulence and the deficiency in α-ketoglutaric acid utilization by the kgtP mutant were restored to wild-type levels by the presence of kgtP in trans. The expression of OsIDH, which is responsible for the synthesis of α-ketoglutaric acid in rice, was enhanced when KgtP was present in the pathogen. To our knowledge, this is the first report demonstrating that KgtP, which is regulated by HrpG and HrpX and secreted by the T3SS in Xanthomonas oryzae pv. oryzae, transports α-ketoglutaric acid when the pathogen infects rice.

  15. Using functional–structural plant models to study, understand and integrate plant development and ecophysiology.

    Science.gov (United States)

    DeJong, Theodore M; Da Silva, David; Vos, Jan; Escobar-Gutiérrez, Abraham J

    2011-10-01

    Functional–structural plant models (FSPMs) explore and integrate relationships between a plant’s structure and processes that underlie its growth and development. In recent years, the range of topics being addressed by scientists interested in functional–structural plant modelling has expanded greatly. FSPM techniques are now being used to dynamically simulate growth and development occurring at the microscopic scale involving cell division in plant meristems to the macroscopic scales of whole plants and plant communities. The plant types studied also cover a broad spectrum from algae to trees. FSPM is highly interdisciplinary and involves scientists with backgrounds in plant physiology, plant anatomy, plant morphology, mathematics, computer science, cellular biology, ecology and agronomy. This special issue of Annals of Botany features selected papers that provide examples of comprehensive functional–structural models, models of key processes such as partitioning of resources, software for modelling plants and plant environments, data acquisition and processing techniques and applications of functional–structural plant models for agronomic purposes.

  16. Coupling of Groundwater Transport and Plant Uptake Models

    DEFF Research Database (Denmark)

    Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan

    2010-01-01

    Plants significantly influence contaminant transport and fate. Important processes are uptake of soil and groundwater contaminants, as well as biodegradation in plants and their root zones. Models for the prediction of chemical uptake into plants are required for the setup of mass balances...... to groundwater transport simulation tools. Exemplary simulations of plant uptake were carried out, in order to estimate concentrations in the soilplant- air system and the influence of plants on contaminant mass fluxes from soil to groundwater....

  17. Tithonia diversifolia, Moringa oleifera and Piper auritum: Alternatives for the control of Sitophilus oryzae

    Directory of Open Access Journals (Sweden)

    Leticia Jiménez Álvarez

    2016-07-01

    Full Text Available With the objective to determine the effect exerted by vegetable powders of Tithonia diversifolia (Hemsl A. Gray, Moringa oleifera (Lam y Piper auritum Kunth on Sitophilus oryzae L., this experiment was performed. In the execution, adult insects were taken to evaluate the increase of them. Petri dishes of 9 cm with 10 insects were used inside additionally 5 g of rice (Oryza sativa L. and 0.4 g of powder was added botanical species (T. diversifolia, M. oleifera, P. auritum previously dried at 40 0C for 72 hours and finely ground. At 40 days the test mounted, the number of insects present per plate was counted, and after testing, Z Multiple Comparison was performed using the software Stadistix. The results allowed us to conclude that these plant species are a viable alternative for the control of S. oryzae.

  18. 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.

  19. Pentachlorophenol sorption in nylon fiber and removal by immobilized Rhizopus oryzae ENHE.

    Science.gov (United States)

    León-Santiestebán, Hugo; Meraz, Mónica; Wrobel, Kazimierz; Tomasini, Araceli

    2011-06-15

    This study describes pentachlophenol (PCP) sorption in nylon fiber in which Rhizopus oryzae ENHE was immobilized to remove the chemical compound. The experimental sorption data were analyzed using the Langmuir, Freundlich, and Redlich-Peterson isotherm models using non-linear error functions to fit the experimental data to the three models. Results showed that the isotherm obtained from the data fitted the three models used. However, the g parameter from Redlich-Peterson model showed that the isotherm obtained approaches the Freundlich model. This support reached the sorption equilibrium concentration at 3mg PCPg(-1)nylon. To study PCP removal capability by R. oryzae ENHE and to eliminate the error caused by PCP sorbed by the nylon fiber during its quantification, nylon fiber at PCP equilibrium sorption concentration was used to immobilize R. oryzae ENHE. It was found that this fungus grew within nylon fiber cubes in presence or not of PCP, even when PCP caused growth inhibition. Maximum biomass accumulated into nylon cubes without PCP was of 32 mg biomass g(-1)nylon and into nylon cubes at PCP equilibrium concentration was of 18 mg g(-1)nylon. The results showed that R. oryzae ENHE immobilized into nylon fiber removed 88.6% and 92% of PCP in cultures with 12.5 and 25 mg PCPL(-1), as initial concentration, respectively. This is the first work to report that a zygomycete, such as R. oryzae ENHE, immobilized into nylon fiber kept its potential to remove PCP.

  20. Identification and functional characterization of small non-coding RNAs in Xanthomonas oryzae pathovar oryzae

    Directory of Open Access Journals (Sweden)

    Zhang Jie-Qiong

    2011-01-01

    Full Text Available Abstract Background Small non-coding RNAs (sRNAs are regarded as important regulators in prokaryotes and play essential roles in diverse cellular processes. Xanthomonas oryzae pathovar oryzae (Xoo is an important plant pathogenic bacterium which causes serious bacterial blight of rice. However, little is known about the number, genomic distribution and biological functions of sRNAs in Xoo. Results Here, we performed a systematic screen to identify sRNAs in the Xoo strain PXO99. A total of 850 putative non-coding RNA sequences originated from intergenic and gene antisense regions were identified by cloning, of which 63 were also identified as sRNA candidates by computational prediction, thus were considered as Xoo sRNA candidates. Northern blot hybridization confirmed the size and expression of 6 sRNA candidates and other 2 cloned small RNA sequences, which were then added to the sRNA candidate list. We further examined the expression profiles of the eight sRNAs in an hfq deletion mutant and found that two of them showed drastically decreased expression levels, and another exhibited an Hfq-dependent transcript processing pattern. Deletion mutants were obtained for seven of the Northern confirmed sRNAs, but none of them exhibited obvious phenotypes. Comparison of the proteomic differences between three of the ΔsRNA mutants and the wild-type strain by two-dimensional gel electrophoresis (2-DE analysis showed that these sRNAs are involved in multiple physiological and biochemical processes. Conclusions We experimentally verified eight sRNAs in a genome-wide screen and uncovered three Hfq-dependent sRNAs in Xoo. Proteomics analysis revealed Xoo sRNAs may take part in various metabolic processes. Taken together, this work represents the first comprehensive screen and functional analysis of sRNAs in rice pathogenic bacteria and facilitates future studies on sRNA-mediated regulatory networks in this important phytopathogen.

  1. Crop plants as models for understanding plant adaptation and diversification

    Directory of Open Access Journals (Sweden)

    Kenneth M Olsen

    2013-08-01

    Full Text Available Since the time of Darwin, biologists have understood the promise of crop plants and their wild relatives for providing insight into the mechanisms of phenotypic evolution. The intense selection imposed by our ancestors during plant domestication and subsequent crop improvement has generated remarkable transformations of plant phenotypes. Unlike evolution in natural settings, descendent and antecedent conditions for crop plants are often both extant, providing opportunities for direct comparisons through crossing and other experimental approaches. Moreover, since domestication has repeatedly generated a suite of domestication syndrome traits that are shared among crops, opportunities exist for gaining insight into the genetic and developmental mechanisms that underlie parallel adaptive evolution. Advances in our understanding of the genetic architecture of domestication-related traits have emerged from combining powerful molecular technologies with advanced experimental designs, including nested association mapping, genome-wide association studies, population genetic screens for signatures of selection, and candidate gene approaches. These studies may be combined with high-throughput evaluations of the various omics involved in trait transformation, revealing a diversity of underlying causative mutations affecting phenotypes and their downstream propagation through biological networks. We summarize the state of our knowledge of the mutational spectrum that generates phenotypic novelty in domesticated plant species, and our current understanding of how domestication can reshape gene expression networks and emergent phenotypes. An exploration of traits that have been subject to similar selective pressures across crops (e.g., flowering time suggests that a diversity of targeted genes and causative mutational changes can underlie parallel adaptation in the context of crop evolution.

  2. Plant growth simulation for landscape scale hydrologic modeling

    Science.gov (United States)

    Landscape scale hydrologic models can be improved by incorporating realistic, process-oriented plant models for simulating crops, grasses, and woody species. The objective of this project was to present some approaches for plant modeling applicable to hydrologic models like SWAT that can affect the...

  3. Mathematical modeling of heat transfer in plant community

    Directory of Open Access Journals (Sweden)

    Finnikov K.A.

    2011-12-01

    Full Text Available The conductive, convective and radiation heat exchange process in a natural system including plants aggregation, air lower layer and ground upper layer, is examined. The mathematical model of process is formulated in 1d unsteady approach. The numerical simulation of plants aggregation cooling is performed for the case of a radiation frost. It is found up that mutual influence of plants in an aggregation on the heat exchange with environment grows with the increase of plants size and plants number per ground area. The influence leads to that lower parts of plants are cooled slower, while upper parts are cooled faster. The estimations are made for the quantity of heat emitted in a thermogenic plant that is enough to prevent the plant cold stress. It is shown that in presence of enforced air flow the rate of plants cooling is noticeably lower, as well as the quantity of heat enough to prevent the plant cold stress.

  4. Multilevel Flow Modelling of Process Plant for Diagnosis and Control

    DEFF Research Database (Denmark)

    Lind, Morten

    1982-01-01

    of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant...... operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as a basis for design of control strategies and for the allocation of control tasks to the computer and the plant operator....

  5. Transfer of bacterial blight resistance from Oryza meyeriana to O.Sativa L.by asymmetric somatic hybridization

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongsheng; CHEN Baotang; YU Shunwu; ZHANG Duanpin; ZHANG Xueqin; YAN Qiusheng

    2004-01-01

    Asymmetric somatic hybrid plants were produced between cultivated rice (Oryza sativa L.) and wild species [O. Meyeriana (Zoll. etMor, exSteud.)] with high resistance to rice bacterial blight. X-ray-irradiated protoplasts of the wild species were used as donor and chemically fused with iodoacetamide-inactivated protoplasts of rice cv. 02428to produce hybrids. Seventy-two plants were regenerated from 623 calli based on metabolic complementation. The morphological characters of the plants closely resembled that of the rice. Simple sequence repeats were employed to identify their hybridity. Cytological analysis of root-tips revealed that their chromosome number varied in the range of 27-38. The somatic hybrids were inoculated with strains of Xanthamonas oryzae pv. Oryzae at adult growth stage and demonstrated the resistance to bacterial blight introgression from the O. Meyeriana.

  6. Fast Visual Modeling for Plant Based on Real Images

    Institute of Scientific and Technical Information of China (English)

    LI Yun-feng; ZHU Qing-sheng; CAO Yu-kun; LIU Yin-bin; HE Xi-ping

    2004-01-01

    Structures of natural plants are complex and difficult to model. This paper proposes a fast visual modeling for plants based on a small set of images, and establishes a reasonable plant model.Based on knowledge about growth patterns of the plant, image segmentation and 3D reconstruction are first performed to construct the plant skeleton (trunk and major branches), from which the remainder of the plant grows. Then the system produces the realistic plant model images based on image synthesis and validation. It is unnecessary to acquire the complex structure (such as the complex production rules of L-systems). The method provides a high degree of control over the final shape by image validation,resulting in realistic reconstruction.

  7. Modelling of nuclear power plant decommissioning financing.

    Science.gov (United States)

    Bemš, J; Knápek, J; Králík, T; Hejhal, M; Kubančák, J; Vašíček, J

    2015-06-01

    Costs related to the decommissioning of nuclear power plants create a significant financial burden for nuclear power plant operators. This article discusses the various methodologies employed by selected European countries for financing of the liabilities related to the nuclear power plant decommissioning. The article also presents methodology of allocation of future decommissioning costs to the running costs of nuclear power plant in the form of fee imposed on each megawatt hour generated. The application of the methodology is presented in the form of a case study on a new nuclear power plant with installed capacity 1000 MW.

  8. Modelling soil-plant-atmosphere interactions by coupling the regional weather model WRF to mechanistic plant models

    Science.gov (United States)

    Klein, C.; Hoffmann, P.; Priesack, E.

    2012-04-01

    Climate change causes altering distributions of meteorological factors influencing plant growth and its interactions between the land surface and the atmosphere. Recent studies show, that uncertainties in regional and global climate simulations are also caused by lacking descriptions of the soil-plant-atmosphere system. Therefore, we couple a mechanistic soil-plant model to a regional climate and forecast model. The detailed simulation of the water and energy exchanges, especially the transpiration of grassland and forests stands, are the key features of the modelling framework. The Weather Research and Forecasting model (WRF) (Skamarock 2008) is an open source mesoscale numerical weather prediction model. The WRF model was modified in a way, to either choose its native, static land surface model NOAH or the mechanistic eco-system model Expert-N 5.0 individually for every single grid point within the simulation domain. The Expert-N 5.0 modelling framework provides a highly modular structure, enabling the development and use of a large variety of different plant and soil models, including heat transfer, nitrogen uptake/turnover/transport as well as water uptake/transport and crop management. To represent the key landuse types grassland and forest, we selected two mechanistic plant models: The Hurley Pasture model (Thornley 1998) and a modified TREEDYN3 forest simulation model (Bossel 1996). The models simulate plant growth, water, nitrogen and carbon flows for grassland and forest stands. A mosaic approach enables Expert-N to use high resolution land use data e.g. CORINE Land Cover data (CLC, 2006) for the simulation, making it possible to simulate different land use distributions within a single grid cell. The coupling results are analyzed for plausibility and compared with the results of the default land surface model NOAH (Fei Chen and Jimy Dudhia 2010). We show differences between the mechanistic and the static model coupling, with focus on the feedback effects

  9. 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.

  10. Image-Based Modeling of Plants and Trees

    CERN Document Server

    Kang, Sing Bang

    2009-01-01

    Plants and trees are among the most complex natural objects. Much work has been done attempting to model them, with varying degrees of success. In this book, we review the various approaches in computer graphics, which we categorize as rule-based, image-based, and sketch-based methods. We describe our approaches for modeling plants and trees using images. Image-based approaches have the distinct advantage that the resulting model inherits the realistic shape and complexity of a real plant or tree. We use different techniques for modeling plants (with relatively large leaves) and trees (with re

  11. Osa-miR169 Negatively Regulates Rice Immunity against the Blast Fungus Magnaporthe oryzae

    Science.gov (United States)

    Li, Yan; Zhao, Sheng-Li; Li, Jin-Lu; Hu, Xiao-Hong; Wang, He; Cao, Xiao-Long; Xu, Yong-Ju; Zhao, Zhi-Xue; Xiao, Zhi-Yuan; Yang, Nan; Fan, Jing; Huang, Fu; Wang, Wen-Ming

    2017-01-01

    miR169 is a conserved microRNA (miRNA) family involved in plant development and stress-induced responses. However, how miR169 functions in rice immunity remains unclear. Here, we show that miR169 acts as a negative regulator in rice immunity against the blast fungus Magnaporthe oryzae by repressing the expression of nuclear factor Y-A (NF-YA) genes. The accumulation of miR169 was significantly increased in a susceptible accession but slightly fluctuated in a resistant accession upon M. oryzae infection. Consistently, the transgenic lines overexpressing miR169a became hyper-susceptible to different M. oryzae strains associated with reduced expression of defense-related genes and lack of hydrogen peroxide accumulation at the infection site. Consequently, the expression of its target genes, the NF-YA family members, was down-regulated by the overexpression of miR169a at either transcriptional or translational level. On the contrary, overexpression of a target mimicry that acts as a sponge to trap miR169a led to enhanced resistance to M. oryzae. In addition, three of miR169’s target genes were also differentially up-regulated in the resistant accession upon M. oryzae infection. Taken together, our data indicate that miR169 negatively regulates rice immunity against M. oryzae by differentially repressing its target genes and provide the potential to engineer rice blast resistance via a miRNA. PMID:28144248

  12. Molecular and pathogenic characterization of new Xanthomonas oryzae pv. oryzae strains from the coastline region of Fangchenggang city in China.

    Science.gov (United States)

    Yang, Shu-Qing; Liu, Shu-Yan; Zhao, Shuai; Yu, Yan-Hua; Li, Rong-Bai; Duan, Cheng-Jie; Tang, Ji-Liang; Feng, Jia-Xun

    2013-04-01

    Virulence assays and DNA polymorphism analyses were used to characterize 33 Xanthomonas oryzae pv. oryzae (Xoo) strains collected from the coastline region of Fangchenggang city in China. Two new pathogenic races (FXP1 and FXP2), were determined by leaf-clipping inoculation of 12 near-isogenic International Rice-Bacterial Blight (IRBB) rice lines, each containing a single resistance gene. Race FXP1 consisted of twenty-eight strains that were incompatible on IRBB5 and IRBB7, while race FXP2 included five strains that were incompatible on IRBB5 and IRBB7 and moderately virulent on IRBB8 containing the xa8 gene. Restriction fragment length polymorphism (RFLP) analysis revealed that each probe of avrXa10 and IS1112 resolved two haplotypes. In a dendrogram generated from the combined RFLP data, the 33 Xoo strains were resolved into two clusters. There was a weak correlation (r = 0.53) between race and haplotype. All of the rice cultivars planted in the coastline region of Fangchenggang city were susceptible to the representative Xoo strains tested above. However, we found that four rice cultivars used as breeding materials in the laboratory could fully resist infection by the Xoo strains, suggesting that the isolated Xoo strains could be used to detect resistant rice cultivars suitable for planting in the local rice field.

  13. Hydraulic modelling of drinking water treatment plant operations

    OpenAIRE

    L. C. Rietveld; Borger, K.J.; Van Schagen, K.M.; Mesman, G.A.M.; G. I. M. Worm

    2008-01-01

    For a drinking water treatment plant simulation, water quality models, a hydraulic model, a process-control model, an object model, data management, training and decision-support features and a graphic user interface have been integrated. The integration of a hydraulic model in the simulator is necessary to correctly determine the division of flows over the plant's lanes and, thus, the flow through the individual treatment units, based on valve positions and pump speeds. The flow through a un...

  14. Chitosan Mediates Germling Adhesion in Magnaporthe oryzae and Is Required for Surface Sensing and Germling Morphogenesis.

    Directory of Open Access Journals (Sweden)

    Ivey A Geoghegan

    2016-06-01

    Full Text Available The fungal cell wall not only plays a critical role in maintaining cellular integrity, but also forms the interface between fungi and their environment. The composition of the cell wall can therefore influence the interactions of fungi with their physical and biological environments. Chitin, one of the main polysaccharide components of the wall, can be chemically modified by deacetylation. This reaction is catalyzed by a family of enzymes known as chitin deacetylases (CDAs, and results in the formation of chitosan, a polymer of β1,4-glucosamine. Chitosan has previously been shown to accumulate in the cell wall of infection structures in phytopathogenic fungi. Here, it has long been hypothesized to act as a 'stealth' molecule, necessary for full pathogenesis. In this study, we used the crop pathogen and model organism Magnaporthe oryzae to test this hypothesis. We first confirmed that chitosan localizes to the germ tube and appressorium, then deleted CDA genes on the basis of their elevated transcript levels during appressorium differentiation. Germlings of the deletion strains showed loss of chitin deacetylation, and were compromised in their ability to adhere and form appressoria on artificial hydrophobic surfaces. Surprisingly, the addition of exogenous chitosan fully restored germling adhesion and appressorium development. Despite the lack of appressorium development on artificial surfaces, pathogenicity was unaffected in the mutant strains. Further analyses demonstrated that cuticular waxes are sufficient to over-ride the requirement for chitosan during appressorium development on the plant surface. Thus, chitosan does not have a role as a 'stealth' molecule, but instead mediates the adhesion of germlings to surfaces, thereby allowing the perception of the physical stimuli necessary to promote appressorium development. This study thus reveals a novel role for chitosan in phytopathogenic fungi, and gives further insight into the mechanisms

  15. Dynamic modeling of Badaling molten salt tower CSP pilot plant

    Science.gov (United States)

    Yang, Zijiang; Lu, Jiahui; Zhang, Qiangqiang; Li, Zhi; Li, Xin; Wang, Zhifeng

    2017-06-01

    Under the collaboration framework between EDF China R&D Centre and CAS-IEE, a preliminary numerical model of 1MWth molten salt tower solar power demonstration plant in Badaling, Beijing is presented in this paper. All key components in the plant are presented throughout detailed modules in the model according to its design specifications. Control strategies are also implemented to maintain the design system performance at transient scenario. By this model some key design figures of plant has been validated and it will be used to guide experiment set-up and plant commissioning.

  16. Model of how plants sense zinc deficiency

    NARCIS (Netherlands)

    Assuncao, A.G.L.; Persson, D.P.; Husted, S.; Schjorring, J.K.; Alexander, R.D.; Aarts, M.G.M.

    2013-01-01

    Plants are capable of inducing a range of physico-chemical and microbial modifications of the rhizosphere which can mobilize mineral nutrients or prevent toxic elements from entering the roots. Understanding how plants sense and adapt to variations in nutrient availability is essential in order to d

  17. Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences

    Science.gov (United States)

    Bucksch, Alexander; Atta-Boateng, Acheampong; Azihou, Akomian F.; Battogtokh, Dorjsuren; Baumgartner, Aly; Binder, Brad M.; Braybrook, Siobhan A.; Chang, Cynthia; Coneva, Viktoirya; DeWitt, Thomas J.; Fletcher, Alexander G.; Gehan, Malia A.; Diaz-Martinez, Diego Hernan; Hong, Lilan; Iyer-Pascuzzi, Anjali S.; Klein, Laura L.; Leiboff, Samuel; Li, Mao; Lynch, Jonathan P.; Maizel, Alexis; Maloof, Julin N.; Markelz, R. J. Cody; Martinez, Ciera C.; Miller, Laura A.; Mio, Washington; Palubicki, Wojtek; Poorter, Hendrik; Pradal, Christophe; Price, Charles A.; Puttonen, Eetu; Reese, John B.; Rellán-Álvarez, Rubén; Spalding, Edgar P.; Sparks, Erin E.; Topp, Christopher N.; Williams, Joseph H.; Chitwood, Daniel H.

    2017-01-01

    The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics. PMID:28659934

  18. Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences

    Directory of Open Access Journals (Sweden)

    Alexander Bucksch

    2017-06-01

    Full Text Available The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics.

  19. Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences.

    Science.gov (United States)

    Bucksch, Alexander; Atta-Boateng, Acheampong; Azihou, Akomian F; Battogtokh, Dorjsuren; Baumgartner, Aly; Binder, Brad M; Braybrook, Siobhan A; Chang, Cynthia; Coneva, Viktoirya; DeWitt, Thomas J; Fletcher, Alexander G; Gehan, Malia A; Diaz-Martinez, Diego Hernan; Hong, Lilan; Iyer-Pascuzzi, Anjali S; Klein, Laura L; Leiboff, Samuel; Li, Mao; Lynch, Jonathan P; Maizel, Alexis; Maloof, Julin N; Markelz, R J Cody; Martinez, Ciera C; Miller, Laura A; Mio, Washington; Palubicki, Wojtek; Poorter, Hendrik; Pradal, Christophe; Price, Charles A; Puttonen, Eetu; Reese, John B; Rellán-Álvarez, Rubén; Spalding, Edgar P; Sparks, Erin E; Topp, Christopher N; Williams, Joseph H; Chitwood, Daniel H

    2017-01-01

    The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics.

  20. Mitochondrial respiratory pathways inhibition in Rhizopus oryzae potentiates activity of posaconazole and itraconazole via apoptosis.

    Directory of Open Access Journals (Sweden)

    Fazal Shirazi

    Full Text Available The incidence of mucormycosis has increased drastically in immunocompromised patients. Also the array of targets whose inhibition results in Mucorales death is limited. Recently, researchers identified mitochondria as important regulators of detoxification and virulence mechanisms in fungi. In this context, targeting the mitochondrial respiratory chain may provide a new platform for antifungal development. We hypothesized that targeting respiratory pathways potentiates triazoles activity via apoptosis. We found that simultaneous administration of antimycin A (AA and benzohydroxamate (BHAM, inhibitors of classical and alternative mitochondrial pathways respectively, resulted in potent activity of posaconazole (PCZ and itraconazole (ICZ against Rhizopus oryzae. We observed cellular changes characteristic of apoptosis in R. oryzae cells treated with PCZ or ICZ in combination with AA and BHAM. The fungicidal activity of this combination against R. oryzae was correlated with intracellular reactive oxygen species accumulation (ROS, phosphatidylserine externalization, mitochondrial membrane depolarization, and increased caspase like activity. DNA fragmentation and condensation assays also revealed apoptosis of R. oryzae cells. These apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine. Taken together, these findings suggest that the use of PCZ or ICZ in combination with AA and BHAM makes R. oryzae exquisitely sensitive to treatment with triazoles via apoptosis. This strategy may serve as a new model for the development of improved or novel antifungal agents.

  1. Fungal Histidine Phosphotransferase Plays a Crucial Role in Photomorphogenesis and Pathogenesis in Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Varsha C. Mohanan

    2017-05-01

    Full Text Available Two-component signal transduction (TCST pathways play crucial roles in many cellular functions such as stress responses, biofilm formation, and sporulation. The histidine phosphotransferase (HPt, which is an intermediate phosphotransfer protein in a two-component system, transfers a phosphate group to a phosphorylatable aspartate residue in the target protein(s, and up-regulates stress-activated MAP kinase cascades. Most fungal genomes carry a single copy of the gene coding for HPt, which are potential antifungal targets. However, unlike the histidine kinases (HK or the downstream response regulators (RR in two-component system, the HPts have not been well-studied in phytopathogenic fungi. In this study, we investigated the role of HPt in the model rice-blast fungal pathogen Magnaporthe oryzae. We found that in M. oryzae an additional isoform of the HPT gene YPD1 was expressed specifically in response to light. Further, the expression of light-regulated genes such as those encoding envoy and blue-light-harvesting protein, and PAS domain containing HKs was significantly reduced upon down-regulation of YPD1 in M. oryzae. Importantly, down-regulation of YPD1 led to a significant decrease in the ability to penetrate the host cuticle and in light-dependent conidiation in M. oryzae. Thus, our results indicate that Ypd1 plays an important role in asexual development and host invasion, and suggest that YPD1 isoforms likely have distinct roles to play in the rice-blast pathogen M. oryzae.

  2. Fungal histidine phosphotransferase plays a crucial role in photomorphogenesis and pathogenesis in Magnaporthe oryzae

    Science.gov (United States)

    Mohanan, Varsha C.; Chandarana, Pinal M.; Chattoo, Bharat. B.; Patkar, Rajesh N.; Manjrekar, Johannes

    2017-05-01

    Two-component signal transduction (TCST) pathways play crucial roles in many cellular functions such as stress responses, biofilm formation and sporulation. The histidine phosphotransferase (HPt), which is an intermediate phosphotransfer protein in a two-component system, transfers a phosphate group to a phosphorylatable aspartate residue in the target protein(s), and up-regulates stress-activated MAP kinase cascades. Most fungal genomes carry a single copy of the gene coding for HPt, which are potential antifungal targets. However, unlike the histidine kinases (HK) or the downstream response regulators (RR) in two-component system, the HPts have not been well studied in phytopathogenic fungi. In this study, we investigated the role of HPt in the model rice-blast fungal pathogen Magnaporthe oryzae. We found that in M. oryzae an additional isoform of the HPT gene YPD1 was expressed specifically in response to light. Further, the expression of light-regulated genes such as those encoding envoy and blue-light-harvesting protein, and PAS domain containing HKs was significantly reduced upon down-regulation of YPD1 in M. oryzae. Importantly, down-regulation of YPD1 led to a significant decrease in the ability to penetrate the host cuticle and in light-dependent conidiation in M. oryzae. Thus, our results indicate that Ypd1 plays an important role in asexual development and host invasion, and suggest that YPD1 isoforms likely have distinct roles to play in the rice-blast pathogen M. oryzae.

  3. An automation model of Effluent Treatment Plant

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Oliveira Lima Roque

    2012-07-01

    on the conservation of water resources, this paper aims to propose an automation model of an Effluent Treatment Plant, using Ladder programming language and supervisory systems.

  4. Computational Modeling of Auxin: A Foundation for Plant Engineering

    Directory of Open Access Journals (Sweden)

    Alejandro Morales-Tapia

    2016-12-01

    Full Text Available Since the development of agriculture, humans have relied on the cultivation of plants to satisfy our increasing demand for food, natural products, and other raw materials. As we understand more about plant development, we can better manipulate plants to fulfill our particular needs.Auxins are a class of simple metabolites that coordinate many developmental activities like growth and the appearance of functional structures in plants. Computational modeling of auxin has proven to be an excellent tool in elucidating many mechanisms that underlie these developmental events. Due to the complexity of these mechanisms, current modelling efforts are concerned only with single phenomena focused on narrow spatial and developmental contexts; but a general model of plant development could be assembled by integrating the insights from all of them.In this perspective, we summarize the current collection of auxin-driven computational models, focusing on how they could come together into a single model for plant development. A model of this nature would allow researchers to test hypotheses in silico and yield accurate predictions about the behavior of a plant under a given set of physical and biochemical constraints. It would also provide a solid foundation towards the establishment of plant engineering, a proposed discipline intended to enable the design and production of plants that exhibit an arbitrarily defined set of features.

  5. 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...... 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...... 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 with time in submerged...

  6. 21 CFR 173.130 - Carbohydrase derived from Rhizopus oryzae.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbohydrase derived from Rhizopus oryzae. 173.130... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.130 Carbohydrase derived from Rhizopus oryzae. Carbohydrase from Rhizopus oryzae may be safely used in the production of dextrose from starch...

  7. A model of plant strategies in fluvial hydrosystems

    NARCIS (Netherlands)

    Bornette, G.; Tabacchi, E.; Hupp, C.; Puijalon, S.; Rostan, J.C.

    2008-01-01

    1. We propose a model of plant strategies in temperate fluvial hydrosystems that considers the hydraulic and geomorphic features that control plant recruitment, establishment and growth in river floodplains. 2. The model describes first how the disturbance gradient and the grain-size of the river be

  8. Multilevel flow modeling of Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

    2011-01-01

    Multilevel Flow Modeling is a method for modeling complex processes on multiple levels of means-end and part-whole abstraction. The modeling method has been applied on a wide range of processes including power plants, chemical engineering plants and power systems. The modeling method is supported...... functions and structure. The paper will describe how MFM can be used to represent the goals and functions of the Japanese Monju Nuclear Power Plant. A detailed explanation will be given of the model describing the relations between levels of goal, function and structural. Furthermore, it will be explained...

  9. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  10. Plant lessons: exploring ABCB functionality through structural modeling

    Directory of Open Access Journals (Sweden)

    Aurélien eBailly

    2012-01-01

    Full Text Available In contrast to mammalian ABCB1 proteins, narrow substrate specificity has been extensively documented for plant orthologs shown to catalyze the transport of the plant hormone, auxin. Using the crystal structures of the multidrug exporters Sav1866 and MmABCB1 as templates, we have developed structural models of plant ABCB proteins with a common architecture. Comparisons of these structures identified kingdom-specific candidate substrate-binding regions within the translocation chamber formed by the transmembrane domains of ABCBs from the model plant Arabidopsis. These results suggest an early evolutionary divergence of plant and mammalian ABCBs. Validation of these models becomes a priority for efforts to elucidate ABCB function and manipulate this class of transporters to enhance plant productivity and quality.

  11. Over-Expression of Rice CBS Domain Containing Protein, OsCBSX3, Confers Rice Resistance to Magnaporthe oryzae Inoculation.

    Science.gov (United States)

    Mou, Shaoliang; Shi, Lanping; Lin, Wei; Liu, Yanyan; Shen, Lei; Guan, Deyi; He, Shuilin

    2015-07-13

    Cystathionine β-synthase (CBS) domain containing proteins (CDCPs) constitute a big family in plants and some members in this family have been implicated in a variety of biological processes, but the precise functions and the underlying mechanism of the majority of this family in plant immunity remain to be elucidated. In the present study, a CBS domain containing protein gene, OsCBSX3, is functionally characterized in rice resistance against Magnaporthe oryzae (M. oryzae). By quantitative real-time PCR, transcripts of OsCBSX3 are up-regulated significantly by inoculation of M. oryzae and the exogenously applied salicylic acid (SA) and methyl jasmonate (MeJA). OsCBSX3 is exclusively localized to the plasma membrane by transient expression of OsCBSX3 fused to green fluorescent protein (GFP) through approach of Agrobacterium infiltration in Nicotiana benthamiana leaves. The plants of homozygous T3 transgenic rice lines of over-expressing OsCBSX3 exhibit significant enhanced resistance to M. oryzae inoculation, manifested by decreased disease symptoms, and inhibition of pathogen growth detected in DNA. Consistently, the over-expression of OsCBSX3 enhances the transcript levels of immunity associated marker genes including PR1a, PR1b, PR5, AOS2, PAL, NH1, and OsWRKY13 in plants inoculated with M. oryzae. These results suggest that OsCBSX3 acts as a positive regulator in resistance of rice to M. oryzae regulated by SA and JA-mediated signaling pathways synergistically.

  12. Over-Expression of Rice CBS Domain Containing Protein, OsCBSX3, Confers Rice Resistance to Magnaporthe oryzae Inoculation

    Directory of Open Access Journals (Sweden)

    Shaoling Mou

    2015-07-01

    Full Text Available Cystathionine β-synthase (CBS domain containing proteins (CDCPs constitute a big family in plants and some members in this family have been implicated in a variety of biological processes, but the precise functions and the underlying mechanism of the majority of this family in plant immunity remain to be elucidated. In the present study, a CBS domain containing protein gene, OsCBSX3, is functionally characterized in rice resistance against Magnaporthe oryzae (M. oryzae. By quantitative real-time PCR, transcripts of OsCBSX3 are up-regulated significantly by inoculation of M. oryzae and the exogenously applied salicylic acid (SA and methyl jasmonate (MeJA. OsCBSX3 is exclusively localized to the plasma membrane by transient expression of OsCBSX3 fused to green fluorescent protein (GFP through approach of Agrobacterium infiltration in Nicotiana benthamiana leaves. The plants of homozygous T3 transgenic rice lines of over-expressing OsCBSX3 exhibit significant enhanced resistance to M. oryzae inoculation, manifested by decreased disease symptoms, and inhibition of pathogen growth detected in DNA. Consistently, the over-expression of OsCBSX3 enhances the transcript levels of immunity associated marker genes including PR1a, PR1b, PR5, AOS2, PAL, NH1, and OsWRKY13 in plants inoculated with M. oryzae. These results suggest that OsCBSX3 acts as a positive regulator in resistance of rice to M. oryzae regulated by SA and JA-mediated signaling pathways synergistically.

  13. Lysimachia foenum-graecum Herba Extract, a Novel Biopesticide, Inhibits ABC Transporter Genes and Mycelial Growth of Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Youngjin Lee

    2016-02-01

    Full Text Available To identify a novel biopesticide controlling rice blast disease caused by Magnaporthe oryzae, 700 plant extracts were evaluated for their inhibitory effects on mycelial growth of M. oryzae. The L. foenum-graecum Herba extract showed the lowest inhibition concentration (IC₅₀ of 39.28 μg/ml, which is lower than the IC₅₀ of blasticidin S (63.06 μg/ml, a conventional fungicide for rice blast disease. When treatments were combined, the IC₅₀ of blasticidin S was dramatically reduced to 10.67 μg/ml. Since ABC transporter genes are involved in fungicide resistance of many organisms, we performed RT-PCR to investigate the transcriptional changes of 40 ABC transporter family genes of M. oryzae treated with the plant extract, blasticidin S, and tetrandrine, a recognized ABC transporter inhibitor. Four ABC transporter genes were prominently activated by blasticidin S treatment, but were suppressed by combinational treatment of blasticidin S with the plant extract, or with tetrandrine that didn’t show cellular toxicity by itself in this study. Mycelial death was detected via confocal microscopy at 24 h after plant extract treatment. Finally, subsequent rice field study revealed that the plant extract had high control efficacy of 63.3% and should be considered a biopesticide for rice blast disease. These results showed that extract of L. foenum graecum Herba suppresses M. oryzae ABC transporter genes inducing mycelial death and therefore may be a potent novel biopesticide.

  14. Characterization of interspecific hybrids and backcross progenies from a cross between Oryza minuta and Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Oryza minuta, a tetraploid wild relative of cultivated rice, is an important source for the genetic improvement. Interspecific hybrids were obtained from the cross of O. sativa L. (IR24) and O. minuta (Acc. No. 101133) with 5.58% crossability, which ranged from 0.11% to 1.62% in the backcross generations. The chromosome numbers of the backcross progenies were 24 to 48. Seven yield-related traits of the parents, hybrid F1, and backcross progenies were evaluated. Simple sequence repeat markers analysis showed that the polymorphism ratio of SSR bands between IR24 and Acc. No. 101133 was 93.2%. The average donor segment number, length, donor genome size, and percentage of donor genome of 92 BC3F1 plants (2n=24) were 24.1, 17.8 cM, 438.4 cM and 26.2%, respectively. They were complex variation and uneven among the chromosomes. These introgression lines could be used to identify the favorable genes of O. minuta and provide a new platform for the genetic improvement of cultivated rice.

  15. Rice (Oryza hemoglobins [v2; ref status: indexed, http://f1000r.es/4vp

    Directory of Open Access Journals (Sweden)

    Raúl Arredondo-Peter

    2014-12-01

    Full Text Available 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 single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O2-transport, O2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs.

  16. Irrigation Optimization by Modeling of Plant-Soil Interaction

    OpenAIRE

    2011-01-01

    Irrigation scheduling is an important issue for crop management, in a general context of limited water resources and increasing concern about agricultural productivity. Methods to optimize crop irrigation should take into account the impact of water stress on plant growth and the water balance in the plant-soil-atmosphere system. In this article, we propose a methodology to solve the irrigation scheduling problem. For this purpose, a plant-soil interaction model is used to simulate the struct...

  17. Patogenicidade de Helminthosporium oryzae a algumas espécies de gramíneas Pathogenicity of Helminthosporium oryzae against some grass species

    Directory of Open Access Journals (Sweden)

    V.H. Artigiani Filho

    1995-04-01

    Full Text Available O fungo Helminthosporium oryzae é um patógeno do arroz. Devido a sua variabilidade patogênica, foi investigada a possibilidade deste fungo infectar outras gramíneas. Através de inoculação artificial, ficou demonstrada a capacidade deste patógeno provocar infecção em aveia, cana, centeio, sorgo, trigo, Brachiaria decumbens e Panicum maximum. Assim, estas espécies vegetais podem ser consideradas potenciais hospedeiros do fungo na natureza.Helminthosporium oryzae is a rice pathogen. Due to its variability in pathogenicity, the possibility of this fungus Infecting other grasses was investigated. The capacity of this pathogen was demonstrated to be able to infect oat, sugar-cane, rye, sorghum, wheat, Brachiaria decumbens and Panicum maximum through artificial inoculations. Therefore, those plant species can be considered potencial hosts for the fungus in nature.

  18. Identiifcation of differentially-expressed genes of rice in overlapping responses to bacterial infection by Xanthomonas oryzae pv. oryzae and nitrogen deifciency

    Institute of Scientific and Technical Information of China (English)

    YU Chao; CHEN Hua-min; TIAN Fang; BI Yong-mei; Rothstein J Steven; Leach E Jan; HE Chen-yang

    2015-01-01

    Bacterial blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of high nitrogen (N) responsive diseases. Rice plants became more disease resistant with decreasing N suggesting that the crosstalk between disease resistance and N utilization pathways might exist. However, the co-regulatory components in such crosstalk have not been elucidated. Here, we comparatively analyzed the gene expression proifling of rice under Xoo inoculation, low N treatment, or a combi-nation of both stresses, and identiifed the differential y-expressed genes (DEGs) in overlapping responses. These DEGs were involved in different biological processes, including innate immunity and nitrogen metabolism. The randomly-selected DEGs expression was validated by quantitative real-time PCR assays. Temporal expression of six genes from different functional categories suggested that N condition was the dominant factor when both stresses were present. These DEGs identiifed provide novel insights into the coordinated regulatory mechanism in biotic and abiotic stress responses in rice.

  19. 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.

  20. Systematic characterization of the peroxidase gene family provides new insights into fungal pathogenicity in Magnaporthe oryzae.

    Science.gov (United States)

    Mir, Albely Afifa; Park, Sook-Young; Abu Sadat, Md; Kim, Seongbeom; Choi, Jaeyoung; Jeon, Junhyun; Lee, Yong-Hwan

    2015-07-02

    Fungal pathogens have evolved antioxidant defense against reactive oxygen species produced as a part of host innate immunity. Recent studies proposed peroxidases as components of antioxidant defense system. However, the role of fungal peroxidases during interaction with host plants has not been explored at the genomic level. Here, we systematically identified peroxidase genes and analyzed their impact on fungal pathogenesis in a model plant pathogenic fungus, Magnaporthe oryzae. Phylogeny reconstruction placed 27 putative peroxidase genes into 15 clades. Expression profiles showed that majority of them are responsive to in planta condition and in vitro H2O2. Our analysis of individual deletion mutants for seven selected genes including MoPRX1 revealed that these genes contribute to fungal development and/or pathogenesis. We identified significant and positive correlations among sensitivity to H2O2, peroxidase activity and fungal pathogenicity. In-depth analysis of MoPRX1 demonstrated that it is a functional ortholog of thioredoxin peroxidase in Saccharomyces cerevisiae and is required for detoxification of the oxidative burst within host cells. Transcriptional profiling of other peroxidases in ΔMoprx1 suggested interwoven nature of the peroxidase-mediated antioxidant defense system. The results from this study provide insight into the infection strategy built on evolutionarily conserved peroxidases in the rice blast fungus.

  1. Single Plant Root System Modeling under Soil Moisture Variation

    Science.gov (United States)

    Yabusaki, S.; Fang, Y.; Chen, X.; Scheibe, T. D.

    2016-12-01

    A prognostic Virtual Plant-Atmosphere-Soil System (vPASS) model is being developed that integrates comprehensively detailed mechanistic single plant modeling with microbial, atmospheric, and soil system processes in its immediate environment. Three broad areas of process module development are targeted: Incorporating models for root growth and function, rhizosphere interactions with bacteria and other organisms, litter decomposition and soil respiration into established porous media flow and reactive transport models Incorporating root/shoot transport, growth, photosynthesis and carbon allocation process models into an integrated plant physiology model Incorporating transpiration, Volatile Organic Compounds (VOC) emission, particulate deposition and local atmospheric processes into a coupled plant/atmosphere model. The integrated plant ecosystem simulation capability is being developed as open source process modules and associated interfaces under a modeling framework. The initial focus addresses the coupling of root growth, vascular transport system, and soil under drought scenarios. Two types of root water uptake modeling approaches are tested: continuous root distribution and constitutive root system architecture. The continuous root distribution models are based on spatially averaged root development process parameters, which are relatively straightforward to accommodate in the continuum soil flow and reactive transport module. Conversely, the constitutive root system architecture models use root growth rates, root growth direction, and root branching to evolve explicit root geometries. The branching topologies require more complex data structures and additional input parameters. Preliminary results are presented for root model development and the vascular response to temporal and spatial variations in soil conditions.

  2. Quantitative plant ecology:statistical and ecological modelling of plant abundance

    OpenAIRE

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com)The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement and statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also mean...

  3. Measurement and modelling of sap flow in maize plants

    Science.gov (United States)

    Heinlein, Florian; Biernath, Christian; Hoffmann, Peter; Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2014-05-01

    Climate change as well as the changing composition of the atmosphere will have an impact on future yield of agricultural plants. In order to better estimate these impacts new, mechanistic plant growth models are needed. These models should be able to dynamically reproduce the plants' reactions to modified climate state variables like temperature, atmospheric CO2-concentration and water availability. In particular, to better describe the crop response to more strongly changing water availability the simulation of plant-internal water and solute transport processes in xylem and phloem needs to be improved. Our existing water transport model consists of two coupled 1-D Richards equations to calculate water transport in the soil and in the plants. This model has already been successfully applied to single Fagus sylvatica L. trees. At present it is adapted to agricultural plants such as maize. To simulate the water transport within the plants a representation of the flow paths, i.e. the plant architecture, is required. Aboveground plant structures are obtained from terrestrial laser scan (TLS) measurements at different development stages. These TLSs have been executed at the lysimeter facilities of Helmholtz Zentrum München and at the TERENO (Terrestrial Environmental Observatories) research farm Scheyern. Additionally, an L-system model is used to simulate aboveground and belowground plant architectures. In a further step, the quality of the explicit water flow model has to be tested using measurements. The Heat-Ratio-Method has been employed to directly measure sap flow in larger maize plants during a two-months-period in summer 2013 with a resolution of 10 minutes and thus, the plants' transpiration can be assessed. Water losses from the soil are determined by measuring the weight of lysimeters. From this evapotranspiration can be calculated. Transpiration and evapotranspiration are also simulated by application of the modelling system Expert-N. This framework

  4. Comparative genomic analysis of the GRF genes in Chinese pear (Pyrus bretschneideri Rehd, poplar (Populous, grape (Vitis vinifera, Arabidopsis and rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Yun Peng Cao

    2016-11-01

    Full Text Available Growth-regulating factors (GRFs are plant-specific transcription factors that have important functions in regulating plant growth and development. Previous studies on GRF family members focused either on a single or a small set of genes. Here, a comparative genomic analysis of the GRF gene family was performed in poplar (a model tree species, Arabidopsis (a model plant for annual herbaceous dicots, grape (one model plant for perennial dicots, rice (a model plant for monocots and Chinese pear (one of the economical fruit crops. In total, 58 GRF genes were identified, 12 genes in rice (Oryza sativa, 8 genes in grape (Vitis vinifera, 9 genes in Arabidopsis thaliana, 19 genes in poplar (Populus trichocarpa and 10 genes in Chinese pear (Pyrus bretschneideri. The GRF genes were divided into five subfamilies based on the phylogenetic analysis, which was supported by their structural analysis. Furthermore, microsynteny analysis indicated that highly conserved regions of microsynteny were identified in all of the five species tested. And Ka/Ks analysis revealed that purifying selection play an important role in the maintenance of GRF genes. Our results provide basic information on GRF genes in five plant species and lay the foundation for future research on the functions of these genes.

  5. Modeling the Buoyancy System of a Wave Energy Power Plant

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Nielsen, Kirsten M.

    2009-01-01

    A nonlinear dynamic model of the buoyancy system in a wave energy power plant is presented. The plant ("Wave Dragon") is a floating device using the potential energy in overtopping waves to produce power. A water reservoir is placed on top of the WD, and hydro turbines lead the water to the sea...

  6. Stoichiometric plant-herbivore models and their interpretation

    NARCIS (Netherlands)

    Kuang, Y.; Huisman, J.; Elser, J.J.

    2004-01-01

    The purpose of this note is to mechanistically formulate a math-ematically tractable model that specifically deals with the dynamics of plant-herbivore interaction in a closed phosphorus (P)-limiting environment. The key to our approach is the employment of the plant cell P quota and the Droop

  7. Modeling the Buoyancy System of a Wave Energy Power Plant

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Nielsen, Kirsten M.

    2009-01-01

    A nonlinear dynamic model of the buoyancy system in a wave energy power plant is presented. The plant ("Wave Dragon") is a floating device using the potential energy in overtopping waves to produce power. A water reservoir is placed on top of the WD, and hydro turbines lead the water to the sea...

  8. Editorial: Plant organ abscission: from models to crops

    Science.gov (United States)

    The shedding of plant organs is a highly coordinated process essential for both vegetative and reproductive development (Addicott, 1982; Sexton and Roberts, 1982; Roberts et al., 2002; Leslie et al., 2007; Roberts and Gonzalez-Carranza, 2007; Estornell et al., 2013). Research with model plants, name...

  9. The development of Arabidopsis as a plant model

    NARCIS (Netherlands)

    Koornneef, M.; Meinke, D.W.

    2010-01-01

    Twenty-five years ago, Arabidopsis thaliana emerged as the model organism of choice for research in plant biology. A consensus was reached about the need to focus on a single organism to integrate the classical disciplines of plant science with the expanding fields of genetics and molecular biology.

  10. Studies on the yield and quality characteristics of YeiweiB plants transformed with Oryza minuta genomic DNA%转小粒野生稻基因种质野威B的产量与米质性状

    Institute of Scientific and Technical Information of China (English)

    匡勇; 杨曼云; 匡逢春; 黄志远; 胡远艺; 夏石头; 赵炳然

    2011-01-01

    野威B是将小粒野生稻(Oryza minuta)的基因组DNA通过穗茎注射法导入杂交水稻亲本V20B中培育出的转基因水稻新种质.与亲本V20B相比,野威B的有效穗数和每穗总粒数小于V20B,但每穗实粒数却高于V20B,平均结实率比V20B增加11.8%,千粒重比V20B的少6 g.野威B倒1叶和倒2叶叶鞘中可溶性糖含量先降低,黄熟期略微升高,蜡熟期降低;V20B倒1叶叶鞘中可溶性糖含量变化不明显,倒2叶叶鞘中可溶性糖含量先升高,乳熟期降低,之后升高.野威B的糙米率和整精米率与V20B相近,垩白粒率比V20B降低47.5%,垩白面积下降62.1%,胶稠度比V20B的高,直链淀粉含量比V20B降低39.0%.%Yewei B, a new rice germplasm was bred through transformed with genomic DNA of Oryza minuta into V20B by earstem injecting.Compared with V20B, the effective panicles numbers and the spikelets number per panicles of Yewei B are smaller, but the filled grains per spike are higher.The average seed setting percentage of Yewei B is found to be 11.8 % higher than that of V20B, but 1 000-grain weight of Yewei B is 6 gram less than that of V20B.The content of soluble sugar in leaf sheath of the topl st and top 2nd leaf decreases first then increases slightly and then decreases again in Yewei B.In V20B, the content of soluble sugar is less distinctly changed in leaf sheath of the top 1st leaf, and it increases first then decreases and then increases again in leaf sheath of the top 2nd leaf.The brown rice percentage and head rice rate of Yewei B is similar to V20B, but the percentage of chalky grain and the area of chalkiness are 47.5% and 62.1%lower than that of V20B respectively.Gel consistency of Yewei B is higher and the content of amylose is 39.0% lower than that of V20B.

  11. 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

  12. 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.

  13. Modeling the kinetics of essential oil hydrodistillation from plant materials

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir Ž.

    2013-01-01

    Full Text Available The present work deals with modeling the kinetics of essential oils extraction from plant materials by water and steam distillation. The experimental data were obtained by studying the hydrodistillation kinetics of essential oil from juniper berries. The literature data on the kinetics of essential oils hydrodistillation from different plant materials were also included into the modeling. A physical model based on simultaneous washing and diffusion of essential oil from plant materials were developed to describe the kinetics of essential oils hydrodistillation, and two other simpler models were derived from this physical model assuming either instantaneous washing followed by diffusion or diffusion with no washing (i.e. the first-order kinetics. The main goal was to compare these models and suggest the optimum ones for water and steam distillation and for different plant materials. All three models described well the experimental kinetic data on water distillation irrespective of the type of distillation equipment and its scale, the type of plant materials and the operational conditions. The most applicable one is the model involving simultaneous washing and diffusion of the essential oil. However, this model was generally inapplicable for steam distillation of essential oils, except for juniper berries. For this hydrodistillation technique, the pseudo first-order model was shown to be the best one. In a few cases, a variation of the essential oil yield with time was observed to be sigmoidal and was modeled by the Boltzmann sigmoid function.

  14. Development of a dynamical systems model of plant programmatic performance on nuclear power plant safety risk

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Stephen M. [Sensortex, Inc., 515 Schoolhouse Road, Kennett Square, PA 19348 (United States)]. E-mail: smhess@sensortex.com; Albano, Alfonso M. [Department of Physics, Bryn Mawr College, Bryn Mawr, PA 19010 (United States); Gaertner, John P. [Electric Power Research Institute, 1300 Harris Boulevard, Charlotte, NC 28262 (United States)

    2005-10-01

    Application of probabilistic risk assessment (PRA) techniques to model nuclear power plant accident sequences has provided a significant contribution to understanding the potential initiating events, equipment failures and operator errors that can lead to core damage accidents. Application of the lessons learned from these analyses has resulted in significant improvements in plant operation and safety. However, this approach has not been nearly as successful in addressing the impact of plant processes and management effectiveness on the risks of plant operation. The research described in this paper presents an alternative approach to addressing this issue. In this paper we propose a dynamical systems model that describes the interaction of important plant processes on nuclear safety risk. We discuss development of the mathematical model including the identification and interpretation of significant inter-process interactions. Next, we review the techniques applicable to analysis of nonlinear dynamical systems that are utilized in the characterization of the model. This is followed by a preliminary analysis of the model that demonstrates that its dynamical evolution displays features that have been observed at commercially operating plants. From this analysis, several significant insights are presented with respect to the effective control of nuclear safety risk. As an important example, analysis of the model dynamics indicates that significant benefits in effectively managing risk are obtained by integrating the plant operation and work management processes such that decisions are made utilizing a multidisciplinary and collaborative approach. We note that although the model was developed specifically to be applicable to nuclear power plants, many of the insights and conclusions obtained are likely applicable to other process industries.

  15. Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

    NARCIS (Netherlands)

    Ruijter, G.J.G.; Visser, J.; Rinzema, A.

    2004-01-01

    Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a(w)) is typically low resulting in osmotic stress. In addition to a high level of mannitol,

  16. The Oryza Map Alignment Project (OMAP) introgression lines for allelic diversity and new germplasm development

    Science.gov (United States)

    The Oryza Map Alignment Project (OMAP) has developed a genus wide model system for the study of rice that will ultimately provide a complete understanding of the genus. The purpose of this project is to capitalize on the strengths of the Arizona Genomics Institute (AGI), OMAP participants and the r...

  17. The ultrasound-enhanced bioscouring performance of four polygalacturonase enzymes obtained from rhizopus oryzae

    Science.gov (United States)

    An analytical and statistical method has been developed to measure the ultrasound-enhanced bioscouring performance of milligram quantities of endo- and exo-polygalacturonase enzymes obtained from Rhizopus oryzae fungi. UV-Vis spectrophotometric data and a general linear mixed models procedure indic...

  18. The High Affinity Iron Permease is a Key Virulence Factor Required for Rhizopus oryzae Pathogenesis

    Science.gov (United States)

    Rhizopus oryzae is the most common cause of mucormycosis, an angioinvasive fungal infection that causes a >/=50% mortality rate despite first-line therapy. Clinical and animal model data clearly demonstrate that the presence of elevated available serum iron predisposes the host to mucormycosis. Th...

  19. Implementing a business improvement model based on integrated plant information

    Directory of Open Access Journals (Sweden)

    Swanepoel, Hendrika Francina

    2016-11-01

    Full Text Available The World Energy Council defines numerous challenges in the global energy arena that put pressure on owners and /operators to operate run existing plant better and more efficiently. As such there is an increasing focus on the use of business and technical plant information and data to make better, more integrated, and more informed decisions on the plant. The research study developed a business improvement model (BIM that can be used to establish an integrated plant information management infrastructure as the core foundation for of business improvement initiatives. Operational research then demonstrated how this BIM approach could be successfully implemented to improve business operations and provide decision-making insight.

  20. Ehd4 encodes a novel and Oryza-genus-specific regulator of photoperiodic flowering in rice.

    Directory of Open Access Journals (Sweden)

    He Gao

    Full Text Available Land plants have evolved increasingly complex regulatory modes of their flowering time (or heading date in crops. Rice (Oryza sativa L. is a short-day plant that flowers more rapidly in short-day but delays under long-day conditions. Previous studies have shown that the CO-FT module initially identified in long-day plants (Arabidopsis is evolutionary conserved in short-day plants (Hd1-Hd3a in rice. However, in rice, there is a unique Ehd1-dependent flowering pathway that is Hd1-independent. Here, we report isolation and characterization of a positive regulator of Ehd1, Early heading date 4 (Ehd4. ehd4 mutants showed a never flowering phenotype under natural long-day conditions. Map-based cloning revealed that Ehd4 encodes a novel CCCH-type zinc finger protein, which is localized to the nucleus and is able to bind to nucleic acids in vitro and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional regulator. Ehd4 expression is most active in young leaves with a diurnal expression pattern similar to that of Ehd1 under both short-day and long-day conditions. We show that Ehd4 up-regulates the expression of the "florigen" genes Hd3a and RFT1 through Ehd1, but it acts independently of other known Ehd1 regulators. Strikingly, Ehd4 is highly conserved in the Oryza genus including wild and cultivated rice, but has no homologs in other species, suggesting that Ehd4 is originated along with the diversification of the Oryza genus from the grass family during evolution. We conclude that Ehd4 is a novel Oryza-genus-specific regulator of Ehd1, and it plays an essential role in photoperiodic control of flowering time in rice.

  1. Plant Phenotyping using Probabilistic Topic Models: Uncovering the Hyperspectral Language of Plants.

    Science.gov (United States)

    Wahabzada, Mirwaes; Mahlein, Anne-Katrin; Bauckhage, Christian; Steiner, Ulrike; Oerke, Erich-Christian; Kersting, Kristian

    2016-03-09

    Modern phenotyping and plant disease detection methods, based on optical sensors and information technology, provide promising approaches to plant research and precision farming. In particular, hyperspectral imaging have been found to reveal physiological and structural characteristics in plants and to allow for tracking physiological dynamics due to environmental effects. In this work, we present an approach to plant phenotyping that integrates non-invasive sensors, computer vision, as well as data mining techniques and allows for monitoring how plants respond to stress. To uncover latent hyperspectral characteristics of diseased plants reliably and in an easy-to-understand way, we "wordify" the hyperspectral images, i.e., we turn the images into a corpus of text documents. Then, we apply probabilistic topic models, a well-established natural language processing technique that identifies content and topics of documents. Based on recent regularized topic models, we demonstrate that one can track automatically the development of three foliar diseases of barley. We also present a visualization of the topics that provides plant scientists an intuitive tool for hyperspectral imaging. In short, our analysis and visualization of characteristic topics found during symptom development and disease progress reveal the hyperspectral language of plant diseases.

  2. Dynamics of an ant-plant-pollinator model

    Science.gov (United States)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  3. Selección preliminar de plantas de arroz con resistencia vertical A pyricularia oryzae Cav por inducción de mutaciones (ING

    Directory of Open Access Journals (Sweden)

    A Cruz

    2016-03-01

    Full Text Available Seeds of rice Oryza sativa L. cv. CR-1113 susceptible to blast disease Pyricularia oryzae Cav. Were subjected to gamma radiation with 60Co using doses of 15 and 20 krads to obtain and select mutant plants with vertical resistance to blast. A total of 80.000 rice plants per treatment were individually evaluated in the second mutant generation (M2 at tillering and panicle emergence. Vertical resistance was observed in 47 and 8 plants from the 15 and 20 krads treatments respectively.

  4. Virus-induced gene silencing as a tool for functional analyses in the emerging model plant Aquilegia (columbine, Ranunculaceae

    Directory of Open Access Journals (Sweden)

    Kramer Elena M

    2007-04-01

    Full Text Available Abstract Background The lower eudicot genus Aquilegia, commonly known as columbine, is currently the subject of extensive genetic and genomic research aimed at developing this taxon as a new model for the study of ecology and evolution. The ability to perform functional genetic analyses is a critical component of this development process and ultimately has the potential to provide insight into the genetic basis for the evolution of a wide array of traits that differentiate flowering plants. Aquilegia is of particular interest due to both its recent evolutionary history, which involves a rapid adaptive radiation, and its intermediate phylogenetic position between core eudicot (e.g., Arabidopsis and grass (e.g., Oryza model species. Results Here we demonstrate the effective use of a reverse genetic technique, virus-induced gene silencing (VIGS, to study gene function in this emerging model plant. Using Agrobacterium mediated transfer of tobacco rattle virus (TRV based vectors, we induce silencing of PHYTOENE DESATURASE (AqPDS in Aquilegia vulgaris seedlings, and ANTHOCYANIDIN SYNTHASE (AqANS and the B-class floral organ identity gene PISTILLATA in A. vulgaris flowers. For all of these genes, silencing phenotypes are associated with consistent reduction in endogenous transcript levels. In addition, we show that silencing of AqANS has no effect on overall floral morphology and is therefore a suitable marker for the identification of silenced flowers in dual-locus silencing experiments. Conclusion Our results show that TRV-VIGS in Aquilegia vulgaris allows data to be rapidly obtained and can be reproduced with effective survival and silencing rates. Furthermore, this method can successfully be used to evaluate the function of early-acting developmental genes. In the future, data derived from VIGS analyses will be combined with large-scale sequencing and microarray experiments already underway in order to address both recent and ancient evolutionary

  5. Model development and validation of a solar cooling plant

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, Darine; Garcia-Gabin, Winston [Escuela de Ingenieria Electrica, Facultad de Ingenieria, Universidad de Los Andes, La Hechicera, Merida 5101 (Venezuela); Bordons, Carlos; Camacho, Eduardo F. [Departamento de Ingenieria de Sistemas y Automatica, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de Los Descubrimientos s/n, Sevilla 41092 (Spain)

    2008-03-15

    This paper describes the dynamic model of a solar cooling plant that has been built for demonstration purposes using market-available technology and has been successfully operational since 2001. The plant uses hot water coming from a field of solar flat collectors which feed a single-effect absorption chiller of 35 kW nominal cooling capacity. The work includes model development based on first principles and model validation with a set of experiments carried out on the real plant. The simulation model has been done in a modular way, and can be adapted to other solar cooling-plants since the main modules (solar field, absorption machine, accumulators and auxiliary heater) can be easily replaced. This simulator is a powerful tool for solar cooling systems both during the design phase, when it can be used for component selection, and also for the development and testing of control strategies. (author)

  6. Applying Functional Modeling for Accident Management of Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2014-01-01

    The paper investigate applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow...

  7. In vitro investigation on antifungal activity of some plant extracts ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Studies were carried out to determine the antifungal attributes of some plant extracts against Pyricularia oryzae. The plant species evaluated were the leaves of Ocimum gratissimum ..... of Pesticide Toxicology, New York, Academic. Press.

  8. Modeling of air pollution from the power plant ash dumps

    Science.gov (United States)

    Aleksic, Nenad M.; Balać, Nedeljko

    A simple model of air pollution from power plant ash dumps is presented, with emission rates calculated from the Bagnold formula and transport simulated by the ATDL type model. Moisture effects are accounted for by assumption that there is no pollution on rain days. Annual mean daily sedimentation rates, calculated for the area around the 'Nikola Tesla' power plants near Belgrade for 1987, show reasonably good agreement with observations.

  9. Structural and Functional Studies of Aspergillus oryzae Cutinase: Enhanced Thermostability and Hydrolytic Activity of Synthetic Ester and Polyester Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z.; Gosser, Y; Baker, P; Ravee, Y; Li, H; Butterfoss, G; Kong, X; Gross, R; Montclare, J; et al.

    2009-01-01

    Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically favored catalytic triad with a continuous and deep groove. These structural features of A. oryzae cutinase are proposed to result in an improved hydrolytic activity and altered substrate specificity profile, enhanced thermostability, and remarkable reactivity toward the degradation of the synthetic polyester polycaprolactone. The results presented here provide insight into engineering new cutinase-inspired biocatalysts with tailor-made properties.

  10. Mutation of the rice XA21 predicted nuclear localization sequence does not affect resistance to Xanthomonas oryzae pv. oryzae

    Science.gov (United States)

    Ho, Yuen Ting

    2016-01-01

    Background The rice receptor kinase XA21 confers robust resistance to the bacterial pathogen Xanthomonas oryzaepv. oryzae(Xoo). We previously reported that XA21 is cleaved in transgenic plants overexpressing XA21 with a GFP tag (Ubi-XA21-GFP) and that the released C-terminal domain is localized to the nucleus. XA21 carries a predicted nuclear localization sequence (NLS) that directs the C-terminal domain to the nucleus in transient assays, whereas alanine substitutions in the NLS disrupt the nuclear localization. Methods To determine if the predicted NLS is required for XA21-mediated immunity in planta, we generated transgenic plants overexpressing an XA21 variant carrying the NLS with the same alanine substitutions (Ubi-XA21nls-GFP). Results Ubi-XA21nls-GFP plants displayed slightly longer lesion lengths, higher Xoobacterial populations after inoculation and lower levels of reactive oxygen species production compared with the Ubi-XA21-GFP control plants. However, the Ubi-XA21nls-GFP plants express lower levels of protein than that observed in Ubi-XA21-GFP. Discussion These results demonstrate that the predicted NLS is not required for XA21-mediated immunity.

  11. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    OpenAIRE

    Simonas Tamaliūnas; Henrikas Sivilevičius

    2011-01-01

    The article presents reclaimed asphalt pavement (RAP) processing technologies and equipment models used in the asphalt mixing plant (AMP). The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  12. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    Directory of Open Access Journals (Sweden)

    Simonas Tamaliūnas

    2011-04-01

    Full Text Available The article presents reclaimed asphalt pavement (RAP processing technologies and equipment models used in the asphalt mixing plant (AMP. The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  13. Linear programming model of a meat processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Shah, S.A.; Okos, M.R.; Reklaitis, G.V.

    1981-01-01

    A multi-period and multi-product production-planning model of an operational meat processing plant is presented. The model input is the time-varying customer demand and the output is the optimum product mix. The model results are interpreted and compared with actual data. Various production strategies are evaluated.

  14. Hydraulic modelling of drinking water treatment plant operations

    Directory of Open Access Journals (Sweden)

    K. J. Borger

    2008-10-01

    Full Text Available For a drinking water treatment plant simulation, water quality models, a hydraulic model, a process-control model, an object model, data management, training and decision-support features and a graphic user interface have been integrated. The integration of a hydraulic model in the simulator is necessary to correctly determine the division of flows over the plant's lanes and, thus, the flow through the individual treatment units, based on valve positions and pump speeds. The flow through a unit is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes. Using this library, a hydraulic model was set up and validated for the drinking water treatment plant Harderbroek.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Model of annual plants dynamics with facilitation and competition.

    Science.gov (United States)

    Droz, Michel; Pękalski, Andrzej

    2013-10-21

    An individual-based model describing the dynamics of one type of annual plants is presented. We use Monte Carlo simulations where each plant has its own history and the interactions among plants are between nearest neighbours. The character of the interaction (positive or negative) depends on local conditions. The plants compete for two external resources-water and light. The amount of water and/or light a plant receives depends on the external factor but also on local arrangement. Survival, growth and seed production of plants are determined by how well their demands for the resources are met. The survival and seeds production tests have a probabilistic character, which makes the dynamics more realistic than by using a deterministic approach. There is a non-linear coupling between the external supplies. Water evaporates from the soil at a rate depending on constant evaporation rate, local conditions and the amount of light. We examine the dynamics of the plant population along two environmental gradients, allowing also for surplus of water and/or light. We show that the largest number of plants is when the demands for both resources are equal to the supplies. We estimate also the role of evaporation and we find that it depends on the situation. It could be negative, but sometimes it has a positive character. We show that the link between the type of interaction (positive or negative) and external conditions has a complex character. In general in favourable environment plants have a stronger tendency for competitive interactions, leading to mostly isolated plants. When the conditions are getting more difficult, cooperation becomes the dominant type of interactions and the plants grow in clusters. The type of plants-sun-loving or shade tolerating, plays also an important role.

  17. A plant-wide energy model for wastewater treatment plants: application to anaerobic membrane bioreactor technology.

    Science.gov (United States)

    Pretel, R; Robles, A; Ruano, M V; Seco, A; Ferrer, J

    2016-09-01

    The aim of this study is to propose a detailed and comprehensive plant-wide model for assessing the energy demand of different wastewater treatment systems (beyond the traditional activated sludge) in both steady- and unsteady-state conditions. The proposed model makes it possible to calculate power and heat requirements (W and Q, respectively), and to recover both power and heat from methane and hydrogen capture. In order to account for the effect of biological processes on heat requirements, the model has been coupled to the extended version of the BNRM2 plant-wide mathematical model, which is implemented in DESSAS simulation software. Two case studies have been evaluated to assess the model's performance: (1) modelling the energy demand of two urban wastewater treatment plants based on conventional activated sludge and submerged anaerobic membrane bioreactor (AnMBR) technologies in steady-state conditions and (2) modelling the dynamics of reactor temperature and heat requirements in an AnMBR plant in unsteady-state conditions. The results indicate that the proposed model can be used to assess the energy performance of different wastewater treatment processes and would thus be useful, for example, WWTP design or upgrading or the development of new control strategies for energy savings.

  18. A dynamical systems model for nuclear power plant risk

    Science.gov (United States)

    Hess, Stephen Michael

    The recent transition to an open access generation marketplace has forced nuclear plant operators to become much more cost conscious and focused on plant performance. Coincidentally, the regulatory perspective also is in a state of transition from a command and control framework to one that is risk-informed and performance-based. Due to these structural changes in the economics and regulatory system associated with commercial nuclear power plant operation, there is an increased need for plant management to explicitly manage nuclear safety risk. Application of probabilistic risk assessment techniques to model plant hardware has provided a significant contribution to understanding the potential initiating events and equipment failures that can lead to core damage accidents. Application of the lessons learned from these analyses has supported improved plant operation and safety over the previous decade. However, this analytical approach has not been nearly as successful in addressing the impact of plant processes and management effectiveness on the risks of plant operation. Thus, the research described in this dissertation presents a different approach to address this issue. Here we propose a dynamical model that describes the interaction of important plant processes among themselves and their overall impact on nuclear safety risk. We first provide a review of the techniques that are applied in a conventional probabilistic risk assessment of commercially operating nuclear power plants and summarize the typical results obtained. The limitations of the conventional approach and the status of research previously performed to address these limitations also are presented. Next, we present the case for the application of an alternative approach using dynamical systems theory. This includes a discussion of previous applications of dynamical models to study other important socio-economic issues. Next, we review the analytical techniques that are applicable to analysis of

  19. Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.

    Science.gov (United States)

    Alamgir, Kabir Md; Hojo, Yuko; Christeller, John T; Fukumoto, Kaori; Isshiki, Ryutaro; Shinya, Tomonori; Baldwin, Ian T; Galis, Ivan

    2016-02-01

    Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants.

  20. 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.

  1. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  2. Public lakes, private lakeshore: modeling protection of native aquatic plants.

    Science.gov (United States)

    Schroeder, Susan A; Fulton, David C

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  3. Development and Identification of Introgression Lines from Cross of Oryza sativa and Oryza minuta

    Institute of Scientific and Technical Information of China (English)

    GUO Si-bin; WEI Yu; LI Xiao-qiong; LIU Kai-qiang; HUANG Feng-kuan; CHEN Cai-hong; GAO Guo-qing

    2013-01-01

    Introgression line population is effectively used in mapping quantitative trait loci (QTLs),identifying favorable genes,discovering hidden genetic variation,evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research.In this study,an advanced backcross and consecutive selfing strategy was used to develop introgression lines (ILs),which derived from an accession of Oryza minuta (accession No.101133) with BBCC genome,as the donor,and an elite indica cultivar IR24 (O.sativa),as the recipient.Introgression segments from O.minuta were screened using 164 polymorphic simple sequence repeat (SSR) markers in the genome of each IL.Introgressed segments carried by 131 ILs covered the whole O.sativa genome.The average number of homozygous O.minuta segments per introgression line was about 9.99.The average length of introgressed segments was approximate 14.78 cM,and about 79.64%of these segments had sizes less than 20 cM.In the genome of each introgression line,the O.minuta chromosomal segments harbored chromosomal fragments of O.sativa ranging from 1.15% to 27.6%,with an overall average of 8.57%.At each locus,the ratio of substitution of O.minuta alleles had a range of 1.5%-25.2%,with an average of 8.3% Based on the evaluation of the phenotype of these ILs,a wide range of alterations in morphological and yield-related traits were found.After inoculation,ILs 41,11 and 7 showed high resistance to bacterial blight,brown planthopper and whitebacked planthopper,respectively.These O.minuta-O.sativa ILs will serve as genetic materials for identifying and using favorable genes from O.minuta.

  4. Non-smooth plant disease models with economic thresholds.

    Science.gov (United States)

    Zhao, Tingting; Xiao, Yanni; Smith, Robert J

    2013-01-01

    In order to control plant diseases and eventually maintain the number of infected plants below an economic threshold, a specific management strategy called the threshold policy is proposed, resulting in Filippov systems. These are a class of piecewise smooth systems of differential equations with a discontinuous right-hand side. The aim of this work is to investigate the global dynamic behavior including sliding dynamics of one Filippov plant disease model with cultural control strategy. We examine a Lotka-Volterra Filippov plant disease model with proportional planting rate, which is globally studied in terms of five types of equilibria. For one type of equilibrium, the global structure is discussed by the iterative equations for initial numbers of plants. For the other four types of equilibria, the bounded global attractor of each type is obtained by constructing appropriate Lyapunov functions. The ideas of constructing Lyapunov functions for Filippov systems, the methods of analyzing such systems and the main results presented here provide scientific support for completing control regimens on plant diseases in integrated disease management. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Steady-state plant model to predict hydrogen levels in power plant components

    Science.gov (United States)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    2017-06-01

    The National Renewable Energy Laboratory (NREL) and Acciona Energy North America developed a full-plant steady-state computational model that estimates levels of hydrogen in parabolic trough power plant components. The model estimated dissolved hydrogen concentrations in the circulating heat transfer fluid (HTF), and corresponding partial pressures within each component. Additionally for collector field receivers, the model estimated hydrogen pressure in the receiver annuli. The model was developed to estimate long-term equilibrium hydrogen levels in power plant components, and to predict the benefit of hydrogen mitigation strategies for commercial power plants. Specifically, the model predicted reductions in hydrogen levels within the circulating HTF that result from purging hydrogen from the power plant expansion tanks at a specified target rate. Our model predicted hydrogen partial pressures from 8.3 mbar to 9.6 mbar in the power plant components when no mitigation treatment was employed at the expansion tanks. Hydrogen pressures in the receiver annuli were 8.3 to 8.4 mbar. When hydrogen partial pressure was reduced to 0.001 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.001 mbar to 0.02 mbar. When hydrogen partial pressure was reduced to 0.3 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.25 mbar to 0.28 mbar. Our results show that controlling hydrogen partial pressure in the expansion tanks allows us to reduce and maintain hydrogen pressures in the receiver annuli to any practical level.

  6. Steady-State Plant Model to Predict Hydroden Levels in Power Plant Components

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    2017-06-27

    The National Renewable Energy Laboratory (NREL) and Acciona Energy North America developed a full-plant steady-state computational model that estimates levels of hydrogen in parabolic trough power plant components. The model estimated dissolved hydrogen concentrations in the circulating heat transfer fluid (HTF), and corresponding partial pressures within each component. Additionally for collector field receivers, the model estimated hydrogen pressure in the receiver annuli. The model was developed to estimate long-term equilibrium hydrogen levels in power plant components, and to predict the benefit of hydrogen mitigation strategies for commercial power plants. Specifically, the model predicted reductions in hydrogen levels within the circulating HTF that result from purging hydrogen from the power plant expansion tanks at a specified target rate. Our model predicted hydrogen partial pressures from 8.3 mbar to 9.6 mbar in the power plant components when no mitigation treatment was employed at the expansion tanks. Hydrogen pressures in the receiver annuli were 8.3 to 8.4 mbar. When hydrogen partial pressure was reduced to 0.001 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.001 mbar to 0.02 mbar. When hydrogen partial pressure was reduced to 0.3 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.25 mbar to 0.28 mbar. Our results show that controlling hydrogen partial pressure in the expansion tanks allows us to reduce and maintain hydrogen pressures in the receiver annuli to any practical level.

  7. Rhizopus Soft Rot on Lily Caused by Rhizopus oryzae in Korea

    Directory of Open Access Journals (Sweden)

    Soo-Sang Hahm

    2014-03-01

    Full Text Available Rhizopus soft rot of lily (Lilium longiflorum caused by Rhizopus oryzae was observed in the experimental field in Taean Lily Experiment Station in Korea, 2012. The typical symptoms were water-soaked lesions on bottom stem and leaf rot. The lesion rapidly expanded and the plant was softened totally. The fungus grew vigorously at an optimum temperature (25oC and brownish colony and black sporangia were formed on potato dextrose agar medium. Sporangiophores formed on end of sporangia were sub-globose, brownish and 6-10 μm in size. Sporangia were globose, blackish and 87-116 μm in size. Sporangiospores were irregularly oval and sub-globose, brownish 4-8 μm in size. On the basis of mycological characteristics, analyzing sequences of internal transcribed spacer region of ribosomal DNA, and pathogenicity test on host plants, the causal fungus was identified as R. oryzae. This is the first report of Rhizopus soft rot on lily caused by R. oryzae in Korea.

  8. Model-based plant-wide optimization of large-scale lignocellulosic bioethanol plants

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Blanke, Mogens; Jakobsen, Jon Geest

    2017-01-01

    with respect to maximum economic profit of a large scale biorefinery plant using a systematic model-based plantwide optimization methodology. The following key process parameters are identified as decision variables: pretreatment temperature, enzyme dosage in enzymatic hydrolysis, and yeast loading per batch...... in fermentation. The plant is treated in an integrated manner taking into account the interactions and trade-offs between the conversion steps. A sensitivity and uncertainty analysis follows at the optimal solution considering both model and feed parameters. It is found that the optimal point is more sensitive...

  9. Aggregated wind power plant models consisting of IEC wind turbine models

    DEFF Research Database (Denmark)

    Altin, Müfit; Göksu, Ömer; Hansen, Anca Daniela

    2015-01-01

    turbines, parameters and models to represent each individual wind turbine in detail makes it necessary to develop aggregated wind power plant models considering the simulation time for power system stability studies. In this paper, aggregated wind power plant models consisting of the IEC 61400-27 variable...

  10. Growth deficiency of a Xanthomonas oryzae pv. oryzae fur mutant in rice leaves is rescued by ascorbic acid supplementation.

    Science.gov (United States)

    Subramoni, Sujatha; Sonti, Ramesh V

    2005-07-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. A mutation was isolated in the ferric uptake regulator (fur) gene of X. oryzae pv. oryzae and it was shown to result in the production of siderophores in a constitutive manner. The fur mutant is hypersensitive to the metallo-antibiotic streptonigrin, a phenotype that is indicative of intracellular free-iron overload, and also exhibits a slow growth phenotype on rich medium. The fur mutant is virulence deficient, hypersensitive to hydrogen peroxide, and exhibits reduced catalase activity. Exogenous supplementation with ascorbic acid (an antioxidant) rescues the growth deficiency of the fur mutant in rice leaves. The virulence deficiency of the X. oryzae pv. oryzae fur mutant is proposed to be due, at least in part, to an impaired ability to cope with the oxidative stress conditions that are encountered during infection.

  11. Simulation model for plant growth in controlled environment systems

    Science.gov (United States)

    Raper, C. D., Jr.; Wann, M.

    1986-01-01

    The role of the mathematical model is to relate the individual processes to environmental conditions and the behavior of the whole plant. Using the controlled-environment facilities of the phytotron at North Carolina State University for experimentation at the whole-plant level and methods for handling complex models, researchers developed a plant growth model to describe the relationships between hierarchial levels of the crop production system. The fundamental processes that are considered are: (1) interception of photosynthetically active radiation by leaves, (2) absorption of photosynthetically active radiation, (3) photosynthetic transformation of absorbed radiation into chemical energy of carbon bonding in solube carbohydrates in the leaves, (4) translocation between carbohydrate pools in leaves, stems, and roots, (5) flow of energy from carbohydrate pools for respiration, (6) flow from carbohydrate pools for growth, and (7) aging of tissues. These processes are described at the level of organ structure and of elementary function processes. The driving variables of incident photosynthetically active radiation and ambient temperature as inputs pertain to characterization at the whole-plant level. The output of the model is accumulated dry matter partitioned among leaves, stems, and roots; thus, the elementary processes clearly operate under the constraints of the plant structure which is itself the output of the model.

  12. Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    B. Wayne Bequette; Priyadarshi Mahapatra

    2010-08-31

    The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

  13. Expression and characterization of recombinant Rhizopus oryzae lipase for enzymatic biodiesel production.

    Science.gov (United States)

    Li, Zhilin; Li, Xun; Wang, Ye; Wang, Youdong; Wang, Fei; Jiang, Jianchun

    2011-10-01

    The Rhizopus oryzae lipase containing prosequence was expressed in Pichia pastoris. Recombinant lipase subunit showed a molecular mass of 32 kDa. The maximum activity of recombinant lipase obtained from Mut(s) recombinant was 90 IU/ml. The enzyme was stable in broad ranges of temperatures and pH, with the optimal temperature at 35 °C and pH 7.0. The crude recombinant R. oryzae lipase can be directly used for the transesterification of plant oils at high-water content of 60-100% (w/w) based on oil weight. The addition of 80% water to the transesterification systems resulted in the yield of methyl ester of 95%, 94% and 92% after 72 h using soybean oil, Jatropha curcas seed raw oil and Pistacia chinensis seed raw oil as raw material, respectively. These results indicate that the recombinant lipase is an effective biocatalyst for enzymatic biodiesel production.

  14. Ectopic expression of PgRab7 in rice plants (Oryza sativa L.) results in differential tolerance at the vegetative and seed setting stage during salinity and drought stress.

    Science.gov (United States)

    Tripathy, Manas Kumar; Tiwari, Budhi Sagar; Reddy, Malireddy K; Deswal, Renu; Sopory, Sudhir K

    2017-01-01

    In this work, we have overexpressed a vesicle trafficking protein, Rab7, from a stress-tolerant plant, Pennisetum glaucum, in a high-yielding but stress-sensitive rice variety Pusa Basmati-1 (PB-1). The transgenic rice plants were tested for tolerance against salinity and drought stress. The transgenic plants showed considerable tolerance at the vegetative stage against both salinity (200 mM NaCl) and drought stress (up to 12 days after withdrawing water). The protection against salt and drought stress may be by regulating Na(+) ion homeostasis, as the transgenic plants showed altered expression of multiple transporter genes, including OsNHX1, OsNHX2, OsSOS1, OsVHA, and OsGLRs. In addition, decreased generation and maintenance of lesser reactive oxygen species (ROS), with maintenance of chloroplast grana and photosynthetic machinery was observed. When evaluated for reproductive growth, 89-96 % of seed setting was maintained in transgenic plants during drought stress; however, under salt stress, a 33-53 % decrease in seed setting was observed. These results indicate that PgRab7 overexpression in rice confers differential tolerance at the seed setting stage during salinity and drought stress and could be a favored target for raising drought-tolerant crops.

  15. [Invasive maxilar sinusitis by Rhizopus oryzae].

    Science.gov (United States)

    Perea, S; del Palacio, A; Gil, R; de la Serna, J; Mata, R; Arribi, A

    1997-12-01

    We herein present a diabetic with non Hodgkin lymphoma patient that had been treated with steroids and developed fungal invasive sinusitis. The patient had intensive facial pain that did not respond to antibiotics and on clinical inspection had a necrotic lesion on right nasal area. A smear and biopsy tissue showed broad non septate hyphae and on cultures Rhizopus oryzae was isolated. There was an unfavorable outcome, and the patient died even though liposomal Amphotericin B was administered and surgical treatment was performed.

  16. Study on seed germination of Oryza rufipogon

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Oryza rufipogon, distributed in tropical and subtropical regions is an important germplasm for rice breeding. Dongxiang (28°14′N, 116°36′E) is the northernmost area of this species recorded in the world, and Chaling (26°50′N, 113°40′E) is near to the northern range limit. Seed dormancy commonly exists in O. rufipogon seeds.

  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

    Directory of Open Access Journals (Sweden)

    Wilson Ferreira de Oliveira

    2007-09-01

    Full Text Available

    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.

    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.

  18. Comparative Analysis on Genomes from Oryza alta and Oryza latifolia by C0t-1 DNA

    Institute of Scientific and Technical Information of China (English)

    WANG De-bin; WANG Yang; WU Qi; ZHAO Hou-ming; LI Gang; QIN Rui; WANG Chun-tai; LIU Hong

    2010-01-01

    In order to reveal the origin and evolutionary relationship between two CCDD genome species, Oryza alta and Oryza latifolia, fluorescence in situ hybridization (FISH) was adopted to analyze the genomes of the two species with C0t-1 DNA from O. alta as a probe. Karyotype was also comparatively analyzed between O. alta and O. latifolia based on their similar band patterns of the hybridization signals. There were a high homology and close relationship between O. alta and O. latifolia, however, the distinction between the hybridization signals was also clear. C0t-1 DNA was proved to be species- and genome type-specific. It is suggested that C0t-1 DNA-FISH could be more efficient to analyze the genomic relationship between different species. According to the comparative analysis of highly and moderately repetitive DNA sequences between the two allotetraploidy species, O. alta and O. latifolia, the possible origin and evolutionary mechanism of allotetraploidy of Oryza were discussed.

  19. How Plant Hydraulics can Improve the Modeling of Plant and Ecosystem Responses to Environment

    Science.gov (United States)

    Sperry, J.; Anderegg, W.; Mackay, D. S.; Venturas, M.

    2016-12-01

    Stomatal regulation is an important, yet problematic component in modeling plant-environment interactions. The problem is that stomata respond to so many environmental cues via complex and uncertain mechanisms. But the assumed end result of regulation is conceptually simple: an optimization of CO2 for H2O exchange in response to changing conditions. Stomata open when photosynthetic opportunity is high and water is cheap. They close if photosynthetic opportunity is low or water is very expensive. Photosynthetic opportunity is relatively easy to model. The cost of water loss is also easy to model if it is assumed to rise with greater proximity to hydraulic failure and desiccation. Unsaturated hydraulic conductivity curves of soil- and plant are used to estimate proximity to failure. At any given instant, a model can calculate opportunity and cost curves associated with greater stomatal opening. If stomata regulate to maximize the instantaneous difference between photosynthetic gain and hydraulic cost, then a model can predict the trajectory of stomatal responses to changes in environment across time. Results of this optimization routine extend the utility of hydraulic predecessor models, and are consistent with widely used empirical models across a wide range of vapor pressure deficit and ambient CO2 concentrations for wet soil. The advantage of the optimization approach is the absence of empirical coefficients, applicability to dry as well as wet soil, and prediction of plant hydraulic status along with gas exchange. The optimization algorithm is a trait- and process-based approach that could improve next generation land surface models.

  20. Bioconversion of Capsaicin by Aspergillus oryzae.

    Science.gov (United States)

    Lee, Minji; Cho, Jeong-Yong; Lee, Yu Geon; Lee, Hyoung Jae; Lim, Seong-Il; Park, So-Lim; Moon, Jae-Hak

    2015-07-08

    This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.

  1. Spectral response of rice(Oryza sativa L.) leaves to Fe2+ stress

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the management of lake eutrophication,the regulation effect of Fe is considered,in addition to the controlling nitrogen-and phosphorus input.Based on the "Fe hypothesis",this paper tentatively applied plant spectral response to the remote sensing early-warning mechanism of lake eutrophication.A laboratory water culture experiment with rice(Oryza sativa L.) was conducted to study Fe uptake by plants and the chlorophyll concentration and visible-near infrared spectrum of vegetable leaves as well as their interrelations under Fe2+ stress.Three spectral indices,i.e.,A1(integral value of the changes of spectral reflectivity in the range 460―670 nm under Fe2+ stress),A2(integral value of the changes of spectral reflectivity in the range of 760―1000 nm under Fe2+ stress) and S(blue-shift range of red edge curve under Fe2+ stress),were used to establish quantitative models about the relationships between the rice leaf spectrum and Fe2+ stress.With the increase of Fe2+ in a culture solution,the Fe content in rice plants increased,while the chlorophyll concentration in vegetative leaves decreased.The spectral reflectivity of vegetable leaves increased in the visible light band but decreased in the near infrared band,and the blue-shift range of the red edge curve increased.The indices A1,A2 and S all had significant correlations with the Fe content in rice leaves,the correlation coefficient being respectively 0.951(P < 0.01),?0.988(P < 0.01) and 0.851(P < 0.01),and simulated(multiple correlation coefficients R2 > 0.96) and predict the Fe level in rice leaves.

  2. 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.

  3. Gasification CFD Modeling for Advanced Power Plant Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zitney, S.E.; Guenther, C.P.

    2005-09-01

    In this paper we have described recent progress on developing CFD models for two commercial-scale gasifiers, including a two-stage, coal slurry-fed, oxygen-blown, pressurized, entrained-flow gasifier and a scaled-up design of the PSDF transport gasifier. Also highlighted was NETL’s Advanced Process Engineering Co-Simulator for coupling high-fidelity equipment models with process simulation for the design, analysis, and optimization of advanced power plants. Using APECS, we have coupled the entrained-flow gasifier CFD model into a coal-fired, gasification-based FutureGen power and hydrogen production plant. The results for the FutureGen co-simulation illustrate how the APECS technology can help engineers better understand and optimize gasifier fluid dynamics and related phenomena that impact overall power plant performance.

  4. Incorporating Plant Phenology Dynamics in a Biophysical Canopy Model

    Science.gov (United States)

    Barata, Raquel A.; Drewry, Darren

    2012-01-01

    The Multi-Layer Canopy Model (MLCan) is a vegetation model created to capture plant responses to environmental change. Themodel vertically resolves carbon uptake, water vapor and energy exchange at each canopy level by coupling photosynthesis, stomatal conductance and leaf energy balance. The model is forced by incoming shortwave and longwave radiation, as well as near-surface meteorological conditions. The original formulation of MLCan utilized canopy structural traits derived from observations. This project aims to incorporate a plant phenology scheme within MLCan allowing these structural traits to vary dynamically. In the plant phenology scheme implemented here, plant growth is dependent on environmental conditions such as air temperature and soil moisture. The scheme includes functionality that models plant germination, growth, and senescence. These growth stages dictate the variation in six different vegetative carbon pools: storage, leaves, stem, coarse roots, fine roots, and reproductive. The magnitudes of these carbon pools determine land surface parameters such as leaf area index, canopy height, rooting depth and root water uptake capacity. Coupling this phenology scheme with MLCan allows for a more flexible representation of the structure and function of vegetation as it responds to changing environmental conditions.

  5. Bypassing both surface attachment and surface recognition requirements for appressorium formation by overactive ras signaling in Magnaporthe oryzae.

    Science.gov (United States)

    Zhou, Xiaoying; Zhao, Xinhua; Xue, Chaoyang; Dai, Yafeng; Xu, Jin-Rong

    2014-09-01

    Magnaporthe oryzae forms a highly specialized infection structure called an appressorium for plant penetration. In M. oryzae and many other plant-pathogenic fungi, surface attachment and surface recognition are two essential requirements for appressorium formation. Development of appressoria in the air has not been reported. In this study, we found that expression of a dominant active MoRAS2(G18V) allele in M. oryzae resulted in the formation of morphologically abnormal appressoria on nonconducive surfaces, in liquid suspensions, and on aerial hyphae without attachment to hard surfaces. Both the Pmk1 mitogen-activated protein kinase cascade and cAMP signaling pathways that regulate surface recognition and appressorium morphogenesis in M. oryzae were overactivated in the MoRAS2(G18V) transformant. In mutants deleted of PMK1 or CPKA, expression of MoRAS2(G18V) had no significant effects on appressorium morphogenesis. Furthermore, expression of dominant MoRAS2 in Colletotrichum graminicola and C. gloeosporioides also caused the formation of appressorium-like structures in aerial hyphae. Overall, our data indicate that MoRas2 functions upstream from both the cAMP-PKA and Pmk1 pathways and overactive Ras signaling leads to improper activation of these two pathways and appressorium formation without surface attachment in appressorium-forming pathogens.

  6. Chemotaxis signaling systems in model beneficial plant-bacteria associations.

    Science.gov (United States)

    Scharf, Birgit E; Hynes, Michael F; Alexandre, Gladys M

    2016-04-01

    Beneficial plant-microbe associations play critical roles in plant health. Bacterial chemotaxis provides a competitive advantage to motile flagellated bacteria in colonization of plant root surfaces, which is a prerequisite for the establishment of beneficial associations. Chemotaxis signaling enables motile soil bacteria to sense and respond to gradients of chemical compounds released by plant roots. This process allows bacteria to actively swim towards plant roots and is thus critical for competitive root surface colonization. The complete genome sequences of several plant-associated bacterial species indicate the presence of multiple chemotaxis systems and a large number of chemoreceptors. Further, most soil bacteria are motile and capable of chemotaxis, and chemotaxis-encoding genes are enriched in the bacteria found in the rhizosphere compared to the bulk soil. This review compares the architecture and diversity of chemotaxis signaling systems in model beneficial plant-associated bacteria and discusses their relevance to the rhizosphere lifestyle. While it is unclear how controlling chemotaxis via multiple parallel chemotaxis systems provides a competitive advantage to certain bacterial species, the presence of a larger number of chemoreceptors is likely to contribute to the ability of motile bacteria to survive in the soil and to compete for root surface colonization.

  7. Applying Functional Modeling for Accident Management of Nucler Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2014-01-01

    The paper investigates applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow...... for information sharing and decision support in accidents beyond design basis is also indicated. A modelling example demonstrating the application of Multilevel Flow Modelling and reasoning for a PWR LOCA is presented....

  8. Predicting plants -modeling traits as a function of environment

    Science.gov (United States)

    Franklin, Oskar

    2016-04-01

    A central problem in understanding and modeling vegetation dynamics is how to represent the variation in plant properties and function across different environments. Addressing this problem there is a strong trend towards trait-based approaches, where vegetation properties are functions of the distributions of functional traits rather than of species. Recently there has been enormous progress in in quantifying trait variability and its drivers and effects (Van Bodegom et al. 2012; Adier et al. 2014; Kunstler et al. 2015) based on wide ranging datasets on a small number of easily measured traits, such as specific leaf area (SLA), wood density and maximum plant height. However, plant function depends on many other traits and while the commonly measured trait data are valuable, they are not sufficient for driving predictive and mechanistic models of vegetation dynamics -especially under novel climate or management conditions. For this purpose we need a model to predict functional traits, also those not easily measured, and how they depend on the plants' environment. Here I present such a mechanistic model based on fitness concepts and focused on traits related to water and light limitation of trees, including: wood density, drought response, allocation to defense, and leaf traits. The model is able to predict observed patterns of variability in these traits in relation to growth and mortality, and their responses to a gradient of water limitation. The results demonstrate that it is possible to mechanistically predict plant traits as a function of the environment based on an eco-physiological model of plant fitness. References Adier, P.B., Salguero-Gómez, R., Compagnoni, A., Hsu, J.S., Ray-Mukherjee, J., Mbeau-Ache, C. et al. (2014). Functional traits explain variation in plant lifehistory strategies. Proc. Natl. Acad. Sci. U. S. A., 111, 740-745. Kunstler, G., Falster, D., Coomes, D.A., Hui, F., Kooyman, R.M., Laughlin, D.C. et al. (2015). Plant functional traits

  9. Tecnomatix Plant Simulation modeling and programming by means of examples

    CERN Document Server

    Bangsow, Steffen

    2015-01-01

    This book systematically introduces the development of simulation models as well as the implementation and evaluation of simulation experiments with Tecnomatix Plant Simulation. It deals with all users of Plant Simulation, who have more complex tasks to handle. It also looks for an easy entry into the program. Particular attention has been paid to introduce the simulation flow language SimTalk and its use in various areas of the simulation. The author demonstrates with over 200 examples how to combine the blocks for simulation models and how to deal with SimTalk for complex control and analys

  10. Dynamic Models for Wind Turbines and Wind Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M.; Santoso, S.

    2011-10-01

    The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

  11. Genomic analysis of the basal lineage fungus Rhizopus oryzae reveals a whole-genome duplication.

    Directory of Open Access Journals (Sweden)

    Li-Jun Ma

    2009-07-01

    Full Text Available Rhizopus oryzae is the primary cause of mucormycosis, an emerging, life-threatening infection characterized by rapid angioinvasive growth with an overall mortality rate that exceeds 50%. As a representative of the paraphyletic basal group of the fungal kingdom called "zygomycetes," R. oryzae is also used as a model to study fungal evolution. Here we report the genome sequence of R. oryzae strain 99-880, isolated from a fatal case of mucormycosis. The highly repetitive 45.3 Mb genome assembly contains abundant transposable elements (TEs, comprising approximately 20% of the genome. We predicted 13,895 protein-coding genes not overlapping TEs, many of which are paralogous gene pairs. The order and genomic arrangement of the duplicated gene pairs and their common phylogenetic origin provide evidence for an ancestral whole-genome duplication (WGD event. The WGD resulted in the duplication of nearly all subunits of the protein complexes associated with respiratory electron transport chains, the V-ATPase, and the ubiquitin-proteasome systems. The WGD, together with recent gene duplications, resulted in the expansion of multiple gene families related to cell growth and signal transduction, as well as secreted aspartic protease and subtilase protein families, which are known fungal virulence factors. The duplication of the ergosterol biosynthetic pathway, especially the major azole target, lanosterol 14alpha-demethylase (ERG11, could contribute to the variable responses of R. oryzae to different azole drugs, including voriconazole and posaconazole. Expanded families of cell-wall synthesis enzymes, essential for fungal cell integrity but absent in mammalian hosts, reveal potential targets for novel and R. oryzae-specific diagnostic and therapeutic treatments.

  12. Cadmium phytoavailability to rice (Oryza sativa L.) grown in representative Chinese soils. A model to improve soil environmental quality guidelines for food safety.

    Science.gov (United States)

    Rafiq, Muhammad T; Aziz, Rukhsanda; Yang, Xiaoe; Xiao, Wendan; Rafiq, Muhammad K; Ali, Basharat; Li, Tingqiang

    2014-05-01

    Food chain contamination by cadmium (Cd) is globally a serious health concern resulting in chronic abnormalities. Rice is a major staple food of the majority world population, therefore, it is imperative to understand the relationship between the bioavailability of Cd in soils and its accumulation in rice grain. Objectives of this study were to establish environment quality standards for seven different textured soils based on human dietary toxicity, total Cd content in soils and bioavailable portion of Cd in soil. Cadmium concentrations in polished rice grain were best related to total Cd content in Mollisols and Udic Ferrisols with threshold levels of 0.77 and 0.32mgkg(-1), respectively. Contrastingly, Mehlich-3-extractable Cd thresholds were more suitable for Calcaric Regosols, Stagnic Anthrosols, Ustic Cambosols, Typic Haplustalfs and Periudic Argosols with thresholds values of 0.36, 0.22, 0.17, 0.08 and 0.03mgkg(-1), respectively. Stepwise multiple regression analysis indicated that phytoavailability of Cd to rice grain was strongly correlated with Mehlich-3-extractable Cd and soil pH. The empirical model developed in this study explains the combined effects of soil properties and extractable soil Cd content on the phytoavailability of Cd to polished rice grain. This study indicates that accumulation of Cd in rice is influenced greatly by soil type, which should be considered in assessment of soil safety for Cd contamination in rice. This investigation concluded that the selection of proper soil type for food crop production can help us to avoid the toxicity of Cd in our daily diet.

  13. A Multiscale Mechanical Model for Plant Tissue Stiffness

    Directory of Open Access Journals (Sweden)

    Damiano Pasini

    2013-06-01

    Full Text Available Plant petioles and stems are hierarchical cellular structures, displaying structuralfeatures defined at multiple length scales. The current work focuses on the multi-scalemodelling of plant tissue, considering two orders of structural hierarchy, cell wall and tissue.The stiffness of plant tissue is largely governed by the geometry of the tissue cells, thecomposition of the cell wall and the structural properties of its constituents. The cell wallis analogous to a fiber reinforced composite, where the cellulose microfibril (CMF is theload bearing component. For multilayered cell wall, the microfibril angle (MFA in themiddle layer of the secondary cell wall (S2 layer largely affects the longitudinal stiffnessfor values up to 40o. The MFA in turn influences the overall wall stiffness. In this work,the effective stiffness of a model system based on collenchyma cell wall of a dicotyledonousplant, the Rheum rhabarbarum, is computed considering generic MFA and volume fractions.At the cellular level, a 2-D Finite Edge Centroidal Voronoi tessellation (FECVT has beendeveloped and implemented to generate the non-periodic microstructure of the plant tissue.The effective elastic properties of the cellular tissue are obtained through finite elementanalysis (FEA of the Voronoi model coupled with the cell wall properties. The stiffness ofthe hierarchically modeled tissue is critically important in determining the overall structuralproperties of plant petioles and stems.

  14. Simulation of wastewater treatment plant within integrated urban wastewater models.

    Science.gov (United States)

    Heusch, S; Kamradt, B; Ostrowski, M

    2010-01-01

    In the federal state of Hesse in Germany the application of an integrated software modelling framework is becoming part of the planning process to attain legal approval for the operation of combined sewer systems. The software allows for parallel simulation of flow and water quality routing in the sewer system and in receiving rivers. It combines existing pollution load model approaches with a simplified version of the River Water Quality Model No. 1 (RWQM1). Comprehensive simulation of the wastewater treatment plant (WWTP) is not considered yet. The paper analyses alternatives for the implementation of a WWTP module to model activated sludge plants. For both primary and secondary clarifiers as well as for the activated sludge process concepts for the integration into the existing software framework were developed. The activated sludge concept which uses a linearized version of the well known ASM1 model is presented in detail.

  15. New model concepts for dynamic plant uptake and mass flux estimates in the soil-plant-air system

    DEFF Research Database (Denmark)

    Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan

    2010-01-01

    Plants significantly influence contaminant transport and fate. Important processes are uptake of soil and groundwater contaminants, as well as biodegradation in plants and their root zones. Models for the prediction of chemical uptake into plants are required for the setup of mass balances...... in environmental systems at different scales. Feedback mechanisms between plants and hydrological systems can play an important role. However, they have received little attention to date. Here, a new model concept for dynamic plant uptake models applying analytical matrix solutions is presented, which can...... be coupled to groundwater transport simulation tools. Exemplary simulations of plant uptake were carried out in order to estimate chemical concentrations in the soil-plant-air system and the influence of plants on contaminant mass fluxes from soil to groundwater....

  16. Computational Identification of Novel Family Members of MicroRNA Genes in Arabidopsis thaliana and Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    Yang LI; Wei LI; You-Xin JIN

    2005-01-01

    MicroRNAs (miRNAs) are a class of endogenous small RNAs that play important regulatory roles in both animals and plants, miRNA genes have been intensively studied in animals, but not in plants. In this study, we adopted a homology search approach to identify homologs of previously validated plant miRNAs in Arabidopsis thaliana and Oryza sativa. We identified 20 potential miRNA genes in Arabidopsis and 40 in O. sativa, providing a relatively complete enumeration of family members for these miRNAs in plants. In addition, a greater number ofArabidopsis miRNAs (MIR168, MIR159 and MIR172) were found to be conserved in rice. With the novel homologs, most of the miRNAs have closely related fellow miRNAs and the number of paralogs varies in the different miRNA families. Moreover, a probable functional segment highly conserved on the elongated stem of pre-miRNA fold-backs of MIR319 and MIR 159 family was identified. These results support a model of variegated miRNA regulation in plants, in which miRNAs with different functional elements on their pre-miRNA fold-backs can differ in their function or regulation, and closely related miRNAs can be diverse in their specificity or competence to downregulate target genes. It appears that the sophisticated regulation of miRNAs can achieve complex biological effects through qualitative and quantitative modulation of gene expression profiles in plants.

  17. Plants as model in biomimetics and biorobotics: new perspectives.

    Science.gov (United States)

    Mazzolai, Barbara; Beccai, Lucia; Mattoli, Virgilio

    2014-01-01

    Especially in robotics, rarely plants have been considered as a model of inspiration for designing and developing new technology. This is probably due to their radically different operational principles compared to animals and the difficulty to study their movements and features. Owing to the sessile nature of their lifestyle, plants have evolved the capability to respond to a wide range of signals and efficiently adapt to changing environmental conditions. Plants in fact are able to show considerable plasticity in their morphology and physiology in response to variability within their environment. This results in movements that are characterized by energy efficiency and high density. Plant materials are optimized to reduce energy consumption during motion and these capabilities offer a plethora of solutions in the artificial world, exploiting approaches that are muscle-free and thus not necessarily animal-like. Plant roots then are excellent natural diggers, and their characteristics such as adaptive growth, low energy consumption movements, and the capability of penetrating soil at any angle are interesting from an engineering perspective. A few examples are described to lay the perspectives of plants in the artificial world.

  18. Plants as model in biomimetics and biorobotics: New perspectives

    Directory of Open Access Journals (Sweden)

    Barbara eMazzolai

    2014-01-01

    Full Text Available Especially in robotics, rarely plants have been considered as a model of inspiration for designing and developing new technology. This is probably due to their radically different operational principles compared to animals and the difficulty to study their movements and features. Owing to the sessile nature of their lifestyle, plants have evolved the capability to respond to a wide range of signals and efficiently adapt to changing environmental conditions. Plants in fact are able to show considerable plasticity in their morphology and physiology in response to variability within their environment. This results in movements that are characterized by energy efficiency and high density. Plant materials are optimized to reduce energy consumption during motion and these capabilities offer a plethora of solutions in the artificial world, exploiting approaches that are muscle-free and thus not necessarily animal-like. Plant roots then are excellent natural diggers, and their characteristics such as adaptive growth, low energy consumption movements, and the capability of penetrating soil at any angle are interesting from an engineering perspective. A few examples are described to lay the perspectives of plants in the artificial world.

  19. Representing plants as rigid cylinders in experiments and models

    Science.gov (United States)

    Vargas-Luna, Andrés; Crosato, Alessandra; Calvani, Giulio; Uijttewaal, Wim S. J.

    2016-07-01

    Simulating the morphological adaptation of water systems often requires including the effects of plants on water and sediment dynamics. Physical and numerical models need representing vegetation in a schematic easily-quantifiable way despite the variety of sizes, shapes and flexibility of real plants. Common approaches represent plants as rigid cylinders, but the ability of these schematizations to reproduce the effects of vegetation on morphodynamic processes has never been analyzed systematically. This work focuses on the consequences of representing plants as rigid cylinders in laboratory tests and numerical simulations. New experiments show that the flow resistance decreases for increasing element Reynolds numbers for both plants and rigid cylinders. Cylinders on river banks can qualitatively reproduce vegetation effects on channel width and bank-related processes. A comparative review of numerical simulations shows that Baptist's method that sums the contribution of bed shear stress and vegetation drag, underestimates bed erosion within sparse vegetation in real rivers and overestimates the mean flow velocity in laboratory experiments. This is due to assuming uniform flow among plants and to an overestimation of the role of the submergence ratio.

  20. 4Mx Soil-Plant Model: Applications, Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Nándor Fodor

    2012-12-01

    Full Text Available Crop simulation models describe the main processes of the soil-plant system in a dynamic way usually in a daily time-step. With the help of these models we may monitor the soil- and plant-related processes of the simulated system as they evolve according to the atmospheric and environmental conditions. Crop models could be successfully applied in the following areas: (1 Education: by promoting the system-oriented thinking a comprehensive overview of the interrelations of the soil-plant system as well as of the environmental protection related aspects of the human activities could be presented. (2 Research: The results of observations as well as of experiments could be extrapolated in time and space, thus, for example, the possible effects of the global climate change could be estimated. (3 Practice: Model calculations could be used in intelligent irrigation control and decision supporting systems as well as for providing scientific background for policy makers. The most spectacular feature of the 4Mx crop model is that its graphical user interface enables the user to alter not only the parameters of the model but the function types of its governing equations as well. The applicability of the 4Mx model is presented via several case-studies.

  1. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties.

    Science.gov (United States)

    Heuer, Sigrid; Miézan, Kouamé M

    2003-09-01

    Interspecific crossing of the African indigenous rice Oryza glaberrima with Oryza sativa cultivars is hindered by crossing barriers causing 100% spikelet sterility in F(1) hybrids. Since hybrids are partially female fertile, fertility can be restored by back crossing (BC) to a recurrent male parent. Distinct genetic models on spikelet sterility have been developed predicting, e.g., the existence of a gamete eliminator and/or a pollen killer. Linkage of sterility to the waxy starch synthase gene and the chromogen gene C, both located on chromosome 6, have been demonstrated. We selected a segregating BC(2)F(3) population of semi-sterile O. glaberrima x O. sativa indica hybrid progenies for analyses with PCR markers located at the respective chromosome-6 region. These analyses revealed that semi-sterile plants were heterozygous for a marker (OSR25) located in the waxy promoter, whereas fertile progenies were homozygous for the O. glaberrima allele. Adjacent markers showed no linkage to spikelet sterility. Semi-sterility of hybrid progenies was maintained at least until the F(4) progeny generation, suggesting the existence of a pollen killer in this plant material. Monitoring of reproductive plant development showed that spikelet sterility was at least partially due to an arrest of pollen development at the microspore stage. In order to address the question whether genes responsible for F(1) sterility in intraspecific hybrids ( O. sativa indica x japonica) also cause spikelet sterility in interspecific hybrids, crossings with wide compatibility varieties (WCV) were performed. WCV accessions possess "neutral" S-loci ( S(n)) improving fertility in intraspecific hybrids. This experiment showed that the tested S(n)-loci had no fertility restoring effect in F(1) interspecific hybrids. Pollen development was completely arrested at the microspore stage and grains were never obtained after selfing. This suggests that distinct or additional S-loci are responsible for sterility

  2. Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

    DEFF Research Database (Denmark)

    Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

    2008-01-01

    This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...

  3. Gene Discovery and Functional Analyses in the Model Plant Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Cai-Ping Feng; John Mundy

    2006-01-01

    The present mini-review describes newer methods and strategies, including transposon and T-DNA insertions,TILLING, Deleteagene, and RNA interference, to functionally analyze genes of interest in the model plant Arabidopsis. The relative advantages and disadvantages of the systems are also discussed.

  4. Gene Discovery and Functional Analyses in the Model Plant Arabidopsis

    DEFF Research Database (Denmark)

    Feng, Cai-ping; Mundy, J.

    2006-01-01

    The present mini-review describes newer methods and strategies, including transposon and T-DNA insertions, TILLING, Deleteagene, and RNA interference, to functionally analyze genes of interest in the model plant Arabidopsis. The relative advantages and disadvantages of the systems are also...

  5. Sex determination in flowering plants: papaya as a model system.

    Science.gov (United States)

    Aryal, Rishi; Ming, Ray

    2014-03-01

    Unisexuality in flowering plants evolved from a hermaphrodite ancestor. Transition from hermaphrodite to unisexual flowers has occurred multiple times across the different lineages of the angiosperms. Sexuality in plants is regulated by genetic, epigenetic and physiological mechanisms. The most specialized mechanism of sex determination is sex chromosomes. The sex chromosomes ensure the stable segregation of sexual phenotypes by preventing the recombination of sex determining genes. Despite continuous efforts, sex determining genes of dioecious plants have not yet been cloned. Concerted efforts with various model systems are necessary to understand the complex mechanism of sex determination in plants. Papaya (Carica papaya L.) is a tropical fruit tree with three sex forms, male, hermaphrodite, and female. Sexuality in papaya is determined by an XY chromosome system that is in an early evolutionary stage. The male and hermaphrodite of papaya are controlled by two different types of Y chromosomes: Y and Y(h). Large amounts of information in the area of genetics, genomics, and epigenetics of papaya have been accumulated over the last few decades. Relatively short lifecycle, small genome size, and readily available genetic and genomic resources render papaya an excellent model system to study sex determination and sex chromosomes in flowering plants.

  6. Trichomes as models for studying plant cell differentiation.

    Science.gov (United States)

    Yang, Changxian; Ye, Zhibiao

    2013-06-01

    Trichomes, originating from epidermal cells, are present on nearly all terrestrial plants. They exist in diverse forms, are readily accessible, and serve as an excellent model system for analyzing the molecular mechanisms in plant cell differentiation, including cell fate choices, cell cycle control, and cell morphogenesis. In Arabidopsis, two regulatory models have been identified that function in parallel in trichome formation; the activator-inhibitor model and the activator-depletion model. Cotton fiber, a similar unicellular structure, is controlled by some functional homologues of Arabidopsis trichome-patterning genes. Multicellular trichomes, as in tobacco and tomato, may form through a distinct pathway from unicellular trichomes. Recent research has shown that cell cycle control participates in trichome formation. In this review, we summarize the molecular mechanisms involved in the formation of unicellular and multicellular trichomes, and discuss the integration of the cell cycle in its initiation and morphogenesis.

  7. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  8. Interaction of malathion, an organophosphorus pesticide with Rhizopus oryzae biomass

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Subhankar; Das, Sujoy K.; Chakravarty, Rajdeep; Chakrabarti, Adrita [Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Ghosh, Subrata [West Bengal Pollution Control Board, Paribesh Bhawan, Kakinara, 24 Parganas (N), PIN - 743126 (India); Guha, Arun K., E-mail: bcakg@mahendra.iacs.res.in [Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2010-02-15

    Adsorption of malathion on Rhizopus oryzae biomass (ROB) with special reference to binding mechanism has been described. ROB has been found to adsorb {approx}85% of malathion from its aqueous solution as against 47-68% by other fungal biomasses. Hydrogen ion concentration does not influence the adsorption of malathion by ROB which follows Langmuir-Freundlich dual equilibrium isotherm model (r{sup 2} = 0.998). Both physical and chemical interactions are responsible for binding of malathion on ROB. Scanning electron micrographs and EDXA spectra exhibit adsorption of the pesticide on cell surface of ROB. Studies with cell surface polysaccharides show that chitosan through its amine groups contributes largely in the adsorption of malathion. Extraction of lipids from ROB decreases its adsorption capacity to the extent of 36.37-94.02%, depending on the polarity of the solvent.

  9. Perspectives on modelling micropollutants in wastewater treatment plants

    DEFF Research Database (Denmark)

    Clouzot, Ludiwine; Cloutier, Frédéric; Vanrolleghem, Peter A.

    2013-01-01

    Models for predicting the fate of micropollutants (MPs) in wastewater treatment plants (WWTPs) have been developed to provide engineers and decision-makers with tools that they can use to improve their understanding of, and evaluate how to optimize, the removal of MPs and determine their impact......) addressing advancements in WWTP treatment technologies, (iii) making use of common approaches to data acquisition for model calibration and (iv) integrating ecotoxicological effects of MPs in receiving waters....

  10. 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.

  11. 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.

    2008-01-01

    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

  12. Dynamic plant uptake model applied for drip irrigation of an insecticide to pepper fruit plants

    DEFF Research Database (Denmark)

    Legind, Charlotte Nielsen; Kennedy, C. M.; Rein, Arno;

    2011-01-01

    irrigation, its application for a soil-applied insecticide and a sensitivity analysis of the model parameters. RESULTS: The model predicted the measured increase and decline of residues following two soil applications of an insecticide to peppers, with an absolute error between model and measurement ranging...... from 0.002 to 0.034 mg kg fw—1. Maximum measured concentrations in pepper fruit were approximately 0.22 mg kg fw—1. Temperature was the most sensitive component for predicting the peak and final concentration in pepper fruit, through its influence on soil and plant degradation rates...

  13. Signalling network construction for modelling plant defence response.

    Directory of Open Access Journals (Sweden)

    Dragana Miljkovic

    Full Text Available Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2 triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be

  14. Model parameters for representative wetland plant functional groups

    Science.gov (United States)

    Williams, Amber S.; Kiniry, James R.; Mushet, David M.; Smith, Loren M.; McMurry, Scott T.; Attebury, Kelly; Lang, Megan; McCarty, Gregory W.; Shaffer, Jill A.; Effland, William R.; Johnson, Mari-Vaughn V.

    2017-01-01

    Wetlands provide a wide variety of ecosystem services including water quality remediation, biodiversity refugia, groundwater recharge, and floodwater storage. Realistic estimation of ecosystem service benefits associated with wetlands requires reasonable simulation of the hydrology of each site and realistic simulation of the upland and wetland plant growth cycles. Objectives of this study were to quantify leaf area index (LAI), light extinction coefficient (k), and plant nitrogen (N), phosphorus (P), and potassium (K) concentrations in natural stands of representative plant species for some major plant functional groups in the United States. Functional groups in this study were based on these parameters and plant growth types to enable process-based modeling. We collected data at four locations representing some of the main wetland regions of the United States. At each site, we collected on-the-ground measurements of fraction of light intercepted, LAI, and dry matter within the 2013–2015 growing seasons. Maximum LAI and k variables showed noticeable variations among sites and years, while overall averages and functional group averages give useful estimates for multisite simulation modeling. Variation within each species gives an indication of what can be expected in such natural ecosystems. For P and K, the concentrations from highest to lowest were spikerush (Eleocharis macrostachya), reed canary grass (Phalaris arundinacea), smartweed (Polygonum spp.), cattail (Typha spp.), and hardstem bulrush (Schoenoplectus acutus). Spikerush had the highest N concentration, followed by smartweed, bulrush, reed canary grass, and then cattail. These parameters will be useful for the actual wetland species measured and for the wetland plant functional groups they represent. These parameters and the associated process-based models offer promise as valuable tools for evaluating environmental benefits of wetlands and for evaluating impacts of various agronomic practices in

  15. Plant model of KIPT neutron source facility simulator

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yan [Argonne National Lab. (ANL), Argonne, IL (United States); Wei, Thomas Y. [Argonne National Lab. (ANL), Argonne, IL (United States); Grelle, Austin L. [Argonne National Lab. (ANL), Argonne, IL (United States); Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine are collaborating on constructing a neutron source facility at KIPT, Kharkov, Ukraine. The facility has 100-kW electron beam driving a subcritical assembly (SCA). The electron beam interacts with a natural uranium target or a tungsten target to generate neutrons, and deposits its power in the target zone. The total fission power generated in SCA is about 300 kW. Two primary cooling loops are designed to remove 100-kW and 300-kW from the target zone and the SCA, respectively. A secondary cooling system is coupled with the primary cooling system to dispose of the generated heat outside the facility buildings to the atmosphere. In addition, the electron accelerator has a low efficiency for generating the electron beam, which uses another secondary cooling loop to remove the generated heat from the accelerator primary cooling loop. One of the main functions the KIPT neutron source facility is to train young nuclear specialists; therefore, ANL has developed the KIPT Neutron Source Facility Simulator for this function. In this simulator, a Plant Control System and a Plant Protection System were developed to perform proper control and to provide automatic protection against unsafe and improper operation of the facility during the steady-state and the transient states using a facility plant model. This report focuses on describing the physics of the plant model and provides several test cases to demonstrate its capabilities. The plant facility model uses the PYTHON script language. It is consistent with the computer language of the plant control system. It is easy to integrate with the simulator without an additional interface, and it is able to simulate the transients of the cooling systems with system control variables changing on real-time.

  16. Modelling energy consumption in a manufacturing plant using productivity KPIs

    Energy Technology Data Exchange (ETDEWEB)

    Gallachoir, Brian O.; Cahill, Caiman (Sustainable Energy Research Group, Dept. of Civil and Environmental Engineering, Univ. College Cork (Ireland))

    2009-07-01

    Energy efficiency initiatives in industrial plants are often focused on getting energy-consuming utilities and devices to operate more efficiently, or on conserving energy. While such device-oriented energy efficiency measures can achieve considerable savings, greater energy efficiency improvement may be achieved by improving the overall productivity and quality of manufacturing processes. The paper highlights the observed relationship between productivity and energy efficiency using aggregated data on unit consumption and production index data for Irish industry. Past studies have developed simple top-down models of final energy consumption in manufacturing plants using energy consumption and production output figures, but these models do not help identify opportunities for energy savings that could achieved through increased productivity. This paper proposes an improved and innovative method of modelling plant final energy demand that introduces standard productivity Key Performance Indicators (KPIs) into the model. The model demonstrates the relationship between energy consumption and productivity, and uses standard productivity metrics to identify the areas of manufacturing activity that offer the most potential for improved energy efficiency. The model provides a means of comparing the effect of device-oriented energy efficiency measures with the potential for improved energy efficiency through increased productivity.

  17. Genetic Analysis of a Biomass Mutant in Oryza sativa%一个水稻生物产量突变体的遗传分析

    Institute of Scientific and Technical Information of China (English)

    廖子荣; 黄东益; 牛杰; 李俏; 吴安迪

    2008-01-01

    [Objective] The study aimed to reveal the genetic model of a biomass mutant in Oryza sativa. [Method] ln the process of seresning and iden-tification of Bar-transgenic rice, a biomass mutant was found in 10 lines of TI progenies. The mutant was investigated for genetic analysis and agronomic traits by herbicide spraying and PCR amplification. [Result] The segregation ratio is consistent with mendelian law(3:1). The mutant assumed not only higher plant height, wider straw and earlier florescence, but also more tillers, bigger spikes and resuhantly higher biomass. PCR detections indicated that no co-segregation was observed between mutant traits and target gene(Bar) in the T-DNA inserted, proving that the mutant is not caused by the insertion of T-DNA containing target gene (Bar). [Conclusion] Our study may avail to understand the cloning of mutant gene and the mechanism of the mutant gene on biomass.

  18. Model-free adaptive control of advanced power plants

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  19. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  20. Model-free adaptive control of advanced power plants

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  1. Development of a plant-wide dynamic model of an integrated gasification combined cycle (IGCC) plant

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2009-01-01

    In this presentation, development of a plant-wide dynamic model of an advanced Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture will be discussed. The IGCC reference plant generates 640 MWe of net power using Illinois No.6 coal as the feed. The plant includes an entrained, downflow, General Electric Energy (GEE) gasifier with a radiant syngas cooler (RSC), a two-stage water gas shift (WGS) conversion process, and two advanced 'F' class combustion turbines partially integrated with an elevated-pressure air separation unit (ASU). A subcritical steam cycle is considered for heat recovery steam generation. Syngas is selectively cleaned by a SELEXOL acid gas removal (AGR) process. Sulfur is recovered using a two-train Claus unit with tail gas recycle to the AGR. A multistage intercooled compressor is used for compressing CO2 to the pressure required for sequestration. Using Illinois No.6 coal, the reference plant generates 640 MWe of net power. The plant-wide steady-state and dynamic IGCC simulations have been generated using the Aspen Plus{reg_sign} and Aspen Plus Dynamics{reg_sign} process simulators, respectively. The model is generated based on the Case 2 IGCC configuration detailed in the study available in the NETL website1. The GEE gasifier is represented with a restricted equilibrium reactor model where the temperature approach to equilibrium for individual reactions can be modified based on the experimental data. In this radiant-only configuration, the syngas from the Radiant Syngas Cooler (RSC) is quenched in a scrubber. The blackwater from the scrubber bottom is further cleaned in the blackwater treatment plant. The cleaned water is returned back to the scrubber and also used for slurry preparation. The acid gas from the sour water stripper (SWS) is sent to the Claus plant. The syngas from the scrubber passes through a sour shift process. The WGS reactors are modeled as adiabatic plug flow reactors with rigorous kinetics based on

  2. Plant Nematodes Occurring in Arkansas

    OpenAIRE

    Wehunt, E. J.; Golden, A. M.; Robbins, R. T.

    1989-01-01

    A total of 110 species of plant nematodes were found in various habitats in Arkansas. Thirty species from 19 genera are reported here for the first time. Included in the new reports are the known plant pathogens Criconemella onoense, Hirshmanniella oryzae, Longidorus elongatus, and Pratylenchus pratensis.

  3. How plant architecture affects light absorption and photosynthesis in tomato: towards an ideotype for plant architecture using a functional-structural plant model

    NARCIS (Netherlands)

    Sarlikioti, V.; Visser, de P.H.B.; Buck-Sorlin, G.H.; Marcelis, L.F.M.

    2011-01-01

    Background and Aims - Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a

  4. How plant architecture affects light absorption and photosynthesis in tomato: towards an ideotype for plant architecture using a functional-structural plant model

    NARCIS (Netherlands)

    Sarlikioti, V.; Visser, de P.H.B.; Buck-Sorlin, G.H.; Marcelis, L.F.M.

    2011-01-01

    Background and Aims - Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a

  5. Verification of Geometric Model-Based Plant Phenotyping Methods for Studies of Xerophytic Plants

    Directory of Open Access Journals (Sweden)

    Paweł Drapikowski

    2016-06-01

    Full Text Available This paper presents the results of verification of certain non-contact measurement methods of plant scanning to estimate morphological parameters such as length, width, area, volume of leaves and/or stems on the basis of computer models. The best results in reproducing the shape of scanned objects up to 50 cm in height were obtained with the structured-light DAVID Laserscanner. The optimal triangle mesh resolution for scanned surfaces was determined with the measurement error taken into account. The research suggests that measuring morphological parameters from computer models can supplement or even replace phenotyping with classic methods. Calculating precise values of area and volume makes determination of the S/V (surface/volume ratio for cacti and other succulents possible, whereas for classic methods the result is an approximation only. In addition, the possibility of scanning and measuring plant species which differ in morphology was investigated.

  6. A compact model for the complex plant circadian clock

    Directory of Open Access Journals (Sweden)

    Didier eGonze

    2016-02-01

    Full Text Available The circadian clock is an endogenous timekeeper that allows organisms to anticipate and adapt to the daily variations of their environment. The plant clock is an intricate network of interlocked feedback loops, in which transcription factors regulate each other to generate oscillations with expression peaks at specific times of the day. Over the last decade, mathematical modeling approaches have been used to understand the inner workings of the clock in the model plant Arabidopsis thaliana. Those efforts have produced a number of models of ever increasing complexity. Here, we present an alternative model that combines a low number of equations and parameters, similar to the very earliest models, with the complex network structure found in more recent ones. This simple model describes the temporal evolution of the abundance of eight clock genes and captures key features of the clock on a qualitative level, namely the entrained and free-running behaviors of the wild type clock, as well as the defects found in knockout mutants (such as altered free-running periods, lack of entrainment, or changes in the expression of other clock genes. Additionally, our model produces complex responses to various light cues, such as extreme photoperiods and non-24h environmental cycles, and can describe the control of hypocotyl growth by the clock. Our model constitutes a useful tool to probe dynamical properties of the clock as well as model more clock-dependent processes.

  7. Azolla - A Model Organism for Plant Genomic Studies

    Institute of Scientific and Technical Information of China (English)

    Yin-Long Qiu; Jun Yu

    2003-01-01

    The aquatic ferns of the genus Azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation. Azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture, its unique position in plant evolution, its symbiotic relationship with the N2-fixing cyanobacterium, Anabaena azollae, and its moderate-sized genome. The goals of this genome project are not only to understand the biology of the Azolla genome to promote its applications in biological research and agriculture practice but also to gain critical insights about evolution of plant genomes. Together with the strategic and technical improvement as well as cost reduction of DNA sequencing, the deciphering of their genetic code is imminent.

  8. Azolla—A Model Organism for Plant Genomic Studies

    Institute of Scientific and Technical Information of China (English)

    Yin-LongQiu; JunYu

    2003-01-01

    The aquatic ferns of the genus Azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation.Azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture,its unique position in plant evolution,its symbiotic relationship with the N2-fixing cyanobacterium,Anabaena azollae,and its moderate-sized genome.The goals of this genome project are not only to understand the biology of the Azolla genome to promote its applications in biological research and agriculture practice but also to gain critical insights about evolution of plant genomes.Together with the strategic and technical improvement as well as cost reduction of DNA sequencing,the deciphering of their genetic code is imminent.

  9. Venation Skeleton-Based Modeling Plant Leaf Wilting

    Directory of Open Access Journals (Sweden)

    Shenglian Lu

    2009-01-01

    Full Text Available A venation skeleton-driven method for modeling and animating plant leaf wilting is presented. The proposed method includes five principal processes. Firstly, a three-dimensional leaf skeleton is constructed from a leaf image, and the leaf skeleton is further used to generate a detailed mesh for the leaf surface. Then a venation skeleton is generated interactively from the leaf skeleton. Each vein in the venation skeleton consists of a segmented vertices string. Thirdly, each vertex in the leaf mesh is banded to the nearest vertex in the venation skeleton. We then deform the venation skeleton by controlling the movement of each vertex in the venation skeleton by rotating it around a fixed vector. Finally, the leaf mesh is mapped to the deformed venation skeleton, as such the deformation of the mesh follows the deformation of the venation skeleton. The proposed techniques have been applied to simulate plant leaf surface deformation resulted from biological responses of plant wilting.

  10. Applying Functional Modeling for Accident Management of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Morten; Zhang Xinxin [Harbin Engineering University, Harbin (China)

    2014-08-15

    The paper investigate applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow Modeling is given and a detailed presentation of the foundational means-end concepts is presented and the conditions for proper use in modelling accidents are identified. It is shown that Multilevel Flow Modeling can be used for modelling and reasoning about design basis accidents. Its possible role for information sharing and decision support in accidents beyond design basis is also indicated. A modelling example demonstrating the application of Multilevel Flow Modelling and reasoning for a PWR LOCA is presented.

  11. Genetic variability among exotic and indigenous maize inbreds for resistance to stored grain weevil (Sitophilus oryzae L. infestation

    Directory of Open Access Journals (Sweden)

    Rajkumar Zunjare

    2016-12-01

    Full Text Available Sitophilus oryzae is one of the most important stored grain pests of maize causing substantial losses. Owing to high cost, environmental and health hazards, chemical control does not provide an acceptable solution. Host plant resistance offers sustainable and cost-effective way to reduce the losses. A set of 162 diverse inbreds were evaluated to assess their responses to infestation of S. oryzae. Significant variation for (1 grain weight loss (GWL (4.19–42.32%, (2 emergence of insect progeny (5.67–75.67, (3 germination of infested seeds (GIS (0.00–81.33%, (4 pericarp thickness (PT of the grain (47.32–194.83 μm and (5 grain hardness (GH (113.00–1,171.67 Newton was observed among inbreds. GWL and emergence of insect progeny were positively correlated, while GIS was negatively correlated with both. PT and GH did not show any association with other characters. CML442 and CM394 earlier reported to be promising against S. zeamais, were also identified as resistant to S. oryzae. SKV21, Pant109, Pant124, MGB1, CML207 and LM13 were identified as resistant inbreds. These inbreds can potentially serve as valuable donors in the resistance breeding programme. The resistant inbreds can also be crossed with diverse susceptible inbreds to generate mapping populations for identifying QTLs conferring resistance to S. oryzae.

  12. Screening of a synthetic peptide combinatorial library to identify inhibitors of the appressorium formation in Magnaporthe oryzae.

    Science.gov (United States)

    Rebollar, Aarón; Marcos, Jose F; López-García, Belén

    2014-11-01

    The rice blast disease caused by Magnaporthe oryzae is one of the most devastating diseases of cultivated rice. One of the most important stages in the infective cycle of M. oryzae is the formation of the dome-shaped structure called appressorium. The purpose of the present study was to identify novel peptides to control the rice blast disease by blocking the appressorium formation through screening of a synthetic peptide combinatorial library. As result of the screening, a set of 29 putative bioactive peptides were identified, synthesized and assayed in comparison with the previously identified peptide PAF104. The peptides MgAPI24, MgAPI40 and MgAPI47 showed improved inhibitory activity on the M. oryzae appressorium formation. Our data show that these peptides have a differential effect on two developmental structures: appressoria and appressorium-like structures. Antimicrobial assays against M. oryzae and other non-target microorganisms showed a weak or no toxicity of these peptides, demonstrating their specific activity blocking the appressorium formation. Therefore, the outcome of this research would be useful in the development of novel target-oriented peptides to use in plant protection.

  13. Stochastic modeling of deterioration in nuclear power plant components

    Science.gov (United States)

    Yuan, Xianxun

    2007-12-01

    The risk-based life-cycle management of engineering systems in a nuclear power plant is intended to ensure safe and economically efficient operation of energy generation infrastructure over its entire service life. An important element of life-cycle management is to understand, model and forecast the effect of various degradation mechanisms affecting the performance of engineering systems, structures and components. The modeling of degradation in nuclear plant components is confounded by large sampling and temporal uncertainties. The reason is that nuclear systems are not readily accessible for inspections due to high level of radiation and large costs associated with remote data collection methods. The models of degradation used by industry are largely derived from ordinary linear regression methods. The main objective of this thesis is to develop more advanced techniques based on stochastic process theory to model deterioration in engineering components with the purpose of providing more scientific basis to life-cycle management of aging nuclear power plants. This thesis proposes a stochastic gamma process (GP) model for deterioration and develops a suite of statistical techniques for calibrating the model parameters. The gamma process is a versatile and mathematically tractable stochastic model for a wide variety of degradation phenomena, and another desirable property is its nonnegative, monotonically increasing sample paths. In the thesis, the GP model is extended by including additional covariates and also modeling for random effects. The optimization of age-based replacement and condition-based maintenance strategies is also presented. The thesis also investigates improved regression techniques for modeling deterioration. A linear mixed-effects (LME) regression model is presented to resolve an inconsistency of the traditional regression models. The proposed LME model assumes that the randomness in deterioration is decomposed into two parts: the unobserved

  14. NEURO-FUZZY MODELLING OF BLENDING PROCESS IN CEMENT PLANT

    Directory of Open Access Journals (Sweden)

    Dauda Olarotimi Araromi

    2015-11-01

    Full Text Available The profitability of a cement plant depends largely on the efficient operation of the blending stage, therefore, there is a need to control the process at the blending stage in order to maintain the chemical composition of the raw mix near or at the desired value with minimum variance despite variation in the raw material composition. In this work, neuro-fuzzy model is developed for a dynamic behaviour of the system to predict the total carbonate content in the raw mix at different clay feed rates. The data used for parameter estimation and model validation was obtained from one of the cement plants in Nigeria. The data was pre-processed to remove outliers and filtered using smoothening technique in order to reveal its dynamic nature. Autoregressive exogenous (ARX model was developed for comparison purpose. ARX model gave high root mean square error (RMSE of 5.408 and 4.0199 for training and validation respectively. Poor fit resulting from ARX model is an indication of nonlinear nature of the process. However, both visual and statistical analyses on neuro-fuzzy (ANFIS model gave a far better result. RMSE of training and validation are 0.28167 and 0.7436 respectively, and the sum of square error (SSE and R-square are 39.6692 and 0.9969 respectively. All these are an indication of good performance of ANFIS model. This model can be used for control design of the process.

  15. A Review for Model Plant Mismatch Measures in Process Monitoring

    Institute of Scientific and Technical Information of China (English)

    王洪; 谢磊; 宋执环

    2012-01-01

    Model is usually necessary for the design of a control loop. Due to simplification and unknown dynamics, model plant mismatch is inevitable in the control loop. In process monitoring, detection of mismatch and evaluation of its influences are demanded. In this paper several mismatch measures are presented based on different model descriptions. They are categorized into different groups from different perspectives and their potential in detection and diagnosis is evaluated. Two case studies on mixing process and distillation process demonstrate the efficacy of the framework of mismatch monitoring.

  16. Genome-wide analysis of basic leucine zipper transcription factor families in Arabidopsis thaliana, Oryza saliva and Populus trichocarpa

    Institute of Scientific and Technical Information of China (English)

    JI Qian; ZHANG Liang-sheng; WANG Yi-fei; WANG Jian

    2009-01-01

    The basic leucine zipper (bZIP) transcription factors form a large gene family that is important in pathogen defense, light and stress signaling, etc. The Completed whole genome sequences of model plants Arabidopsis (Arabidopsis thaliana), rice (Oryza saliva) and poplar (Populus trichocarpa) constitute a valuable resource for genome-wide analysis and genomic comparative analysis, as they are representatives of the two major evolutionary lineages within the angiosperms: the monocotyledons and the dicotyledons. In this study, bioinformatics analysis identified 74, 89 and 88 bZIP genes respectively in Arabidopsis, rice and poplar. Moreover, a comprehensive overview of this gene family is presented, including the gene structure, phylogeny, chromosome distribution, conserved motifs. As a result, the plant bZIPs were organized into 10 subfamilies on basis of phylogenetic relationship. Gene duplication events during the family evolution history were also investigated. And it was further concluded that chromosomal/segmental duplication might have played a key role in gene expansion of bZIP gene family.

  17. Differential microRNA expression between shoots and rhizomes in Oryza longistaminata using high-throughput RNA sequencing

    Institute of Scientific and Technical Information of China (English)

    Ying; Zong; Liyu; Huang; Ting; Zhang; Qiao; Qin; Wensheng; Wang; Xiuqin; Zhao; Fengyi; Hu; Binying; Fu; Zhikang; Li

    2014-01-01

    Plant microRNAs(miRNAs)play important roles in biological processes such as development and stress responses.Although the diverse functions of miRNAs in model organisms have been well studied,their function in wild rice is poorly understood.In this study,high-throughput small RNA sequencing was performed to characterize tissue-specific transcriptomes in Oryza longistaminata.A total of 603 miRNAs,380 known rice miRNAs,72 conserved plant miRNAs,and151 predicted novel miRNAs were identified as being expressed in aerial shoots and rhizomes.Additionally,99 and 79 miRNAs were expressed exclusively or differentially,respectively,in the two tissues,and 144 potential targets were predicted for the differentially expressed miRNAs in the rhizomes.Functional annotation of these targets suggested that transcription factors,including squamosa promoter binding proteins and auxin response factors,function in rhizome growth and development.The expression levels of several miRNAs and target genes in the rhizomes were quantified by RT-PCR,and the results indicated the existence of complex regulatory mechanisms between the miRNAs and their targets.Eight target cleavage sites were verified by RNA ligase-mediated rapid 5′end amplification.These results provide valuable information on the composition,expression and function of miRNAs in O.longistaminata,and will aid in understanding the molecular mechanisms of rhizome development.

  18. Overexpression of Thiamin Biosynthesis Genes in Rice Increases Leaf and Unpolished Grain Thiamin Content But Not Resistance to Xanthomonas oryzae pv. oryzae

    Science.gov (United States)

    Dong, Wei; Thomas, Nicholas; Ronald, Pamela C.; Goyer, Aymeric

    2016-01-01

    Thiamin diphosphate (ThDP), also known as vitamin B1, serves as an enzymatic cofactor in glucose metabolism, the Krebs cycle, and branched-chain amino acid biosynthesis in all living organisms. Unlike plants and microorganisms, humans are not able to synthesize ThDP de novo and must obtain it from their diet. Staple crops such as rice are poor sources of thiamin. Hence, populations that mainly consume rice commonly suffer thiamin deficiency. In addition to thiamin’s nutritional function, studies in rice have shown that some thiamin biosynthesis genes are involved in resistance to Xanthomonas oryzae, which causes a serious disease in rice fields. This study shows that overexpression of two thiamin biosynthesis genes, 4-methyl-5-β-hydroxyethylthiazole phosphate synthase and 4-amino-2-methyl-5-hydroxymethylpyrimidine phosphate synthase, involved in the first steps of the thiazole and pyrimidine synthesis branches, respectively, increased thiamin content up to fivefold in unpolished seeds that retain the bran. However, thiamin levels in polished seeds with removed bran were similar to those found in polished control seeds. Plants with higher accumulation of thiamin did not show enhanced resistance to X. oryzae. These results indicate that stacking of two traits can enhance thiamin accumulation in rice unpolished grain. We discuss potential roadblocks that prevent thiamin accumulation in the endosperm. PMID:27242822

  19. Simulation Model of Hydro Power Plant Using Matlab/Simulink

    Directory of Open Access Journals (Sweden)

    Mousa Sattouf

    2014-01-01

    Full Text Available Hydropower has now become the best source of electricity on earth. It is produced due to the energy provided by moving or falling water. History proves that the cost of this electricity remains constant over the year. Because of the many advantages, most of the countries now have hydropower as the source of major electricity producer. The most important advantage of hydropower is that t is green energy, which mean that no air or water pollutants are produced, also no greenhouse gases like carbon dioxide are produced which makes this source of energy environment-friendly. It prevents us from the danger of global warming. This paper describes a generalized model which can be used to simulate a hydro power plant using MATLAB/SIMULINK. The plant consists of hydro turbine connected to synchronous generator, which is connected to public grid. Simulation of hydro turbine and synchronous generator can be done using various simulation tools, In this work, SIMULINK/MATLAB is favored over other tools in modeling the dynamics of a hydro turbine and synchronous machine. The SIMULINK program in MATLAB is used to obtain a schematic model of the hydro plant by means of basic function blocks. This approach is pedagogically better than using a compilation of program code as in other software programs .The library of SIMULINK software programs includes function blocks which can be linked and edited to model. The main objectives of this model are aimed to achieve some operating modes of the hydro plant and some operating tests.

  20. Future of Plant Functional Types in Terrestrial Biosphere Models

    Science.gov (United States)

    Wullschleger, S. D.; Euskirchen, E. S.; Iversen, C. M.; Rogers, A.; Serbin, S.

    2015-12-01

    Earth system models describe the physical, chemical, and biological processes that govern our global climate. While it is difficult to single out one component as being more important than another in these sophisticated models, terrestrial vegetation is a critical player in the biogeochemical and biophysical dynamics of the Earth system. There is much debate, however, as to how plant diversity and function should be represented in these models. Plant functional types (PFTs) have been adopted by modelers to represent broad groupings of plant species that share similar characteristics (e.g. growth form) and roles (e.g. photosynthetic pathway) in ecosystem function. In this review the PFT concept is traced from its origin in the early 1800s to its current use in regional and global dynamic vegetation models (DVMs). Special attention is given to the representation and parameterization of PFTs and to validation and benchmarking of predicted patterns of vegetation distribution in high-latitude ecosystems. These ecosystems are sensitive to changing climate and thus provide a useful test case for model-based simulations of past, current, and future distribution of vegetation. Models that incorporate the PFT concept predict many of the emerging patterns of vegetation change in tundra and boreal forests, given known processes of tree mortality, treeline migration, and shrub expansion. However, representation of above- and especially belowground traits for specific PFTs continues to be problematic. Potential solutions include developing trait databases and replacing fixed parameters for PFTs with formulations based on trait co-variance and empirical trait-environment relationships. Surprisingly, despite being important to land-atmosphere interactions of carbon, water, and energy, PFTs such as moss and lichen are largely absent from DVMs. Close collaboration among those involved in modelling with the disciplines of taxonomy, biogeography, ecology, and remote sensing will be

  1. Modelling of the Nutrient Medium for Plants Cultivation in Spaceflight

    Science.gov (United States)

    Nechitailo, Galina S.

    2016-07-01

    MODELLING OF THE NUTRIENT MEDIUM FOR PLANTS CULTIVATION IN SPACEFLIGHT Nechitajlo G.S.*, Rakhmetova A.A.**, Bogoslovskaja O.A.**, Ol'hovskay I.P.**, Glushchenko N.N.** *Emanuel Institute of Biochemical Physics of Russian Academy of Sciences (IBCP RAS) mail: spacemal@mail.ru **V.L. Talrose Institute for Energy Problems of Chemical Physics of Russian Academy of Science (INEPCP RAS) mail: nnglu@ mail.ru The valuable life and fruitful activity of cosmonauts and researchers in conditions of spaceflights and prolonged work at space stations are only possible with creating life area providing fresh air, natural food, comfortable psychological conditions, etc. The solution of that problem under space conditions seems impossible without use of high nano- and biotechnologies for plants growth. A priority should be given not only to choose species of growth plants in space, but also to improve conditions for their growth which includes optimal nourishing components for plants, preparation of nutrient mediums, illumination and temperature. We are deeply convinced that just manipulations with growing conditions for cultivated plants, but not genes changes, is a guarantee of success in the decision of this problem. For improving the method of plants growing on the artificial nutrient medium with balanced content of components, being necessary for growth and development of plants, we added essential metal elements: Fe, Zn, Cu - in an electroneutral state in the form of nanoparticles instead of sulfates or other easily dissolving salts. Nanoparticulated metals are known to have a number of advantages in comparison with salts: metals in an electroneutral form are characterized with the prolonged and multifunctional action, low toxicity per se and appearing to be much below the toxicity of the same metals in the ionic forms, accumulation as a reserve being used in biotic dozes, active distribution in bodies and organs of plants and stimulation of vital processes. A high reactivity

  2. Modelling of Water Turbidity Parameters in a Water Treatment Plant

    Directory of Open Access Journals (Sweden)

    A. S. KOVO

    2005-01-01

    Full Text Available The high cost of chemical analysis of water has necessitated various researches into finding alternative method of determining portable water quality. This paper is aimed at modelling the turbidity value as a water quality parameter. Mathematical models for turbidity removal were developed based on the relationships between water turbidity and other water criteria. Results showed that the turbidity of water is the cumulative effect of the individual parameters/factors affecting the system. A model equation for the evaluation and prediction of a clarifier’s performance was developed:Model: T = T0(-1.36729 + 0.037101∙10λpH + 0.048928t + 0.00741387∙alkThe developed model will aid the predictive assessment of water treatment plant performance. The limitations of the models are as a result of insufficient variable considered during the conceptualization.

  3. MODELING OF HIGH STORAGE SHEET DEPOT WITH PLANT SIMULATION

    Directory of Open Access Journals (Sweden)

    Andrzej Jardzioch

    2013-03-01

    Full Text Available Manufacturing processes are becoming increasingly automated. Introduction of innovative solutions often necessitate processing very large number of signals from various devices. Correctness tests of the components configuration becomes a compiled operation requiring vast expenditure of time and knowledge. The models may be a mathematical reflection of the actual object. Many actions can be computer-assisted to varying degree. One example is construction of simulation models. These can also be simulation models developed in advanced software. The stages of creating a model may be purely random. This paper aims at a closer analysis of the simulation model based on the high storage sheet depot modeling using Plant Simulation software. The results of analysis can be used for optimization, but this stage is a separate issue.

  4. Route and Regulation of Zinc, Cadmium, and Iron Transport in Rice Plants (Oryza sativa L. during Vegetative Growth and Grain Filling: Metal Transporters, Metal Speciation, Grain Cd Reduction and Zn and Fe Biofortification

    Directory of Open Access Journals (Sweden)

    Tadakatsu Yoneyama

    2015-08-01

    Full Text Available Zinc (Zn and iron (Fe are essential but are sometimes deficient in humans, while cadmium (Cd is toxic if it accumulates in the liver and kidneys at high levels. All three are contained in the grains of rice, a staple cereal. Zn and Fe concentrations in rice grains harvested under different levels of soil/hydroponic metals are known to change only within a small range, while Cd concentrations show greater changes. To clarify the mechanisms underlying such different metal contents, we synthesized information on the routes of metal transport and accumulation in rice plants by examining metal speciation, metal transporters, and the xylem-to-phloem transport system. At grain-filling, Zn and Cd ascending in xylem sap are transferred to the phloem by the xylem-to-phloem transport system operating at stem nodes. Grain Fe is largely derived from the leaves by remobilization. Zn and Fe concentrations in phloem-sap and grains are regulated within a small range, while Cd concentrations vary depending on xylem supply. Transgenic techniques to increase concentrations of the metal chelators (nicotianamine, 2′-deoxymugineic acid are useful in increasing grain Zn and Fe concentrations. The elimination of OsNRAMP5 Cd-uptake transporter and the enhancement of root cell vacuolar Cd sequestration reduce uptake and root-to-shoot transport, respectively, resulting in a reduction of grain Cd accumulation.

  5. Route and Regulation of Zinc, Cadmium, and Iron Transport in Rice Plants (Oryza sativa L.) during Vegetative Growth and Grain Filling: Metal Transporters, Metal Speciation, Grain Cd Reduction and Zn and Fe Biofortification.

    Science.gov (United States)

    Yoneyama, Tadakatsu; Ishikawa, Satoru; Fujimaki, Shu

    2015-08-13

    Zinc (Zn) and iron (Fe) are essential but are sometimes deficient in humans, while cadmium (Cd) is toxic if it accumulates in the liver and kidneys at high levels. All three are contained in the grains of rice, a staple cereal. Zn and Fe concentrations in rice grains harvested under different levels of soil/hydroponic metals are known to change only within a small range, while Cd concentrations show greater changes. To clarify the mechanisms underlying such different metal contents, we synthesized information on the routes of metal transport and accumulation in rice plants by examining metal speciation, metal transporters, and the xylem-to-phloem transport system. At grain-filling, Zn and Cd ascending in xylem sap are transferred to the phloem by the xylem-to-phloem transport system operating at stem nodes. Grain Fe is largely derived from the leaves by remobilization. Zn and Fe concentrations in phloem-sap and grains are regulated within a small range, while Cd concentrations vary depending on xylem supply. Transgenic techniques to increase concentrations of the metal chelators (nicotianamine, 2'-deoxymugineic acid) are useful in increasing grain Zn and Fe concentrations. The elimination of OsNRAMP5 Cd-uptake transporter and the enhancement of root cell vacuolar Cd sequestration reduce uptake and root-to-shoot transport, respectively, resulting in a reduction of grain Cd accumulation.

  6. A user friendly method to isolate and single spore the fungi Magnaporthe oryzae and Magnaporthe grisea obtained from diseased field samples

    Science.gov (United States)

    The fungus Magnaporthe oryzae is the causal agent for a wide range of plant diseases including diseases of rice, wheat, rye grass, turfgrass and pearl millet. A simple robust procedure for fungal isolation is not publicly available. In the present study, a user friendly method was developed to iso...

  7. Biochemical and physiological responses of rice (Oryza sativa L.) grown on different sewage sludge amendments rates.

    Science.gov (United States)

    Singh, R P; Agrawal, M

    2010-05-01

    Using sewage sludge, a biological residue from sewage treatment processes, in agriculture is an alternative disposal technique of waste. To study the biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments (SSA) rates a field experiment was conducted by mixing sewage sludge at 0, 3, 4.5, 6, 9, 12 kg m(-2) rate to the agricultural soil. Rate of photosynthesis and stomatal conductance increased in plants grown at different SSA rate. Chlorophyll and protein contents also increased due to different SSA rates. Lipid peroxidation, ascorbic acid, peroxidase activity and proline content increased, however, thiol and phenol content decreased in plants grown at different SSA rates. The study concludes that for rice plant sewage sludge amendment in soil may be a good option as plant has adequate heavy metal tolerance mechanism showed by increased rate of photosynthesis and chlorophyll content and various antioxidant levels.

  8. Health-aware Model Predictive Control of Pasteurization Plant

    Science.gov (United States)

    Karimi Pour, Fatemeh; Puig, Vicenç; Ocampo-Martinez, Carlos

    2017-01-01

    In order to optimize the trade-off between components life and energy consumption, the integration of a system health management and control modules is required. This paper proposes the integration of model predictive control (MPC) with a fatigue estimation approach that minimizes the damage of the components of a pasteurization plant. The fatigue estimation is assessed with the rainflow counting algorithm. Using data from this algorithm, a simplified model that characterizes the health of the system is developed and integrated with MPC. The MPC controller objective is modified by adding an extra criterion that takes into account the accumulated damage. But, a steady-state offset is created by adding this extra criterion. Finally, by including an integral action in the MPC controller, the steady-state error for regulation purpose is eliminated. The proposed control scheme is validated in simulation using a simulator of a utility-scale pasteurization plant.

  9. Hydraulic modelling of drinking water treatment plant operations

    Directory of Open Access Journals (Sweden)

    L. C. Rietveld

    2009-06-01

    Full Text Available The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand filtration and cascade and tower aeration. Using this treatment step library, a hydraulic model was set up, calibrated and validated for the drinking water treatment plant Harderbroek. With the actual valve position and pump speeds, the flows were calculated through the several treatment steps. A case shows the use of the model to calculate the new setpoints for the current frequency converters of the effluent pumps during a filter backwash.

  10. Plants: a unique model for research on high diluted substances

    Directory of Open Access Journals (Sweden)

    Tatiana Vladimirovna Novasadyuk

    2011-09-01

    adding Coca 1000 СН remedy, and then in one month the upper part of the plant was sprayed with Echinacea 30 СН. The same amounts of similar plants of the same breeds treated according to conventional agricultural technology were used as a control group. Results: As a result earlier ripening was found in the Typhoon F1 tomato breed: it occurred by 19 days earlier: that is by 18.3% than in the control group. The Titan tomatoes group ripened by 14.3% faster than in the control one. Every plant of the Typhoon breed produced an average of 45 tomato fruits, while in the control group the average number amounted to 14 (i.e. there was an increase of 221.4% in the test group. An average of 78 tomato fruits were produced by the Titan breed plants, while in the control group this number was only 20 (increase by 290%. Mean weight of the Typhoon tomato fruit increased by 59.5 g from the control values, i.e. by 180.8%. Mean weight of the Titan tomato fruit increased by 128.5 i.e. by 208.9%. A notable difference was found by all observers in the taste of experimental and control vegetables. The experimental plants had significantly better taste characteristics and they were also more resistant to buck eye rot. Conclusion: In such a way, the studies performed confirm the existence of homeopathic phenomenon in live organisms in the absence of the placebo effect. It has been demonstrated that the use of homeopathic remedies is effective in improvement of agricultural productivity. Plants are unique model for research of ultrahigh dilutions of substances.

  11. Cloning and functional validation of early inducible Magnaporthe oryzae responsive CYP76M7 promoter from rice

    Directory of Open Access Journals (Sweden)

    Joshitha eVijayan

    2015-05-01

    Full Text Available Cloning and functional characterization of plant pathogen inducible promoters is of great significance for their use in the effective management of plant diseases. The rice gene CYP76M7 was up regulated at 24, 48 and 72 hours post inoculation (hpi with two isolates of Magnaporthe oryzae Mo-ei-11 and Mo-ni-25. In this study, the promoter of CYP76M7 gene was cloned from rice cultivar HR-12, characterized and functionally validated. The Transcription Start Site of CYP76M7 was mapped at 45 bases upstream of the initiation codon. To functionally validate the promoter, 5′ deletion analysis of the promoter sequences was performed and the deletion fragments fused with the GUS reporter gene were used for generating stable transgenic Arabidopsis plants as well as for transient expression in rice. The spatial and temporal expression pattern of GUS in transgenic Arabidopsis plants and also in transiently expressed rice leaves revealed that the promoter of CYP76M7 gene was induced by M. oryzae. The induction of CYP76M7 promoter was observed at 24 hpi with M. oryzae. We report that, sequences spanning -222 bp to -520 bp, with the cluster of three W-boxes, two ASF1 motifs and a single GT-1 element may contribute to the M. oryzae inducible nature of CYP76M7 promoter. The promoter characterized in this study would be an ideal candidate for the overexpression of defence genes in rice for developing durable blast resistance rice lines.

  12. Population Dynamics Among six Major Groups of the Oryza rufipogon Species Complex, Wild Relative of Cultivated Asian Rice

    OpenAIRE

    Kim, Hyunjung; Jung, Janelle; Singh, Namrata; Greenberg, Anthony; Jeff J. Doyle; Tyagi, Wricha; Chung, Jong-Wook; Kimball, Jennifer; Hamilton, Ruaraidh Sackville; McCouch, Susan R.

    2016-01-01

    Background Understanding population structure of the wild progenitor of Asian cultivated rice (O. sativa), the Oryza rufipogon species complex (ORSC), is of interest to plant breeders and contributes to our understanding of rice domestication. A collection of 286 diverse ORSC accessions was evaluated for nuclear variation using genotyping-by-sequencing (113,739 SNPs) and for chloroplast variation using Sanger sequencing (25 polymorphic sites). Results Six wild subpopulations were identified, ...

  13. Multilevel Flow Modeling for Nuclear Power Plant Diagnosis

    DEFF Research Database (Denmark)

    Gola, G; Thunem, Harald P-J; Thunem, Atoosa P-J

    2012-01-01

    As complexity and safety requirements of current and future nuclear power plants increase, innovative methods are being investigated to perform accurate and reliable system diagnoses. Detecting malfunctions, identifying their causes and possibly predicting their consequences are major challenges...... detected anomalies. The combination of a data reconciliation system and the Multilevel Flow Modeling approach is illustrated with regard to the secondary loop of the Loviisa-2 Pressurized Water Reactor located in Finland....

  14. Stochastic models for plant microtubule self-organization and structure.

    Science.gov (United States)

    Eren, Ezgi C; Dixit, Ram; Gautam, Natarajan

    2015-12-01

    One of the key enablers of shape and growth in plant cells is the cortical microtubule (CMT) system, which is a polymer array that forms an appropriately-structured scaffolding in each cell. Plant biologists have shown that stochastic dynamics and simple rules of interactions between CMTs can lead to a coaligned CMT array structure. However, the mechanisms and conditions that cause CMT arrays to become organized are not well understood. It is prohibitively time-consuming to use actual plants to study the effect of various genetic mutations and environmental conditions on CMT self-organization. In fact, even computer simulations with multiple replications are not fast enough due to the spatio-temporal complexity of the system. To redress this shortcoming, we develop analytical models and methods for expeditiously computing CMT system metrics that are related to self-organization and array structure. In particular, we formulate a mean-field model to derive sufficient conditions for the organization to occur. We show that growth-prone dynamics itself is sufficient to lead to organization in presence of interactions in the system. In addition, for such systems, we develop predictive methods for estimation of system metrics such as expected average length and number of CMTs over time, using a stochastic fluid-flow model, transient analysis, and approximation algorithms tailored to our problem. We illustrate the effectiveness of our approach through numerical test instances and discuss biological insights.

  15. 利用稻瘟霉模型筛选粗疣合叶苔内生真菌中的活性菌株%Screening of active strains in endophytic fungi from Scapania verrucosa using biological model of Pyricularia oryzae

    Institute of Scientific and Technical Information of China (English)

    郭蕾; 吴锦忠; 许强芝; 韩婷; 秦路平

    2009-01-01

    Objective To rapidly screen the bioactive strains in endophytic fungi from Scapania verru-cosa by Pyricularia oryzae P-2b model and to identify the active strain T11. Methods The endophytic fungi were firstly isolated from S. verrucosa and the morphological deformation induced by ethyl acetate extract of bioactive fungi or growth inhibition of mycelia germinated from the conidia of P. oryzae were observed to screen the bioactive strains whose in vitro antifungus activity and cytotoxic effect on tumor cell lines were studied furtherly. The active strain Tll with the best activity was identified by morphological method. Results A total of 47 endophytic fungi were isolated from liverwort S. verrucosa. Among them,40 strains (85.1%) of endophytes could induce morphological abnormality of P. oryzae. The strain T11 could inhibit tumor cells proliferation and fungal mycelia growth effectively. Conclusion Endophytes from S. verrucosa have antifungal activity and cytotoxic effect and could be a potential resource for the develop-ment of antifungal and antitumor agent.%目的 利用稻瘟霉模型快速筛选粗疣合叶苔内生真菌中具有生物活性的菌株,并对活性菌株T11进行鉴定.方法 首次对粗疣合叶苔内生真菌进行了分离,通过观察内生真菌醋酸乙酯提取物引起稻瘟霉分生孢子或菌丝形态生长异常或生长抑制的情况,初步确定具有生物活性的菌株,进一步进行体外抗真菌及抗肿瘤活性筛选,对活性最好的T11菌株进行了分类鉴定.结果 粗疣合叶苔分离得到47株内生真菌,具有抗稻瘟霉活性的活性菌株40株,占总分离菌株的85.1%.其中T11号菌株可明显抑制真菌生长和肿瘤细胞增殖.结论 粗疣合叶苔内生真菌具有明显的抗真菌和细胞毒作用,是潜在的抗菌、抗肿瘤药物资源.

  16. Decentralized Disturbance Accommodation with Limited Plant Model Information

    CERN Document Server

    Farokhi, F; Johansson, K H

    2011-01-01

    The design of optimal disturbance accommodation and servomechanism controllers with limited plant model information is considered in this paper. Their closed-loop performance are compared using a performance metric called competitive ratio which is the worst-case ratio of the cost of a given control design strategy to the cost of the optimal control design with full model information. It was recently shown that when it comes to designing optimal centralized or partially structured decentralized state-feedback controllers with limited model information, the best control design strategy in terms of competitive ratio is a static one. This is true even though the optimal structured decentralized state-feedback controller with full model information is dynamic. In this paper, we show that, in contrast, the best limited model information control design strategy for the disturbance accommodation problem gives a dynamic controller. We find an explicit minimizer of the competitive ratio and we show that it is undomina...

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

    Science.gov (United States)

    Patil, Prabhu B; Sonti, Ramesh V

    2004-01-01

    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 respectively

  18. Host-Induced Gene Silencing of Rice Blast Fungus Magnaporthe oryzae Pathogenicity Genes Mediated by the Brome Mosaic Virus.

    Science.gov (United States)

    Zhu, Lin; Zhu, Jian; Liu, Zhixue; Wang, Zhengyi; Zhou, Cheng; Wang, Hong

    2017-09-26

    Magnaportheoryzae is a devastating plant pathogen, which has a detrimental impact on rice production worldwide. Despite its agronomical importance, some newly-emerging pathotypes often overcome race-specific disease resistance rapidly. It is thus desirable to develop a novel strategy for the long-lasting resistance of rice plants to ever-changing fungal pathogens. Brome mosaic virus (BMV)-induced RNA interference (RNAi) has emerged as a useful tool to study host-resistance genes for rice blast protection. Planta-generated silencing of targeted genes inside biotrophic pathogens can be achieved by expression of M.oryzae-derived gene fragments in the BMV-mediated gene silencing system, a technique termed host-induced gene silencing (HIGS). In this study, the effectiveness of BMV-mediated HIGS in M.oryzae was examined by targeting three predicted pathogenicity genes, MoABC1,MoMAC1 and MoPMK1. Systemic generation of fungal gene-specific small interfering RNA (siRNA) molecules induced by inoculation of BMV viral vectors inhibited disease development and reduced the transcription of targeted fungal genes after subsequent M.oryzae inoculation. Combined introduction of fungal gene sequences in sense and antisense orientation mediated by the BMV silencing vectors significantly enhanced the efficiency of this host-generated trans-specific RNAi, implying that these fungal genes played crucial roles in pathogenicity. Collectively, our results indicated that BMV-HIGS system was a great strategy for protecting host plants against the invasion of pathogenic fungi.

  19. Effector Diversification Contributes to Xanthomonas oryzae pv. oryzae Phenotypic Adaptation in a Semi-Isolated Environment

    Science.gov (United States)

    Quibod, Ian Lorenzo; Perez-Quintero, Alvaro; Booher, Nicholas J.; Dossa, Gerbert S.; Grande, Genelou; Szurek, Boris; Vera Cruz, Casiana; Bogdanove, Adam J.; Oliva, Ricardo

    2016-01-01

    Understanding the processes that shaped contemporary pathogen populations in agricultural landscapes is quite important to define appropriate management strategies and to support crop improvement efforts. Here, we took advantage of an historical record to examine the adaptation pathway of the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo) in a semi-isolated environment represented in the Philippine archipelago. By comparing genomes of key Xoo groups we showed that modern populations derived from three Asian lineages. We also showed that diversification of virulence factors occurred within each lineage, most likely driven by host adaptation, and it was essential to shape contemporary pathogen races. This finding is particularly important because it expands our understanding of pathogen adaptation to modern agriculture. PMID:27667260

  20. A Stochastic Unit Commitment Model for a Local CHP Plant

    DEFF Research Database (Denmark)

    Ravn, Hans V.; Riisom, Jannik; Schaumburg-Müller, Camilla

    2005-01-01

    Local CHP development in Denmark has during the 90’s been characterised by large growth primarily due to government subsidies in the form of feed-in tariffs. In line with the liberalisation process in the EU, Danish local CHPs of a certain size must operate on market terms from 2005. This paper...... presents a stochastic unit commitment model for a single local CHP plant (consisting of CHP unit, boiler, and heat storage facility) which takes into account varying spot prices. Further, additional technology is implemented in the model in the form of an immersion heater. Simulations are conducted using...

  1. Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

    DEFF Research Database (Denmark)

    Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

    2008-01-01

    This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...... reference tracking and disturbance rejection in an economically optimal way. The performance function is chosen as a mixture of the `1-norm and a linear weighting to model the economics of the system. Simulations show a significant improvement of the performance of the MPC compared to the current...

  2. RESPONSE OF PLANT-BACTERIA INTERACTION MODELS TO NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Giuliano Degrassi

    2012-07-01

    Full Text Available The aim of this study was to evaluate the possibility of using some models developed to study the plant-bacteria interaction mechanisms for the assessment of the impact of chronic exposure to nanoparticles. Rice-associated bacteria showed that some models are sensitive to the presence of NPs and allow a quantification of the effects. Further work needs to be performed in order to set appropriate reference baselines and standards to assess the impact of NPs on the proposed biological systems.

  3. Modeling Forest Structure and Vascular Plant Diversity in Piedmont Forests

    Science.gov (United States)

    Hakkenberg, C.

    2014-12-01

    When the interacting stressors of climate change and land cover/land use change (LCLUC) overwhelm ecosystem resilience to environmental and climatic variability, forest ecosystems are at increased risk of regime shifts and hyperdynamism in process rates. To meet the growing range of novel biotic and environmental stressors on human-impacted ecosystems, the maintenance of taxonomic diversity and functional redundancy in metacommunities has been proposed as a risk spreading measure ensuring that species critical to landscape ecosystem functioning are available for recruitment as local systems respond to novel conditions. This research is the first in a multi-part study to establish a dynamic, predictive model of the spatio-temporal dynamics of vascular plant diversity in North Carolina Piedmont mixed forests using remotely sensed data inputs. While remote sensing technologies are optimally suited to monitor LCLUC over large areas, direct approaches to the remote measurement of plant diversity remain a challenge. This study tests the efficacy of predicting indices of vascular plant diversity using remotely derived measures of forest structural heterogeneity from aerial LiDAR and high spatial resolution broadband optical imagery in addition to derived topo-environmental variables. Diversity distribution modelling of this sort is predicated upon the idea that environmental filtering of dispersing species help define fine-scale (permeable) environmental envelopes within which biotic structural and compositional factors drive competitive interactions that, in addition to background stochasticity, determine fine-scale alpha diversity. Results reveal that over a range of Piedmont forest communities, increasing structural complexity is positively correlated with measures of plant diversity, though the nature of this relationship varies by environmental conditions and community type. The diversity distribution model is parameterized and cross-validated using three high

  4. An implicit approach to model plant infestation by insect pests.

    Science.gov (United States)

    Lopes, Christelle; Spataro, Thierry; Doursat, Christophe; Lapchin, Laurent; Arditi, Roger

    2007-09-07

    Various spatial approaches were developed to study the effect of spatial heterogeneities on population dynamics. We present in this paper a flux-based model to describe an aphid-parasitoid system in a closed and spatially structured environment, i.e. a greenhouse. Derived from previous work and adapted to host-parasitoid interactions, our model represents the level of plant infestation as a continuous variable corresponding to the number of plants bearing a given density of pests at a given time. The variation of this variable is described by a partial differential equation. It is coupled to an ordinary differential equation and a delay-differential equation that describe the parasitized host population and the parasitoid population, respectively. We have applied our approach to the pest Aphis gossypii and to one of its parasitoids, Lysiphlebus testaceipes, in a melon greenhouse. Numerical simulations showed that, regardless of the number and distribution of hosts in the greenhouse, the aphid population is slightly larger if parasitoids display a type III rather than a type II functional response. However, the population dynamics depend on the initial distribution of hosts and the initial density of parasitoids released, which is interesting for biological control strategies. Sensitivity analysis showed that the delay in the parasitoid equation and the growth rate of the pest population are crucial parameters for predicting the dynamics. We demonstrate here that such a flux-based approach generates relevant predictions with a more synthetic formalism than a common plant-by-plant model. We also explain how this approach can be better adapted to test different management strategies and to manage crops of several greenhouses.

  5. Alterations in Gas Exchange and Oxidative Metabolism in Rice Leaves Infected by Pyricularia oryzae are Attenuated by Silicon.

    Science.gov (United States)

    Domiciano, Gisele Pereira; Cacique, Isaías Severino; Chagas Freitas, Cecília; Filippi, Marta Cristina Corsi; DaMatta, Fábio Murilo; do Vale, Francisco Xavier Ribeiro; Rodrigues, Fabrício Ávila

    2015-06-01

    Rice blast, caused by Pyricularia oryzae, is the most important disease in rice worldwide. This study investigated the effects of silicon (Si) on the photosynthetic gas exchange parameters (net CO2 assimilation rate [A], stomatal conductance to water vapor [gs], internal-to-ambient CO2 concentration ratio [Ci/Ca], and transpiration rate [E]); chlorophyll fluorescence a (Chla) parameters (maximum photochemical efficiency of photosystem II [Fv/Fm], photochemical [qP] and nonphotochemical [NPQ] quenching coefficients, and electron transport rate [ETR]); concentrations of pigments, malondialdehyde (MDA), and hydrogen peroxide (H2O2); and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and lypoxigenase (LOX) in rice leaves. Rice plants were grown in a nutrient solution containing 0 or 2 mM Si (-Si or +Si, respectively) with and without P. oryzae inoculation. Blast severity decreased with higher foliar Si concentration. The values of A, gs and E were generally higher for the +Si plants in comparison with the -Si plants upon P. oryzae infection. The Fv/Fm, qp, NPQ, and ETR were greater for the +Si plants relative to the -Si plants at 108 and 132 h after inoculation (hai). The values for qp and ETR were significantly higher for the -Si plants in comparison with the +Si plants at 36 hai, and the NPQ was significantly higher for the -Si plants in comparison with the +Si plants at 0 and 36 hai. The concentrations of Chla, Chlb, Chla+b, and carotenoids were significantly greater in the +Si plants relative to the -Si plants. For the -Si plants, the MDA and H2O2 concentrations were significantly higher than those in the +Si plants. The LOX activity was significantly higher in the +Si plants than in the -Si plants. The SOD and GR activities were significantly higher for the -Si plants than in the +Si plants. The CAT and APX activities were significantly higher in the +Si plants than in the -Si plants. The supply of

  6. Conceptual hierarchical modeling to describe wetland plant community organization

    Science.gov (United States)

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

  7. Genomic selection and association mapping in rice (Oryza sativa): effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Science.gov (United States)

    Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R

    2015-02-01

    Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  8. Genomic selection and association mapping in rice (Oryza sativa: effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Directory of Open Access Journals (Sweden)

    Jennifer Spindel

    2015-02-01

    Full Text Available Genomic Selection (GS is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  9. Simulating Phenology, Growth and Yield of Transplanted Rice at Different Seedling Ages in Northern Iran Using ORYZA2000

    Institute of Scientific and Technical Information of China (English)

    B. Amiri LARIJANI; Z. T. SARVESTANI; Gh. NEMATZADEH; A. M. MANSCHADI; E. AMIRI

    2011-01-01

    Rice crop growth and yield in the north Iran are affected by crop duration and phenology.The purpose of this study was to calibrate and validate the ORYZA2000 model under potential production based on experimental data for simulating and quantifying the phenological development,crop duration and yield prediction of rice crop influenced by different seedling ages.In order to calibrate and validate the crop parameters of ORYZA2000 model,a two-year field experiment was conducted under potential growth condition for transplanted lowland rice during the 2008-2009 rice growing seasons,using three rice varieties with three seedling ages (17,24 and 33 days old).The results showed that the seedling age changed crop duration from 7 to 10 d.The ORYZA2000 model could predict well,but consistently underestimated the length of growing period.The range in normalized root mean square error (RMSEn) values for each phenological stage was between 4% and 6%.From our evaluation,we concluded that ORYZA2000 was sufficiently accurate in simulation of yield,leaf area index (LAI) and biomass of crop organs over time.On average,RMSEn values were 13%-15% for total biomass,18% 21% for green leaf biomass,17%-20% for stem biomass,16%-23% for panicle biomass and 24%-26% for LAI.The RMSEn values for final yield and biomass were 12%-16% and 6%-9%,respectively.Generally,the model simulated LAI,an exceeded measured value for younger seedlings,and best-fit was observed for older seedlings of short-duration varieties.The results revealed that the ORYZA2000 model can be applied as a supportive research tool for selecting the most appropriate strategies for rice yield improvement across the north Iran.

  10. 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.

  11. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    Science.gov (United States)

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  12. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    Science.gov (United States)

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  13. Comparison of Genomes of Three Xanthomonas oryzae Bacteriophages

    Directory of Open Access Journals (Sweden)

    Chen Hui-Yi

    2007-11-01

    Full Text Available Abstract Background Xp10 and OP1 are phages of Xanthomonas oryzae pv. oryzae (Xoo, the causative agent of bacterial leaf blight in rice plants, which were isolated in 1967 in Taiwan and in 1954 in Japan, respectively. We recently isolated the Xoo phage Xop411. Results The linear Xop411 genome (44,520 bp, 58 ORFs sequenced here is 147 bp longer than that of Xp10 (60 ORFs and 735 bp longer than that of OP1 (59 ORFs. The G+C contents of OP1 (51% and Xop411 and Xp10 (52% each are less than that of the host (65%. The 9-bp 3'-overhangs (5'-GGACAGTCT-3' in Xop411 and Xp10 are absent from OP1. More of the deduced Xop411 proteins share higher degrees of identity with Xp10 than with OP1 proteins, while the right end of the genomes of Xp10 and OP1, containing all predicted promoters, share stronger homology. Xop411, Xp10, and OP1 contain 8, 7, and 6 freestanding HNH endonuclease genes, respectively. These genes can be classified into five groups depending on their possession of the HNH domain (HNN or HNH type and/or AP2 domain in intact or truncated forms. While the HNN-AP2 type endonuclease genes dispersed in the genome, the HNH type endonuclease genes, each with a unique copy, were located within the same genome context. Mass spectrometry and N-terminal sequencing showed nine Xop411 coat proteins, among which three were identified, six were assigned as coat proteins (4 and conserved phage proteins (2 in Xp10. The major coat protein, in which only the N-terminal methionine is removed, appears to exist in oligomeric forms containing 2 to 6 subunits. The three phages exhibit different patterns of domain duplication in the N-terminus of the tail fiber, which are involved in determination of the host range. Many short repeated sequences are present in and around the duplicated domains. Conclusion Geographical separation may have confined lateral gene transfer among the Xoo phages. The HNN-AP2 type endonucleases were more likely to transfer their genes

  14. The role of plant phenology in stomatal ozone flux modeling.

    Science.gov (United States)

    Anav, Alessandro; Liu, Qiang; De Marco, Alessandra; Proietti, Chiara; Savi, Flavia; Paoletti, Elena; Piao, Shilong

    2017-07-19

    Plant phenology plays a pivotal role in the climate system as it regulates the gas exchange between the biosphere and the atmosphere. The uptake of ozone by forest is estimated through several meteorological variables and a specific function describing the beginning and the termination of plant growing season; actually, in many risk assessment studies, this function is based on a simple latitude and topography model. In this study, using two satellite datasets, we apply and compare six methods to estimate the start and the end dates of the growing season across a large region covering all Europe for the year 2011. Results show a large variability between the green-up and dormancy dates estimated using the six different methods, with differences greater than one month. However, interestingly, all the methods display a common spatial pattern in the uptake of ozone by forests with a marked change in the magnitude, up to 1.9 TgO3 /year, and corresponding to a difference of 25% in the amount of ozone that enters the leaves. Our results indicate that improved estimates of ozone fluxes require a better representation of plant phenology in the models used for O3 risk assessment. © 2017 John Wiley & Sons Ltd.

  15. Geochemical modeling of cyanide in tailing dam gold processing plant

    Science.gov (United States)

    Khodadadi, Ahmad; Monjezi, M.; Mehrpouya, H.; Dehghani, H.

    2009-09-01

    This research is aimed at investigating possible neutralization of cyanide in tailing dam of Muteh gold processing plant in Isfahan, Iran at various conditions such as pH and temperature using USEPA Visual MINTEQ geochemical model simulation. The model is based on geochemical equilibrium which uses the simultaneous solution of the non-linear mass action expressions and linear mass balance relationships to formulate and solve the multiple-component chemical equilibrium problems. In this study the concentration of aqueous species in tailing dam as an aqueous, solid and gaseous were used as input in the model. Temperature and pH variation were simulated. The results of the model indicated that cyanide may be complexes in 10 < pH < 5. In other pH values complexation is not important. The results also indicated that cyanide reduction mechanism in acidic pH and temperature above 30°C is due to cyanide acid formation which is vaporized.

  16. Building and Researching the Bidding Model Based on the Cost of Power Plant

    Institute of Scientific and Technical Information of China (English)

    秦春申; 叶春; 赵景峰

    2004-01-01

    A bidding model of neural network was presented to pursue the largest benefit according to the policy of separating power plants from network and bidding transaction. This model bases on the cost of power plant and its research object is a power plant in the market. The market clearing price (MCP) can be predicted and an optimized load curve can be decided in this model. The model may provide technical support for the power plant.

  17. Genotoxin Induced Mutagenesis in the Model Plant Physcomitrella patens

    Directory of Open Access Journals (Sweden)

    Marcela Holá

    2013-01-01

    Full Text Available The moss Physcomitrella patens is unique for the high frequency of homologous recombination, haploid state, and filamentous growth during early stages of the vegetative growth, which makes it an excellent model plant to study DNA damage responses. We used single cell gel electrophoresis (comet assay to determine kinetics of response to Bleomycin induced DNA oxidative damage and single and double strand breaks in wild type and mutant lig4 Physcomitrella lines. Moreover, APT gene when inactivated by induced mutations was used as selectable marker to ascertain mutational background at nucleotide level by sequencing of the APT locus. We show that extensive repair of DSBs occurs also in the absence of the functional LIG4, whereas repair of SSBs is seriously compromised. From analysis of induced mutations we conclude that their accumulation rather than remaining lesions in DNA and blocking progression through cell cycle is incompatible with normal plant growth and development and leads to sensitive phenotype.

  18. Experimental validation of a solar-chimney power plant model

    Science.gov (United States)

    Fathi, Nima; Wayne, Patrick; Trueba Monje, Ignacio; Vorobieff, Peter

    2016-11-01

    In a solar chimney power plant system (SCPPS), the energy of buoyant hot air is converted to electrical energy. SCPPS includes a collector at ground level covered with a transparent roof. Solar radiation heats the air inside and the ground underneath. There is a tall chimney at the center of the collector, and a turbine located at the base of the chimney. Lack of detailed experimental data for validation is one of the important issues in modeling this type of power plants. We present a small-scale experimental prototype developed to perform validation analysis for modeling and simulation of SCCPS. Detailed velocity measurements are acquired using particle image velocimetry (PIV) at a prescribed Reynolds number. Convection is driven by a temperature-controlled hot plate at the bottom of the prototype. Velocity field data are used to perform validation analysis and measure any mismatch of the experimental results and the CFD data. CFD Code verification is also performed, to assess the uncertainly of the numerical model with respect to our grid and the applied mathematical model. The dimensionless output power of the prototype is calculated and compared with a recent analytical solution and the experimental results.

  19. Change of plant phenophases explained by survival modeling

    Science.gov (United States)

    Templ, Barbara; Fleck, Stefan; Templ, Matthias

    2017-05-01

    It is known from many studies that plant species show a delay in the timing of flowering events with an increase in latitude and altitude, and an advance with an increase in temperature. Furthermore, in many locations and for many species, flowering dates have advanced over the long-term. New insights using survival modeling are given based on data collected (1970-2010) along a 3000-km long transect from northern to eastern central Europe. We could clearly observe that in the case of dandelion ( Taraxacum officinale) the risk of flowering time, in other words the probability that flowering occurs, is higher for an earlier day of year in later decades. Our approach assume that temperature has greater influence than precipitation on the timing of flowering. Evaluation of the predictive power of tested models suggests that Cox models may be used in plant phenological research. The applied Cox model provides improved predictions of flowering dates compared to traditional regression methods and gives further insights into drivers of phenological events.

  20. CFD Modeling of Particulate Matter Dispersion from Kerman Cement Plant

    Directory of Open Access Journals (Sweden)

    M. Panahandeh

    2010-04-01

    Full Text Available "n "n "nBackgrounds and Objectives: The dispersion of particulate matter has been known as the most serious environmental pollution of cement plants. In the present work, dispersion of the particulate matter from stack of Kerman Cement Plant was investigated using Computational Fluid Dynamics (CFD modeling."nMaterials and Methods: In order to study the dispersion of particulate matter from the stack, a calculation domain with dimensions of 8000m × 800m × 400m was considered. The domain was divided to 936781 tetrahedral control volumes. The mixture two-phase model was employed to model the interaction of the particulate matter (dispersed phase and air (continuous phase. The Large Eddy Simulation (LES method was used for turbulence modeling."nResults: The concentration of particulate matter in the whole calculation domain was computed. The predicted concentrations were compared to the measured values from the literature and a good agreement was observed. The predicted concentration profiles at different cross sections were analyzed."nConclusion:The results of the present work showed that CFD is a useful tool for understanding the dispersion of particulate matter in air. Although the obtained results were promising, more investigations on the properties of the dispersed phase, turbulent parameters and the boundary layer effect is needed to obtain more accurate results.

  1. A soil-plant model applied to phytoremediation of metals.

    Science.gov (United States)

    Lugli, Francesco; Mahler, Claudio Fernando

    2016-01-01

    This study reports a phytoremediation pot experiment using an open-source program. Unsaturated water flow was described by the Richards' equation and solute transport by the advection-dispersion equation. Sink terms in the governing flow and transport equations accounted for root water and solute uptake, respectively. Experimental data were related to application of Vetiver grass to soil contaminated by metal ions. Sensitivity analysis revealed that due to the specific experimental set-up (bottom flux not allowed), hydraulic model parameters did not influence root water (and contaminant) uptake. In contrast, the results were highly correlated with plant solar radiation interception efficiency (leaf area index). The amounts of metals accumulated in the plant tissue were compared to numerical values of cumulative uptake. Pb(2+) and Zn(2+) uptake was satisfactorily described using a passive model. However, for Ni(2+) and Cd(2+), a specific calibration of the active uptake model was necessary. Calibrated MM parameters for Ni(2+), Cd(2+), and Pb(2+) were compared to values in the literature, generally suggesting lower rates and saturation advance. A parameter (saturation ratio) was introduced to assess the efficiency of contaminant uptake. Numerical analysis, applying actual field conditions, showed the limitation of the active model for being independent of the transpiration rate.

  2. Change of plant phenophases explained by survival modeling

    Science.gov (United States)

    Templ, Barbara; Fleck, Stefan; Templ, Matthias

    2016-11-01

    It is known from many studies that plant species show a delay in the timing of flowering events with an increase in latitude and altitude, and an advance with an increase in temperature. Furthermore, in many locations and for many species, flowering dates have advanced over the long-term. New insights using survival modeling are given based on data collected (1970-2010) along a 3000-km long transect from northern to eastern central Europe. We could clearly observe that in the case of dandelion (Taraxacum officinale) the risk of flowering time, in other words the probability that flowering occurs, is higher for an earlier day of year in later decades. Our approach assume that temperature has greater influence than precipitation on the timing of flowering. Evaluation of the predictive power of tested models suggests that Cox models may be used in plant phenological research. The applied Cox model provides improved predictions of flowering dates compared to traditional regression methods and gives further insights into drivers of phenological events.

  3. Modeling temperature variations in a pilot plant thermophilic anaerobic digester.

    Science.gov (United States)

    Valle-Guadarrama, Salvador; Espinosa-Solares, Teodoro; López-Cruz, Irineo L; Domaschko, Max

    2011-05-01

    A model that predicts temperature changes in a pilot plant thermophilic anaerobic digester was developed based on fundamental thermodynamic laws. The methodology utilized two simulation strategies. In the first, model equations were solved through a searching routine based on a minimal square optimization criterion, from which the overall heat transfer coefficient values, for both biodigester and heat exchanger, were determined. In the second, the simulation was performed with variable values of these overall coefficients. The prediction with both strategies allowed reproducing experimental data within 5% of the temperature span permitted in the equipment by the system control, which validated the model. The temperature variation was affected by the heterogeneity of the feeding and extraction processes, by the heterogeneity of the digestate recirculation through the heating system and by the lack of a perfect mixing inside the biodigester tank. The use of variable overall heat transfer coefficients improved the temperature change prediction and reduced the effect of a non-ideal performance of the pilot plant modeled.

  4. A dynamic model of plants' blossom based on L-system

    Science.gov (United States)

    Zhang, Ruoran; Zhang, Wenhui; Zhu, Ying; Wang, Huijao

    2010-11-01

    The article study L-system theory to modeling a visualization system which can expresses plants' growth and blossom by the Delphi language. This is according to growth process in the topology evolution and fractal geometry shape of plant, which extracts plant's growth rules to establish blossom models. The simulation is aim at modeling dynamic procedures, which can produces the lifelike plant images and demonstrates animations of growth processes. This new model emphasizes various parts of plant between space's and time's relationships. This mathematical models use biology to produce plant compartments of blossoms on growth of plants with correct images which ranges from time to time, and provides the lifelike continual growth sequence and through the natural principles to imitates and controls plants' blossoms and plant's diseases.

  5. Diversity of the Ty-1 copia retrotransposon Tos17 in rice (Oryza sativa L.) and the AA genome of the Oryza genus.

    Science.gov (United States)

    Petit, Julie; Bourgeois, Emmanuelle; Stenger, Wilfried; Bès, Martine; Droc, Gaétan; Meynard, Donaldo; Courtois, Brigitte; Ghesquière, Alain; Sabot, François; Panaud, Olivier; Guiderdoni, Emmanuel

    2009-12-01

    Retrotransposons are mobile genetic elements, ubiquitous in Eukaryotic genomes, which have proven to be major genetic tools in determining phylogeny and structuring genetic diversity, notably in plants. We investigate here the diversity of the Ty1-copia retrotransposon Tos17 in the cultivated rice of Asian origin (Oryza sativa L.) and related AA genome species of the Oryza genus, to contribute understanding of the complex evolutionary history in this group of species through that of the element in the lineages. In that aim, we used a combination of Southern hybridization with a reverse transcriptase (RT) probe and an adapter-PCR mediated amplification, which allowed the sequencing of the genomic regions flanking Tos17 insertions. This analysis was carried out in a collection of 47 A-genome Oryza species accessions and 202 accessions of a core collection of Oryza sativa L. representative of the diversity of the species. Our Southern hybridization results show that Tos17 is present in all the accessions of the A-genome Oryza species, except for the South American species O. glumaepatula and the African species O. glaberrima and O. breviligulata. In O. sativa, the number of putative copies of Tos17 per accession ranged from 1 to 11 and multivariate analysis based on presence/absence of putative copies yielded a varietal clustering which is consistent with the isozyme classification of rice. Adapter PCR amplification and sequencing of flanking regions of Tos17 insertions in A-genome species other than O. sativa, followed by anchoring on the Nipponbare genome sequence, revealed 13 insertion sites of Tos17 in the surveyed O. rufipogon and O. longistaminata accessions, including one shared by both species. In O. sativa, the same approach revealed 25 insertions in the 6 varietal groups. Four insertion sites located on chromosomes 1, 2, 10, and 11 were found orthologous in O. rufipogon and O. sativa. The chromosome 1 insertion was also shared between O. rufipogon and O

  6. 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.

  7. Modeling Operating Modes for the Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, H.; Jørgensen, Sten Bay

    2012-01-01

    The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...... for the Japanese fast breeder reactor plant MONJU....

  8. EFFICIENCY AND COST MODELLING OF THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Péter Bihari

    2010-01-01

    Full Text Available The proper characterization of energy suppliers is one of the most important components in the modelling of the supply/demand relations of the electricity market. Power generation capacity i. e. power plants constitute the supply side of the relation in the electricity market. The supply of power stations develops as the power stations attempt to achieve the greatest profit possible with the given prices and other limitations. The cost of operation and the cost of load increment are thus the most important characteristics of their behaviour on the market. In most electricity market models, however, it is not taken into account that the efficiency of a power station also depends on the level of the load, on the type and age of the power plant, and on environmental considerations. The trade in electricity on the free market cannot rely on models where these essential parameters are omitted. Such an incomplete model could lead to a situation where a particular power station would be run either only at its full capacity or else be entirely deactivated depending on the prices prevailing on the free market. The reality is rather that the marginal cost of power generation might also be described by a function using the efficiency function. The derived marginal cost function gives the supply curve of the power station. The load level dependent efficiency function can be used not only for market modelling, but also for determining the pollutant and CO2 emissions of the power station, as well as shedding light on the conditions for successfully entering the market. Based on the measurement data our paper presents mathematical models that might be used for the determination of the load dependent efficiency functions of coal, oil, or gas fuelled power stations (steam turbine, gas turbine, combined cycle and IC engine based combined heat and power stations. These efficiency functions could also contribute to modelling market conditions and determining the

  9. Diversity of bacteriophages infecting Xanthomonas oryzae pv. oryzae in paddy fields and its potential to control bacterial leaf blight of rice.

    Science.gov (United States)

    Chae, Jong-Chan; Hung, Nguyen Bao; Yu, Sang-Mi; Lee, Ha Kyung; Lee, Yong Hoon

    2014-06-28

    Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice-growing regions of the world. In spite of their economic importance, there are no effective ways of protecting rice plants from this disease. Bacteriophages infecting Xoo affect the population dynamics of the pathogen and consequently the occurrence of the disease. In this study, we investigated the diversity, host range, and infectivity of Xoo phages, and their use as a bicontrol agent on BLB was tested. Among the 34 phages that were isolated from floodwater in paddy fields, 29 belonged to the Myoviridae family, which suggests that the dominant phage in the ecosystem was Myoviridae. The isolated phages were classified into two groups based on plaque size produced on the lawn of Xoo. In general, there was a negative relationship between plaque size and host range, and interestingly the phages having a narrow host range had low efficiency of infectivity. The deduced protein sequence analysis of htf genes indicated that the gene was not a determinant of host specificity. Although the difference in host range and infectivity depending on morphotype needs to be addressed, the results revealed deeper understanding of the interaction between the phages and Xoo strains in floodwater and damp soil environments. The phage mixtures reduced the occurrence of BLB when they were treated with skim milk. The results indicate that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

  10. Identiifcation and Genetic Analysis of a Novel Rice Spotted-Leaf Mutant with Broad-Spectrum Resistance to Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    SHEN Hai-chao; SHI Yong-feng; FENG Bao-hua; WANG Hui-mei; XU Xia; HUANG Qi-na; LÜ Xiang-guang; WU Jian-li

    2014-01-01

    A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were signiifcantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was signiifcantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1 023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was ifnally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identiifed near the chromosomal region.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Micrasterias as a Model System in Plant Cell Biology

    Science.gov (United States)

    Lütz-Meindl, Ursula

    2016-01-01

    The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells. PMID:27462330

  13. Micrasterias as a model system in plant cell biology

    Directory of Open Access Journals (Sweden)

    Ursula Luetz-Meindl

    2016-07-01

    Full Text Available The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its extraordinary star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 µm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

  14. Biomimetic polymers of plant cutin: an approach from molecular modeling.

    Science.gov (United States)

    San-Miguel, Miguel A; Oviedo, Jaime; Heredia-Guerrero, Jose Alejandro; Heredia, Antonio; Benitez, Jose Jesus

    2014-07-01

    Biomimetics of materials is based on adopting and reproducing a model in nature with a well-defined functionality optimized through evolution. An example is barrier polymers that protect living tissues from the environment. The protecting layer of fruits, leaves, and non-lignified stems is the plant cuticle. The cuticle is a complex system in which the cutin is the main component. Cutin is a biopolyester made of polyhydroxylated carboxylic acids of 16 and 18 carbon atoms. The biosynthesis of cutin in plants is not well understood yet, but a direct chemical route involving the self-assembly of either molecules or molecular aggregates has been proposed. In this work, we present a combined study using experimental and simulation techniques on self-assembled layers of monomers selectively functionalized with hydroxyl groups. Our results demonstrate that the number and position of the hydroxyl groups are critical for the interaction between single molecules and the further rearrangement. Also, the presence of lateral hydroxyl groups reinforces lateral interactions and favors the bi-dimensional growth (2D), while terminal hydroxyl groups facilitate the formation of a second layer caused by head-tail interactions. The balance of 2D/3D growth is fundamental for the plant to create a protecting layer both large enough in 2D and thick enough in 3D.

  15. Simulation Modeling in Plant Breeding: Principles and Applications

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-kang; Wolfgang H Pfeiffer

    2007-01-01

    Conventional plant breeding largely depends on phenotypic selection and breeder's experience, therefore the breeding efficiency is low and the predictions are inaccurate. Along with the fast development in molecular biology and biotechnology, a large amount of biological data is available for genetic studies of important breeding traits in plants,which in turn allows the conduction of genotypic selection in the breeding process. However, gene information has not been effectively used in crop improvement because of the lack of appropriate tools. The simulation approach can utilize the vast and diverse genetic information, predict the cross performance, and compare different selection methods. Thus,the best performing crosses and effective breeding strategies can be identified. QuLine is a computer tool capable of defining a range, from simple to complex genetic models, and simulating breeding processes for developing final advanced lines. On the basis of the results from simulation experiments, breeders can optimize their breeding methodology and greatly improve the breeding efficiency. In this article, the underlying principles of simulation modeling in crop enhancement is initially introduced, following which several applications of QuLine are summarized, by comparing the different selection strategies, the precision parental selection, using known gene information, and the design approach in breeding. Breeding simulation allows the definition of complicated genetic models consisting of multiple alleles, pleiotropy, epistasis, and genes, by environment interaction, and provides a useful tool for breeders, to efficiently use the wide spectrum of genetic data and information available.

  16. Pigment and Virulence Deficiencies Associated with Mutations in the aroE Gene of Xanthomonas oryzae pv. oryzae

    OpenAIRE

    2001-01-01

    Xanthomonadins are yellow, membrane-bound pigments produced by members of the genus Xanthomonas. We identified an ethyl methanesulfonate-induced Xanthomonas oryzae pv. oryzae mutant (BXO65) that is deficient for xanthomonadin production and virulence on rice, as well as auxotrophic for aromatic amino acids (Pig− Vir− Aro−). Reversion analysis indicated that these multiple phenotypes are due to a single mutation. A genomic library of the wild-type strain was used to isolate a 7.0-kb clone that...

  17. Mathematical modelling of plant water and nutrient uptake

    Science.gov (United States)

    Roose, Tiina

    2010-05-01

    In this presentation I will describe a model of plant water and nutrient uptake and how to translate this model and experimental data from the single root scale to the root branching structure scale. The model starts at the single root scale and describes the water and nutrient movement in the soil using Richards' equation (water uptake) and diffusion-convection equation (nutrient uptake). The water and nutrient uptake in the single root scale model is represented by boundary conditions. In the case of nutrient uptake this has the form of a non-linear Michaelis-Menten uptake law and in the case of water this is given by a soil-xylem pressure difference boundary condition. The flow of water in the xylem is modeled as Poiseuille flow. We solve the single root scale models using the analytic approximate technique of asymptotic expansions similar to Oseen expansions known from fluid dynamics. We will then discuss how to use the analytic expression to estimate the water and nutrient uptake by growing root branching systems. We model the growth of the root system using a dynamic population model to describe the branching and elongation of roots in the branching system. This root branching population model results in a hyperbolic equation similar to age dependent population models and it can be solved fully analytically using the method of characteristics. Thus we have a fully analytic description of the root branching system evolution. We use this branching model to estimate the nutrient uptake in a scenario when the competition between subbranches is small, i.e., as it is in the case of phosphate, potassium and arsenic. We compare our approximate analytic model to a full 3d simulation of the root system phosphate uptake and find that the analytic model almost perfectly reproduces the 3d numerical model. In addition the analytic model can be included in larger field/catchment/climate scale models something which is not practically possible with the numerical simulations

  18. Plant functional type mapping for earth system models

    Directory of Open Access Journals (Sweden)

    B. Poulter

    2011-08-01

    Full Text Available The sensitivity of global carbon and water cycling to climate variability is coupled directly to land cover and the distribution of vegetation. To investigate biogeochemistry-climate interactions, earth system models require a representation of vegetation distributions that are either prescribed from remote sensing data or simulated via biogeography models. However, the abstraction of earth system state variables in models means that data products derived from remote sensing need to be post-processed for model-data assimilation. Dynamic global vegetation models (DGVM rely on the concept of plant functional types (PFT to group shared traits of thousands of plant species into just several classes. Available databases of observed PFT distributions must be relevant to existing satellite sensors and their derived products, and to the present day distribution of managed lands. Here, we develop four PFT datasets based on land-cover information from three satellite sensors (EOS-MODIS 1 km and 0.5 km, SPOT4-VEGETATION 1 km, and ENVISAT-MERIS 0.3 km spatial resolution that are merged with spatially-consistent Köppen-Geiger climate zones. Using a beta (β diversity metric to assess reclassification similarity, we find that the greatest uncertainty in PFT classifications occur most frequently between cropland and grassland categories, and in dryland systems between shrubland, grassland and forest categories because of differences in the minimum threshold required for forest cover. The biogeography-biogeochemistry DGVM, LPJmL, is used in diagnostic mode with the four PFT datasets prescribed to quantify the effect of land-cover uncertainty on climatic sensitivity of gross primary productivity (GPP and transpiration fluxes. Our results show that land-cover uncertainty has large effects in arid regions, contributing up to 30 % (20 % uncertainty in the sensitivity of GPP (transpiration to precipitation. The availability of plant functional type datasets that

  19. Wind Plant Models in IEC 61400-27-2 and WECC - latest developments in international standards on wind turbine and wind plant modeling

    DEFF Research Database (Denmark)

    Fortmann, Jens; Miller, Nicholas; Kazachkov, Yuri

    This paper describes the latest developments in the standardization of wind plant and wind plant controller models. As a first step IEC TC88 WG 27 and WECC jointly developed generic wind turbine models which have been published by WECC in 2014 and IEC in 2015 as IEC 61400-27-1, which also included...... a draft plant controller model in an informative annex. In a second step, parallel activities have been going on in WECC and IEC TC88 WG 27 to create plant models that can include a number of wind turbines, a plant controller and optional equipment. The WECC models are intended to be finalized in 2015......, the IEC models are expected to be published in 2017....

  20. Effects of cadmium on enzymatic and non-enzymatic antioxidative defences of rice (Oryza sativa L.).

    Science.gov (United States)

    Yu, Fangming; Liu, Kehui; Li, Mingshun; Zhou, Zhenming; Deng, Hua; Chen, Bin

    2013-01-01

    The effects of 60-d cadmium (Cd) exposure on enzymatic and non-enzymatic antioxidative system of Oryza sativa L. seedlings at tillering stage were studied using soil culture experiment. Research findings showed that chlorophyll content of Oryza sativa L. declined with the increase in soil metal concentration. Cd pollution induced the antioxidant stress by inducing O2(-1) and H2O2, which increased in plants; at the same time, MDA as the final product of peroxidation of membrane lipids, accumulated in plant. The antioxidant enzyme system was initiated under the Cd exposure, i.e. almost all the activities of superoxide dismutase (SOD), peroxidase, catalase, glutathione peroxidase, and ascorbate peroxidase were elevated both in leaves and roots. The non-protein thiols including phytochelatins and glutathione to scavenge toxic free radicals caused by Cd stress was also studied. The contents of phytochelatins and glutathione were about 3.12-6.65-fold and 3.27-10.73-fold in leaves, against control; and the corresponding values were about 3.53-9.37-fold and 1.41-5.11-fold in roots, accordingly.

  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. Higher plant modelling for life support applications: first results of a simple mechanistic model

    Science.gov (United States)

    Hezard, Pauline; Dussap, Claude-Gilles; Sasidharan L, Swathy

    2012-07-01

    In the case of closed ecological life support systems, the air and water regeneration and food production are performed using microorganisms and higher plants. Wheat, rice, soybean, lettuce, tomato or other types of eatable annual plants produce fresh food while recycling CO2 into breathable oxygen. Additionally, they evaporate a large quantity of water, which can be condensed and used as potable water. This shows that recycling functions of air revitalization and food production are completely linked. Consequently, the control of a growth chamber for higher plant production has to be performed with efficient mechanistic models, in order to ensure a realistic prediction of plant behaviour, water and gas recycling whatever the environmental conditions. Purely mechanistic models of plant production in controlled environments are not available yet. This is the reason why new models must be developed and validated. This work concerns the design and test of a simplified version of a mathematical model coupling plant architecture and mass balance purposes in order to compare its results with available data of lettuce grown in closed and controlled chambers. The carbon exchange rate, water absorption and evaporation rate, biomass fresh weight as well as leaf surface are modelled and compared with available data. The model consists of four modules. The first one evaluates plant architecture, like total leaf surface, leaf area index and stem length data. The second one calculates the rate of matter and energy exchange depending on architectural and environmental data: light absorption in the canopy, CO2 uptake or release, water uptake and evapotranspiration. The third module evaluates which of the previous rates is limiting overall biomass growth; and the last one calculates biomass growth rate depending on matter exchange rates, using a global stoichiometric equation. All these rates are a set of differential equations, which are integrated with time in order to provide

  3. A quantitative and dynamic model for plant stem cell regulation.

    Directory of Open Access Journals (Sweden)

    Florian Geier

    Full Text Available Plants maintain pools of totipotent stem cells throughout their entire life. These stem cells are embedded within specialized tissues called meristems, which form the growing points of the organism. The shoot apical meristem of the reference plant Arabidopsis thaliana is subdivided into several distinct domains, which execute diverse biological functions, such as tissue organization, cell-proliferation and differentiation. The number of cells required for growth and organ formation changes over the course of a plants life, while the structure of the meristem remains remarkably constant. Thus, regulatory systems must be in place, which allow for an adaptation of cell proliferation within the shoot apical meristem, while maintaining the organization at the tissue level. To advance our understanding of this dynamic tissue behavior, we measured domain sizes as well as cell division rates of the shoot apical meristem under various environmental conditions, which cause adaptations in meristem size. Based on our results we developed a mathematical model to explain the observed changes by a cell pool size dependent regulation of cell proliferation and differentiation, which is able to correctly predict CLV3 and WUS over-expression phenotypes. While the model shows stem cell homeostasis under constant growth conditions, it predicts a variation in stem cell number under changing conditions. Consistent with our experimental data this behavior is correlated with variations in cell proliferation. Therefore, we investigate different signaling mechanisms, which could stabilize stem cell number despite variations in cell proliferation. Our results shed light onto the dynamic constraints of stem cell pool maintenance in the shoot apical meristem of Arabidopsis in different environmental conditions and developmental states.

  4. Fob1 and Fob2 Proteins Are Virulence Determinants of Rhizopus oryzae via Facilitating Iron Uptake from Ferrioxamine.

    Science.gov (United States)

    Liu, Mingfu; Lin, Lin; Gebremariam, Teclegiorgis; Luo, Guanpingsheng; Skory, Christopher D; French, Samuel W; Chou, Tsui-Fen; Edwards, John E; Ibrahim, Ashraf S

    2015-05-01

    Dialysis patients with chronic renal failure receiving deferoxamine for treating iron overload are uniquely predisposed for mucormycosis, which is most often caused by Rhizopus oryzae. Although the deferoxamine siderophore is not secreted by Mucorales, previous studies established that Rhizopus species utilize iron from ferrioxamine (iron-rich form of deferoxamine). Here we determined that the CBS domain proteins of Fob1 and Fob2 act as receptors on the cell surface of R. oryzae during iron uptake from ferrioxamine. Fob1 and Fob2 cell surface expression was induced in the presence of ferrioxamine and bound radiolabeled ferrioxamine. A R. oryzae strain with targeted reduced Fob1/Fob2 expression was impaired for iron uptake, germinating, and growing on medium with ferrioxamine as the sole source of iron. This strain also exhibited reduced virulence in a deferoxamine-treated, but not the diabetic ketoacidotic (DKA), mouse model of mucormycosis. The mechanism by which R. oryzae obtains iron from ferrioxamine involves the reductase/permease uptake system since the growth on ferrioxamine supplemented medium is associated with elevated reductase activity and the use of the ferrous chelator bathophenanthroline disulfonate abrogates iron uptake and growth on medium supplemented with ferrioxamine as a sole source of iron. Finally, R. oryzae mutants with reduced copies of the high affinity iron permease (FTR1) or with decreased FTR1 expression had an impaired iron uptake from ferrioxamine in vitro and reduced virulence in the deferoxamine-treated mouse model of mucormycosis. These two receptors appear to be conserved in Mucorales, and can be the subject of future novel therapy to maintain the use of deferoxamine for treating iron-overload.

  5. Drosophila melanogaster "a potential model organism" for identification of pharmacological properties of plants/plant-derived components.

    Science.gov (United States)

    Panchal, Komal; Tiwari, Anand K

    2017-03-18

    Plants/plant-derived components have been used from ancient times to treat/cure several human diseases. Plants and their parts possess several chemical components that play the vital role in the improvement of human health and their life expectancy. Allopathic medicines have been playing a key role in the treatment of several diseases. Though allopathic medicines provide fast relief, long time consumption cause serious health concerns such as hyperallergic reactions, liver damage, etc. So, the study of medicinal plants which rarely cause any side effect is very important to mankind. Plants contain many health benefit properties like antioxidant, anti-aging, neuroprotective, anti-genotoxic, anti-mutagenic and bioinsecticidal activity. Thus, identification of pharmacological properties of plants/plant-derived components are of utmost importance to be explored. Several model organisms have been used to identify the pharmacological properties of the different plants or active components therein and Drosophila is one of them. Drosophila melanogaster "fruit fly" is a well understood, high-throughput model organism being used more than 110 years to study the different biological aspects related to the development and diseases. Most of the developmental and cell signaling pathways and ∼75% human disease-related genes are conserved between human and Drosophila. Using Drosophila, one can easily analyze the pharmacological properties of plants/plant-derived components by performing several assays available with flies such as survivorship, locomotor, antioxidant, cell death, etc. The current review focuses on the potential of Drosophila melanogaster for the identification of medicinal/pharmacological properties associated with plants/plant-derived components.

  6. A two-genome microarray for the rice pathogens Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola and its use in the discovery of a difference in their regulation of hrp genes

    Directory of Open Access Journals (Sweden)

    Lin Ye

    2008-06-01

    Full Text Available Abstract Background Xanthomonas oryzae pv. oryzae (Xoo and X. oryzae pv. oryzicola (Xoc are bacterial pathogens of the worldwide staple and grass model, rice. Xoo and Xoc are closely related but Xoo invades rice vascular tissue to cause bacterial leaf blight, a serious disease of rice in many parts of the world, and Xoc colonizes the mesophyll parenchyma to cause bacterial leaf streak, a disease of emerging importance. Both pathogens depend on hrp genes for type III secretion to infect their host. We constructed a 50–70 mer oligonucleotide microarray based on available genome data for Xoo and Xoc and compared gene expression in Xoo strains PXO99A and Xoc strain BLS256 grown in the rich medium PSB vs. XOM2, a minimal medium previously reported to induce hrp genes in Xoo strain T7174. Results Three biological replicates of the microarray experiment to compare global gene expression in representative strains of Xoo and Xoc grown in PSB vs. XOM2 were carried out. The non-specific error rate and the correlation coefficients across biological replicates and among duplicate spots revealed that the microarray data were robust. 247 genes of Xoo and 39 genes of Xoc were differentially expressed in the two media with a false discovery rate of 5% and with a minimum fold-change of 1.75. Semi-quantitative-RT-PCR assays confirmed differential expression of each of 16 genes each for Xoo and Xoc selected for validation. The differentially expressed genes represent 17 functional categories. Conclusion We describe here the construction and validation of a two-genome microarray for the two pathovars of X. oryzae. Microarray analysis revealed that using representative strains, a greater number of Xoo genes than Xoc genes are differentially expressed in XOM2 relative to PSB, and that these include hrp genes and other genes important in interactions with rice. An exception was the rax genes, which are required for production of the host resistance elicitor AvrXa21

  7. Modelling Hotspots for Invasive Alien Plants in India.

    Directory of Open Access Journals (Sweden)

    Dibyendu Adhikari

    Full Text Available Identification of invasion hotspots that support multiple invasive alien species (IAS is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM using species occurrence data from the Global Biodiversity Information Facility (GBIF. The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species.

  8. Modelling Hotspots for Invasive Alien Plants in India.

    Science.gov (United States)

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species.

  9. Mesoscopic Models of Plants Composed of Metallic Nanowires

    Institute of Scientific and Technical Information of China (English)

    Galina K.Strukova; Gennady V.Strukov; Evgeniya Yu.Postnova; Alexander Yu.Rusanov; Ivan S.Veshchunov

    2013-01-01

    Various metallic structures of complex shape resembling living plant organisms (biomimetics) are produced as a result of self-assembly of nanowires growing on porous membranes in the course of pulse current electrodeposition.These structures occur if the electroplating is continued after the nanowires appear on the membrane surface.By varying the membrane geometry,pulse current electroplating parameters,and alternating electrodeposition from two baths composed of a variety of electrolytes,diverse models were fabricated,including a hollow container with a wall thickness of 10 nm-20 nm.This biomimetic method suggests an analogy between the shape-forming processes of plants and their metallic models.Nanostructured mesostructures of various metals (Ag,Pd,Ni),alloys (PdNi,PbIn) and hybrid structures.(PdNi/Pb,PdNi/PbIn) were obtained.They can be of interest for fundamental research (self-assembly,morphogenesis) as well as for applications in nanotechnology (catalysis,nanoplasmonics,medicine,superhydrophobic surfaces).

  10. Comparative assessment of PV plant performance models considering climate effects

    DEFF Research Database (Denmark)

    Tina, Giuseppe; Ventura, Cristina; Sera, Dezso

    2017-01-01

    The paper investigates the effect of climate conditions on the accuracy of PV system performance models (physical and interpolation methods) which are used within a monitoring system as a reference for the power produced by a PV system to detect inefficient or faulty operating conditions....... The methodological approach is based on comparative tests of the analyzed models applied to two PV plants installed respectively in north of Denmark (Aalborg) and in the south of Italy (Agrigento). The different ambient, operating and installation conditions allow to understand how these factors impact the precision...... and effectiveness of such approaches, among these factors it is worth mentioning the different percentage of diffuse component of the yearly solar radiation on the global one. The experimental results show the effectiveness of the proposed approach. In order to have the possibility to analyze and compare...

  11. Modeling Operating Modes for the Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

    2012-01-01

    The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...

  12. Development of probabilistic models for quantitative pathway analysis of plant pests introduction for the EU territory

    NARCIS (Netherlands)

    Douma, J.C.; Robinet, C.; Hemerik, L.; Mourits, M.C.M.; Roques, A.; Werf, van der W.

    2015-01-01

    The aim of this report is to provide EFSA with probabilistic models for quantitative pathway analysis of plant pest introduction for the EU territory through non-edible plant products or plants. We first provide a conceptualization of two types of pathway models. The individual based PM simulates an

  13. Impact of genomics approaches on plant genetics and physiology.

    Science.gov (United States)

    Tabata, Satoshi

    2002-08-01

    Comprehensive analysis of genetic information in higher plants is under way for several plants of biological and agronomical importance. Among them, Arabidopsis thaliana, a member of Brassica family, and Oryza sativa(rice) have been chosen as model plants most suitable for genome analysis. Sequencing of the genome of A. thaliana was completed in December 2000, and rice genome sequencing is in progress. The accumulated genome sequences, together with the hundreds of thousands of ESTs from several tens of plant species, have drastically changed the strategy of plant genetics. By utilizing the information on the genome and gene structures, comprehensive approaches for genome-wide functional analysis of the genes, including transcriptome analysis using microarray systems and a comprehensive analysis of a large number of insertion mutant lines, have been widely adopted. As a consequence, a large quantity of information on both the structure and function of genes in these model plants has been accumulated. However, other plant species may have their own characteristics and advantages to study individual phenomena. Application of knowledge from the model plants to other plant species and vice versa through the common language, namely the genome information, should facilitate understanding of the genetic systems underlying a variety of biological phenomena. Introduction of this common language may not be very simple, especially in the case of complex pathways such as a process of cell-covering formation. Nevertheless, it should be emphasized that genomics approaches are the most promising way to understand these processes.

  14. Overexpression of MoSM1, encoding for an immunity-inducing protein from Magnaporthe oryzae, in rice confers broad-spectrum resistance against fungal and bacterial diseases

    Science.gov (United States)

    Hong, Yongbo; Yang, Yayun; Zhang, Huijuan; Huang, Lei; Li, Dayong; Song, Fengming

    2017-01-01

    Potential of MoSM1, encoding for a cerato-platanin protein from Magnaporthe oryzae, in improvement of rice disease resistance was examined. Transient expression of MoSM1 in rice leaves initiated hypersensitive response and upregulated expression of defense genes. When transiently expressed in tobacco leaves, MoSM1 targeted to plasma membrane. The MoSM1-overexpressing (MoSM1-OE) transgenic rice lines showed an improved resistance, as revealed by the reduced disease severity and decreased in planta pathogen growth, against 2 strains belonging to two different races of M. oryzae, causing blast disease, and against 2 strains of Xanthomonas oryzae pv. oryzae, causing bacterial leaf blight disease. However, no alteration in resistance to sheath blight disease was observed in MoSM1-OE lines. The MoSM1-OE plants contained elevated levels of salicylic acid (SA) and jasmonic acid (JA) and constitutively activated the expression of SA and JA signaling-related regulatory and defense genes. Furthermore, the MoSM1-OE plants had no effect on drought and salt stress tolerance and on grain yield. We conclude that MoSM1 confers a broad-spectrum resistance against different pathogens through modulating SA- and JA-mediated signaling pathways without any penalty on abiotic stress tolerance and grain yield, providing a promising potential for application of MoSM1 in improvement of disease resistance in crops. PMID:28106116

  15. Cell-cell signalling promotes ferric iron uptake in Xanthomonas oryzae pv. oryzicola that contribute to its virulence and growth inside rice.

    Science.gov (United States)

    Rai, Rikky; Javvadi, Sreegowrinadh; Chatterjee, Subhadeep

    2015-05-01

    Cell-cell communication mediated by diffusible signal factor (DSF) plays an important role in virulence of several Xanthomonas group of plant pathogens. In the bacterial pathogen of rice, Xanthomonas oryzae pv. oryzicola, DSF is required for virulence and in planta growth. In order to understand the role of DSF in promoting in planta growth and virulence, we have characterized the DSF deficient mutant of X. oryzae pv. oryzicola. Mutant analysis by expression analysis, radiolabelled iron uptake studies and growth under low-iron conditions indicated that DSF positively regulates ferric iron uptake. Further, the DSF deficient mutant of X. oryzae pv. oryzicola exhibited a reduced capacity to use ferric form of iron for growth under low-iron conditions. Exogenous iron supplementation in the rice leaves rescued the in planta growth deficiency of the DSF deficient mutant. These data suggest that DSF promotes in planta growth of X. oryzae pv. oryzicola by positively regulating functions involved in ferric iron uptake which is important for its virulence. Our results also indicate that requirement of iron uptake strategies to utilize either Fe(3+) or Fe(2+) form of iron for colonization may vary substantially among closely related members of the Xanthomonas group of plant pathogens.

  16. Carbohydrate-active enzymes from the zygomycete fungus Rhizopus oryzae: a highly specialized approach to carbohydrate degradation depicted at genome level

    Directory of Open Access Journals (Sweden)

    Henrissat Bernard

    2011-01-01

    Full Text Available Abstract Background Rhizopus oryzae is a zygomycete filamentous fungus, well-known as a saprobe ubiquitous in soil and as a pathogenic/spoilage fungus, causing Rhizopus rot and mucomycoses. Results Carbohydrate Active enzyme (CAZy annotation of the R. oryzae identified, in contrast to other filamentous fungi, a low number of glycoside hydrolases (GHs and a high number of glycosyl transferases (GTs and carbohydrate esterases (CEs. A detailed analysis of CAZy families, supported by growth data, demonstrates highly specialized plant and fungal cell wall degrading abilities distinct from ascomycetes and basidiomycetes. The specific genomic and growth features for degradation of easily digestible plant cell wall mono- and polysaccharides (starch, galactomannan, unbranched pectin, hexose sugars, chitin, chitosan, β-1,3-glucan and fungal cell wall fractions suggest specific adaptations of R. oryzae to its environment. Conclusions CAZy analyses of the genome of the zygomycete fungus R. oryzae and comparison to ascomycetes and basidiomycete species revealed how evolution has shaped its genetic content with respect to carbohydrate degradation, after divergence from the Ascomycota and Basidiomycota.

  17. Modeling and control for closed environment plant production systems

    Science.gov (United States)

    Fleisher, David H.; Ting, K. C.; Janes, H. W. (Principal Investigator)

    2002-01-01

    A computer program was developed to study multiple crop production and control in controlled environment plant production systems. The program simulates crop growth and development under nominal and off-nominal environments. Time-series crop models for wheat (Triticum aestivum), soybean (Glycine max), and white potato (Solanum tuberosum) are integrated with a model-based predictive controller. The controller evaluates and compensates for effects of environmental disturbances on crop production scheduling. The crop models consist of a set of nonlinear polynomial equations, six for each crop, developed using multivariate polynomial regression (MPR). Simulated data from DSSAT crop models, previously modified for crop production in controlled environments with hydroponics under elevated atmospheric carbon dioxide concentration, were used for the MPR fitting. The model-based predictive controller adjusts light intensity, air temperature, and carbon dioxide concentration set points in response to environmental perturbations. Control signals are determined from minimization of a cost function, which is based on the weighted control effort and squared-error between the system response and desired reference signal.

  18. Chemometric analysis of in-line multi-wavelength fluorescence measurements obtained during cultivations with a lipase producing Aspergillus oryzae strain

    DEFF Research Database (Denmark)

    Haack, Martin Brian; Eliasson Lantz, Anna; Mortensen, P.P.

    2007-01-01

    Thermomyces lanuginosus. Spectra of multi-wavelength fluorescence were collected every 5 min with the BioView system (DELTA, Denmark) and both explorative and predictive models, correlating the fluorescence data with cell mass and lipase activity, were built. During the cultivations, A. oryzae displayed......, estimating the cell mass, showed correlations between 0.73 and 0.97 with root mean square error of cross validation (RMSECV) values between 1.48 and 0.77 g (.) kg(-1). A model estimating the lipase activity was also constructed for the fed-batch cultivations with a correlation of 0.93. The results presented......The filamentous fungus, Aspergillus oryzae, was cultivated in batch and fed-batch cultivations in order to investigate the use of multi-wavelength fluorescence for monitoring course of events during filamentous fungi cultivations. The A. oryzae strain applied expressed a fungal lipase from...

  19. Modelling and characterization of primary settlers in view of whole plant and resource recovery modelling.

    Science.gov (United States)

    Bachis, Giulia; Maruéjouls, Thibaud; Tik, Sovanna; Amerlinck, Youri; Melcer, Henryk; Nopens, Ingmar; Lessard, Paul; Vanrolleghem, Peter A

    2015-01-01

    Characterization and modelling of primary settlers have been neglected pretty much to date. However, whole plant and resource recovery modelling requires primary settler model development, as current models lack detail in describing the dynamics and the diversity of the removal process for different particulate fractions. This paper focuses on the improved modelling and experimental characterization of primary settlers. First, a new modelling concept based on particle settling velocity distribution is proposed which is then applied for the development of an improved primary settler model as well as for its characterization under addition of chemicals (chemically enhanced primary treatment, CEPT). This model is compared to two existing simple primary settler models (Otterpohl and Freund; Lessard and Beck), showing to be better than the first one and statistically comparable to the second one, but with easier calibration thanks to the ease with which wastewater characteristics can be translated into model parameters. Second, the changes in the activated sludge model (ASM)-based chemical oxygen demand fractionation between inlet and outlet induced by primary settling is investigated, showing that typical wastewater fractions are modified by primary treatment. As they clearly impact the downstream processes, both model improvements demonstrate the need for more detailed primary settler models in view of whole plant modelling.

  20. Large-Scale Gene Disruption in Magnaporthe oryzae Identifies MC69, a Secreted Protein Required for Infection by Monocot and Dicot Fungal Pathogens

    Science.gov (United States)

    Saitoh, Hiromasa; Fujisawa, Shizuko; Mitsuoka, Chikako; Ito, Akiko; Hirabuchi, Akiko; Ikeda, Kyoko; Irieda, Hiroki; Yoshino, Kae; Yoshida, Kentaro; Matsumura, Hideo; Tosa, Yukio; Win, Joe; Kamoun, Sophien; Takano, Yoshitaka; Terauchi, Ryohei

    2012-01-01

    To search for virulence effector genes of the rice blast fungus, Magnaporthe oryzae, we carried out a large-scale targeted disruption of genes for 78 putative secreted proteins that are expressed during the early stages of infection of M. oryzae. Disruption of the majority of genes did not affect growth, conidiation, or pathogenicity of M. oryzae. One exception was the gene MC69. The mc69 mutant showed a severe reduction in blast symptoms on rice and barley, indicating the importance of MC69 for pathogenicity of M. oryzae. The mc69 mutant did not exhibit changes in saprophytic growth and conidiation. Microscopic analysis of infection behavior in the mc69 mutant revealed that MC69 is dispensable for appressorium formation. However, mc69 mutant failed to develop invasive hyphae after appressorium formation in rice leaf sheath, indicating a critical role of MC69 in interaction with host plants. MC69 encodes a hypothetical 54 amino acids protein with a signal peptide. Live-cell imaging suggested that fluorescently labeled MC69 was not translocated into rice cytoplasm. Site-directed mutagenesis of two conserved cysteine residues (Cys36 and Cys46) in the mature MC69 impaired function of MC69 without affecting its secretion, suggesting the importance of the disulfide bond in MC69 pathogenicity function. Furthermore, deletion of the MC69 orthologous gene reduced pathogenicity of the cucumber anthracnose fungus Colletotrichum orbiculare on both cucumber and Nicotiana benthamiana leaves. We conclude that MC69 is a secreted pathogenicity protein commonly required for infection of two different plant pathogenic fungi, M. oryzae and C. orbiculare pathogenic on monocot and dicot plants, respectively. PMID:22589729

  1. Large-scale gene disruption in Magnaporthe oryzae identifies MC69, a secreted protein required for infection by monocot and dicot fungal pathogens.

    Directory of Open Access Journals (Sweden)

    Hiromasa Saitoh

    Full Text Available To search for virulence effector genes of the rice blast fungus, Magnaporthe oryzae, we carried out a large-scale targeted disruption of genes for 78 putative secreted proteins that are expressed during the early stages of infection of M. oryzae. Disruption of the majority of genes did not affect growth, conidiation, or pathogenicity of M. oryzae. One exception was the gene MC69. The mc69 mutant showed a severe reduction in blast symptoms on rice and barley, indicating the importance of MC69 for pathogenicity of M. oryzae. The mc69 mutant did not exhibit changes in saprophytic growth and conidiation. Microscopic analysis of infection behavior in the mc69 mutant revealed that MC69 is dispensable for appressorium formation. However, mc69 mutant failed to develop invasive hyphae after appressorium formation in rice leaf sheath, indicating a critical role of MC69 in interaction with host plants. MC69 encodes a hypothetical 54 amino acids protein with a signal peptide. Live-cell imaging suggested that fluorescently labeled MC69 was not translocated into rice cytoplasm. Site-directed mutagenesis of two conserved cysteine residues (Cys36 and Cys46 in the mature MC69 impaired function of MC69 without affecting its secretion, suggesting the importance of the disulfide bond in MC69 pathogenicity function. Furthermore, deletion of the MC69 orthologous gene reduced pathogenicity of the cucumber anthracnose fungus Colletotrichum orbiculare on both cucumber and Nicotiana benthamiana leaves. We conclude that MC69 is a secreted pathogenicity protein commonly required for infection of two different plant pathogenic fungi, M. oryzae and C. orbiculare pathogenic on monocot and dicot plants, respectively.

  2. Coordination of Leaf Photosynthesis, Transpiration, and Structural Traits in Rice and Wild Relatives (Genus Oryza).

    Science.gov (United States)

    Giuliani, Rita; Koteyeva, Nuria; Voznesenskaya, Elena; Evans, Marc A; Cousins, Asaph B; Edwards, Gerald E

    2013-07-01

    The genus Oryza, which includes rice (Oryza sativa and Oryza glaberrima) and wild relatives, is a useful genus to study leaf properties in order to identify structural features that control CO(2) access to chloroplasts, photosynthesis, water use efficiency, and drought tolerance. Traits, 26 structural and 17 functional, associated with photosynthesis and transpiration were quantified on 24 accessions (representatives of 17 species and eight genomes). Hypotheses of associations within, and between, structure, photosynthesis, and transpiration were tested. Two main clusters of positively interrelated leaf traits were identified: in the first cluster were structural features, leaf thickness (Thick(leaf)), mesophyll (M) cell surface area exposed to intercellular air space per unit of leaf surface area (S(mes)), and M cell size; a second group included functional traits, net photosynthetic rate, transpiration rate, M conductance to CO(2) diffusion (g(m)), stomatal conductance to gas diffusion (g(s)), and the g(m)/g(s) ratio.While net photosynthetic rate was positively correlated with gm, neither was significantly linked with any individual structural traits. The results suggest that changes in gm depend on covariations of multiple leaf (S(mes)) and M cell (including cell wall thickness) structural traits. There was an inverse relationship between Thick(leaf) and transpiration rate and a significant positive association between Thick(leaf) and leaf transpiration efficiency. Interestingly, high g(m) together with high g(m)/g(s) and a low S(mes)/g(m) ratio (M resistance to CO(2) diffusion per unit of cell surface area exposed to intercellular air space) appear to be ideal for supporting leaf photosynthesis while preserving water; in addition, thick M cell walls may be beneficial for plant drought tolerance.

  3. Nonlinear Fuzzy Model Predictive Control for a PWR Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xiangjie Liu

    2014-01-01

    Full Text Available Reliable power and temperature control in pressurized water reactor (PWR nuclear power plant is necessary to guarantee high efficiency and plant safety. Since the nuclear plants are quite nonlinear, the paper presents nonlinear fuzzy model predictive control (MPC, by incorporating the realistic constraints, to realize the plant optimization. T-S fuzzy modeling on nuclear power plant is utilized to approximate the nonlinear plant, based on which the nonlinear MPC controller is devised via parallel distributed compensation (PDC scheme in order to solve the nonlinear constraint optimization problem. Improved performance compared to the traditional PID controller for a TMI-type PWR is obtained in the simulation.

  4. Optimization of Protease Production from Aspergillus Oryzae Sp. Using Box-Behnken Experimental Design

    Directory of Open Access Journals (Sweden)

    G. Srinu Babu

    2007-01-01

    Full Text Available Protease production by Aspergillus oryzae was optimized in shake-flask cultures using Box-Behnken experimental design. An empirical model was developed through response surface methodology to describe the relationship between tested variable (peptone, glucose, soyabeanmeal and pH. Maximum enzyme activity was attained with Peptone at 4 g∕L; temperature at 30 °C glucose at 6 g∕L; 30 °C and pH at 10. Experimental verification of the model showed a validation of 95%, which is more than 3-fold increase compare to the basal medium.

  5. ZERO-DIMENSIONAL MODEL OF A DIMETHYL ETHER (DME) PLANT BASED ON GASIFICATION OF TORREFIED BIOMASS

    OpenAIRE

    Clausen, Lasse Røngaard; Elmegaard, Brian; Houbak, Niels; Braun, Robert J.

    2009-01-01

    A model of a DME fuel production plant was designed and analyzed in Aspen Plus. The plant produces DME by catalytic conversion of a syngas generated by gasification of torrefied woody biomass. Torrefication is a mild pyrolysis process that takes place at 200-300°C. Torrefied biomass has properties similar to coal, which enables the use of commercially available coal gasification processing equipment. The DME plant model is integrated with a steam cycle that utilizes waste heat from the plant ...

  6. Plant functional type mapping for earth system models

    Directory of Open Access Journals (Sweden)

    B. Poulter

    2011-11-01

    Full Text Available The sensitivity of global carbon and water cycling to climate variability is coupled directly to land cover and the distribution of vegetation. To investigate biogeochemistry-climate interactions, earth system models require a representation of vegetation distributions that are either prescribed from remote sensing data or simulated via biogeography models. However, the abstraction of earth system state variables in models means that data products derived from remote sensing need to be post-processed for model-data assimilation. Dynamic global vegetation models (DGVM rely on the concept of plant functional types (PFT to group shared traits of thousands of plant species into usually only 10–20 classes. Available databases of observed PFT distributions must be relevant to existing satellite sensors and their derived products, and to the present day distribution of managed lands. Here, we develop four PFT datasets based on land-cover information from three satellite sensors (EOS-MODIS 1 km and 0.5 km, SPOT4-VEGETATION 1 km, and ENVISAT-MERIS 0.3 km spatial resolution that are merged with spatially-consistent Köppen-Geiger climate zones. Using a beta (ß diversity metric to assess reclassification similarity, we find that the greatest uncertainty in PFT classifications occur most frequently between cropland and grassland categories, and in dryland systems between shrubland, grassland and forest categories because of differences in the minimum threshold required for forest cover. The biogeography-biogeochemistry DGVM, LPJmL, is used in diagnostic mode with the four PFT datasets prescribed to quantify the effect of land-cover uncertainty on climatic sensitivity of gross primary productivity (GPP and transpiration fluxes. Our results show that land-cover uncertainty has large effects in arid regions, contributing up to 30% (20% uncertainty in the sensitivity of GPP (transpiration to precipitation. The availability of PFT datasets that are consistent

  7. Modeling Operating Modes for the Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

    2012-01-01

    The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition...... of the process plant, its function and its structural elements. The paper explains how the means-end concepts of MFM can be used to provide formalized definitions of plant operation modes. The paper will introduce the mode types defined by MFM and show how selected operation modes can be represented...

  8. Genome-wide analysis of potential cross-reactive endogenous allergens in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Fang Chao Zhu

    2015-01-01

    Full Text Available The proteins in the food are the source of common allergic components to certain patients. Current lists of plant endogenous allergens were based on the medical/clinical reports as well as laboratory results. Plant genome sequences made it possible to predict and characterize the genome-wide of putative endogenous allergens in rice (Oryza sativa L.. In this work, we identified and characterized 122 candidate rice allergens including the 22 allergens in present databases. Conserved domain analysis also revealed 37 domains among rice allergens including one novel domain (histidine kinase-, DNA gyrase B-, and HSP90-like ATPase, PF13589 adding to the allergen protein database. Phylogenetic analysis of the allergens revealed the diversity among the Prolamin superfamily and DnaK protein family, respectively. Additionally, some allergens proteins clustered on the rice chromosome might suggest the molecular function during the evolution.

  9. Phosphate uptake and allocation – a closer look at Arabidopsis thaliana L. and Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Ewa Młodzińska

    2016-08-01

    Full Text Available This year marks the 20th anniversary of the discovery and characterization of the two Arabidopsis PHT1 genes encoding the phosphate transporter in Arabidopsis thaliana. So far, multiple inorganic phosphate (Pi transporters have been described, and the molecular basis of Pi acquisition by plants has been well characterized. These genes are involved in Pi acquisition, allocation and/or signal transduction. This review summarizes how Pi is taken up by the roots and further distributed within two plants: Arabidopsis thaliana and Oryza sativa L. by plasma membrane phosphate transporters PHT1 and PHO1 as well as by intracellular transporters: PHO1, PHT2, PHT3, PHT4, PHT5 (VPT1, SPX-MFS and phosphate translocators family. We also describe the role of the PHT1 transporters in mycorrhizal roots of rice as an adaptive strategy to cope with limited phosphate availability in soil.

  10. First report of wheat blast caused by magnaporthe oryzae pathotype triticum in Bangladesh

    Science.gov (United States)

    Wheat blast or ‘brusone’, caused by the ascomycetous fungus Magnaporthe oryzae B.C. Couch (synonym Pyricularia oryzae Cavara), was first identified in 1985 in Brazil. M. oryzae is composed of a range of morphologically identical but genetically different host-specific pathotypes that are specialized...

  11. Cell biology of the Koji mold Aspergillus oryzae.

    Science.gov (United States)

    Kitamoto, Katsuhiko

    2015-01-01

    Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

  12. Modeling of biobasins of an oil refinery wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    RADOSTIN K. KUTSAROV

    2015-04-01

    Full Text Available The biobasins of the largest wastewater treatment plant (WWTP on the Balkans has been examined. Samples were taken four times from the inlet and outlet flow. The concentration of the total hydrocarbons, benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene and styrene in the wastewater has been obtained by gas chromatography. The average experimental concentrations were used when the mass balance was made. The results indicate that about 60% of pollutants are emitted in the air, about 22% are assimilated through biodegradation, and nearly 18% leave WWTP with the purified water. The measured concentrations were also modeled by Water 9.3 program. Comparison between the measured amounts of pollution concentrations and those forecasted by the Water 9.3 program has been made.

  13. A reductive aminase from Aspergillus oryzae

    Science.gov (United States)

    Aleku, Godwin A.; France, Scott P.; Man, Henry; Mangas-Sanchez, Juan; Montgomery, Sarah L.; Sharma, Mahima; Leipold, Friedemann; Hussain, Shahed; Grogan, Gideon; Turner, Nicholas J.

    2017-10-01

    Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm, Uniprot code Q2TW47) that can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to employ a 1:1 ratio of the substrates, forming amine products with up to 94% conversion. Steady-state kinetic studies establish that the enzyme is capable of catalysing imine formation as well as reduction. Crystal structures of AspRedAm in complex with NADP(H) and also with both NADP(H) and the pharmaceutical ingredient (R)-rasagiline are reported. We also demonstrate preparative scale reductive aminations with wild-type and Q240A variant biocatalysts displaying total turnover numbers of up to 32,000 and space time yields up to 3.73 g l‑1 d‑1.

  14. A new diketopiperazine alkaloid from Aspergillus oryzae.

    Science.gov (United States)

    Shaaban, Mohamed; El-Metwally, Mohammad Magdy; Nasr, Hamdi

    2014-01-01

    Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M2 medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid L-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), α-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, α-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps.

  15. Population genomic insights into variation and evolution of Xanthomonas oryzae pv. oryzae

    Science.gov (United States)

    Midha, Samriti; Bansal, Kanika; Kumar, Sanjeet; Girija, Anil Madhusoodana; Mishra, Deo; Brahma, Kranthi; Laha, Gouri Sankar; Sundaram, Raman Meenakshi; Sonti, Ramesh V.; Patil, Prabhu B.

    2017-01-01

    Xanthomonas oryzae pv. oryzae ( Xoo) is a serious pathogen of rice causing bacterial leaf blight disease. Resistant varieties and breeding programs are being hampered by the emergence of highly virulent strains. Herein we report population based whole genome sequencing and analysis of 100 Xoo strains from India. Phylogenomic analysis revealed the clustering of Xoo strains from India along with other Asian strains, distinct from African and US Xo strains. The Indian Xoo population consists of a major clonal lineage and four minor but highly diverse lineages. Interestingly, the variant alleles, gene clusters and highly pathogenic strains are primarily restricted to minor lineages L-II to L-V and in particularly to lineage L-III. We could also find the association of an expanded CRISPR cassette and a highly variant LPS gene cluster with the dominant lineage. Molecular dating revealed that the major lineage, L-I is youngest and of recent origin compared to remaining minor lineages that seems to have originated much earlier in the past. Further, we were also able to identify core effector genes that may be helpful in efforts towards building durable resistance against this pathogen. PMID:28084432

  16. Cloning and expression of a IuxRhomologue from Xanthomonas oryzae pv.Oryzae

    Institute of Scientific and Technical Information of China (English)

    Liang Bin; Guo Bin; Yang Chen; Zhang Xinjun; Dai Luyuan; Yu Tengqiong; Shen Daleng

    2006-01-01

    LuxR homologues are the main components of LuxR/LuxI circuit in Quorum Sensing(QS)of Gram-negative bacteria.A luxR homologue,designated as xooR,was cloned from Ⅹ.oryzae pv.oryzae.The xooR gene is atranscription factor with 765 bp inlength,and encodes a 254-amino acid putative protein with a molecular weight and an isoelectric point of 28.3 ku and 8.72 respectively.Amino acids 15 to 171 from the N-terminus are the Autoin-bind domain of XooR whereas amino acids 191 to 245 form a helix-turn-helix(HTH)motif that serves as the DNA-binding domain.In this study,XooR was expressed as a fusion protein along with green fluorescent protein(GFP),using pET-24a-d(+),a prokaryotic expression vector.Western blot showed that the xooR gene was successfully expressed in vitro in E.coli as a XooR-GFP fusion protein with a size of 54 ku.

  17. Deciphering the Role of Tyrosine Sulfation in Xanthomonas oryzae pv. oryzae Using Shotgun Proteomic Analysis

    Directory of Open Access Journals (Sweden)

    Hye-Jee Park

    2016-06-01

    Full Text Available A bacterial tyrosine sulfotransferase, RaxST, is required for activation of rice XA21-mediated immunity, and it catalyzes sulfation of tyrosine residues of Omp1X and RaxX in Xanthomonas oryzae pv. oryzae, a causal agent of bacterial blight in rice. Although RaxST is biochemically well-characterized, biological functions of tyrosine sulfation have not been fully elucidated. We compared protein expression patterns between the wildtype and a raxST knockout mutant using shotgun proteomic analysis. Forty nine proteins displayed a more than 1.5-fold difference in their expression between the wildtype and the mutant strains. Clusters of orthologous groups analysis revealed that proteins involved in cell motility were most abundant, and phenotypic observation also showed that the twitching motility of the mutant was dramatically changed. These results indicate that tyrosine sulfation by RaxST is essential for Xoo movement, and they provide new insights into the biological roles of RaxST in cellular processes.

  18. Role of DetR in defence is critical for virulence of Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Nguyen, Minh-Phuong; Park, Jongchan; Cho, Man-Ho; Lee, Sang-Won

    2016-05-01

    Like other bacteria, Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight disease in rice, possesses intracellular signalling systems, known as two-component regulatory systems (TCSs), which regulate pathogenesis and biological processes. Completion of the genome sequences of three Xoo strains has facilitated the functional study of genes, including those of TCSs, but the biological functions of most Xoo TCSs have not yet been uncovered. To identify TCSs involved in Xoo pathogenesis, we generated knockout strains lacking response regulators (RRs, a cytoplasmic signalling component of the TCS) and examined the virulence of the RR knockout strains. This study presents a knockout strain (detR(-) ) lacking the PXO_04659 gene which shows dramatically reduced virulence relative to the wild-type. Our studies to elucidate detR function in Xoo pathogenesis revealed a reduction in extracellular polysaccharide (EPS), intolerance to reactive oxygen species (ROS) and deregulation of iron homeostasis in the detR(-) strain. Moreover, gene expression of regulatory factors, including other RRs and transcription factors (TFs), was altered in the absence of DetR protein, as determined by reverse transcription-polymerase chain reaction (RT-PCR) and/or real-time quantitative RT-PCR analyses. All evidence leads to the conclusion that DetR is essential for Xoo virulence through the regulation of the Xoo defence system including EPS synthesis, ROS detoxification and iron homeostasis, solely or cooperatively with other regulatory factors.

  19. Modeling photosynthesis of discontinuous plant canopies by linking Geometric Optical Radiative Transfer model with biochemical processes

    Science.gov (United States)

    Xin, Q.; Gong, P.; Li, W.

    2015-02-01

    Modeling vegetation photosynthesis is essential for understanding carbon exchanges between terrestrial ecosystems and the atmosphere. The radiative transfer process within plant canopies is one of the key drivers that regulate canopy photosynthesis. Most vegetation cover consists of discrete plant crowns, of which the physical observation departs from the underlying assumption of a homogenous and uniform medium in classic radiative transfer theory. Here we advance the Geometric Optical Radiative Transfer (GORT) model to simulate photosynthesis activities for discontinuous plant canopies. We separate radiation absorption into two components that are absorbed by sunlit and shaded leaves, and derive analytical solutions by integrating over the canopy layer. To model leaf-level and canopy-level photosynthesis, leaf light absorption is then linked to the biochemical process of gas diffusion through leaf stomata. The canopy gap probability derived from GORT differs from classic radiative transfer theory, especially when the leaf area index is high, due to leaf clumping effects. Tree characteristics such as tree density, crown shape, and canopy length affect leaf clumping and regulate radiation interception. Modeled gross primary production (GPP) for two deciduous forest stands could explain more than 80% of the variance of flux tower measurements at both near hourly and daily time scales. We also demonstrate that the ambient CO2 concentration influences daytime vegetation photosynthesis, which needs to be considered in state-of-the-art biogeochemical models. The proposed model is complementary to classic radiative transfer theory and shows promise in modeling the radiative transfer process and photosynthetic activities over discontinuous forest canopies.

  20. Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C.

    2010-07-01

    This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

  1. Using Network Extracted Ontologies to Identify Novel Genes with Roles in Appressorium Development in the Rice Blast Fungus Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Ryan M. Ames

    2017-01-01

    Full Text Available Magnaporthe oryzae is the causal agent of rice blast disease, the most important infection of rice worldwide. Half the world’s population depends on rice for its primary caloric intake and, as such, rice blast poses a serious threat to food security. The stages of M. oryzae infection are well defined, with the formation of an appressorium, a cell type that allows penetration of the plant cuticle, particularly well studied. However, many of the key pathways and genes involved in this disease stage are yet to be identified. In this study, I have used network-extracted ontologies (NeXOs, hierarchical structures inferred from RNA-Seq data, to identify pathways involved in appressorium development, which in turn highlights novel genes with potential roles in this process. This study illustrates the use of NeXOs for pathway identification from large-scale genomics data and also identifies novel genes with potential roles in disease. The methods presented here will be useful to study disease processes in other pathogenic species and these data represent predictions of novel targets for intervention in M. oryzae.

  2. Yeast whole-cell biocatalyst constructed by intracellular overproduction of Rhizopus oryzae lipase is applicable to biodiesel fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, T.; Fukuda, H. [Kobe University, Kobe (Japan). Graduate School of Science and Technology, Division of Molecular Science; Takahashi, S.; Ueda, M.; Tanaka, A. [Kyoto University, Kyoto (Japan). Dept. of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering; Kaieda, M.; Kondo, A. [Kobe University, Kobe (Japan). Faculty of Engineering, Dept. of Chemical Science and Engineering

    2001-07-01

    Yeast whole-cell biocatalysts for lipase-catalyzed reactions were constructed by intracellularly overproducing Rhizopus oryzae lipase (ROL) in Saccharomyces cerevisiae MT8-1. The gene encoding lipase from R. oryzae IFO4697 was cloned, and intracellular overproduction systems of a recombinant ROL with a pro-sequence (rPRoROL) were constructed. When rProROL from R. oryzae IFO4697 was produced under the control of the 5'-upstream region of the isocitrate lyase gene of Candida tropicalis (UPR-ICL) at 30 C for 98 h by two-stage cultivation using SDC medium (SD medium with 2% casamino acids) containing 2.0% and 0.5% glucose, intracellular lipase activity reached levels up to 474.5 IU/l. These whole-cell biocatalysts were permeabilized by air-drying and used for the synthesis of methyl esters (MEs), a potential biodiesel fuel, from plant oil and methanol in a solvent-free and water-containing system. The ME content in the reaction mixture was 71 wt% after a 165-h reaction at 37 C with stepwise addition of methanol. These results indicate that an efficient whole-cell biocatalyst can be prepared by intracellular overproduction of lipase in yeast cells and their permeabilization. (orig.)

  3. A modelling framework to simulate foliar fungal epidemics using functional-structural plant models.

    Science.gov (United States)

    Garin, Guillaume; Fournier, Christian; Andrieu, Bruno; Houlès, Vianney; Robert, Corinne; Pradal, Christophe

    2014-09-01

    Sustainable agriculture requires the identification of new, environmentally responsible strategies of crop protection. Modelling of pathosystems can allow a better understanding of the major interactions inside these dynamic systems and may lead to innovative protection strategies. In particular, functional-structural plant models (FSPMs) have been identified as a means to optimize the use of architecture-related traits. A current limitation lies in the inherent complexity of this type of modelling, and thus the purpose of this paper is to provide a framework to both extend and simplify the modelling of pathosystems using FSPMs. Different entities and interactions occurring in pathosystems were formalized in a conceptual model. A framework based on these concepts was then implemented within the open-source OpenAlea modelling platform, using the platform's general strategy of modelling plant-environment interactions and extending it to handle plant interactions with pathogens. New developments include a generic data structure for representing lesions and dispersal units, and a series of generic protocols to communicate with objects representing the canopy and its microenvironment in the OpenAlea platform. Another development is the addition of a library of elementary models involved in pathosystem modelling. Several plant and physical models are already available in OpenAlea and can be combined in models of pathosystems using this framework approach. Two contrasting pathosystems are implemented using the framework and illustrate its generic utility. Simulations demonstrate the framework's ability to simulate multiscaled interactions within pathosystems, and also show that models are modular components within the framework and can be extended. This is illustrated by testing the impact of canopy architectural traits on fungal dispersal. This study provides a framework for modelling a large number of pathosystems using FSPMs. This structure can accommodate both

  4. Genotype × Environment Interactions of Yield Traits in Backcross Introgression Lines Derived from Oryza sativa cv. Swarna/Oryza nivara

    Science.gov (United States)

    Balakrishnan, Divya; Subrahmanyam, Desiraju; Badri, Jyothi; Raju, Addanki Krishnam; Rao, Yadavalli Venkateswara; Beerelli, Kavitha; Mesapogu, Sukumar; Surapaneni, Malathi; Ponnuswamy, Revathi; Padmavathi, G.; Babu, V. Ravindra; Neelamraju, Sarla

    2016-01-01

    Advanced backcross introgression lines (BILs) developed from crosses of Oryza sativa var. Swarna/O. nivara accessions were grown and evaluated for yield and related traits. Trials were conducted for consecutive three seasons in field conditions in a randomized complete block design with three replications. Data on yield traits under irrigated conditions were analyzed using the Additive Main Effect and Multiplicative Interaction (AMMI), Genotype and Genotype × Environment Interaction (GGE) and modified rank-sum statistic (YSi) for yield stability. BILs viz., G3 (14S) and G6 (166S) showed yield stability across the seasons along with high mean yield performance. G3 is early in flowering with high yield and has good grain quality and medium height, hence could be recommended for most of the irrigated locations. G6 is a late duration genotype, with strong culm strength, high grain number and panicle weight. G6 has higher yield and stability than Swarna but has Swarna grain type. Among the varieties tested DRRDhan 40 and recurrent parent Swarna showed stability for yield traits across the seasons. The component traits thousand grain weight, panicle weight, panicle length, grain number and plant height explained highest genotypic percentage over environment and interaction factors and can be prioritized to dissect stable QTLs/ genes. These lines were genotyped using microsatellite markers covering the entire rice genome and also using a set of markers linked to previously reported yield QTLs. It was observed that wild derived lines with more than 70% of recurrent parent genome were stable and showed enhanced yield levels compared to genotypes with higher donor genome introgressions.

  5. Increase of Fungal Pathogenicity and Role of Plant Glutamine in Nitrogen-Induced Susceptibility (NIS) To Rice Blast

    Science.gov (United States)

    Huang, Huichuan; Nguyen Thi Thu, Thuy; He, Xiahong; Gravot, Antoine; Bernillon, Stéphane; Ballini, Elsa; Morel, Jean-Benoit

    2017-01-01

    Highlight  Modifications in glutamine synthetase OsGS1-2 expression and fungal pathogenicity underlie nitrogen-induced susceptibility to rice blast. Understanding why nitrogen fertilization increase the impact of many plant diseases is of major importance. The interaction between Magnaporthe oryzae and rice was used as a model for analyzing the molecular mechanisms underlying Nitrogen-Induced Susceptibility (NIS). We show that our experimental system in which nitrogen supply strongly affects rice blast susceptibility only slightly affects plant growth. In order to get insights into the mechanisms of NIS, we conducted a dual RNA-seq experiment on rice infected tissues under two nitrogen fertilization regimes. On the one hand, we show that enhanced susceptibility was visible despite an over-induction of defense gene expression by infection under high nitrogen regime. On the other hand, the fungus expressed to high levels effectors and pathogenicity-related genes in plants under high nitrogen regime. We propose that in plants supplied with elevated nitrogen fertilization, the observed enhanced induction of plant defense is over-passed by an increase in the expression of the fungal pathogenicity program, thus leading to enhanced susceptibility. Moreover, some rice genes implicated in nitrogen recycling were highly induced during NIS. We further demonstrate that the OsGS1-2 glutamine synthetase gene enhances plant resistance to M. oryzae and abolishes NIS and pinpoint glutamine as a potential key nutrient during NIS. PMID:28293247

  6. Development and characterization of interspecific hybrids between Oryza sativa and O. latifolia by in situ hybridization

    Institute of Scientific and Technical Information of China (English)

    YI ChuanDeng; TANG ShuZhu; ZHOU Yong; LIANG GuoHua; GONG ZhiYun; GU MingHong

    2008-01-01

    Oryza sativa and O. latifolia belong to the AA and CCDD genomes of Oryza, respectively. In this study, interspecific hybrids of these species were obtained using the embryo rescue technique. Hybrid pani-cle traits, such as long awns, small grain, exoteric large purple stigma, grain shattering and dispersed panicles, resemble that of the paternal parent, O. latifolia, whereas there is obvious heterosis in such respects as plant height, tillering ability and vegetative vigor. Chromosome pairing and the genomic components of the hybrid were subsequently investigated using genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH) analysis. Based on the mitotic metaphase chromosome numbers of the root tips investigated, the hybrid is a triploid with 36 chromosomes. The genomic con-stitution of the hybrid is ACD. In the meiotic metaphase I of the hybrid pollen mother cell, poor chro-mosome pairing was identified and most of the chromosomes were univalent, which resulted in com-plete male sterility in the hybrid.

  7. Genetics of resistance to stored grain weevil (Sitophilus oryzae L. in maize

    Directory of Open Access Journals (Sweden)

    Rajkumar Zunjare

    2015-12-01

    Full Text Available Stored grain weevil (Sitophilus oryzae has emerged as important storage grain pest of maize, causing substantial economic losses. Owing to high costs and environmental hazards of pesticides, host plant resistance holds promise for effective control of weevils. In the present study, a set of experimental maize hybrids generated using line × tester mating design were evaluated against S. oryzae. Significant variation for grain weight loss (GWL (6.0–49.1%, number of insect progeny emerged (NIP (17.8–203.3, grain hardness (GH (263.1–495.4 N, and pericarp thickness (PT (60.3–161.0 μm was observed. Strong positive association was observed between GWL and NIP. GH and PT did not show any correlation with GWL and NIP. Additive and non-additive gene actions were important for both GWL and NIP. Promising inbreds and experimental crosses identified can be effectively utilized in the resistance breeding programme. In majority of promising