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Sample records for maize pathogen ustilago

  1. Establishment of compatibility in the Ustilago maydis/maize pathosystem

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    Doehlemann, Gunther; Wahl, Ramon; Vranes, Miroslav; de Vries, Ronald P; Kämper, Jörg; Kahmann, Regine

    The fungus Ustilago maydis is a biotrophic pathogen parasitizing on maize. The most prominent symptoms of the disease are large tumors in which fungal proliferation and spore differentiation occur. In this study, we have analyzed early and late tumor stages by confocal microscopy. We show that

  2. Utilizing virus-induced gene silencing for the functional characterization of maize genes during infection with the fungal pathogen Ustilago maydis.

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    van der Linde, Karina; Doehlemann, Gunther

    2013-01-01

    While in dicotyledonous plants virus-induced gene silencing (VIGS) is well established to study plant-pathogen interaction, in monocots only few examples of efficient VIGS have been reported so far. One of the available systems is based on the brome mosaic virus (BMV) which allows gene silencing in different cereals including barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays).Infection of maize plants by the corn smut fungus Ustilago maydis leads to the formation of large tumors on stem, leaves, and inflorescences. During this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed comprehensive and stage-specific changes in host gene expression during disease progression.To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a VIGS system based on the Brome mosaic virus (BMV) to maize at conditions that allow successful U. maydis infection of BMV pre-infected maize plants. This setup enables quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (q(RT)-PCR)-based readout.

  3. The WOPR Protein Ros1 Is a Master Regulator of Sporogenesis and Late Effector Gene Expression in the Maize Pathogen Ustilago maydis.

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    Marie Tollot

    2016-06-01

    Full Text Available The biotrophic basidiomycete fungus Ustilago maydis causes smut disease in maize. Hallmarks of the disease are large tumors that develop on all aerial parts of the host in which dark pigmented teliospores are formed. We have identified a member of the WOPR family of transcription factors, Ros1, as major regulator of spore formation in U. maydis. ros1 expression is induced only late during infection and hence Ros1 is neither involved in plant colonization of dikaryotic fungal hyphae nor in plant tumor formation. However, during late stages of infection Ros1 is essential for fungal karyogamy, massive proliferation of diploid fungal cells and spore formation. Premature expression of ros1 revealed that Ros1 counteracts the b-dependent filamentation program and induces morphological alterations resembling the early steps of sporogenesis. Transcriptional profiling and ChIP-seq analyses uncovered that Ros1 remodels expression of about 30% of all U. maydis genes with 40% of these being direct targets. In total the expression of 80 transcription factor genes is controlled by Ros1. Four of the upregulated transcription factor genes were deleted and two of the mutants were affected in spore development. A large number of b-dependent genes were differentially regulated by Ros1, suggesting substantial changes in this regulatory cascade that controls filamentation and pathogenic development. Interestingly, 128 genes encoding secreted effectors involved in the establishment of biotrophic development were downregulated by Ros1 while a set of 70 "late effectors" was upregulated. These results indicate that Ros1 is a master regulator of late development in U. maydis and show that the biotrophic interaction during sporogenesis involves a drastic shift in expression of the fungal effectome including the downregulation of effectors that are essential during early stages of infection.

  4. Nutritional value of huitlacoche, maize mushroom caused by Ustilago maydis

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    Mehmet AYDOĞDU

    2017-09-01

    Full Text Available Abstract Smutty maize cobs, caused by Ustilago maydis ((DC Corda., a fungus belonging to Basidiomycetes, can be seen wherever maize is grown. It is considered as a fungal disease limiting maize yield worldwide. However, in Mesoamerica, it is called as “huitlacoche” and evaluated as an edible mushroom. The present study was conducted to examine nutritional characteristics of this mushroom. In the study, smutty cobs naturally infected by U. maydis were randomly gleaned from plants in maize producing areas in the Mediterranean region of Turkey, in 2015. Huitlacoche was analyzed in terms of proximate composition, fatty acids, mineral elements, total phenolic and flavonoid matters and antioxidant activity. Average protein content was 12%, while fatty acids ranged from 0.44 to 42.49% (dry basis. Of the 11 fatty acids, oleic and linoleic acids had the highest percentages. Phosphorus (342.07 mg/kg and magnesium (262.69 mg/kg were found in high quantities. As for total phenolic and flavonoid matters were 113.11 mg GAE/kg and 28.51 mg CE/kg, respectively. The study suggests that huitlacoche has numerous good nutritional features for human diet, thus, it can be evaluated as a valuable food source in international cuisines.

  5. Systemic virus-induced gene silencing allows functional characterization of maize genes during biotrophic interaction with Ustilago maydis.

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    van der Linde, Karina; Kastner, Christine; Kumlehn, Jochen; Kahmann, Regine; Doehlemann, Gunther

    2011-01-01

    Infection of maize (Zea mays) plants with the corn smut fungus Ustilago maydis leads to the formation of large tumors on the stem, leaves and inflorescences. In this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed massive and stage-specific changes in host gene expression during disease progression. To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a virus-induced gene silencing (VIGS) system based on the brome mosaic virus (BMV) for maize. Conditions were established that allowed successful U. maydis infection of BMV-preinfected maize plants. This set-up enabled quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (qRT-PCR)-based readout. In proof-of-principle experiments, an U. maydis-induced terpene synthase was shown to negatively regulate disease development while a protein involved in cell death inhibition was required for full virulence of U. maydis. The results suggest that this system is a versatile tool for the rapid identification of maize genes that determine compatibility with U. maydis. © (2010) Max Planck Society. Journal compilation © New Phytologist Trust (2010).

  6. Two members of the Ustilago maydis velvet family influence teliospore development and virulence on maize seedlings.

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    Karakkat, Brijesh B; Gold, Scott E; Covert, Sarah F

    2013-12-01

    Members of the fungal-specific velvet protein family regulate sexual and asexual spore production in the Ascomycota. We predicted, therefore, that velvet homologs in the basidiomycetous plant pathogen Ustilago maydis would regulate sexual spore development, which is also associated with plant disease progression in this fungus. To test this hypothesis, we studied the function of three U. maydis velvet genes, umv1, umv2 and umv3. Using a gene replacement strategy, deletion mutants were made in all three genes in compatible haploid strains, and additionally for umv1 and umv2 in the solopathogenic strain, SG200. None of the mutants showed novel morphological phenotypes during yeast-like, in vitro growth. However, the Δumv1 mutants failed to induce galls or teliospores in maize. Chlorazol black E staining of leaves infected with Δumv1 dikaryons revealed that the Δumv1 hyphae did not proliferate normally and were blocked developmentally before teliospore formation. The Δumv2 mutants were able to induce galls and teliospores in maize, but were slow to do so and thus reduced in virulence. The Δumv3 mutants were not affected in teliospore formation or disease progression. Complementation of the Δumv1 and Δumv2 mutations in the SG200 background produced disease indices similar to those of SG200. These results indicate that two U. maydis velvet family members, umv1 and umv2, are important for normal teliospore development and disease progression in maize seedlings. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Selection of aggressive pathogenic and solopathogenic strains of Ustilago maydis to improve Huitlacoche production

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    Porfirio Raúl Galicia-García

    Full Text Available ABSTRACT Ustilago maydis is a basidiomycete known as the causative agent of 'common smut', worldwide disease of maize that is recognized by the galls it forms, which have considerable potential as a gourmet food. Results of infection are quite variable, even under optimal greenhouse conditions. In order to find pathogenic strains able to be used as a highly infective and stable inoculum for the successful production of galls either in greenhouses or in the field, ears with gall symptoms containing teliospores were recovered from maize plants. The teliospores were suspended in water and plated on nutrient-rich medium. Twenty-six colonies developed, containing three types of yeast-like colonies: saprotrophic, pathogenic, and solopathogenic. DAPI staining confirmed the presence of solopathogenic strains with diploid sporidia. Groups of different mating types were found when pairs of the 26 strains were arranged resembling partial-diallel combinations. Amplification of the partial b locus revealed that the strains found harbor the alleles b3 and b4, allowing the formation in dikaryotic strains of heterodimeric regulatory proteins associated with fungal development and pathogenicity. In this study, we isolated compatible haploid and solopathogenic diploid strains for their high capacity for inducing smut.

  8. Compatibility in the Ustilago maydis-maize interaction requires inhibition of host cysteine proteases by the fungal effector Pit2.

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    André N Mueller

    2013-02-01

    Full Text Available The basidiomycete Ustilago maydis causes smut disease in maize, with large plant tumors being formed as the most prominent disease symptoms. During all steps of infection, U. maydis depends on a biotrophic interaction, which requires an efficient suppression of plant immunity. In a previous study, we identified the secreted effector protein Pit2, which is essential for maintenance of biotrophy and induction of tumors. Deletion mutants for pit2 successfully penetrate host cells but elicit various defense responses, which stops further fungal proliferation. We now show that Pit2 functions as an inhibitor of a set of apoplastic maize cysteine proteases, whose activity is directly linked with salicylic-acid-associated plant defenses. Consequently, protease inhibition by Pit2 is required for U. maydis virulence. Sequence comparisons with Pit2 orthologs from related smut fungi identified a conserved sequence motif. Mutation of this sequence caused loss of Pit2 function. Consequently, expression of the mutated protein in U. maydis could not restore virulence of the pit2 deletion mutant, indicating that the protease inhibition by Pit2 is essential for fungal virulence. Moreover, synthetic peptides of the conserved sequence motif showed full activity as protease inhibitor, which identifies this domain as a new, minimal protease inhibitor domain in plant-pathogenic fungi.

  9. The role of repellents and hydrophobins in Ustilago maydis

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    Teertstra, W.R.

    2009-01-01

    Ustilago maydis is an important model organism to study fungal pathogenicity. U. maydis can grow yeast-like and filamentous. In the latter form this fungus infects maize. In my Thesis the expression and function of hydrophobins and repellents of U. maydis were studied. Hydrophobins are produced by

  10. The transcription factor Rbf1 is the master regulator for b-mating type controlled pathogenic development in Ustilago maydis.

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    Kai Heimel

    Full Text Available In the phytopathogenic basidiomycete Ustilago maydis, sexual and pathogenic development are tightly connected and controlled by the heterodimeric bE/bW transcription factor complex encoded by the b-mating type locus. The formation of the active bE/bW heterodimer leads to the formation of filaments, induces a G2 cell cycle arrest, and triggers pathogenicity. Here, we identify a set of 345 bE/bW responsive genes which show altered expression during these developmental changes; several of these genes are associated with cell cycle coordination, morphogenesis and pathogenicity. 90% of the genes that show altered expression upon bE/bW-activation require the zinc finger transcription factor Rbf1, one of the few factors directly regulated by the bE/bW heterodimer. Rbf1 is a novel master regulator in a multilayered network of transcription factors that facilitates the complex regulatory traits of sexual and pathogenic development.

  11. Pathogen Trojan Horse Delivers Bioactive Host Protein to Alter Maize Anther Cell Behavior in Situ.

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    van der Linde, Karina; Timofejeva, Ljudmilla; Egger, Rachel L; Ilau, Birger; Hammond, Reza; Teng, Chong; Meyers, Blake C; Doehlemann, Gunther; Walbot, Virginia

    2018-03-01

    Small proteins are crucial signals during development, host defense, and physiology. The highly spatiotemporal restricted functions of signaling proteins remain challenging to study in planta. The several month span required to assess transgene expression, particularly in flowers, combined with the uncertainties from transgene position effects and ubiquitous or overexpression, makes monitoring of spatiotemporally restricted signaling proteins lengthy and difficult. This situation could be rectified with a transient assay in which protein deployment is tightly controlled spatially and temporally in planta to assess protein functions, timing, and cellular targets as well as to facilitate rapid mutagenesis to define functional protein domains. In maize ( Zea mays ), secreted ZmMAC1 (MULTIPLE ARCHESPORIAL CELLS1) was proposed to trigger somatic niche formation during anther development by participating in a ligand-receptor module. Inspired by Homer's Trojan horse myth, we engineered a protein delivery system that exploits the secretory capabilities of the maize smut fungus Ustilago maydis , to allow protein delivery to individual cells in certain cell layers at precise time points. Pathogen-supplied ZmMAC1 cell-autonomously corrected both somatic cell division and differentiation defects in mutant Zm mac1-1 anthers. These results suggest that exploiting host-pathogen interactions may become a generally useful method for targeting host proteins to cell and tissue types to clarify cellular autonomy and to analyze steps in cell responses. © 2018 American Society of Plant Biologists. All rights reserved.

  12. The Filament-specific Rep1-1 Repellent of the Phytopathogen Ustilago maydis Forms Functional Surface-active Amyloid-like Fibrils

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    Teertstra, Wieke R.; van der Velden, Gisela J.; de Jong, Jan F.; Kruijtzer, John A. W.; Liskamp, Rob M. J.; Kroon-Batenburg, Loes M. J.; Muller, Wally H.; Gebbink, Martijn F. B. G.; Wosten, Han A. B.

    2009-01-01

    Repellents of the maize pathogen Ustilago maydis are involved in formation of hydrophobic aerial hyphae and in cellular attachment. These peptides, called Rep1-1 to Rep1-11, are encoded by the rep1 gene and result from cleavage of the precursor protein Rep1 during passage of the secretion pathway.

  13. A novel high-affinity sucrose transporter is required for virulence of the plant pathogen Ustilago maydis.

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    Ramon Wahl

    2010-02-01

    Full Text Available Plant pathogenic fungi cause massive yield losses and affect both quality and safety of food and feed produced from infected plants. The main objective of plant pathogenic fungi is to get access to the organic carbon sources of their carbon-autotrophic hosts. However, the chemical nature of the carbon source(s and the mode of uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1 from the corn smut fungus Ustilago maydis and its characterization as a fungal virulence factor. Srt1 has an unusually high substrate affinity, is absolutely sucrose specific, and allows the direct utilization of sucrose at the plant/fungal interface without extracellular hydrolysis and, thus, without the production of extracellular monosaccharides known to elicit plant immune responses. srt1 is expressed exclusively during infection, and its deletion strongly reduces fungal virulence. This emphasizes the central role of this protein both for efficient carbon supply and for avoidance of apoplastic signals potentially recognized by the host.

  14. KP4 to control Ustilago tritici in wheat: Enhanced greenhouse resistance to loose smut and changes in transcript abundance of pathogen related genes in infected KP4 plants.

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    Quijano, Carolina Diaz; Wichmann, Fabienne; Schlaich, Thomas; Fammartino, Alessandro; Huckauf, Jana; Schmidt, Kerstin; Unger, Christoph; Broer, Inge; Sautter, Christof

    2016-09-01

    Ustilago tritici causes loose smut, which is a seed-borne fungal disease of wheat, and responsible for yield losses up to 40%. Loose smut is a threat to seed production in developing countries where small scale farmers use their own harvest as seed material. The killer protein 4 (KP4) is a virally encoded toxin from Ustilago maydis and inhibits growth of susceptible races of fungi from the Ustilaginales. Enhanced resistance in KP4 wheat to stinking smut, which is caused by Tilletia caries, had been reported earlier. We show that KP4 in genetically engineered wheat increased resistance to loose smut up to 60% compared to the non-KP4 control under greenhouse conditions. This enhanced resistance is dose and race dependent. The overexpression of the transgene kp4 and its effect on fungal growth have indirect effects on the expression of endogenous pathogen defense genes.

  15. KP4 to control Ustilago tritici in wheat: Enhanced greenhouse resistance to loose smut and changes in transcript abundance of pathogen related genes in infected KP4 plants

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    Carolina Diaz Quijano

    2016-09-01

    Full Text Available Ustilago tritici causes loose smut, which is a seed-borne fungal disease of wheat, and responsible for yield losses up to 40%. Loose smut is a threat to seed production in developing countries where small scale farmers use their own harvest as seed material. The killer protein 4 (KP4 is a virally encoded toxin from Ustilago maydis and inhibits growth of susceptible races of fungi from the Ustilaginales. Enhanced resistance in KP4 wheat to stinking smut, which is caused by Tilletia caries, had been reported earlier. We show that KP4 in genetically engineered wheat increased resistance to loose smut up to 60% compared to the non-KP4 control under greenhouse conditions. This enhanced resistance is dose and race dependent. The overexpression of the transgene kp4 and its effect on fungal growth have indirect effects on the expression of endogenous pathogen defense genes.

  16. Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective

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    Olga Pechanova

    2015-11-01

    Full Text Available Maize (Zea mays L. is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus.

  17. Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective.

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    Pechanova, Olga; Pechan, Tibor

    2015-11-30

    Maize (Zea mays L.) is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus.

  18. Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal.

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    Sargın, İdris; Arslan, Gulsin; Kaya, Murat

    2016-03-15

    Designing effective chitosan-based biosorbents from unexploited biomass for heavy metal removal has received much attention over the past decade. Ustilago, loose smut, is a ubiquitous fungal plant pathogen infecting over 4000 species including maize and weed. This study aimed to establish whether the spores of the phytopathogenic microfungi Ustilago spores can be immobilised in cross-linked chitosan matrix, and it reports findings on heavy metal sorption performance of chitosan/Ustilago composite microcapsules. Immobilisation of Ustilago maydis and U. digitariae spores (from maize and weed) in chitosan microcapsules was achieved via glutaraldehyde cross-linking. The cross-linked microcapsules were characterised using scanning electron microscopy, FT-IR spectroscopy and thermogravimetric analysis. Sorption capacities of chitosan-U. maydis and chitosan-U. digitariae microcapsules were investigated and compared to cross-linked chitosan beads: Cu(II): 66.72, 69.26, 42.57; Cd(II): 49.46, 53.96, 7.87; Cr(III): 35.88, 49.40, 43.68; Ni(II): 41.67, 33.46, 16.43 and Zn(II): 30.73, 60.81, 15.04mg/g, respectively. Sorption experiments were conducted as a function of initial metal ion concentration (2-10mg/L), contact time (60-480min), temperature (25, 35 and 45°C), amount of the sorbent (0.05-0.25g) and pH of the metal solution. The microcapsules with spores exhibited better performance over the plain chitosan beads, demonstrating their potential use in water treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Gene discovery and transcript analyses in the corn smut pathogen Ustilago maydis: expressed sequence tag and genome sequence comparison

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    Saville Barry J

    2007-09-01

    Full Text Available Abstract Background Ustilago maydis is the basidiomycete fungus responsible for common smut of corn and is a model organism for the study of fungal phytopathogenesis. To aid in the annotation of the genome sequence of this organism, several expressed sequence tag (EST libraries were generated from a variety of U. maydis cell types. In addition to utility in the context of gene identification and structure annotation, the ESTs were analyzed to identify differentially abundant transcripts and to detect evidence of alternative splicing and anti-sense transcription. Results Four cDNA libraries were constructed using RNA isolated from U. maydis diploid teliospores (U. maydis strains 518 × 521 and haploid cells of strain 521 grown under nutrient rich, carbon starved, and nitrogen starved conditions. Using the genome sequence as a scaffold, the 15,901 ESTs were assembled into 6,101 contiguous expressed sequences (contigs; among these, 5,482 corresponded to predicted genes in the MUMDB (MIPS Ustilago maydis database, while 619 aligned to regions of the genome not yet designated as genes in MUMDB. A comparison of EST abundance identified numerous genes that may be regulated in a cell type or starvation-specific manner. The transcriptional response to nitrogen starvation was assessed using RT-qPCR. The results of this suggest that there may be cross-talk between the nitrogen and carbon signalling pathways in U. maydis. Bioinformatic analysis identified numerous examples of alternative splicing and anti-sense transcription. While intron retention was the predominant form of alternative splicing in U. maydis, other varieties were also evident (e.g. exon skipping. Selected instances of both alternative splicing and anti-sense transcription were independently confirmed using RT-PCR. Conclusion Through this work: 1 substantial sequence information has been provided for U. maydis genome annotation; 2 new genes were identified through the discovery of 619

  20. Post-genomic analyses of fungal lignocellulosic biomass degradation reveal the unexpected potential of the plant pathogen Ustilago maydis

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    Couturier Marie

    2012-02-01

    Full Text Available Abstract Background Filamentous fungi are potent biomass degraders due to their ability to thrive in ligno(hemicellulose-rich environments. During the last decade, fungal genome sequencing initiatives have yielded abundant information on the genes that are putatively involved in lignocellulose degradation. At present, additional experimental studies are essential to provide insights into the fungal secreted enzymatic pools involved in lignocellulose degradation. Results In this study, we performed a wide analysis of 20 filamentous fungi for which genomic data are available to investigate their biomass-hydrolysis potential. A comparison of fungal genomes and secretomes using enzyme activity profiling revealed discrepancies in carbohydrate active enzymes (CAZymes sets dedicated to plant cell wall. Investigation of the contribution made by each secretome to the saccharification of wheat straw demonstrated that most of them individually supplemented the industrial Trichoderma reesei CL847 enzymatic cocktail. Unexpectedly, the most striking effect was obtained with the phytopathogen Ustilago maydis that improved the release of total sugars by 57% and of glucose by 22%. Proteomic analyses of the best-performing secretomes indicated a specific enzymatic mechanism of U. maydis that is likely to involve oxido-reductases and hemicellulases. Conclusion This study provides insight into the lignocellulose-degradation mechanisms by filamentous fungi and allows for the identification of a number of enzymes that are potentially useful to further improve the industrial lignocellulose bioconversion process.

  1. Lipid droplets accumulation and other biochemical changes induced in the fungal pathogen Ustilago maydis under nitrogen-starvation.

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    Aguilar, Lucero Romero; Pardo, Juan Pablo; Lomelí, Mónica Montero; Bocardo, Oscar Ivan Luqueño; Juárez Oropeza, Marco A; Guerra Sánchez, Guadalupe

    2017-10-01

    In many organisms, the growth under nitrogen-deprivation or a poor nitrogen source impacts on the carbon flow distribution and causes accumulation of neutral lipids, which are stored as lipid droplets (LDs). Efforts are in progress to find the mechanism of LDs synthesis and degradation, and new organisms capable of accumulating large amounts of lipids for biotechnological applications. In this context, when Ustilago maydis was cultured in the absence of a nitrogen source, there was a large accumulation of lipid bodies containing mainly triacylglycerols. The most abundant fatty acids in lipid bodies at the stationary phase were palmitic, linoleic, and oleic acids, and they were synthesized de novo by the fatty-acid synthase. In regard to the production of NADPH for the synthesis of fatty acids, the cytosolic NADP + -dependent isocitrate dehydrogenase and the glucose-6-phosphate and 6-phosphogluconate dehydrogenases couple showed the highest specific activities, with a lower activity of the malic enzyme. The ATP-citrate lyase activity was not detected in any of the culture conditions, which points to a different mechanism for the transfer of acetyl-CoA into the cytosol. Protein and RNA contents decreased when U. maydis was grown without a nitrogen source. Due to the significant accumulation of triacylglycerols and the particular composition of fatty acids, U. maydis can be considered an alternative model for biotechnological applications.

  2. Characterization of the largest effector gene cluster of Ustilago maydis.

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    Thomas Brefort

    2014-07-01

    Full Text Available In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.

  3. The Ustilago maydis effector Pep1 suppresses plant immunity by inhibition of host peroxidase activity.

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    Christoph Hemetsberger

    Full Text Available The corn smut Ustilago maydis establishes a biotrophic interaction with its host plant maize. This interaction requires efficient suppression of plant immune responses, which is attributed to secreted effector proteins. Previously we identified Pep1 (Protein essential during penetration-1 as a secreted effector with an essential role for U. maydis virulence. pep1 deletion mutants induce strong defense responses leading to an early block in pathogenic development of the fungus. Using cytological and functional assays we show that Pep1 functions as an inhibitor of plant peroxidases. At sites of Δpep1 mutant penetrations, H₂O₂ strongly accumulated in the cell walls, coinciding with a transcriptional induction of the secreted maize peroxidase POX12. Pep1 protein effectively inhibited the peroxidase driven oxidative burst and thereby suppresses the early immune responses of maize. Moreover, Pep1 directly inhibits peroxidases in vitro in a concentration-dependent manner. Using fluorescence complementation assays, we observed a direct interaction of Pep1 and the maize peroxidase POX12 in vivo. Functional relevance of this interaction was demonstrated by partial complementation of the Δpep1 mutant defect by virus induced gene silencing of maize POX12. We conclude that Pep1 acts as a potent suppressor of early plant defenses by inhibition of peroxidase activity. Thus, it represents a novel strategy for establishing a biotrophic interaction.

  4. PATHOGENICITY OF FUSARIUM SPP. ISOLATED FROM WEEDS AND PLANT DEBRIS IN EASTERN CROATIA TO WHEAT AND MAIZE

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    Jelena Ilić

    2012-12-01

    Full Text Available Pathogenicity of thirty isolates representing 14 Fusarium species isolated from weeds and plant debris in eastern Croatia was investigated in the laboratory. Pathogenicity tests were performed on wheat and maize seedlings. The most pathogenic Fusarium spp. was F. graminearum isolated from Amaranthus retroflexus, Abutilon theophrasti and Chenopodium album. There was a noticeable inter- and intraspecies variability in pathogenicity towards wheat and maize. Isolates of F. solani from Sonchus arvensis and F. verticillioides from C. album were highly pathogenic to wheat seedlings and apathogenic to maize seedlings. Isolates of F. venenatum were very pathogenic to wheat and maize being the first report about pathogenicity of this species. This experiment proves that weeds and plant debris can serve as alternate hosts and source of inoculum of plant pathogens.

  5. Insights into Host Cell Modulation and Induction of New Cells by the Corn Smut Ustilago maydis

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    Amey Redkar

    2017-05-01

    Full Text Available Many filamentous fungal pathogens induce drastic modulation of host cells causing abnormal infectious structures such as galls, or tumors that arise as a result of re-programming in the original developmental cell fate of a colonized host cell. Developmental consequences occur predominantly with biotrophic phytopathogens. This suggests that these host structures result as an outcome of efficient defense suppression and intimate fungal–host interaction to suit the pathogen’s needs for completion of its infection cycle. This mini-review mainly summarizes host cell re-programming that occurs in the Ustilago maydis – maize interaction, in which the pathogen deploys cell-type specific effector proteins with varying activities. The fungus senses the physiological status and identity of colonized host cells and re-directs the endogenous developmental program of its host. The disturbance of host cell physiology and cell fate leads to novel cell shapes, increased cell size, and/or the number of host cells. We particularly highlight the strategies of U. maydis to induce physiologically varied host organs to form the characteristic tumors in both vegetative and floral parts of maize.

  6. Characterization of stuA mutants in the mycotoxigenic maize pathogen Fusarium verticillioides

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    Fusarium verticillioides is a major pathogen of maize, causing root, stalk and ear rots and seedling blight. It also produces fumonisin mycotoxins. Ingestion of fumonisin-contaminated corn causes acute toxicity in livestock and is a potential carcinogen to humans. StuA, an APSES protein class transc...

  7. The metabolome and transcriptome of the interaction between Ustilago maydis and Fusarium verticillioides in vitro

    Science.gov (United States)

    The metabolome and transcriptome of the maize-infecting fungi Ustilago maydis and Fusarium verticillioides were analyzed as the two fungi interact. Both fungi were grown for seven days in liquid medium alone or together in order to study how this interaction changes their metabolomic and transcripto...

  8. Variability of Pathogenicity of Fusarium spp. Originating from Maize and Wheat Grains

    Directory of Open Access Journals (Sweden)

    Sonja Tančić

    2009-01-01

    Full Text Available Differences in the pathogenicity of 93 isolates of seven species belonging to the genus Fusarium (F. graminearum, F. verticillioides, F. proliferatum, F. subglutinans, F. sporotrichioides, F. semitectum and F. equiseti, originating from maize kernels (61 and wheat grains (32, were examined based on the germination percentage of inoculated seeds. The studied species demonstrated inter- and intraspecies variability regarding the effects on maize seed germination. On the average, the greatest germination reduction was found in seeds inoculated with the spore suspensions of F. sporotrichioides and F. graminearum. A similar reduction was detected in seeds inoculated with F. proliferatum and F. subglutinans. The effect of F. subglutinans on seed germination reduction was higher compared to the two latter species, while the effects of F. semitectum and F. equiseti were smallest. The majority of isolates were of moderate pathogenicity, while the lowest number of isolates was either very pathogenic (7 or apathogenic (10. Pathogenicity of the isolates originating from wheat grains was generally lower than the pathogenicity of isolates originating from maize kernels, with the exception of F. sporotrichioides.

  9. Detection of Ustilago nuda (Jensen) Rostrup in winter barley seed

    OpenAIRE

    Ignjatov Maja; Petrović Dragana; Vujaković Milka; Taški-Ajduković Ksenija; Nikolić Zorica; Jovičić Dušica

    2011-01-01

    Barley is one of the most important cereals grown in our agroecological conditions. The causal agent of loose smut on barley Ustilago nuda (Jensen) Rostrup occurs frequently as varieties susceptible to this pathogen are present in the production. Disease symptoms are manifested on barley head (spike). Parasite is transmitted by seed (seedborne) and stays in the embryo tissue of the infected kernel as dormant mycelium. Recommended method for detection of U. nuda is given by ISTA Rules (method ...

  10. Ecological genetics of the Bromus tectorum (Poaceae) - Ustilago Bullata (Ustilaginaceae): A role for frequency dependent selection?

    Science.gov (United States)

    Susan E. Meyer; David L. Nelson; Suzette Clement; Alisa Ramakrishnan

    2010-01-01

    Evolutionary processes that maintain genetic diversity in plants are likely to include selection imposed by pathogens. Negative frequency-dependent selection is a mechanism for maintenance of resistance polymorphism in plant - pathogen interactions. We explored whether such selection operates in the Bromus tectorum - Ustilago bullata pathosystem. Gene-for-gene...

  11. Genetics of Resistance and Pathogenicity in the Maize/Setosphaeria turcica Pathosystem and Implications for Breeding

    Directory of Open Access Journals (Sweden)

    Ana L. Galiano-Carneiro

    2017-08-01

    Full Text Available Northern corn leaf blight (NCLB, the most devastating leaf pathogen in maize (Zea mays L., is caused by the heterothallic ascomycete Setosphaeria turcica. The pathogen population shows an extremely high genetic diversity in tropical and subtropical regions. Varietal resistance is the most efficient technique to control NCLB. Host resistance can be qualitative based on race-specific Ht genes or quantitative controlled by many genes with small effects. Quantitative resistance is moderately to highly effective and should be more durable combatting all races of the pathogen. Quantitative resistance must, however, be analyzed in many environments (= location × year combinations to select stable resistances. In the tropical and subtropical environments, quantitative resistance is the preferred option to manage NCLB epidemics. Resistance level can be increased in practical breeding programs by several recurrent selection cycles based on disease severity rating and/or by genomic selection. This review aims to address two important aspects of the NCLB pathosystem: the genetics of the fungus S. turcica and the modes of inheritance of the host plant maize, including successful breeding strategies regarding NCLB resistance. Both drivers of this pathosystem, pathogen, and host, must be taken into account to result in more durable resistance.

  12. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

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    Alberto Elías-Villalobos

    2015-08-01

    Full Text Available Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

  13. The effect of local population of Ustilago trichophora on Echinochloa crus-galli

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    Wojciech Pusz

    2014-08-01

    Full Text Available Ustilago trichophora is a pathogenic fungus infecting the grass of Echinochloa genus. The effect of this pathogen on the growth of Echinochloa was not yet described. Ustilago trichophora was found and described first time in Poland in 1998 on Echinochloa crus-galli specimen. ThenU. trichophora was found in several places in the region of Lower Silesia in the following years. The aim of the investigation was to study the effects of Ustilago trichophora on the biometric parameters of plants as well as of seeds of Echinochloa crus-galli. The infected specimens of barnyards grass were found lower, they displayed poorer tillering and they produced a smaller number of panicles than the healthy plants. Seeds from infected bunches weight, were characterized by lower germination and energy capacity than the control ones.

  14. Characterization of ApB73, a virulence factor important for colonization of Zea mays by the smut Ustilago maydis.

    Science.gov (United States)

    Stirnberg, Alexandra; Djamei, Armin

    2016-12-01

    The biotrophic fungus Ustilago maydis, the causal agent of corn smut disease, uses numerous small secreted effector proteins to suppress plant defence responses and reshape the host metabolism. However, the role of specific effectors remains poorly understood. Here, we describe the identification of ApB73 (Apathogenic in B73), an as yet uncharacterized protein essential for the successful colonization of maize by U. maydis. We show that apB73 is transcriptionally induced during the biotrophic stages of the fungal life cycle. The deletion of the apB73 gene results in cultivar-specific loss of gall formation in the host. The ApB73 protein is conserved among closely related smut fungi. However, using virulence assays, we show that only the orthologue of the maize-infecting head smut Sporisorium reilianum can complement the mutant phenotype of U. maydis. Although microscopy shows that ApB73 is secreted into the biotrophic interface, it seems to remain associated with fungal cell wall components or the fungal plasma membrane. Taken together, the results show that ApB73 is a conserved and important virulence factor of U. maydis that localizes to the interface between the pathogen and its host Zea mays. © 2016 THE AUTHORS. MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

  15. Evidence for resistance polymorphism in the Bromus tectorum/Ustilago bullata pathosystem: implications for biocontrol

    Science.gov (United States)

    S. E. Meyer; D. L. Nelson; S. Clement

    2001-01-01

    Bromus tectorum L. (cheatgrass or downy brome) is an important exotic weed in natural ecosystems as well as in winter cereal cropland in semiarid western North America. The systemic, seedling-infecting head smut pathogen Ustilago bullata Berk. commonly infects cheatgrass stands, often at epidemic levels. We examined factors...

  16. Huitlacoche yield in some maize varieties in the Mediterranean region of Turkey

    Directory of Open Access Journals (Sweden)

    Mehmet Aydoğdu

    2015-06-01

    Full Text Available Huitlacoche is the Aztecs name given to the smut galls on ears of maize caused by the pathogenic plant fungus Ustilago maydis [(DC Corda.]. It is known as maize mushroom, and it has been considered a delicacy and in Mesoamerica. The aim of the present study was to determine the responses of some maize varieties to the growth of the fungus in order to evaluate the prospect production of these smutty ears as a maize mushroom. A 2-year study was conducted in the Mediterranean region of Turkey in 2010 and 2011. Inoculations were performed by injecting inoculum into the ear through the silk channel of plants in plots. Each treatment had control plots. Average ear-gall (huitlacoche severity and incidence of all the varieties were at the rates of 4.0 and 41.6%, respectively. However, the highest severity of ear-gall (6.5 and incidence (60.6% were found in Karadeniz Yıldızı flint maize variety; colossal smutty ears were formed in the maize cultivars. This study showed that certain maize cultivars (flint corn and dent corn can be used efficiently in the production of huitlacoche.

  17. Molecular variability in the maize grey leaf spot pathogens in Brazil

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    Kátia R. Brunelli

    2008-01-01

    Full Text Available Isolates of Cercospora species from leaves displaying symptoms of grey leaf spot were collected in maize-producing areas of south-central Brazil in 2001 and 2002. Restriction digests of the internal transcribed spacer region of rDNA detected the presence of the same two Cercospora species described on maize in the United States, namely C. zeae-maydis and the recently described species, C. zeina . Genetic variability among isolates was assessed by analysing 104 amplified fragment length polymorphism loci. Cluster analysis confirmed the genetic separation of isolates into two species with a mean similarity of 35%. Similarity levels within species were high, averaging 93% and 92% among isolates of C. zeae-maydis and C. zeina , respectively. The mean genetic similarity between C. zeae-maydis and C. zeina and two isolates of C. sorghi f. sp. maydis was 45% and 35%, respectively. Results of this study showed that populations of the grey leaf spot pathogens in Brazil are similar to those in the United States regarding species composition and that C. zeina is also present in Brazil.

  18. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identity novel genes expressed during vegetative infectious, and repoductive growth

    NARCIS (Netherlands)

    Bluhm, B.H.; Lindquist, E.; Kema, G.H.J.; Goodwin, S.B.; Dunkle, L.D.

    2008-01-01

    The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The

  19. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Poten tial Mycotoxin Production in China

    Directory of Open Access Journals (Sweden)

    Canxing Duan

    2016-06-01

    Full Text Available Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B1, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China.

  20. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Potential Mycotoxin Production in China

    Science.gov (United States)

    Duan, Canxing; Qin, Zihui; Yang, Zhihuan; Li, Weixi; Sun, Suli; Zhu, Zhendong; Wang, Xiaoming

    2016-01-01

    Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B1, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China. PMID:27338476

  1. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Potential Mycotoxin Production in China.

    Science.gov (United States)

    Duan, Canxing; Qin, Zihui; Yang, Zhihuan; Li, Weixi; Sun, Suli; Zhu, Zhendong; Wang, Xiaoming

    2016-06-21

    Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B₁, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China.

  2. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identity novel genes expressed during vegetative infectious, and repoductive growth

    OpenAIRE

    Bluhm, B.H.; Lindquist, E.; Kema, G.H.J.; Goodwin, S.B.; Dunkle, L.D.

    2008-01-01

    The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from C. zeae-maydis and evaluate their expression during vegetative, infectious, and reproductive growth. R...

  3. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

    OpenAIRE

    Bluhm, Burton H; Dhillon, Braham; Lindquist, Erika A; Kema, Gert HJ; Goodwin, Stephen B; Dunkle, Larry D

    2008-01-01

    Abstract Background The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from C. zeae-maydis and evaluate their expression during vegetative, infectious, and re...

  4. Pep1, a secreted effector protein of Ustilago maydis, is required for successful invasion of plant cells.

    Directory of Open Access Journals (Sweden)

    Gunther Doehlemann

    2009-02-01

    Full Text Available The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1, that is essential for penetration. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, Deltapep1 mutants arrest during penetration of the epidermal cell and elicit a strong plant defense response. Using Affymetrix maize arrays, we identified 116 plant genes which are differentially regulated in Deltapep1 compared to wild type infections. Most of these genes are related to plant defense. By in vivo immunolocalization, live-cell imaging and plasmolysis approaches, we detected Pep1 in the apoplastic space as well as its accumulation at sites of cell-to-cell passages. Site-directed mutagenesis identified two of the four cysteine residues in Pep1 as essential for function, suggesting that the formation of disulfide bridges is crucial for proper protein folding. The barley covered smut fungus Ustilago hordei contains an ortholog of pep1 which is needed for penetration of barley and which is able to complement the U. maydis Deltapep1 mutant. Based on these results, we conclude that Pep1 has a conserved function essential for establishing compatibility that is not restricted to the U. maydis / maize interaction.

  5. Induction of infection in Teosinte (Zea diploperennis through the phytopathogen Ustilago maydis.

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    Martha Concepción Pérez Díaz

    2017-01-01

    Full Text Available Introduction: The corn and teosinte share morphological and molecular similarities latter being those that support the theory of teosinte (Zea parviglumis as its predecessor, both species are attacked by specific pathogens like Ustilago maydis. Objective: To analyze the infectious process that presents U. maydis on the variety of the teosinte Zea diploperennis. Materials and Methods: We used the strain of U. maydis FB-D12, which was kept a culture media rich in nutrients (CPES pH 7.0. Viable cells without morphological alterations to the inoculation method of puncture in teosinte seedlings were used. Monitoring of infection was carried out every 24 hours by measuring concentration of chlorophyll and plant tissue through microscopic observation Results: In the seedlings of Zea diploperennis inoculated with U. maydis the symptoms of the infection were presented, wilt and chlorosis in the leaves; The chlorosis was confirmed with the low concentration of chlorophyll 12 days later to the inoculation. In the microscopic observation of cuts of the tissue plant was found mycelium long and branched from the third day of the inoculation, until the appearance of tumors in seedlings of 45 days. Conclusions: The typical signs of infection with Ustilago maydis in the variety of teosinte Zea diploperennis do not differ from those reported for corn. Ustilago maydis presents its full life cycle within the plant, confirming that the diploperennis variety is susceptible.

  6. Deletion of the Ustilago maydis ortholog of the Aspergillus sporulation regulator medA affects mating and virulence through pheromone response

    Science.gov (United States)

    Mating of compatible haploid cells of Ustilago maydis is essential for infection and disease development in the host. For mating and subsequent filamentous growth and pathogenicity, the transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regul...

  7. Identification of O-mannosylated virulence factors in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Alfonso Fernández-Álvarez

    Full Text Available The O-mannosyltransferase Pmt4 has emerged as crucial for fungal virulence in the animal pathogens Candida albicans or Cryptococcus neoformans as well as in the phytopathogenic fungus Ustilago maydis. Pmt4 O-mannosylates specific target proteins at the Endoplasmic Reticulum. Therefore a deficient O-mannosylation of these target proteins must be responsible for the loss of pathogenicity in pmt4 mutants. Taking advantage of the characteristics described for Pmt4 substrates in Saccharomyces cerevisiae, we performed a proteome-wide bioinformatic approach to identify putative Pmt4 targets in the corn smut fungus U. maydis and validated Pmt4-mediated glycosylation of candidate proteins by electrophoretic mobility shift assays. We found that the signalling mucin Msb2, which regulates appressorium differentiation upstream of the pathogenicity-related MAP kinase cascade, is O-mannosylated by Pmt4. The epistatic relationship of pmt4 and msb2 showed that both are likely to act in the same pathway. Furthermore, constitutive activation of the MAP kinase cascade restored appressorium development in pmt4 mutants, suggesting that during the initial phase of infection the failure to O-mannosylate Msb2 is responsible for the virulence defect of pmt4 mutants. On the other hand we demonstrate that during later stages of pathogenic development Pmt4 affects virulence independently of Msb2, probably by modifying secreted effector proteins. Pit1, a protein required for fungal spreading inside the infected leaf, was also identified as a Pmt4 target. Thus, O-mannosylation of different target proteins affects various stages of pathogenic development in U. maydis.

  8. Pathogenicity of two seed-borne fungi commonly involved in maize ...

    African Journals Online (AJOL)

    Nazar Hussain

    2013-03-20

    Mar 20, 2013 ... pathogenicity on seeds and 6.55% on seedlings, whilst Aspergillus niger had 62.87% .... Nigrospora oryzae .... PDA culture in test tubes slants; (b) Fusarium moniliforme PDA culture in test tubes slants; (c) Mycoflora culture of.

  9. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth.

    Science.gov (United States)

    Bluhm, Burton H; Dhillon, Braham; Lindquist, Erika A; Kema, Gert Hj; Goodwin, Stephen B; Dunkle, Larry D

    2008-11-04

    The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from C. zeae-maydis and evaluate their expression during vegetative, infectious, and reproductive growth. A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of C. zeae-maydis. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value zeae-maydis, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of Cercospora and other groups of plant pathogenic fungi.

  10. Detection of Ustilago nuda (Jensen Rostrup in winter barley seed

    Directory of Open Access Journals (Sweden)

    Ignjatov Maja

    2011-01-01

    Full Text Available Barley is one of the most important cereals grown in our agroecological conditions. The causal agent of loose smut on barley Ustilago nuda (Jensen Rostrup occurs frequently as varieties susceptible to this pathogen are present in the production. Disease symptoms are manifested on barley head (spike. Parasite is transmitted by seed (seedborne and stays in the embryo tissue of the infected kernel as dormant mycelium. Recommended method for detection of U. nuda is given by ISTA Rules (method 7-013. In tests, nine samples (weighing 120 g each of naturally infected barley seed (about 1000 seeds, depending on the absolute mass of seed were examined, observed and described using a Zeiss microscope with sub stage illumination with magnification range x 40 or higher. Mycelium of the fungus approximately 3 μ thick, golden brown in colour was detected and visible without a stain. The percentage of infected embryos in the examined samples of barley seeds ranged from 0.8% to 5.2%.

  11. Characterization and comparative analysis of the genome of Puccinia sorghi Schwein, the causal agent of maize common rust.

    Science.gov (United States)

    Rochi, Lucia; Diéguez, María José; Burguener, Germán; Darino, Martín Alejandro; Pergolesi, María Fernanda; Ingala, Lorena Romina; Cuyeu, Alba Romina; Turjanski, Adrián; Kreff, Enrique Domingo; Sacco, Francisco

    2018-03-01

    Rust fungi are one of the most devastating pathogens of crop plants. The biotrophic fungus Puccinia sorghi Schwein (Ps) is responsible for maize common rust, an endemic disease of maize (Zea mays L.) in Argentina that causes significant yield losses in corn production. In spite of this, the Ps genomic sequence was not available. We used Illumina sequencing to rapidly produce the 99.6Mbdraft genome sequence of Ps race RO10H11247, derived from a single-uredinial isolate from infected maize leaves collected in the Argentine Corn Belt Region during 2010. High quality reads were obtained from 200bppaired-end and 5000bpmate-paired libraries and assembled in 15,722 scaffolds. A pipeline which combined an ab initio program with homology-based models and homology to in planta enriched ESTs from four cereal pathogenic fungus (the three sequenced wheat rusts and Ustilago maydis) was used to identify 21,087 putative coding sequences, of which 1599 might be part of the Ps RO10H11247 secretome. Among the 458 highly conserved protein families from the euKaryotic Orthologous Groups (KOG) that occur in a wide range of eukaryotic organisms, 97.5% have at least one member with high homology in the Ps assembly (TBlastN, E-value⩽e-10) covering more than 50% of the length of the KOG protein. Comparative studies with the three sequenced wheat rust fungus, and microsynteny analysis involving Puccinia striiformis f. sp. tritici (Pst, wheat stripe rust fungus), support the quality achieved. The results presented here show the effectiveness of the Illumina strategy for sequencing dikaryotic genomes of non-model organisms and provides reliable DNA sequence information for genomic studies, including pathogenic mechanisms of this maize fungus and molecular marker design. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Pathogenicity of fumonisin-producing and nonproducing strains of Aspergillus species in section Nigri to maize ears and seedlings

    Science.gov (United States)

    Species of Aspergillus section Nigri are commonly associated with maize kernels, and some strains can produce fumonisin mycotoxins. However, there is little information about the extent to which these fungi contribute to fumonisin contamination in grain, the damage they cause to maize ears, or their...

  13. A Restriction Fragment Length Polymorphism Map and Electrophoretic Karyotype of the Fungal Maize Pathogen Cochliobolus Heterostrophus

    Science.gov (United States)

    Tzeng, T. H.; Lyngholm, L. K.; Ford, C. F.; Bronson, C. R.

    1992-01-01

    A restriction fragment length polymorphism (RFLP) map has been constructed of the nuclear genome of the plant pathogenic ascomycete Cochliobolus heterostrophus. The segregation of 128 RFLP and 4 phenotypic markers was analyzed among 91 random progeny of a single cross; linkages were detected among 126 of the markers. The intact chromosomal DNAs of the parents and certain progeny were separated using pulsed field gel electrophoresis and hybridized with probes used to detect the RFLPs. In this way, 125 markers were assigned to specific chromosomes and linkages among 120 of the markers were confirmed. These linkages totalled 941 centimorgans (cM). Several RFLPs and a reciprocal translocation were identified tightly linked to Tox1, a locus controlling host-specific virulence. Other differences in chromosome arrangement between the parents were also detected. Fourteen gaps of at least 40 cM were identified between linkage groups on the same chromosomes; the total map length was therefore estimated to be, at a minimum, 1501 cM. Fifteen A chromosomes ranging from about 1.3 megabases (Mb) to about 3.7 Mb were identified; one of the strains also has an apparent B chromosome. This chromosome appears to be completely dispensable; in some progeny, all of 15 markers that mapped to this chromosome were absent. The total genome size was estimated to be roughly 35 Mb. Based on these estimates of map length and physical genome size, the average kb/cM ratio in this cross was calculated to be approximately 23. This low ratio of physical to map distance should make this RFLP map a useful tool for cloning genes. PMID:1346261

  14. Patterns of variation at Ustilago maydis virulence clusters 2A and 19A largely reflect the demographic history of its populations.

    Directory of Open Access Journals (Sweden)

    Ronny Kellner

    Full Text Available The maintenance of an intimate interaction between plant-biotrophic fungi and their hosts over evolutionary times involves strong selection and adaptative evolution of virulence-related genes. The highly specialised maize pathogen Ustilago maydis is assigned with a high evolutionary capability to overcome host resistances due to its high rates of sexual recombination, large population sizes and long distance dispersal. Unlike most studied fungus-plant interactions, the U. maydis - Zea mays pathosystem lacks a typical gene-for-gene interaction. It exerts a large set of secreted fungal virulence factors that are mostly organised in gene clusters. Their contribution to virulence has been experimentally demonstrated but their genetic diversity within U. maydis remains poorly understood. Here, we report on the intraspecific diversity of 34 potential virulence factor genes of U. maydis. We analysed their sequence polymorphisms in 17 isolates of U. maydis from Europe, North and Latin America. We focused on gene cluster 2A, associated with virulence attenuation, cluster 19A that is crucial for virulence, and the cluster-independent effector gene pep1. Although higher compared to four house-keeping genes, the overall levels of intraspecific genetic variation of virulence clusters 2A and 19A, and pep1 are remarkably low and commensurate to the levels of 14 studied non-virulence genes. In addition, each gene is present in all studied isolates and synteny in cluster 2A is conserved. Furthermore, 7 out of 34 virulence genes contain either no polymorphisms or only synonymous substitutions among all isolates. However, genetic variation of clusters 2A and 19A each resolve the large scale population structure of U. maydis indicating subpopulations with decreased gene flow. Hence, the genetic diversity of these virulence-related genes largely reflect the demographic history of U. maydis populations.

  15. Maize terpene volatiles serve as precursors to an array of defensive phytoalexins following insect and pathogen attack

    Science.gov (United States)

    Phytoalexins are inducible biochemicals that locally protect plant tissues against biotic attack. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquiterpene vol...

  16. Maize EMBRYO SAC family peptides interact differentially with pollen tubes and fungal cells.

    Science.gov (United States)

    Woriedh, Mayada; Merkl, Rainer; Dresselhaus, Thomas

    2015-08-01

    EMBRYO SAC1-4 (ES1-4) peptides belong to the defensin subgroup of cysteine-rich peptides known to mediate pollen tube burst in Zea mays (maize). ES1-4 are reported here to also be capable of inhibiting germination and growth of the maize fungal pathogens Fusarium graminearum and Ustilago maydis at higher concentrations. Dividing the peptides into smaller pieces showed that a 15-amino-acid peptide located in a highly variable loop region lacking similarity to other defensins or defensin-like peptides binds to maize pollen tube surfaces, causing swelling prior to burst. This peptide fragment and a second conserved neighbouring fragment showed suppression of fungal germination and growth. The two peptides caused swelling of fungal cells, production of reactive oxygen species, and finally the formation of big vacuoles prior to burst at high peptide concentration. Furthermore, peptide fragments were found to bind differently to fungal cells. In necrotrophic F. graminearum, a peptide fragment named ES-d bound only at cell surfaces whereas the peptide ES-c bound at cell surfaces and also accumulated inside cells. Conversely, in biotrophic U. maydis, both peptide fragments accumulated inside cells, but, if applied at higher concentration, ES-c but not ES-d accumulated mainly in vacuoles. Mapping of peptide interaction sites identified amino acids differing in pollen tube burst and fungal response reactions. In summary, these findings indicate that residues targeting pollen tube burst in maize are specific to the ES family, while residues targeting fungal growth are conserved within defensins and defensin-like peptides. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. RNA polymerase activity of Ustilago maydis virus

    Energy Technology Data Exchange (ETDEWEB)

    Yie, S.W.

    1986-01-01

    Ustilago maydis virus has an RNA polymerase enzyme which is associated with virion capsids. In the presence of Mg/sup 2 +/ ion and ribonucleotide triphosphate, the enzyme catalyzes the in vitro synthesis of mRNA by using dsRNA as a template. The products of the UmV RNA polymerase were both ssRNA and dsRNA. The dsRNA was determined by characteristic mobilities in gel electrophoresis, lack of sensitivity to RNase, and specific hybridization tests. The ssRNAs were identified by elution from a CF-11 column and by their RNase sensitivity. On the basis of the size of ssRNAs, it was concluded that partial transcripts were produced from H dsRNA segments, and full length transcripts were produced from M and L dsRNA segments. The following observations indicates that transcription occurs by strand displacement; (1) Only the positive strand of M2 dsRNA was labeled by the in vitro reaction. (2) The M2 dsRNA which had been labeled with /sup 32/''P-UTP in vitro could be chased from dsRNA with unlabeled UTP. The transcription products of three UmV strains were compared, and the overall pattern of transcription was very similar among them.

  18. Construction and functional analysis of Trichoderma harzianum mutants that modulate maize resistance to the pathogen Curvularia lunata.

    Science.gov (United States)

    Fan, Lili; Fu, Kehe; Yu, Chuanjin; Ma, Jia; Li, Yaqian; Chen, Jie

    2014-01-01

    Agrobacterium tumefaciens-mediated transformation (ATMT) was used to generate an insertional mutant library of the mycelial fungus Trichoderma harzianum. From a total of 450 mutants, six mutants that showed significant influence on maize resistance to C. lunata were analyzed in detail. Maize coated with these mutants was more susceptible to C. lunata compared with those coated with a wild-type (WT) strain. Similar to other fungal ATMT libraries, all six mutants were single copy integrations, which occurred preferentially in noncoding regions (except two mutants) and were frequently accompanied by the loss of border sequences. Two mutants (T66 and T312) that were linked to resistance were characterized further. Maize seeds coated with T66 and T312 were more susceptible to C. lunata than those treated with WT. Moreover, the mutants affected the resistance of maize to C. lunata by enhancing jasmonate-responsive gene expression. T66 and T312 induced maize resistance to C. lunata infection through a jasmonic acid-dependent pathway.

  19. Comparative Genomics of Smut Pathogens: Insights From Orphans and Positively Selected Genes Into Host Specialization

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    Juliana Benevenuto

    2018-04-01

    Full Text Available Host specialization is a key evolutionary process for the diversification and emergence of new pathogens. However, the molecular determinants of host range are poorly understood. Smut fungi are biotrophic pathogens that have distinct and narrow host ranges based on largely unknown genetic determinants. Hence, we aimed to expand comparative genomics analyses of smut fungi by including more species infecting different hosts and to define orphans and positively selected genes to gain further insights into the genetics basis of host specialization. We analyzed nine lineages of smut fungi isolated from eight crop and non-crop hosts: maize, barley, sugarcane, wheat, oats, Zizania latifolia (Manchurian rice, Echinochloa colona (a wild grass, and Persicaria sp. (a wild dicot plant. We assembled two new genomes: Ustilago hordei (strain Uhor01 isolated from oats and U. tritici (strain CBS 119.19 isolated from wheat. The smut genomes were of small sizes, ranging from 18.38 to 24.63 Mb. U. hordei species experienced genome expansions due to the proliferation of transposable elements and the amount of these elements varied among the two strains. Phylogenetic analysis confirmed that Ustilago is not a monophyletic genus and, furthermore, detected misclassification of the U. tritici specimen. The comparison between smut pathogens of crop and non-crop hosts did not reveal distinct signatures, suggesting that host domestication did not play a dominant role in shaping the evolution of smuts. We found that host specialization in smut fungi likely has a complex genetic basis: different functional categories were enriched in orphans and lineage-specific selected genes. The diversification and gain/loss of effector genes are probably the most important determinants of host specificity.

  20. Genetic diversity of Ustilago scitaminea Syd. in Southern China ...

    African Journals Online (AJOL)

    The polymorphism and similarity relationships among 35 mating-type isolates of Ustilago scitaminea collected from Southern China were determined with random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses. These fungal isolates were collected from 16 sugarcane cultivars ...

  1. Comparison of different inoculating methods to evaluate the pathogenicity and virulence of Aspergillus niger on two maize hybrids

    Science.gov (United States)

    A two-year field study was conducted to determine the effects of inoculation techniques on the aggressiveness of Aspergillus niger kernel infection in A. flavus resistant and susceptible maize hybrids. Ears were inoculated with the silk-channel, side-needle, and spray techniques 7 days after midsilk...

  2. Mycosarcoma (Ustilaginaceae), a resurrected generic name for corn smut (Ustilago maydis) and its close relatives with hypertrophied, tubular sori

    NARCIS (Netherlands)

    McTaggart, Alistair R; Shivas, Roger G; Boekhout, Teun; Oberwinkler, Franz; Vánky, Kálmán; Pennycook, Shaun R; Begerow, Dominik

    2016-01-01

    Ustilago is a polyphyletic genus of smut fungi found mainly on Poaceae. The development of a taxonomy that reflects phylogeny requires subdivision of Ustilago into smaller monophyletic genera. Several separate systematic analyses have determined that Macalpinomyces mackinlayi, M. tubiformis,

  3. ChLae1 and ChVel1 regulate T-toxin production, virulence, oxidative stress response, and development of the maize pathogen Cochliobolus heterostrophus.

    Directory of Open Access Journals (Sweden)

    Dongliang Wu

    2012-02-01

    Full Text Available LaeA and VeA coordinate secondary metabolism and differentiation in response to light signals in Aspergillus spp. Their orthologs, ChLae1 and ChVel1, were identified in the maize pathogen Cochliobolus heterostrophus, known to produce a wealth of secondary metabolites, including the host selective toxin, T-toxin. Produced by race T, T-toxin promotes high virulence to maize carrying Texas male sterile cytoplasm (T-cms. T-toxin production is significantly increased in the dark in wild type (WT, whereas Chvel1 and Chlae1 mutant toxin levels are much reduced in the dark compared to WT. Correspondingly, expression of T-toxin biosynthetic genes (Tox1 is up-regulated in the dark in WT, while dark-induced expression is much reduced/minimal in Chvel1 and Chlae1 mutants. Toxin production and Tox1 gene expression are increased in ChVEL1 overexpression (OE strains grown in the dark and in ChLAE1 strains grown in either light or dark, compared to WT. These observations establish ChLae1 and ChVel1 as the first factors known to regulate host selective toxin production. Virulence of Chlae1 and Chvel1 mutants and OE strains is altered on both T-cms and normal cytoplasm maize, indicating that both T-toxin mediated super virulence and basic pathogenic ability are affected. Deletion of ChLAE1 or ChVEL1 reduces tolerance to H(2O(2. Expression of CAT3, one of the three catalase genes, is reduced in the Chvel1 mutant. Chlae1 and Chvel1 mutants also show decreased aerial hyphal growth, increased asexual sporulation and female sterility. ChLAE1 OE strains are female sterile, while ChVEL1 OE strains are more fertile than WT. ChLae1 and ChVel1 repress expression of 1,8-dihydroxynaphthalene (DHN melanin biosynthesis genes, and, accordingly, melanization is enhanced in Chlae1 and Chvel1 mutants, and reduced in OE strains. Thus, ChLae1 and ChVel1 positively regulate T-toxin biosynthesis, pathogenicity and super virulence, oxidative stress responses, sexual development, and

  4. A gene encoding maize caffeoyl-CoA O-methyltransferase confers quantitative resistance to multiple pathogens.

    Science.gov (United States)

    Yang, Qin; He, Yijian; Kabahuma, Mercy; Chaya, Timothy; Kelly, Amy; Borrego, Eli; Bian, Yang; El Kasmi, Farid; Yang, Li; Teixeira, Paulo; Kolkman, Judith; Nelson, Rebecca; Kolomiets, Michael; L Dangl, Jeffery; Wisser, Randall; Caplan, Jeffrey; Li, Xu; Lauter, Nick; Balint-Kurti, Peter

    2017-09-01

    Alleles that confer multiple disease resistance (MDR) are valuable in crop improvement, although the molecular mechanisms underlying their functions remain largely unknown. A quantitative trait locus, qMdr 9.02 , associated with resistance to three important foliar maize diseases-southern leaf blight, gray leaf spot and northern leaf blight-has been identified on maize chromosome 9. Through fine-mapping, association analysis, expression analysis, insertional mutagenesis and transgenic validation, we demonstrate that ZmCCoAOMT2, which encodes a caffeoyl-CoA O-methyltransferase associated with the phenylpropanoid pathway and lignin production, is the gene within qMdr 9.02 conferring quantitative resistance to both southern leaf blight and gray leaf spot. We suggest that resistance might be caused by allelic variation at the level of both gene expression and amino acid sequence, thus resulting in differences in levels of lignin and other metabolites of the phenylpropanoid pathway and regulation of programmed cell death.

  5. Complementation of CTB7 in the Maize Pathogen Cercospora zeina Overcomes the Lack of In Vitro Cercosporin Production.

    Science.gov (United States)

    Swart, Velushka; Crampton, Bridget G; Ridenour, John B; Bluhm, Burt H; Olivier, Nicholas A; Meyer, J J Marion; Berger, Dave K

    2017-09-01

    Gray leaf spot (GLS), caused by the sibling species Cercospora zeina or Cercospora zeae-maydis, is cited as one of the most important diseases threatening global maize production. C. zeina fails to produce cercosporin in vitro and, in most cases, causes large coalescing lesions during maize infection, a symptom generally absent from cercosporin-deficient mutants in other Cercospora spp. Here, we describe the C. zeina cercosporin toxin biosynthetic (CTB) gene cluster. The oxidoreductase gene CTB7 contained several insertions and deletions as compared with the C. zeae-maydis ortholog. We set out to determine whether complementing the defective CTB7 gene with the full-length gene from C. zeae-maydis could confer in vitro cercosporin production. C. zeina transformants containing C. zeae-maydis CTB7 were generated by Agrobacterium tumefaciens-mediated transformation and were evaluated for in vitro cercosporin production. When grown on nitrogen-limited medium in the light-conditions conducive to cercosporin production in other Cercospora spp.-one transformant accumulated a red pigment that was confirmed to be cercosporin by the KOH assay, thin-layer chromatography, and ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Our results indicated that C. zeina has a defective CTB7, but all other necessary machinery required for synthesizing cercosporin-like molecules and, thus, C. zeina may produce a structural variant of cercosporin during maize infection.

  6. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

    Directory of Open Access Journals (Sweden)

    Kema Gert HJ

    2008-11-01

    Full Text Available Abstract Background The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs from C. zeae-maydis and evaluate their expression during vegetative, infectious, and reproductive growth. Results A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of C. zeae-maydis. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10-05 to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as Zephyr, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth. Conclusion Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in C. zeae-maydis, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of Cercospora and other groups of plant pathogenic fungi.

  7. LOCATION OF ACYL GROUPS ON TWO PARTLY ACYLATED GLYCOLIPIDS FROM STRAINS OF USTILAGO (SMUT FUNGI),

    Science.gov (United States)

    erythritol from Ustilago sp. (probably U. nuda (Jens.) Rostr. = U. tritici (Pers.) Rostr.) PRL-627 were acetalated with methyl vinyl ether, deacylated...Partly acylated ustilagic acids 8 (from Ustilago maydis (DC) Corda (= U. zeae Unger) PRL-119), consisting of partially esterified beta-cellobiosyl

  8. Occurrence of a Carboxin-Resistant Strain of Ustilago nuda in Italy

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    J. Menzies

    2005-08-01

    Full Text Available Loose smut of barley, caused by Ustilago nuda (Jens. Rostr., is commonly controlled through the use of systemic seed-treatment fungicides. The most widely used active ingredient in these fungicides has been carboxin. However, isolates of U. nuda resistant to carboxin have been reported in France. In 1996 and 1997, unsatisfactory levels of loose smut of barley were observed near Perugia (central Italy, despite the treatment of the barley seed with a carboxin-based fungicide. An isolate of U. nuda (97-255 was collected from this field to determine if the pathogen had developed resistance to carboxin. Germination tests on carboxin-amended agar media indicated that isolate 97- 255 was more resistant to carboxin than a wild type isolate of U. nuda collected in Canada. In tests in which isolate 97-255 was inoculated onto barley cv. Regal, the percentage of smutted plants arising from the inoculated seed was not reduced by a carboxin seed treatment. This is the first report of resistance to carboxin in populations of U. nuda from Italy.

  9. Characterization of pathogenic races of the sugarcane smut fungus by neutron activation analysis

    International Nuclear Information System (INIS)

    Amire, O.A.; Schmitt, R.A.; Trione, E.J.

    1982-01-01

    Representative samples of five major races of Ustilago scitaminea, the causal organism of the smut disease of sugarcane, were obtained from infected sugarcane fields in the Western hemisphere. The variations in concentration of 10 elements (Na, Mg, Al, Cl, K, Ca, Mn, Fe, Co, and Zn) in the sporidial yeast-like cells of this fungal pathogen were analyzed by neutron activation analysis. Comparative analysis of the elemental compositions in the different races of the fungus showed that the five pathogenic races of Ustilago scitaminea may be distinguished from each other on the basis of elemental compositions. (author)

  10. The general transcriptional repressor Tup1 is required for dimorphism and virulence in a fungal plant pathogen.

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2011-09-01

    Full Text Available A critical step in the life cycle of many fungal pathogens is the transition between yeast-like growth and the formation of filamentous structures, a process known as dimorphism. This morphological shift, typically triggered by multiple environmental signals, is tightly controlled by complex genetic pathways to ensure successful pathogenic development. In animal pathogenic fungi, one of the best known regulators of dimorphism is the general transcriptional repressor, Tup1. However, the role of Tup1 in fungal dimorphism is completely unknown in plant pathogens. Here we show that Tup1 plays a key role in orchestrating the yeast to hypha transition in the maize pathogen Ustilago maydis. Deletion of the tup1 gene causes a drastic reduction in the mating and filamentation capacity of the fungus, in turn leading to a reduced virulence phenotype. In U. maydis, these processes are controlled by the a and b mating-type loci, whose expression depends on the Prf1 transcription factor. Interestingly, Δtup1 strains show a critical reduction in the expression of prf1 and that of Prf1 target genes at both loci. Moreover, we observed that Tup1 appears to regulate Prf1 activity by controlling the expression of the prf1 transcriptional activators, rop1 and hap2. Additionally, we describe a putative novel prf1 repressor, named Pac2, which seems to be an important target of Tup1 in the control of dimorphism and virulence. Furthermore, we show that Tup1 is required for full pathogenic development since tup1 deletion mutants are unable to complete the sexual cycle. Our findings establish Tup1 as a key factor coordinating dimorphism in the phytopathogen U. maydis and support a conserved role for Tup1 in the control of hypha-specific genes among animal and plant fungal pathogens.

  11. Two phosphodiesterases from Ustilago maydis share structural and biochemical properties with non-fungal phosphodiesterases

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    Charu eAgarwal

    2010-11-01

    Full Text Available The dependence of Protein Kinase A (PKA activity on cAMP levels is an important facet of the dimorphic switch between budding and filamentous growth as well as for pathogenicity in some fungi. To better understand these processes in the pathogenic fungus Ustilago maydis, we characterized the structure and biochemical functions of two phosphodiesterase (PDE genes. Phosphodiesterases are enzymes involved in cAMP turnover and thus, contribute to the regulation of the cAMP-PKA signaling pathway. Two predicted homologues of PDEs were identified in the genome of U. maydis and hypothesized to be involved in cAMP turnover, thus regulating activity of the PKA catalytic subunit. Both umpde1 and umpde2 genes contain domains associated with phosphodiesterase activity predicted by InterPro analysis. Biochemical characterization of recombinantly produced UmPde1 (U. maydis Phosphodiesterase I and UmPde2 demonstrated that both enzymes have phosphodiesterase activity in vitro, yet neither was inhibited by the phosphodiesterase inhibitor IBMX. Moreover, UmPde1 is specific for cAMP, while UmPde2 has broader substrate specificity, utilizing cAMP and cGMP as substrates. In addition, UmPde2 was also found to have nucleotide phosphatase activity that was higher with GMP compared to AMP. These results demonstrate that UmPde1 is a bona fide phosphodiesterase, while UmPde2 has more general activity as a cyclic nucleotide phosphodiesterase and/or GMP/AMP phosphatase. Thus, UmPde1 and UmPde2 likely have important roles in cell morphology and development and share some characteristics with a variety of non-fungal phosphodiesterases.

  12. Heterologous production and characterization of a chlorogenic acid esterase from Ustilago maydis with a potential use in baking.

    Science.gov (United States)

    Nieter, Annabel; Kelle, Sebastian; Takenberg, Meike; Linke, Diana; Bunzel, Mirko; Popper, Lutz; Berger, Ralf G

    2016-10-15

    Ustilago maydis, an edible mushroom growing on maize (Zea mays), is consumed as the food delicacy huitlacoche in Mexico. A chlorogenic acid esterase from this basidiomycete was expressed in good yields cultivating the heterologous host Pichia pastoris on the 5L bioreactor scale (reUmChlE; 45.9UL(-1)). In contrast to previously described chlorogenic acid esterases, the reUmChlE was also active towards feruloylated saccharides. The enzyme preferred substrates with the ferulic acid esterified to the O-5 position of arabinose residues, typical of graminaceous monocots, over the O-2 position of arabinose or the O-6 position of galactose residues. Determination of kcat/Km showed that the reUmChlE hydrolyzed chlorogenic acid 18-fold more efficiently than methyl ferulate, p-coumarate or caffeate. Phenolic acids were released by reUmChlE from natural substrates, such as destarched wheat bran, sugar beet pectin and coffee pulp. Treatment of wheat dough using reUmChlE resulted in a noticeable softening indicating a potential application of the enzyme in bakery and confectionery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Septins from the phytopathogenic fungus Ustilago maydis are required for proper morphogenesis but dispensable for virulence.

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    Isabel Alvarez-Tabarés

    Full Text Available BACKGROUND: Septins are a highly conserved family of GTP-binding proteins involved in multiple cellular functions, including cell division and morphogenesis. Studies of septins in fungal cells underpin a clear correlation between septin-based structures and fungal morphology, providing clues to understand the molecular frame behind the varied morphologies found in fungal world. METHODOLOGY/PRINCIPAL FINDINGS: Ustilago maydis genome has the ability to encode four septins. Here, using loss-of-function as well as GFP-tagged alleles of these septin genes, we investigated the roles of septins in the morphogenesis of this basidiomycete fungus. We described that septins in U. maydis could assemble into at least three different structures coexisting in the same cell: bud neck collars, band-like structures at the growing tip, and long septin fibers that run from pole to pole near the cell cortex. We also found that in the absence of septins, U. maydis cells lost their elongated shape, became wider at the central region and ended up losing their polarity, pointing to an important role of septins in the morphogenesis of this fungus. These morphological defects were alleviated in the presence of an osmotic stabilizer suggesting that absence of septins affected the proper formation of the cell wall, which was coherent with a higher sensitivity of septin defective cells to drugs that affect cell wall construction as well as exocytosis. As U. maydis is a phytopathogen, we analyzed the role of septins in virulence and found that in spite of the described morphological defects, septin mutants were virulent in corn plants. CONCLUSIONS/SIGNIFICANCE: Our results indicated a major role of septins in morphogenesis in U. maydis. However, in contrast to studies in other fungal pathogens, in which septins were reported to be necessary during the infection process, we found a minor role of septins during corn infection by U. maydis.

  14. Gene Network Polymorphism Illuminates Loss and Retention of Novel RNAi Silencing Components in the Cryptococcus Pathogenic Species Complex.

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    Marianna Feretzaki

    2016-03-01

    Full Text Available RNAi is a ubiquitous pathway that serves central functions throughout eukaryotes, including maintenance of genome stability and repression of transposon expression and movement. However, a number of organisms have lost their RNAi pathways, including the model yeast Saccharomyces cerevisiae, the maize pathogen Ustilago maydis, the human pathogen Cryptococcus deuterogattii, and some human parasite pathogens, suggesting there may be adaptive benefits associated with both retention and loss of RNAi. By comparing the RNAi-deficient genome of the Pacific Northwest Outbreak C. deuterogattii strain R265 with the RNAi-proficient genomes of the Cryptococcus pathogenic species complex, we identified a set of conserved genes that were lost in R265 and all other C. deuterogattii isolates examined. Genetic and molecular analyses reveal several of these lost genes play roles in RNAi pathways. Four novel components were examined further. Znf3 (a zinc finger protein and Qip1 (a homolog of N. crassa Qip were found to be essential for RNAi, while Cpr2 (a constitutive pheromone receptor and Fzc28 (a transcription factor are involved in sex-induced but not mitosis-induced silencing. Our results demonstrate that the mitotic and sex-induced RNAi pathways rely on the same core components, but sex-induced silencing may be a more specific, highly induced variant that involves additional specialized or regulatory components. Our studies further illustrate how gene network polymorphisms involving known components of key cellular pathways can inform identification of novel elements and suggest that RNAi loss may have been a core event in the speciation of C. deuterogattii and possibly contributed to its pathogenic trajectory.

  15. The cAMP Signaling and MAP Kinase Pathways in Plant Pathogenic Fungi

    NARCIS (Netherlands)

    Mehrabi, R.; Zhao, X.; Kim, Y.; Xu, J.R.

    2009-01-01

    The key components of the well conserved cyclic AMP signaling and MAP kinase pathways have been functionally characterized in the corn smut Ustilago maydis, rice blast fungus Magnaporthe grisea, and a few other fungal pathogens. In general, the cAMP signaling and the MAP kinase cascade homologous to

  16. Stable carbon isotope discrimination in the smut fungus Ustilago violacea

    International Nuclear Information System (INIS)

    Will, O.H. III; Tieszen, L.L.; Kellen, M.; Gerlach, T.

    1986-01-01

    Haploid strains 15.10, I.C429, and I.C2y and diploid strain JK2 of Ustilago Piolacea were grown on one or more of the following carbon sources: glucose, sucrose, maltose, inulin, starch, inositol, glycerol, casein, and yeast extract. The media, both before and after fungal growth, and the fungal cells were analyzed for 13 C/ 12 C content (δ 13 values) using an isotope ratio mass spectrometer after combustion to CO 2 . In all cases, the used and unused media had identical δ 13 C values. Strain 15.10 had significantly less 13 C than the media when grown on glucose, sucrose, maltose, and inositol; significantly more 13 C when grown on inulin, starch, and glycerol; and no significant difference in δ 13 C values when grown on casein and yeast extract media. Other haploid strains responded similarly to 15.10. Diploid strain JK2 was also depleted in 13 C when grown on glucose and enriched in 13 C when grown on glycerol; however, JK2 was slightly depleted in 13 C when grown on casein, whereas all the tested haploid strains were enriched in 13 C

  17. Genetics of Ustilago violacea. I. Carotenoid mutants and carotenogenesis

    International Nuclear Information System (INIS)

    Garber, E.D.; Baird, M.L.; Chapman, D.J.

    1975-01-01

    Wild-type strains of Ustilago violacea produce pink colonies on laboratory medium and yield white, orange, pumpkin, and yellow colonies after uv mutagenesis. The wild-type strains contain neurosporene and lycopene; one orange mutant, γ-carotene; and one yellow mutant, β-carotene. One white mutant had no detectable carotenoids. Diploid colonies heterozygous for wild type and orange, pumpkin, yellow, or white are phenotypically wild type. Diploid colonies heterozygous for yellow and orange are also phenotypically wild type. Diploid colonies heterozygous for white and orange; white and yellow; and white, yellow, and orange are phenotypically light orange, light yellow, and orange-yellow, respectively. The white mutants give a circular complementation map; the color mutants fit a linear complementation map. We propose a multienzyme of four identical dehydrogenases and one or two identical cyclases for carotenogenesis in this species. The white and color mutants represent structural mutations altering the conformation of the dehydrogenase or cyclase, respectively. Furthermore, cyclases may or may not aggregate in association with the dehydrogenase aggregate to form the multienzyme aggregate responsible for the color mutants

  18. Plant surface cues prime Ustilago maydis for biotrophic development.

    Directory of Open Access Journals (Sweden)

    Daniel Lanver

    2014-07-01

    Full Text Available Infection-related development of phytopathogenic fungi is initiated by sensing and responding to plant surface cues. This response can result in the formation of specialized infection structures, so-called appressoria. To unravel the program inducing filaments and appressoria in the biotrophic smut fungus Ustilago maydis, we exposed cells to a hydrophobic surface and the cutin monomer 16-hydroxy hexadecanoic acid. Genome-wide transcriptional profiling at the pre-penetration stage documented dramatic transcriptional changes in almost 20% of the genes. Comparisons with the U. maydis sho1 msb2 double mutant, lacking two putative sensors for plant surface cues, revealed that these plasma membrane receptors regulate a small subset of the surface cue-induced genes comprising mainly secreted proteins including potential plant cell wall degrading enzymes. Targeted gene deletion analysis ascribed a role to up-regulated GH51 and GH62 arabinofuranosidases during plant penetration. Among the sho1/msb2-dependently expressed genes were several secreted effectors that are essential for virulence. Our data also demonstrate specific effects on two transcription factors that redirect the transcriptional regulatory network towards appressorium formation and plant penetration. This shows that plant surface cues prime U. maydis for biotrophic development.

  19. Przenoszenie się grzyba Ustilago perennans Bostr. z nasionami rajgrasu wyniosłego [Transmission of Ustilago perennans Rostr. with tall oat grass seeds

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    J. W. Tomala-Bednarek

    2015-06-01

    Full Text Available It was established that the mycelium of Ustilago perennans does not grow into the pericarp and seed coat of Arrhenatherum elatius caryopses. The main source of seedling infection at this year .seeds sowing were mycelium and gemmes present in hull tissues whereas ait last-year seeds sowing-the spores wintering on the hull and caryopsis surfaces, as they proved to be more survived. The ability of the fungus to seedling infection was decreasing gradually with the seed ageing.

  20. Compensatory role for Rad52 during recombinational repair in Ustilago maydis

    DEFF Research Database (Denmark)

    Kojic, Milorad; Mao, Ninghui; Zhou, Qingwen

    2008-01-01

    A single Rad52-related protein is evident by blast analysis of the Ustilago maydis genome database. Mutants created by disruption of the structural gene exhibited few discernible defects in resistance to UV, ionizing radiation, chemical alkylating or cross-linking agents. No deficiency was noted...

  1. Genetics of Ustilago violacea. XXXII. Genetic evidence for transposable elements.

    Science.gov (United States)

    Garber, E D; Ruddat, M

    1994-12-01

    Crosses between Ustilago violacea mutant strains with different color phenotypes that were derived from the 1.A1 and 2.A2 laboratory strains yielded, as expected, bisectored teliospore colonies with the parental colors as well as the a-1 and the a-2 mating-types. Generally, wild teliospore collections usually produced sporidia of both mating-types, providing two-mating-type (TMT) strains. Occasionally, however, sporidia with only one mating-type allele, a-1 or a-2, were obtained from teliospores, providing one-mating-type (OMT) strains. Crosses between OMT and laboratory strains with different color phenotypes gave (1) bisectored teliospore colonies with the parental colors or colonies with a parental color and a nonparental color and (2) nonsectored colonies with the nonparental color or with the parental color. The frequencies for the occurrence of non-parental color ranged from 41% to 93%, depending on the strain. The yield of teliospore colonies was usually reduced for these crosses. In many of these teliospore colonies, morphologically-altered sporidia (MAS phenotype) were observed. The morphology and the size of the sporidia with the MAS phenotype differed from those of teliospore colonies of the crosses between the laboratory strains. In addition, these sporidia did not form conjugants. A cross involving the TMT strains C449 yielded the MAS phenotype as well as a high incidence of tetrad colonies with a nonparental color. The high degree of instability of the parental color phenotypes, and the high frequency of the appearance of nonparental color phenotypes as well as the appearance of the MAS phenotype, are in accord with the presence of active and inactive transposable elements in the OMT strains, TMT strains, and laboratory strains.

  2. Three regulators of G protein signaling differentially affect mating, morphology and virulence in the smut fungus Ustilago maydis.

    Science.gov (United States)

    Moretti, Marino; Wang, Lei; Grognet, Pierre; Lanver, Daniel; Link, Hannes; Kahmann, Regine

    2017-09-01

    Regulators of G protein signaling (RGS) proteins modulate heterotrimeric G protein signaling negatively. To broaden an understanding of the roles of RGS proteins in fungal pathogens, we functionally characterized the three RGS protein-encoding genes (rgs1, rgs2 and rgs3) in the phytopathogenic fungus Ustilago maydis. It was found that RGS proteins played distinct roles in the regulation of development and virulence. rgs1 had a minor role in virulence when deleted in a solopathogenic strain. In crosses, rgs1 was dispensable for mating and filamentation, but was required for teliospore production. Haploid rgs2 mutants were affected in cell morphology, growth, mating and were unable to cause disease symptoms in crosses. However, virulence was unaffected when rgs2 was deleted in a solopathogenic strain, suggesting an exclusive involvement in pre-fusion events. These rgs2 phenotypes are likely connected to elevated intracellular cAMP levels. rgs3 mutants were severely attenuated in mating, in their response to pheromone, virulence and formation of mature teliospores. The mating defect could be traced back to reduced expression of the transcription factor rop1. It was speculated that the distinct roles of the three U. maydis RGS proteins were achieved by direct modulation of the Gα subunit-activated signaling pathways as well as through Gα-independent functions. © 2017 John Wiley & Sons Ltd.

  3. Biomass pretreatment affects Ustilago maydis in producing itaconic acid

    Directory of Open Access Journals (Sweden)

    Klement Tobias

    2012-04-01

    Full Text Available Abstract Background In the last years, the biotechnological production of platform chemicals for fuel components has become a major focus of interest. Although ligno-cellulosic material is considered as suitable feedstock, the almost inevitable pretreatment of this recalcitrant material may interfere with the subsequent fermentation steps. In this study, the fungus Ustilago maydis was used to produce itaconic acid as platform chemical for the synthesis of potential biofuels such as 3-methyltetrahydrofuran. No studies, however, have investigated how pretreatment of ligno-cellulosic biomass precisely influences the subsequent fermentation by U. maydis. Thus, this current study aims to first characterize U. maydis in shake flasks and then to evaluate the influence of three exemplary pretreatment methods on the cultivation and itaconic acid production of this fungus. Cellulose enzymatically hydrolysed in seawater and salt-assisted organic-acid catalysed cellulose were investigated as substrates. Lastly, hydrolysed hemicellulose from fractionated beech wood was applied as substrate. Results U. maydis was characterized on shake flask level regarding its itaconic acid production on glucose. Nitrogen limitation was shown to be a crucial condition for the production of itaconic acid. For itaconic acid concentrations above 25 g/L, a significant product inhibition was observed. Performing experiments that simulated influences of possible pretreatment methods, U. maydis was only slightly affected by high osmolarities up to 3.5 osmol/L as well as of 0.1 M oxalic acid. The production of itaconic acid was achieved on pretreated cellulose in seawater and on the hydrolysed hemicellulosic fraction of pretreated beech wood. Conclusion The fungus U. maydis is a promising producer of itaconic acid, since it grows as single cells (yeast-like in submerged cultivations and it is extremely robust in high osmotic media and real seawater. Moreover, U. maydis can grow on

  4. Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2015-11-01

    Full Text Available Fungi, as every living organism, interact with the external world and have to adapt to its fluctuations. For pathogenic fungi, such interaction involves adapting to the hostile environment of their host. Survival depends on the capacity of fungi to detect and respond to external stimuli, which is achieved through a tight and efficient genetic control. Chromatin modifications represent a well-known layer of regulation that controls gene expression in response to environmental signals. However, less is known about the chromatin modifications that are involved in fungal virulence and the specific cues and signalling pathways that target chromatin modifications to specific genes. In a recently published study, our research group identified one such regulatory pathway. We demonstrated that the histone deacetylase (HDAC Hos2 is involved in yeast-to-hyphal transition (dimorphism and it is associated with the virulence of the maize pathogen Ustilago maydis, the causative agent of smut disease in corn. Hos2 activates mating-type genes by directly binding to their gene bodies. Furthermore, Hos2 acts downstream of the nutrient-sensing cyclic AMP-Protein Kinase A pathway. We also found that another HDAC, Clr3, contributes to this regulation, possibly in cooperation with Hos2. As a whole, our data suggest that there is a direct link between changes in the environment and acetylation of nucleosomes within certain genes. We propose that histone acetylation is critical to the proper timing and induction of transcription of the genes encoding factors that coordinate changes in morphology with pathogenesis.

  5. Significant characteristics of the new maize hybrid Rubin-7

    Directory of Open Access Journals (Sweden)

    Jeličić Zora

    2003-01-01

    Full Text Available The Rubin-7 maize hybrid belongs to the FAO 700 maturity group. It is characterized by high yield potential for kernels, which was proven during investigations by the Committee for Species. During the three year monitoring period, from 1999 to 2001, the average yield of kernel was 9.412 t/ha which is 5% above the ZP 704 standard, and was highly statistically significant. Resistance to disease was high for Ustilago maydis 0.49, Fusarium spp. 0.13, and Exerohilum turcicum 1.25. Tolerance against Ostrinia nubilalis is 3-33. All of the above parameters and the agreeable phenotype of this hybrid indicate the value of Rubin-7. .

  6. Infection Structure–Specific Expression of β-1,3-Glucan Synthase Is Essential for Pathogenicity of Colletotrichum graminicola and Evasion of β-Glucan–Triggered Immunity in Maize[W

    Science.gov (United States)

    Oliveira-Garcia, Ely; Deising, Holger B.

    2013-01-01

    β-1,3-Glucan and chitin are the most prominent polysaccharides of the fungal cell wall. Covalently linked, these polymers form a scaffold that determines the form and properties of vegetative and pathogenic hyphae. While the role of chitin in plant infection is well understood, the role of β-1,3-glucan is unknown. We functionally characterized the β-1,3-glucan synthase gene GLS1 of the maize (Zea mays) pathogen Colletotrichum graminicola, employing RNA interference (RNAi), GLS1 overexpression, live-cell imaging, and aniline blue fluorochrome staining. This hemibiotroph sequentially differentiates a melanized appressorium on the cuticle and biotrophic and necrotrophic hyphae in its host. Massive β-1,3-glucan contents were detected in cell walls of appressoria and necrotrophic hyphae. Unexpectedly, GLS1 expression and β-1,3-glucan contents were drastically reduced during biotrophic development. In appressoria of RNAi strains, downregulation of β-1,3-glucan synthesis increased cell wall elasticity, and the appressoria exploded. While the shape of biotrophic hyphae was unaffected in RNAi strains, necrotrophic hyphae showed severe distortions. Constitutive expression of GLS1 led to exposure of β-1,3-glucan on biotrophic hyphae, massive induction of broad-spectrum defense responses, and significantly reduced disease symptom severity. Thus, while β-1,3-glucan synthesis is required for cell wall rigidity in appressoria and fast-growing necrotrophic hyphae, its rigorous downregulation during biotrophic development represents a strategy for evading β-glucan–triggered immunity. PMID:23898035

  7. Evidence for a Ustilago maydis Steroid 5α-Reductase by Functional Expression in Arabidopsis det2-1 Mutants1

    Science.gov (United States)

    Basse, Christoph W.; Kerschbamer, Christine; Brustmann, Markus; Altmann, Thomas; Kahmann, Regine

    2002-01-01

    We have identified a gene (udh1) in the basidiomycete Ustilago maydis that is induced during the parasitic interaction with its host plant maize (Zea mays). udh1 encodes a protein with high similarity to mammalian and plant 5α-steroid reductases. Udh1 differs from those of known 5α-steroid reductases by six additional domains, partially predicted to be membrane-spanning. A fusion protein of Udh1 and the green fluorescent protein provided evidence for endoplasmic reticulum localization in U. maydis. The function of the Udh1 protein was demonstrated by complementing Arabidopsis det2-1 mutants, which display a dwarf phenotype due to a mutation in the 5α-steroid reductase encoding DET2 gene. det2-1 mutant plants expressing either the udh1 or the DET2 gene controlled by the cauliflower mosaic virus 35S promoter differed from wild-type Columbia plants by accelerated stem growth, flower and seed development and a reduction in size and number of rosette leaves. The accelerated growth phenotype of udh1 transgenic plants was stably inherited and was favored under reduced light conditions. Truncation of the N-terminal 70 amino acids of the Udh1 protein abolished the ability to restore growth in det2-1 plants. Our results demonstrate the existence of a 5α-steroid reductase encoding gene in fungi and suggest a common ancestor between fungal, plant, and mammalian proteins. PMID:12068114

  8. Romanian maize

    DEFF Research Database (Denmark)

    Sauer, Johannes; Balint, Borbala

    This research aims at shedding empirical light on the relative efficiency of small-scale maize producers in Romania. Farmers in transition countries still face heavily distorted price systems resulting from imperfect market conditions and socioeconomic and institutional constraints. To capture...

  9. Occurrence of a Carboxin-Resistant Strain of Ustilago nuda in Italy

    OpenAIRE

    J. Menzies; R. McLeod; L. Tosi; C. Cappelli

    2005-01-01

    Loose smut of barley, caused by Ustilago nuda (Jens.) Rostr., is commonly controlled through the use of systemic seed-treatment fungicides. The most widely used active ingredient in these fungicides has been carboxin. However, isolates of U. nuda resistant to carboxin have been reported in France. In 1996 and 1997, unsatisfactory levels of loose smut of barley were observed near Perugia (central Italy), despite the treatment of the barley seed with a carboxin-based fungicide. An i...

  10. Cloning and characterization of the rec2 gene of Ustilago maydis

    International Nuclear Information System (INIS)

    Bauchwitz, R.P.; Holloman, W.K.

    1989-01-01

    The authors are exploring the molecular basis for genetic recombination using the corn smut fungus Ustilago maydis, from which the first two eucaryotic DNA repair and recombination mutants, rec1 and rec2, were described. Cells mutant at the rec2 locus are unable to repair lethal damage to their DNA from UV and X irradiation or from chemical alkylating agents such as N-methyl-nitrosoguanidine. Rec2 mutants retain only a residual level of DNA-damage inducible mitotic recombination, and are unable to complete meiosis. Using an autonomously replicating plasmid vector for Ustilago, they established the first nonintegrating plasmid library of the Ustilago genome. The rec2 locus was cloned by complementation of the rec2 mutation in vivo. One clone was found to restore all of the deficient activities. Although this rec2 complementing clone is present on a multicopy plasmid, the authors observed that it fully restored but did not further increase the fifty-fold inducibility of heteroallelic recombination at the nitrate reductase and inositol loci of rec2 or wild type cells. Northern blot analysis using the rec2 complementing clone revealed three UV inducible transcripts, one of which is absent in a rec2 mutant strain. This transcript organization resembles that of the yeast rad10 and the human ERCC-1 genes (MCB 9:1794), but sequence obtained to date from rec2 does not show homology with these genes. They have also observed that the rec2 mutation may alter the level of homologous integration of transformed DNA markers. Integration of a Leu1 complementing plasmid by Scott Fotheringham of the lab has shown that while much of plasmid integration in wild type Ustilago is nonhomologous, integration in at least some rec2 strains is entirely homologous. They are using the cloned rec2 gene to confirm that rec2 is indeed involved in altering the level of homologous integration in Ustilago, and if so, they plan to clone a mammalian analogue of rec2

  11. Inverse pH regulation of plant and fungal sucrose transporters: a mechanism to regulate competition for sucrose at the host/pathogen interface?

    Directory of Open Access Journals (Sweden)

    Kathrin Wippel

    Full Text Available BACKGROUND: Plant sucrose transporter activities were shown to respond to changes in the extracellular pH and redox status, and oxidizing compounds like glutathione (GSSG or H(2O(2 were reported to effect the subcellular targeting of these proteins. We hypothesized that changes in both parameters might be used to modulate the activities of competing sucrose transporters at a plant/pathogen interface. We, therefore, compared the effects of redox-active compounds and of extracellular pH on the sucrose transporters UmSRT1 and ZmSUT1 known to compete for extracellular sucrose in the Ustilago maydis (corn smut/Zea mays (maize pathosystem. METHODOLOGY/PRINCIPAL FINDINGS: We present functional analyses of the U. maydis sucrose transporter UmSRT1 and of the plant sucrose transporters ZmSUT1 and StSUT1 in Saccharomyces cerevisiae or in Xenopus laevis oocytes in the presence of different extracellular pH-values and redox systems, and study the possible effects of these treatments on the subcellular targeting. We observed an inverse regulation of host and pathogen sucrose transporters by changes in the apoplastic pH. Under none of the conditions analyzed, we could confirm the reported effects of redox-active compounds. CONCLUSIONS/SIGNIFICANCE: Our data suggest that changes in the extracellular pH but not of the extracellular redox status might be used to oppositely adjust the transport activities of plant and fungal sucrose transporters at the host/pathogen interface.

  12. Uniparental mitochondrial DNA inheritance is not affected in Ustilago maydis Δatg11 mutants blocked in mitophagy.

    Science.gov (United States)

    Wagner-Vogel, Gaby; Lämmer, Frauke; Kämper, Jörg; Basse, Christoph W

    2015-02-06

    Maternal or uniparental inheritance (UPI) of mitochondria is generally observed in sexual eukaryotes, however, the underlying mechanisms are diverse and largely unknown. Recently, based on the use of mutants blocked in autophagy, it has been demonstrated that autophagy is required for strict maternal inheritance in the nematode Caenorhabditis elegans. Uniparental mitochondrial DNA (mtDNA) inheritance has been well documented for numerous fungal species, and in particular, has been shown to be genetically governed by the mating-type loci in the isogamous species Cryptococcus neoformans, Phycomyces blakesleeanus and Ustilago maydis. Previously, we have shown that the a2 mating-type locus gene lga2 is decisive for UPI during sexual development of U. maydis. In axenic culture, conditional overexpression of lga2 triggers efficient loss of mtDNA as well as mitophagy. To assess a functional relationship, we have investigated UPI in U. maydis Δatg11 mutants, which are blocked in mitophagy. This study has revealed that Δatg11 mutants are not affected in pathogenic development and this has allowed us to analyse UPI under comparable developmental conditions between mating-compatible wild-type and mutant strain combinations. Explicitly, we have examined two independent strain combinations that gave rise to different efficiencies of UPI. We demonstrate that in both cases UPI is atg11-independent, providing evidence that mitophagy is not critical for UPI in U. maydis, even under conditions of strict UPI. Until now, analysis of a role of mitophagy in UPI has not been reported for microbial species. Our study suggests that selective autophagy does not contribute to UPI in U. maydis, but is rather a consequence of selective mtDNA elimination in response to mitochondrial damage.

  13. Metabolic and biofungicidal properties of maize rhizobacteria for ...

    African Journals Online (AJOL)

    BALOGOUN

    2015-03-04

    Mar 4, 2015 ... Fusarium verticillioides, that is an important maize pathogenic. ... range of substances as carbon or nitrogen sources. (Karuppiah and Rajaram, 2011). ..... isolated PGPR Bacillus spp. on Fusarium oxysporum. Int. J. Appl. Sci.

  14. Siderophores as iron storage compounds in the yeasts Rhodotorula minuta and Ustilago sphaerogena detected by in vivo Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Matzanke, B.F.; Winkelmann, G.; Bill, E.; Trautwein, A.X.

    1990-01-01

    In the yeasts Rhodotorula minuta and Ustilago sphaerogena siderophores represent the main intracellular iron pool. We suggest a ferritin substituting function of these siderophores in addition to their role as iron transport agents. In Rhodotorula transport and storage siderophore is the same compound whereas in Ustilago the iron-storage siderophore is ferrichrome. Besides siderophores, merely two iron metabolites can be observed. Other iron-requiring compounds are at least one order of magnitude less abundant in these yeasts. The ferrous metabolite has been detected in many other microbial systems and seems to be of general occurence and importance. (orig.)

  15. Bacterial endophytes from wild maize suppress Fusarium graminearum in modern maize and inhibit mycotoxin accumulation

    Directory of Open Access Journals (Sweden)

    Walaa Kamel Mousa

    2015-10-01

    Full Text Available Wild maize (teosinte has been reported to be less susceptible to pests than their modern maize (corn relatives. Endophytes, defined as microbes that inhabit plants without causing disease, are known for their ability to antagonize plant pests and pathogens. We hypothesized that the wild relatives of modern maize may host endophytes that combat pathogens. Fusarium graminearum is the fungus that causes Gibberella Ear Rot (GER in modern maize and produces the mycotoxin, deoxynivalenol (DON. In this study, 215 bacterial endophytes, previously isolated from diverse maize genotypes including wild teosintes, traditional landraces and modern varieties, were tested for their ability to antagonize F. graminearum in vitro. Candidate endophytes were then tested for their ability to suppress GER in modern maize in independent greenhouse trials. The results revealed that three candidate endophytes derived from wild teosintes were most potent in suppressing F. graminearum in vitro and GER in a modern maize hybrid. These wild teosinte endophytes could suppress a broad spectrum of fungal pathogens of modern crops in vitro. The teosinte endophytes also suppressed DON mycotoxin during storage to below acceptable safety threshold levels. A fourth, less robust anti-fungal strain was isolated from a modern maize hybrid. Three of the anti-fungal endophytes were predicted to be Paenibacillus polymyxa, along with one strain of Citrobacter. Microscopy studies suggested a fungicidal mode of action by all four strains. Molecular and biochemical studies showed that the P. polymyxa strains produced the previously characterized anti-Fusarium compound, fusaricidin. Our results suggest that the wild relatives of modern crops may serve as a valuable reservoir for endophytes in the ongoing fight against serious threats to modern agriculture. We discuss the possible impact of crop evolution and domestication on endophytes in the context of plant defense.

  16. Common motifs in the response of cereal primary metabolism to fungal pathogens are not based on similar transcriptional reprogramming

    Directory of Open Access Journals (Sweden)

    Lars Matthias Voll

    2011-08-01

    Full Text Available During compatible interactions with their host plants, biotrophic plant pathogens subvert host metabolism to ensure the sustained provision of nutrient assimilates by the colonized host cells. To investigate, whether common motifs can be revealed in the response of primary carbon and nitrogen metabolism towards colonization with biotrophic fungi in cereal leaves, we have conducted a combined metabolome and transcriptome study of three quite divergent pathosystems, the barley powdery mildew fungus (Blumeria graminis f.sp. hordei, the corn smut fungus Ustilago maydis and the maize anthracnose fungus Colletotrichum graminicola, the latter being a hemibiotroph that only exhibits an initial biotrophic phase during its establishment.Based on the analysis of 42 water-soluble metabolites, we were able to separate early biotrophic from late biotrophic interactions by hierarchical cluster analysis and principal component analysis, irrespective of the plant host. Interestingly, the corresponding transcriptome dataset could not discriminate between these stages of biotrophy, irrespective, of whether transcript data for genes of central metabolism or the entire transcriptome dataset was used. Strong differences in the transcriptional regulation of photosynthesis, glycolysis, the TCA cycle, lipid biosynthesis, and cell wall metabolism were observed between the pathosystems. Increased contents of Gln, Asn, and glucose as well as diminished contents of PEP and 3-PGA were common to early post-penetration stages of all interactions. On the transcriptional level, genes of the TCA cycle, nucleotide energy metabolism and amino acid biosynthesis exhibited consistent trends among the compared biotrophic interactions, identifying the requirement for metabolic energy and the rearrangement of amino acid pools as common transcriptional motifs during early biotrophy. Both metabolome and transcript data were employed to generate models of leaf primary metabolism during

  17. Harnessing maize biodiversity

    Science.gov (United States)

    Maize is a remarkably diverse species, adapted to a wide range of climatic conditions and farming practices. The latitudinal range of maize is immense, ranging from 54°N in Alberta, Canada, to 45°S in the province of Chubut, Argentina. In terms of altitude, maize is cultivated from sea level to 4000...

  18. The promoter of the glucoamylase-encoding gene of Aspergillus niger functions in Ustilago maydis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T.L. (Dept. of Agriculture, Madison, WI (United States) Univ. of Wisconsin, Madison (United States)); Gaskell, J.; Cullen, D. (Dept. of Agriculture, Madison, WI (United States)); Berka, R.M.; Yang, M.; Henner, D.J. (Genentech Inc., San Francisco, CA (United States))

    1990-01-01

    Promoter sequences from the Aspergillus niger glucoamylase-encoding gene (glaA) were linked to the bacterial hygromycin (Hy) phosphotransferase-encoding gene (hph) and this chimeric marker was used to select Hy-resistant (Hy[sup R]) Ustilago maydis transformants. This is an example of an Ascomycete promoter functioning in a Basidiomycete. Hy[sup R] transformants varied with respect to copy number of integrated vector, mitotic stability, and tolerance to Hy. Only 216 bp of glaA promoter sequence is required for expression in U. maydis but this promoter is not induced by starch as it is in Aspergillus spp. The transcription start points are the same in U. maydis and A. niger.

  19. The telomerase reverse transcriptase subunit from the dimorphic fungus Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Dolores Bautista-España

    Full Text Available In this study, we investigated the reverse transcriptase subunit of telomerase in the dimorphic fungus Ustilago maydis. This protein (Trt1 contains 1371 amino acids and all of the characteristic TERT motifs. Mutants created by disrupting trt1 had senescent traits, such as delayed growth, low replicative potential, and reduced survival, that were reminiscent of the traits observed in est2 budding yeast mutants. Telomerase activity was observed in wild-type fungus sporidia but not those of the disruption mutant. The introduction of a self-replicating plasmid expressing Trt1 into the mutant strain restored growth proficiency and replicative potential. Analyses of trt1 crosses in planta suggested that Trt1 is necessary for teliospore formation in homozygous disrupted diploids and that telomerase is haploinsufficient in heterozygous diploids. Additionally, terminal restriction fragment analysis in the progeny hinted at alternative survival mechanisms similar to those of budding yeast.

  20. The effect of some organic substances on the mycelium of the fungus Ustilago nuda (Jens.) Rostr.

    Science.gov (United States)

    Krátká, J

    1976-01-01

    Research was performed for studying the effect of some organic compounds, considered by many authors as the products ob barley seed metabolism generated after anaerobic seed treatment, on the mycelium of the fungus Ustilago nuda (Jens.) Rostr. The author examined the effectiveness of ethylacohol, acetaldehyde, acetic acid, succinic acid, lactic acid, and hydroquinone in concentrations from 1 M to 10(-6) M, and the effectiveness of extracts from disinfected seeds in doses from 10 g to 0.001 g/l. The effect of the mentioned solutions was examined as exerted on the growth of dicaryotic mycelium and on the growth of the haploid promycelium of the fungus. The dicaryotic mycelium of Ustilago nuda (Jens.) Rostr. was cultivated on potato agar with benzoic acid. The presence of the acid prevents mitosis, and the chlamydospores germinate on the nutritive medium with two fibres having binuclear cells. The haploid promycelium was cultivated on potato agar; chlamydospores germinated with one four-cell fibre, and individual cells are mononuclear and haploid. Only later, a dicarytic mycelium is created in a complex process. In all the substances used, the concentration of 1 M was found to stop further growth of mycelium. The concentration of 10(-1) M of acetic acid and hydroquinone also stopped growth, the same concentration of acetaldehyde, lactic acid, succinic acid, ethylacohol stimulated mycelium growth in comparison with the control. The concentration of 10(-6) M stimulated mycelium growth in a majority of cases. Extracts from disinfected seeds did not influence mycelium growth significantly in all cases in comparison with the control. The results were similar in the two types of mycelium.

  1. Aflatoxins and fumonisin contamination of marketed maize, maize ...

    African Journals Online (AJOL)

    Aflatoxins and fumonisin contamination of marketed maize, maize bran and maize used as animal feed in northern ... PROMOTING ACCESS TO AFRICAN RESEARCH ... African Journal of Food, Agriculture, Nutrition and Development.

  2. Chemical and nutritional values of maize and maize products ...

    African Journals Online (AJOL)

    Maize and maize products in selected grain markets within Kaduna, Nigeria, were obtained and investigated for proximate and mineral composition analysis using Atomic Absorption Spectrophotometer (AAS) and flame photometer. Proximate composition of maize and maize products were in the range of 11.6- 20 .0% ...

  3. Resistance of maize varieties to the maize weevil Sitophilus zeamais

    African Journals Online (AJOL)

    This study aimed at evaluating commonly used maize varieties, collected from Melkasa and Bako Agricultural Research Centers and Haramaya University, Ethiopia, against the maize weevil Sitophilus zeamais Motsch., one of the most important cosmopolitan stored product pests in maize. A total of 13 improved maize ...

  4. Aggressiveness of Cephalosporium maydis causing late wilt of maize in Spain

    OpenAIRE

    García-Carneros, Ana B.; Girón, I.; Molinero-Ruiz, Leire

    2012-01-01

    Late wilt of maize, caused by the vascular and soilborne pathogen Cephalosporium maydis, was identified in the Iberian Peninsula in 2008. During the last years the incidence and economical impact of the disease has importantly increased both in Portugal and Spain. Varieties of maize displaying tolerance to the pathogen are available, but the effectiveness can be dependent on the virulence of the fungus (i.e. ability to cause disease on a specific genotype). On the other hand, strains of crop ...

  5. Siderophores as iron storage compounds in the yeasts Rhodotorula minuta and Ustilago sphaerogena detected by in vivo Mössbauer spectroscopy

    Science.gov (United States)

    Matzanke, B. F.; Bill, E.; Trautwein, A. X.; Winkelmann, G.

    1990-07-01

    In the yeasts Rhodotorula minuta and Ustilago sphaerogena siderophores represent the main intracellular iron pool. We suggest a ferritin substituting function of these siderophores in addition to their role as iron transport agents. In Rhodotorula transport and storage siderophore is the same compound whereas in Ustilago the iron-storage siderophore is ferrichrome. Besides siderophores, merely two iron metabolites can be observed. Other iron-requiring compounds are at least one order of magnitude less abundant in these yeasts. The ferrous metabolite has been detected in many other microbial systems and seems to be of general occurence and importance.

  6. Applying Unconventional Secretion in Ustilago maydis for the Export of Functional Nanobodies

    Directory of Open Access Journals (Sweden)

    Marius Terfrüchte

    2017-04-01

    Full Text Available Exploiting secretory pathways for production of heterologous proteins is highly advantageous with respect to efficient downstream processing. In eukaryotic systems the vast majority of heterologous proteins for biotechnological application is exported via the canonical endoplasmic reticulum–Golgi pathway. In the endomembrane system target proteins are often glycosylated and may thus be modified with foreign glycan patterns. This can be destructive for their activity or cause immune reactions against therapeutic proteins. Hence, using unconventional secretion for protein expression is an attractive alternative. In the fungal model Ustilago maydis, chitinase Cts1 is secreted via an unconventional pathway connected to cell separation which can be used to co-export heterologous proteins. Here, we apply this mechanism for the production of nanobodies. First, we achieved expression and unconventional secretion of a functional nanobody directed against green fluorescent protein (Gfp. Second, we found that Cts1 binds to chitin and that this feature can be applied to generate a Gfp-trap. Thus, we demonstrated the dual use of Cts1 serving both as export vehicle and as purification tag. Finally, we established and optimized the production of a nanobody against botulinum toxin A and hence describe the first pharmaceutically relevant target exported by Cts1-mediated unconventional secretion.

  7. Cloning of the PYR3 gene of Ustilago maydis and its use in DNA transformation

    Energy Technology Data Exchange (ETDEWEB)

    Banks, G.R.; Taylor, S.Y. (National Institute for Medical Research, London (England))

    1988-12-01

    The Ustilago maydis PYR3 gene encoding dihydroorotase activity was cloned by direct complementation of Escherichia coli pyrC mutations. PYR3 transformants of E. coli pyrC mutants expressed homologous transcripts of a variety of sizes and regained dihydroorotase activity. PYR3 also complemented Saccharomyces cerevisiae ura4 mutations, and again multiple transcripts were expressed in transformants, and enzyme activity was regained. A 1.25-kilobase poly(rA)+ PYR3 transcript was detected in U. maydis itself. Linear DNA carrying the PYR3 gene transformed a U. maydis pyr3-1 pyrimidine auxotroph to prototrophy. Hybridization analysis revealed that three different types of transformants could be generated, depending on the structure of the transforming DNA used. The first type involved exchange of chromosomal mutant gene sequences with the cloned wild-type plasmid sequences. A second type had integrated linear transforming DNA at the chromosomal PYR3 locus, probably via a single crossover event. The third type had integrated transforming DNA sequences at multiple sites in the U. maydis genome. In the last two types, tandemly reiterated copies of the transforming DNA were found to have been integrated. All three types had lost the sensitivity of the parental pyr3-1 mutant to UV irradiation. They had also regained dihydroorotase activity, although its level did not correlate with the PYR3 gene copy number.

  8. Differential chromosomal and mitochondrial DNA synthesis in temperature-sensitive mutants of Ustilago maydis

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.

    1977-01-01

    The amount and type of residual DNA synthesis was determined in eight temperature-sensitive mutants of the smut fungus Ustilago maydis after incubation at the restrictive temperature (32/sup 0/C) for eight hours. Mutants ts-220, ts-207, ts-432 and ts-346 were found to have an overall reduction in the synthesis of both nuclear and mitochondrial DNA in comparison to the wild-type. In mutants ts-20, tsd 1-1, ts-84 and pol 1-1 nuclear DNA synthesis was depressed relative to mitochondrial synthesis. The DNA-polymerase mutant pol 1-1 had persistent nuclear synthesis at about 50% of the rate of synthesis of mitochondrial DNA and similar behavior was observed in a diploid homozygous strain. Mutant ts-84 had an initial burst of DNA synthesis which was reduced for nuclear but not mitochondrial synthesis after three hours preincubation at 32/sup 0/C. tsd 1-1 and ts-20 had nuclear residual synthesis amounting to about 25% of the relative rate of mitochondrial synthesis which correlates to increasing UV sensitivity of these strains on incubation at 32/sup 0/C. A pol 1-1 ts-84 double mutant had an additive loss of nuclear DNA synthesis which indicates that the steps of replication involved may be sequential.

  9. Response of Ustilago maydis against the Stress Caused by Three Polycationic Chitin Derivatives

    Directory of Open Access Journals (Sweden)

    Dario Rafael Olicón-Hernández

    2017-12-01

    Full Text Available Chitosan is a stressing molecule that affects the cells walls and plasma membrane of fungi. For chitosan derivatives, the action mode is not clear. In this work, we used the yeast Ustilago maydis to study the effects of these molecules on the plasma membrane, focusing on physiologic and stress responses to chitosan (CH, oligochitosan (OCH, and glycol-chitosan (GCH. Yeasts were cultured with each of these molecules at 1 mg·mL−1 in minimal medium. To compare plasma membrane damage, cells were cultivated in isosmolar medium. Membrane potential (Δψ as well as oxidative stress were measured. Changes in the total plasma membrane phospholipid and protein profiles were analyzed using standard methods, and fluorescence-stained mitochondria were observed. High osmolarity did not protect against CH inhibition and neither affected membrane potential. The OCH did produce higher oxidative stress. The effects of these molecules were evidenced by modifications in the plasma membrane protein profile. Also, mitochondrial damage was evident for CH and OCH, while GCH resulted in thicker cells with fewer mitochondria and higher glycogen accumulation.

  10. Inheritance of Carboxin Resistance in a European Field Isolate of Ustilago nuda.

    Science.gov (United States)

    Newcombe, G; Thomas, P L

    2000-02-01

    ABSTRACT Two carboxin-resistant field isolates of Ustilago nuda from Europe were crossed with a carboxin-sensitive field isolate from North America. Meiotic tetrads isolated from germinating F(1) teliospores of one of the hybrids were tested for carboxin resistance and mating type. Carboxin resistance was shown to be controlled by a single gene (CBX1R), because a 1:1 segregation of carboxin resistance was observed in all 27 tetrads. Tetrad analysis indicated that the loci for carboxin resistance (Cbx1) and mating type (MAT1) segregate independently but may be located on the same chromosome. Tetrad analysis was not possible with the F(1) hybrid of he other field isolate, and its resistance cannot yet be attributed to CBX1R. Carboxin resistance was qualitatively dominant to sensitivity in vitro, as demonstrated by triad analysis of germinating F(1) teliospores. Quantitative in planta infection percents supported the conclusion that CBX1R is dominant, although incompletely, in the F(1) hybrid of one of the field isolates. Also, fewer than expected carboxin-sensitive F(2) individuals were observed in planta. However, inoculations of host plants with U. nuda have resulted in similar, unexpected variation in the past.

  11. Production of itaconic acid by Ustilago maydis from agro wastes in solid state fermentation

    Directory of Open Access Journals (Sweden)

    MOKULA MD. RAFI

    2014-08-01

    Full Text Available Itaconic acid (IA is one of the hopeful substances within the cluster of organic acids. IA is used in artificial glass, bioactive compounds in pharmacy, medicine, agriculture, for the synthesis of fiber, resin, plastic, rubber, paints, surfactant, ion-exchange resins and lubricant. Most recurrently used microorganism for commercial production of IA is Aspergillus terreus. Some filamentous fungi belonging to Ustilaginales also produce IA. In the present work, an attempt was made to produce IA by Ustilago maydis employing Solid State Fermentation (SSF from various agro wastes like ground nut shells, rice bran, rice husk, orange pulp, ground nut oil cake, orange pulp and sugarcane bagasse as carbon substrates, which were used after pretreatment. 10 g of each substrate was taken in a 500 ml conical flasks separately and supplemented with 20 mL nutrient solution containing glucose, at pH 3. One milliliter inoculum containing 1×107 spores was added and moisture was maintained at 60%. After incubation at 32°C for 5 days, the acid production was estimated by spectrophotometric method and by HPLC analysis. Interestingly, the yield of itaconic acid was promising with all the above substrates, where orange pulp, sugarcane bagasse and rice bran supported higher yields.

  12. Fusarium graminearum and Fusarium verticillioides infection on maize seeds

    Directory of Open Access Journals (Sweden)

    Dayana Portes Ramos

    2014-03-01

    Full Text Available The previous knowledge of the infection process and pathogens behavior, for evaluating the physiological potential of maize seeds, is essential for decision making on the final destination of lots that can endanger sowing. This research was carried out in order to study the minimum period required for maize seeds contamination by Fusarium graminearum Schwabe and Fusarium verticillioides (Sacc. Nirenberg, as well as these pathogens influence on seed germination and vigor, by using the cold test. Three maize seeds hybrids, kept in contact with the pathogens for different periods, were evaluated with and without surface disinfection. After determining the most suitable period, new samples were contaminated by F. graminearum and F. verticillioides, under different infection levels, and subjected to germination tests in sand. The cold test was conducted with healthy and contaminated seeds, at different periods, in a cold chamber. The contact of maize seeds with F. graminearum and F. verticillioides for 16 hours was enough to cause infection. F. graminearum and F. verticillioides did not affect the maize seeds germination, however, F. graminearum reduced the vigor of seeds lots.

  13. Radiation preservation of maize

    International Nuclear Information System (INIS)

    Wasito.

    1980-01-01

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  14. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize

    Science.gov (United States)

    Phytoalexins constitute a broad category of pathogen and insect-inducible biochemicals that locally protect plant tissues. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquite...

  15. Inducement and identification of an endosperm mutant in maize

    African Journals Online (AJOL)

    ajl yemi

    2011-11-30

    Nov 30, 2011 ... Drummond EP, Ausubel FM (2000). Three unique mutants of. Arabidopsis identify eds loci required for limiting growth of a biotrophic fungal pathogen. Plant J. 24(2): 205-218. Dinges JR, Colleoni C, Myers AM, James MG (2001). Molecular structure of three mutations at the maize sugary1 locus and their.

  16. The Dent Stage of Maize Kernels Is the Most Conducive for Fumonisin Biosynthesis under Field Conditions ▿

    OpenAIRE

    Picot, Adeline; Barreau, Christian; Pinson-Gadais, Laëtitia; Piraux, François; Caron, Daniel; Lannou, Christian; Richard-Forget, Florence

    2011-01-01

    The fungal pathogen Fusarium verticillioides infects maize ears and produces fumonisins, known for their adverse effects on human and animal health. Basic questions remain unanswered regarding the kernel stage(s) associated with fumonisin biosynthesis and the kernel components involved in fumonisin regulation during F. verticillioides-maize interaction under field conditions. In this 2-year field study, the time course of F. verticillioides growth and fumonisin accumulation in developing maiz...

  17. Validation of candidate genes putatively associated with resistance to SCMV and MDMV in maize (Zea mays L.) by expression profiling

    DEFF Research Database (Denmark)

    Uzarowska, Anna; Dionisio, Giuseppe; Sarholz, Barbara

    2009-01-01

    Background The potyviruses sugarcane mosaic virus (SCMV) and maize dwarf mosaic virus (MDMV) are major pathogens of maize worldwide. Two loci, Scmv1 and Scmv2, have ealier been shown to confer complete resistance to SCMV. Custom-made microarrays containing previously identified SCMV resistance...... the effectiveness and reliability of the combination of different expression profiling approaches for the identification and validation of candidate genes. Genes identified in this study represent possible future targets for manipulation of SCMV resistance in maize....

  18. Maize (Zea mays L.).

    Science.gov (United States)

    Frame, Bronwyn; Warnberg, Katey; Main, Marcy; Wang, Kan

    2015-01-01

    Agrobacterium tumefaciens-mediated transformation is an effective method for introducing genes into maize. In this chapter, we describe a detailed protocol for genetic transformation of the maize genotype Hi II. Our starting plant material is immature embryos cocultivated with an Agrobacterium strain carrying a standard binary vector. In addition to step-by-step laboratory transformation procedures, we include extensive details in growing donor plants and caring for transgenic plants in the greenhouse.

  19. Researches on detection of barley varieties and lines against Ustilago nuda hordei “Jens.â€? Rostr. Schaffn.in Marmara Region

    OpenAIRE

    Gümüştekin, H.; Akın, K.

    2008-01-01

    This research has been started in 1994 to test barley varieties and lines against Ustilago nuda hordei “Jens.â€? Rostr. Schaffn. In 1994, 14 barley varieties and lines and in 1995 23 barley varieties and lines were tested. After testing 37 varieties and lines, 27 of them were found resistant (R), and 10 of them susceptible (S).

  20. Frequency-Dependent Disease Transmission and the Dynamics of the Silene-Ustilago Host-Pathogen System

    NARCIS (Netherlands)

    Thrall, P.H.; Biere, A.; Uyenoyama, M.K.

    1995-01-01

    Models incorporating density-dependent disease transmission functions generally provide a good fit for airborne and directly transmitted bacterial or viral diseases. However, the transmission dynamics of sexually transmitted and vector-borne diseases are likely to be frequency- rather than density-

  1. Genome comparison of barley and maize smut fungi reveals targeted loss of RNA silencing components and species-specific presence of transposable elements.

    Science.gov (United States)

    Laurie, John D; Ali, Shawkat; Linning, Rob; Mannhaupt, Gertrud; Wong, Philip; Güldener, Ulrich; Münsterkötter, Martin; Moore, Richard; Kahmann, Regine; Bakkeren, Guus; Schirawski, Jan

    2012-05-01

    Ustilago hordei is a biotrophic parasite of barley (Hordeum vulgare). After seedling infection, the fungus persists in the plant until head emergence when fungal spores develop and are released from sori formed at kernel positions. The 26.1-Mb U. hordei genome contains 7113 protein encoding genes with high synteny to the smaller genomes of the related, maize-infecting smut fungi Ustilago maydis and Sporisorium reilianum but has a larger repeat content that affected genome evolution at important loci, including mating-type and effector loci. The U. hordei genome encodes components involved in RNA interference and heterochromatin formation, normally involved in genome defense, that are lacking in the U. maydis genome due to clean excision events. These excision events were possibly a result of former presence of repetitive DNA and of an efficient homologous recombination system in U. maydis. We found evidence of repeat-induced point mutations in the genome of U. hordei, indicating that smut fungi use different strategies to counteract the deleterious effects of repetitive DNA. The complement of U. hordei effector genes is comparable to the other two smuts but reveals differences in family expansion and clustering. The availability of the genome sequence will facilitate the identification of genes responsible for virulence and evolution of smut fungi on their respective hosts.

  2. Genome Comparison of Barley and Maize Smut Fungi Reveals Targeted Loss of RNA Silencing Components and Species-Specific Presence of Transposable Elements[W

    Science.gov (United States)

    Laurie, John D.; Ali, Shawkat; Linning, Rob; Mannhaupt, Gertrud; Wong, Philip; Güldener, Ulrich; Münsterkötter, Martin; Moore, Richard; Kahmann, Regine; Bakkeren, Guus; Schirawski, Jan

    2012-01-01

    Ustilago hordei is a biotrophic parasite of barley (Hordeum vulgare). After seedling infection, the fungus persists in the plant until head emergence when fungal spores develop and are released from sori formed at kernel positions. The 26.1-Mb U. hordei genome contains 7113 protein encoding genes with high synteny to the smaller genomes of the related, maize-infecting smut fungi Ustilago maydis and Sporisorium reilianum but has a larger repeat content that affected genome evolution at important loci, including mating-type and effector loci. The U. hordei genome encodes components involved in RNA interference and heterochromatin formation, normally involved in genome defense, that are lacking in the U. maydis genome due to clean excision events. These excision events were possibly a result of former presence of repetitive DNA and of an efficient homologous recombination system in U. maydis. We found evidence of repeat-induced point mutations in the genome of U. hordei, indicating that smut fungi use different strategies to counteract the deleterious effects of repetitive DNA. The complement of U. hordei effector genes is comparable to the other two smuts but reveals differences in family expansion and clustering. The availability of the genome sequence will facilitate the identification of genes responsible for virulence and evolution of smut fungi on their respective hosts. PMID:22623492

  3. A review on important maize diseases and their management in Nepal

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2015-12-01

    Full Text Available In Nepal, maize ranks second after rice both in area and production. In recent years, maize area and production has shown a steady increase, but productivity has been low (2.46 t/ha. The major maize producing regions in Nepal are mid hill (72.85%, terai (17.36% and high hill (9.79% respectively. A literature review was carried out to explore major maize diseases and their management in Nepal. The omnipresent incidence of diseases at the pre harvest stage has been an important bottleneck in increasing production. Till now, a total of 78 (75 fungal and 3 bacterial species are pathogenic to maize crop in Nepal. The major and economically important maize diseases reported are Gray leaf spot, Northern leaf blight, Southern leaf Blight, Banded leaf and sheath blight, Ear rot, Stalk rot, Head smut, Common rust, Downy mildew and Brown spot. Information on bacterial and virus diseases, nematodes and yield loss assessment is also given. Description of the major maize diseases, their causal organisms, distribution, time and intensity of disease incidence, symptoms, survival, spreads, environmental factors for disease development, yield losses and various disease management strategies corresponded to important maize diseases of Nepal are gathered and compiled thoroughly from the available publications. Concerted efforts of NARC commodity programs, divisions, ARS and RARS involving research on maize pathology and their important outcomes are mentioned. The use of disease management methods focused on host resistance has also been highlighted.

  4. Breeding of speciality maize for industrial purposes

    OpenAIRE

    Pajić Zorica; Radosavljević Milica; Filipović Milomir; Todorović Goran; Srdić Jelena; Pavlov Milovan

    2010-01-01

    The breeding programme on speciality maize with specific traits was established at the Maize Research Institute, Zemun Polje, several decades ago. The initial material was collected, new methods applying to breeding of speciality maize, i.e. popping maize, sweet maize and white-seeded maize, were introduced. The aim was to enhance and improve variability of the initial material for breeding these three types of maize. Then, inbred lines of good combining abilities were developed and used as c...

  5. Influence of introduced potential biocontrol agents on maize seedling growth and bacterial community structure in the rhizosphere

    NARCIS (Netherlands)

    Kozdroj, J; Trevors, JT; van Elsas, JD

    Two species of Pseudomonas chromosomally tagged with gfp, which had shown antagonistic activity against the tomato pathogen Ralstonia solanacearum in a previous study, were assessed for their impact in the rhizosphere of maize. Plant growth characteristics, numbers of indigenous heterotrophic

  6. Cambios postcosecha del hongo comestible huitlacoche (Ustilago maydis (D. C. Corda

    Directory of Open Access Journals (Sweden)

    A. Martínez-Flores

    2008-01-01

    Full Text Available El huitlacoche [(Ustilago maydis (D.C. Corda] ha sido un importante alimento en la dieta de los habitantes de la región Centro-Sur de México desde épocas precolombinas. Recientemente, su aceptación a nivel mundial se ha incrementado. A pesar de que es un producto muy perecedero no existen estudios postcosecha, por lo cual, el objetivo de este estudio fue identificar el cambio de parámetros físicos y fisiológicos en postcosecha de huitlacoche entero (mazorca y desgranado (agallas a temperatura ambiente, 3 y 10 °C, durante 11 días. Se evaluó el cambio de aspecto, color, pérdida de peso, respiración, producción de etileno y cambio en aminoácidos. La respiración promedio del huitlacoche entero a temperatura ambiente, 10 y 3 °C fue de 320.8, 120.8 y 71. 5 mlCO2·kg- 1·h-1, respectivamente; en tanto que para el desgranado fue de 372.8, 346.7 y 164.1 mlCO2·kg-1·h-1 a temperatura ambiente, 10 y 3 °C respectivamente. A los 7 días de almacenamiento, el hongo presentó pérdida de peso arriba del 80, 60 y 22 % a temperatura ambiente, 10 y 3 °C respectivamente. Se encontraron 18 aminoácidos, del contenido total los esenciales representaron 37.8 % de los cuales lisina representó el 27.2 %. Después del almacenamiento, el huitlacoche no mostró un cambio importante en el contenido de aminoácidos. A 3 °C el huitlacoche entero conservó mejor su apariencia, color y peso. No se detectó producción de etileno en las temperaturas evaluadas.

  7. Breeding of maize types with specific traits at the Maize Research Institute, Zemun Polje

    OpenAIRE

    Pajić Zorica

    2007-01-01

    Maize is primarily grown as an energy crop, but the use of different specific versions, such as high-oil maize, high-lysine maize, waxy maize, white-seeded maize, popping maize and sweet maize, is quite extensive. Speciality maize, due to its traits and genetic control of these traits, requires a particular attention in handling breeding material during the processes of breeding. It is especially related to prevention of uncontrolled pollination. In order to provide successful selection for a...

  8. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  9. Fungal Secretome Analysis via PepSAVI-MS: Identification of the Bioactive Peptide KP4 from Ustilago maydis

    Science.gov (United States)

    Kirkpatrick, Christine L.; Parsley, Nicole C.; Bartges, Tessa E.; Cooke, Madeline E.; Evans, Wilaysha S.; Heil, Lilian R.; Smith, Thomas J.; Hicks, Leslie M.

    2018-05-01

    Fungal secondary metabolites represent a rich and largely untapped source for bioactive molecules, including peptides with substantial structural diversity and pharmacological potential. As methods proceed to take a deep dive into fungal genomes, complimentary methods to identify bioactive components are required to keep pace with the expanding fungal repertoire. We developed PepSAVI-MS to expedite the search for natural product bioactive peptides and herein demonstrate proof-of-principle applicability of the pipeline for the discovery of bioactive peptides from fungal secretomes via identification of the antifungal killer toxin KP4 from Ustilago maydis P4. This work opens the door to investigating microbial secretomes with a new lens, and could have broad applications across human health, agriculture, and food safety. [Figure not available: see fulltext.

  10. Ustilago maydis: ascenso de un hongo mexicano de la gastronomía local al mundo científico

    OpenAIRE

    José Ruiz Herrera

    2008-01-01

    En el presente trabajo se describe la naturaleza del hongo Ustilago maydis, su papel como causante de una enfermedad del maíz, su uso en la cocina mexicana y las condiciones que lo llevaron a convertirse en material de estudio científico, además de algunas características descollantes de su fisiología, genética y bioquímica. U. maydis es un hongo patógeno biotrófico específico del maíz, y el teozintle, siendo el agente causal del "huitlacoche" o carbón común, una enfermedad de distribución m...

  11. Molecular confirmation of Maize rayado fino virus as the Brazilian corn streak virus

    OpenAIRE

    Hammond,Rosemarie Wahnbaeck; Bedendo,Ivan Paulo

    2005-01-01

    Maize rayado fino virus (MRFV), present in various countries in Latin America, has shown similarities to corn streak virus that occurs in Brazil, regarding pathogenic, serological and histological characteristics. In the current report both virus were molecularly compared to confirm the similarities between them. MRFV was identified by nucleic acid hybridization in samples of maize tissues exhibiting symptoms of "corn stunt" disease, collected from two Brazilian States - São Paulo and Minas G...

  12. Tartronate semialdehyde reductase defines a novel rate-limiting step in assimilation and bioconversion of glycerol in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Yanbin Liu

    Full Text Available BACKGROUND: Glycerol is a by-product of biodiesel production. Currently, it has limited applications with low bioconversion efficiency to most metabolites reported. This is partly attributed to the poor knowledge on the glycerol metabolic pathway in bacteria and fungi. METHODOLOGY/PRINCIPAL FINDINGS: We have established a fast screening method for identification of genes that improve glycerol utilization in Ustilago maydis. This was done by comparing the growth rates of T-DNA tagged mutant colonies on solid medium using glycerol as the sole carbon source. We present a detailed characterization of one of the mutants, GUM1, which contains a T-DNA element inserted into the promoter region of UM02592 locus (MIPS Ustilago maydis database, MUMDB, leading to enhanced and constitutive expression of its mRNA. We have demonstrated that um02592 encodes a functional tartronate semialdehyde reductase (Tsr1, which showed dual specificity to cofactors NAD(+ and NADP(+ and strong substrate specificity and enantioselectivity for D-glycerate. Improved glycerol assimilation in GUM1 was associated with elevated expression of tsr1 mRNA and this could be phenocopied by over-expression of the gene. Glycolipid accumulation was reduced by 45.2% in the knockout mutant whereas introduction of an extra copy of tsr1 driven by the glyceraldehyde phosphate dehydrogenase promoter increased it by 40.4%. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that tartronate semialdehyde reductase (TSR plays an important role in glycerol assimilation in U. maydis and defines a novel target in genetic engineering for improved conversion of glycerol to higher value products. Our results add significant depth to the understanding of the glycerol metabolic pathway in fungi. We have demonstrated, for the first time, a biological role of a eukaryotic TSR.

  13. Biotechnology in maize breeding

    Directory of Open Access Journals (Sweden)

    Mladenović-Drinić Snežana

    2004-01-01

    Full Text Available Maize is one of the most important economic crops and the best studied and most tractable genetic system among monocots. The development of biotechnology has led to a great increase in our knowledge of maize genetics and understanding of the structure and behaviour of maize genomes. Conventional breeding practices can now be complemented by a number of new and powerful techniques. Some of these often referred to as molecular methods, enable scientists to see the layout of the entire genome of any organism and to select plants with preferred characteristics by "reading" at the molecular level, saving precious time and resources. DNA markers have provided valuable tools in various analyses ranging from phylogenetic analysis to the positional cloning of genes. Application of molecular markers for genetic studies of maize include: assessment of genetic variability and characterization of germ plasm, identification and fingerprinting of genotypes, estimation of genetic distance, detection of monogamic and quantitative trait loci, marker assisted selection, identification of sequence of useful candidate genes, etc. The development of high-density molecular maps which has been facilitated by PCR-based markers, have made the mapping and tagging of almost any trait possible and serve as bases for marker assisted selection. Sequencing of maize genomes would help to elucidate gene function, gene regulation and their expression. Modern biotechnology also includes an array of tools for introducing or deieting a particular gene or genes to produce plants with novel traits. Development of informatics and biotechnology are resulted in bioinformatic as well as in expansion of microarrey technique. Modern biotechnologies could complement and improve the efficiency of traditional selection and breeding techniques to enhance agricultural productivity.

  14. Intercropping Maize With Legumes for Sustainable Highland Maize Production

    Directory of Open Access Journals (Sweden)

    Adirek Punyalue

    2018-02-01

    Full Text Available Residue burning to prepare soil for maize growing deprives the soil of both protective cover and organic matter, and it exacerbates environmental issues such as Southeast Asia's haze problem. This paper reports on a study that evaluated the effectiveness of maize/legume intercropping as an alternative to maize cultivation with residue burning. Cowpea (Vigna unguiculata, mung bean (V. radiata, rice bean (V. umbellata, and lablab (Lablab purpureus were sown into a standing maize crop 30 days before harvest, and the results were compared with a maize crop grown using residue burning as the method for land preparation at Pang Da Agricultural Station in Chiang Mai, Thailand, in a replicated trial conducted over 3 growing seasons from 2012 to 2014. Intercropping increased maize grain yield by 31–53% and left 70–170% more residue containing 113–230% more nitrogen than the maize sown after residue burning, depending on the legume, and decreased weed dry weight by two-thirds after 2 seasons. Soil biodiversity was enriched by the intercrops, with a doubling in the spore density of arbuscular mycorrhizal fungi in the root-zone soil and increased abundance, diversity (Shannon index, and richness of the soil macrofauna. The abundance of soil animals increased with crop residue dry weight (r = 0.90, P < 0.05 and nitrogen content (r = 0.98, P < 0.01. The effect of intercropping on maize grain yield and accumulation of residue and nitrogen were then confirmed in a participatory experiment involving farmers in 2 highland villages in the Phrao and Chiang Dao districts of Chiang Mai Province with maize and rice bean in 2015. The effects of maize/legume intercropping—increased nitrogen accumulation and crop residue, enhanced soil biodiversity, suppression of weeds, and protection of the soil surface, which enabled the maize to be sown without land clearing with fire—should all contribute to sustainable highland maize production.

  15. Resistance of Hordeum chilense against loose smuts of wheat and barley (Ustilago tritici and U. nuda) and its expression in amphiploids with wheat

    OpenAIRE

    Rubiales, Diego; Moral, Ana

    2011-01-01

    Hordeum chilense is wild barley with high potential for cereal breeding purposes given its high crossability with other members of the Triticeae tribe. It is resistant to loose smuts of wheat (Ustilago tritici). The resistance is expressed in xTritordeum amphipoids, offering perspectives for its utilization both in tritordeum breeding and for its transfer to wheat. H. chilense and tritordeums are also resistant to barley loose smut (U. nuda). © 2010 Blackwell Verlag GmbH.

  16. Effecf of pH and some cations on activity of acid phosphatase secreted from Ustilago sp. isolated from acid sulphate soil

    Directory of Open Access Journals (Sweden)

    Chairatana Nilnond

    2007-03-01

    Full Text Available Acid phosphatase secreted from Ustilago sp. is able to hydrolyze organic phosphorus. These soil yeast microorganisms were isolated from rice roots grown in acid sulphate soil that generally contains highamount of aluminum (Al, iron (Fe and manganese (Mn ions. Therefore, the objectives of this study were to examine the effect of pH and some cations on acid phosphatase activity. Two isolates of Ustilago sp., AR101and AR102, were cultured in 100 mL of modified Pikovskaya's broth containing Na-phytate, pH 4, and acid phosphatase activity was determined at pH 2.0-7.0. Effect of Al, Fe, and Mn, including calcium (Ca ions,on growth of AR101 and AR102, secreted acid phosphatase activity, and the ability of acid phosphatase on the phosphorus release from Na-phytate by Ustilago sp. were investigated. It was found that the optimum pH for acid phosphatase activity was 3.5-4.5. The activity of acid phosphatase secreted from AR101 (3,690nmol min-1 mL-1 was remarkably higher than that from AR102 (956 nmol min-1 mL-1. Aluminum, iron, manganese and calcium ions in the medium did not affect the growth of either isolate. The activity of secretedacid phosphatase of AR101 was inhibited by Al and Ca ion, and synthesis of acid phosphatase of Ustilago sp. AR102 was possibly stimulated by Fe ion. Both AR101 and AR102 solubilized Na-phytate, resulting in therelease of P. However, some amount of released P was then precipitated with Al and Fe ions as the highly insoluble Fe- or Al- phosphate.

  17. Use of inter-simple sequence repeats and amplified fragment length polymorphisms to analyze genetic relationships among small grain-infecting species of ustilago.

    Science.gov (United States)

    Menzies, J G; Bakkeren, G; Matheson, F; Procunier, J D; Woods, S

    2003-02-01

    ABSTRACT In the smut fungi, few features are available for use as taxonomic criteria (spore size, shape, morphology, germination type, and host range). DNA-based molecular techniques are useful in expanding the traits considered in determining relationships among these fungi. We examined the phylogenetic relationships among seven species of Ustilago (U. avenae, U. bullata, U. hordei, U. kolleri, U. nigra, U. nuda, and U. tritici) using inter-simple sequence repeats (ISSRs) and amplified fragment length polymorphisms (AFLPs) to compare their DNA profiles. Fifty-four isolates of different Ustilago spp. were analyzed using ISSR primers, and 16 isolates of Ustilago were studied using AFLP primers. The variability among isolates within species was low for all species except U. bullata. The isolates of U. bullata, U. nuda, and U. tritici were well separated and our data supports their speciation. U. avenae and U. kolleri isolates did not separate from each other and there was little variability between these species. U. hordei and U. nigra isolates also showed little variability between species, but the isolates from each species grouped together. Our data suggest that U. avenae and U. kolleri are monophyletic and should be considered one species, as should U. hordei and U. nigra.

  18. A maize resistance gene functions against bacterial streak disease in rice.

    Science.gov (United States)

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-10-25

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, which causes bacterial streak disease. Bacterial streak is an important disease of rice in Asia, and no simply inherited sources of resistance have been identified in rice. Although X. o. pv. oryzicola does not cause disease on maize, we identified a maize gene, Rxo1, that conditions a resistance reaction to a diverse collection of pathogen strains. Surprisingly, Rxo1 also controls resistance to the unrelated pathogen Burkholderia andropogonis, which causes bacterial stripe of sorghum and maize. The same gene thus controls resistance reactions to both pathogens and nonpathogens of maize. Rxo1 has a nucleotide-binding site-leucine-rich repeat structure, similar to many previously identified R genes. Most importantly, Rxo1 functions after transfer as a transgene to rice, demonstrating the feasibility of nonhost R gene transfer between cereals and providing a valuable tool for controlling bacterial streak disease.

  19. Maize kernel evolution:From teosinte to maize

    Science.gov (United States)

    Maize is the most productive and highest value commodity in the US and around the world: over 1 billion tons were produced each year in 2013 and 2014. Together, maize, rice and wheat comprise over 60% of the world’s caloric intake, with wide regional variability in the importance of each crop. The i...

  20. Maize variety and method of production

    Science.gov (United States)

    Pauly, Markus; Hake, Sarah; Kraemer, Florian J

    2014-05-27

    The disclosure relates to a maize plant, seed, variety, and hybrid. More specifically, the disclosure relates to a maize plant containing a Cal-1 allele, whose expression results in increased cell wall-derived glucan content in the maize plant. The disclosure also relates to crossing inbreds, varieties, and hybrids containing the Cal-1 allele to produce novel types and varieties of maize plants.

  1. In Silico Analysis of the Structural and Biochemical Features of the NMD Factor UPF1 in Ustilago maydis.

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    Nancy Martínez-Montiel

    Full Text Available The molecular mechanisms regulating the accuracy of gene expression are still not fully understood. Among these mechanisms, Nonsense-mediated Decay (NMD is a quality control process that detects post-transcriptionally abnormal transcripts and leads them to degradation. The UPF1 protein lays at the heart of NMD as shown by several structural and functional features reported for this factor mainly for Homo sapiens and Saccharomyces cerevisiae. This process is highly conserved in eukaryotes but functional diversity can be observed in various species. Ustilago maydis is a basidiomycete and the best-known smut, which has become a model to study molecular and cellular eukaryotic mechanisms. In this study, we performed in silico analysis to investigate the structural and biochemical properties of the putative UPF1 homolog in Ustilago maydis. The putative homolog for UPF1 was recognized in the annotated genome for the basidiomycete, exhibiting 66% identity with its human counterpart at the protein level. The known structural and functional domains characteristic of UPF1 homologs were also found. Based on the crystal structures available for UPF1, we constructed different three-dimensional models for umUPF1 in order to analyze the secondary and tertiary structural features of this factor. Using these models, we studied the spatial arrangement of umUPF1 and its capability to interact with UPF2. Moreover, we identified the critical amino acids that mediate the interaction of umUPF1 with UPF2, ATP, RNA and with UPF1 itself. Mutating these amino acids in silico showed an important effect over the native structure. Finally, we performed molecular dynamic simulations for UPF1 proteins from H. sapiens and U. maydis and the results obtained show a similar behavior and physicochemical properties for the protein in both organisms. Overall, our results indicate that the putative UPF1 identified in U. maydis shows a very similar sequence, structural organization

  2. In Silico Analysis of the Structural and Biochemical Features of the NMD Factor UPF1 in Ustilago maydis.

    Science.gov (United States)

    Martínez-Montiel, Nancy; Morales-Lara, Laura; Hernández-Pérez, Julio M; Martínez-Contreras, Rebeca D

    2016-01-01

    The molecular mechanisms regulating the accuracy of gene expression are still not fully understood. Among these mechanisms, Nonsense-mediated Decay (NMD) is a quality control process that detects post-transcriptionally abnormal transcripts and leads them to degradation. The UPF1 protein lays at the heart of NMD as shown by several structural and functional features reported for this factor mainly for Homo sapiens and Saccharomyces cerevisiae. This process is highly conserved in eukaryotes but functional diversity can be observed in various species. Ustilago maydis is a basidiomycete and the best-known smut, which has become a model to study molecular and cellular eukaryotic mechanisms. In this study, we performed in silico analysis to investigate the structural and biochemical properties of the putative UPF1 homolog in Ustilago maydis. The putative homolog for UPF1 was recognized in the annotated genome for the basidiomycete, exhibiting 66% identity with its human counterpart at the protein level. The known structural and functional domains characteristic of UPF1 homologs were also found. Based on the crystal structures available for UPF1, we constructed different three-dimensional models for umUPF1 in order to analyze the secondary and tertiary structural features of this factor. Using these models, we studied the spatial arrangement of umUPF1 and its capability to interact with UPF2. Moreover, we identified the critical amino acids that mediate the interaction of umUPF1 with UPF2, ATP, RNA and with UPF1 itself. Mutating these amino acids in silico showed an important effect over the native structure. Finally, we performed molecular dynamic simulations for UPF1 proteins from H. sapiens and U. maydis and the results obtained show a similar behavior and physicochemical properties for the protein in both organisms. Overall, our results indicate that the putative UPF1 identified in U. maydis shows a very similar sequence, structural organization, mechanical stability

  3. Rhamnolipid Biosurfactant against Fusarium verticillioides to Control Stalk and Ear Rot Disease of Maize

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    Siddhartha Narayan Borah

    2016-09-01

    Full Text Available Antifungal activity of rhamnolipids (RLs has been widely studied against many plant pathogenic fungi, but not against Fusarium verticillioides, a major pathogen of maize (Zea mays L.. F. verticillioides causes stalk and ear rot of maize or asymptomatically colonizes the plant and ears resulting in moderate to heavy crop loss throughout the world. F. verticillioides produces fumonisin mycotoxins, reported carcinogens, which makes the contaminated ears unsuitable for consumption. In this study, the RL produced using glucose as sole carbon source was characterized by FTIR and LCMS analyses and its antifungal activity against F. verticillioides was evaluated in vitro on maize stalks and seeds. Further, the effect of RL on the mycelia of F. verticillioides was investigated by scanning electron microscopy which revealed visible damage to the mycelial structure as compared to control samples. In planta, treatment of maize seeds with a RL concentration of 50 mg l-1 resulted in improved biomass and fruiting compared to those of healthy control plants and complete suppression of characteristic disease symptoms and colonization of maize by F. verticillioides. The study highlights the potential of RLs to be used for an effective biocontrol strategy against colonization of maize plant by F. verticillioides.

  4. The pathogenesis-related maize seed (PRms) gene plays a role in resistance to Aspergillus flavus infection and aflatoxin contamination

    Science.gov (United States)

    Aspergillus flavus is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize (Zea mays ssp. mays L.). Pathogenesis-related proteins serve as a first line of defense against invading pathogens by confer...

  5. Advances in Maize Transformation Technologies and Development of Transgenic Maize.

    Science.gov (United States)

    Yadava, Pranjal; Abhishek, Alok; Singh, Reeva; Singh, Ishwar; Kaul, Tanushri; Pattanayak, Arunava; Agrawal, Pawan K

    2016-01-01

    Maize is the principal grain crop of the world. It is also the crop where genetic engineering has been employed to a great extent to improve its various traits. The ability to transform maize is a crucial step for application of gene technology in maize improvement. There have been constant improvements in the maize transformation technologies over past several years. The choice of genotype and the explant material to initiate transformation and the different types of media to be used in various stages of tissue culture can have significant impact on the outcomes of the transformation efforts. Various methods of gene transfer, like the particle bombardment, protoplast transformation, Agrobacterium -mediated, in planta transformation, etc., have been tried and improved over years. Similarly, various selection systems for retrieval of the transformants have been attempted. The commercial success of maize transformation and transgenic development is unmatched by any other crop so far. Maize transformation with newer gene editing technologies is opening up a fresh dimension in transformation protocols and work-flows. This review captures the various past and recent facets in improvement in maize transformation technologies and attempts to present a comprehensive updated picture of the current state of the art in this area.

  6. MaizeGDB: The Maize Genetics and Genomics Database.

    Science.gov (United States)

    Harper, Lisa; Gardiner, Jack; Andorf, Carson; Lawrence, Carolyn J

    2016-01-01

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website ( http://www.maizegdb.org ) are custom interfaces enabling researchers to browse data and to seek out specific information matching explicit search criteria. In addition, pre-compiled reports are made available for particular types of data and bulletin boards are provided to facilitate communication and coordination among members of the community of maize geneticists.

  7. Genetic resources in maize breeding

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    Anđelković Violeta

    2017-01-01

    Full Text Available Maize, wheat and rice are the most important cereals grown in the world. It is predicted that by 2025 maize is likely to become the crop with the greatest production globally. Conservation of maize germplasm provides the main resources for increased food and feed production. Conservation in gene banks (ex-situ is dominant strategy for maize conservation. More than 130 000 maize accessions, e.g. about 40% of total number, are stored in ten largest gene banks worldwide and Maize Research Institute Zemun Polje (MRIZP gene bank, with about 6000 accessions, is among them. Organized collecting missions started in 1961. in the former Yugoslavian territory, and up today, more than 2000 local maize landraces were stored. Pre-breeding activities that refer to identification of desirable traits from unadapted germplasm within genebank, result in materials expected to be included in breeding programs. Successful examples are LAMP, GEM and GENRES projects. At the end of XX century, at MRIZP genebank two pre-breeding activities were undertaken: eco-core and elite-core collections were created and landraces fulfilled particular criteria were chosen. In the last decade, MRIZP genebank collection was used for identification of sources for drought tolerance and improved grain quality. According to agronomic traits and general combining ability, two mini-core collections were created and included in commercial breeding programs.

  8. Unfolded Protein Response (UPR Regulator Cib1 Controls Expression of Genes Encoding Secreted Virulence Factors in Ustilago maydis.

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    Martin Hampel

    Full Text Available The unfolded protein response (UPR, a conserved eukaryotic signaling pathway to ensure protein homeostasis in the endoplasmic reticulum (ER, coordinates biotrophic development in the corn smut fungus Ustilago maydis. Exact timing of UPR activation is required for virulence and presumably connected to the elevated expression of secreted effector proteins during infection of the host plant Zea mays. In the baker's yeast Saccharomyces cerevisiae, expression of UPR target genes is induced upon binding of the central regulator Hac1 to unfolded protein response elements (UPREs in their promoters. While a role of the UPR in effector secretion has been described previously, we investigated a potential UPR-dependent regulation of genes encoding secreted effector proteins. In silico prediction of UPREs in promoter regions identified the previously characterized effector genes pit2 and tin1-1, as bona fide UPR target genes. Furthermore, direct binding of the Hac1-homolog Cib1 to the UPRE containing promoter fragments of both genes was confirmed by quantitative chromatin immunoprecipitation (qChIP analysis. Targeted deletion of the UPRE abolished Cib1-dependent expression of pit2 and significantly affected virulence. Furthermore, ER stress strongly increased Pit2 expression and secretion. This study expands the role of the UPR as a signal hub in fungal virulence and illustrates, how biotrophic fungi can coordinate cellular physiology, development and regulation of secreted virulence factors.

  9. Confirmação molecular do 'Maize rayado fino virus' como vírus da estria do milho

    OpenAIRE

    Hammond, Rosemarie Wahnbaeck; Bedendo, Ivan Paulo

    2005-01-01

    Maize rayado fino virus (MRFV), present in various countries in Latin America, has shown similarities to corn streak virus that occurs in Brazil, regarding pathogenic, serological and histological characteristics. In the current report both virus were molecularly compared to confirm the similarities between them. MRFV was identified by nucleic acid hybridization in samples of maize tissues exhibiting symptoms of "corn stunt" disease, collected from two Brazilian States - São Paulo and Minas G...

  10. Breeding of maize types with specific traits at the Maize Research Institute, Zemun Polje

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    Pajić Zorica

    2007-01-01

    Full Text Available Maize is primarily grown as an energy crop, but the use of different specific versions, such as high-oil maize, high-lysine maize, waxy maize, white-seeded maize, popping maize and sweet maize, is quite extensive. Speciality maize, due to its traits and genetic control of these traits, requires a particular attention in handling breeding material during the processes of breeding. It is especially related to prevention of uncontrolled pollination. In order to provide successful selection for a certain trait, the following specific procedures in evaluation of the trait are necessary: the estimation of a popping volume and flake quality in popping maize; the determination of sugars and harvest maturity in sweet maize; the determination of oil in selected samples of high-oil maize types, and so forth. Breeding programmes for speciality maize, except high-amylose maize, have been implemented at the Maize Research Institute, Zemun Polje, Belgrade, for the last 45 years. A great number of high-yielding sweet maize hybrids, popping maize, high-oil and high-lysine, flint and white-seeded maize hybrids were developed during this 45-year period. Auspicious selection and breeding for these traits is facilitated by the abundant genetic variability and technical and technological possibilities necessary for successful selection.

  11. Aggressiveness of Cephalosporium maydis causing late wilt of maize in Spain.

    Science.gov (United States)

    García-Carneros, A B; Girón, I; Molinero-Ruiz, L

    2012-01-01

    Late wilt of maize, caused by the vascular and soilborne pathogen Cephalosporium maydis, was identified in the Iberian Peninsula in 2008. During the last years the incidence and economical impact of the disease has importantly increased both in Portugal and Spain. Varieties of maize displaying tolerance to the pathogen are available, but the effectiveness can be dependent on the virulence of the fungus (i.e. ability to cause disease on a specific genotype). On the other hand, strains of crop pathogens from different geographic origins can differ with regard to the degree of disease caused on a specific genotype (i.e. aggressiveness). Our working hypothesis was that isolates of C. maydis from different maize growing areas may differ in aggressiveness towards maize plants. Seven fungal strains were isolated in 2009 from diseased plants collected in the most important maize growing regions of Spain and used to inoculate two susceptible maize varieties grown in shadehouse from March to July 2010. The experimental unit consisted of two 4-day-old seedlings planted in an 8-liter pot filled with sand/silt previously infested with 200 g of wheat grains colonized by the fungi. Non colonized wheat grains were used for the control treatments. Six replications (pots) were established for each variety/isolate combination according to a complete randomized 2 x 8 factorial design. The percentage of necrotic and dry aboveground tissues was recorded 14 weeks after inoculation and thereafter weekly until physiological senescence of the control plants. At the end of the experiment, weights of roots and aboveground parts of the plants were recorded. Initial occurrence of symptoms in the plants was significantly dependent on the isolate of C. maydis and on the maize variety. However, final severity of aboveground symptoms (leaf necroses and drying up) was only dependent on the fungal isolate. All the isolates significantly reduced the root weight of both varieties of maize. The highest

  12. Deregulation of Lesotho's maize market

    OpenAIRE

    van Schalkwyk, Herman D.; van Zyl, Johan; Botha, P.W.; Bayley, B.

    1997-01-01

    During the past year, there have been major policy reforms in Lesotho and South Africa with respect to maize pricing and marketing. In Lesotho the impact of deregulation on producers, consumers and government revenues was substantially lower than it should have been, and as a result Lesotho was not able to reap the full benefits of these changes. This is partly because information on the changes to the maize marketing system did not reach the potential beneficiaries of the new system. Free an...

  13. Molecular Basis of Resistance to Fusarium Ear Rot in Maize

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    Alessandra Lanubile

    2017-10-01

    Full Text Available The impact of climate change has been identified as an emerging issue for food security and safety, and the increased incidence of mycotoxin contamination in maize over the last two decades is considered a potential emerging hazard. Disease control by chemical and agronomic approaches is often ineffective and increases the cost of production; for this reason the exploitation of genetic resistance is the most sustainable method for reducing contamination. The review focuses on the significant advances that have been made in the development of transcriptomic, genetic and genomic information for maize, Fusarium verticillioides molds, and their interactions, over recent years. Findings from transcriptomic studies have been used to outline a specific model for the intracellular signaling cascade occurring in maize cells against F. verticillioides infection. Several recognition receptors, such as receptor-like kinases and R genes, are involved in pathogen perception, and trigger down-stream signaling networks mediated by mitogen-associated protein kinases. These signals could be orchestrated primarily by hormones, including salicylic acid, auxin, abscisic acid, ethylene, and jasmonic acid, in association with calcium signaling, targeting multiple transcription factors that in turn promote the down-stream activation of defensive response genes, such as those related to detoxification processes, phenylpropanoid, and oxylipin metabolic pathways. At the genetic and genomic levels, several quantitative trait loci (QTL and single-nucleotide polymorphism markers for resistance to Fusarium ear rot deriving from QTL mapping and genome-wide association studies are described, indicating the complexity of this polygenic trait. All these findings will contribute to identifying candidate genes for resistance and to applying genomic technologies for selecting resistant maize genotypes and speeding up a strategy of breeding to contrast disease, through plants

  14. The fungus Ustilago maydis and humans share disease-related proteins that are not found in Saccharomyces cerevisiae

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    Steinberg Gero

    2007-12-01

    Full Text Available Abstract Background The corn smut fungus Ustilago maydis is a well-established model system for molecular phytopathology. In addition, it recently became evident that U. maydis and humans share proteins and cellular processes that are not found in the standard fungal model Saccharomyces cerevisiae. This prompted us to do a comparative analysis of the predicted proteome of U. maydis, S. cerevisiae and humans. Results At a cut off at 20% identity over protein length, all three organisms share 1738 proteins, whereas both fungi share only 541 conserved proteins. Despite the evolutionary distance between U. maydis and humans, 777 proteins were shared. When applying a more stringent criterion (≥ 20% identity with a homologue in one organism over at least 50 amino acids and ≥ 10% less in the other organism, we found 681 proteins for the comparison of U. maydis and humans, whereas the both fungi share only 622 fungal specific proteins. Finally, we found that S. cerevisiae and humans shared 312 proteins. In the U. maydis to H. sapiens homology set 454 proteins are functionally classified and 42 proteins are related to serious human diseases. However, a large portion of 222 proteins are of unknown function. Conclusion The fungus U. maydis has a long history of being a model system for understanding DNA recombination and repair, as well as molecular plant pathology. The identification of functionally un-characterized genes that are conserved in humans and U. maydis opens the door for experimental work, which promises new insight in the cell biology of the mammalian cell.

  15. The SPF27 homologue Num1 connects splicing and kinesin 1-dependent cytoplasmic trafficking in Ustilago maydis.

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    Nikola Kellner

    2014-01-01

    Full Text Available The conserved NineTeen protein complex (NTC is an integral subunit of the spliceosome and required for intron removal during pre-mRNA splicing. The complex associates with the spliceosome and participates in the regulation of conformational changes of core spliceosomal components, stabilizing RNA-RNA- as well as RNA-protein interactions. In addition, the NTC is involved in cell cycle checkpoint control, response to DNA damage, as well as formation and export of mRNP-particles. We have identified the Num1 protein as the homologue of SPF27, one of NTC core components, in the basidiomycetous fungus Ustilago maydis. Num1 is required for polarized growth of the fungal hyphae, and, in line with the described NTC functions, the num1 mutation affects the cell cycle and cell division. The num1 deletion influences splicing in U. maydis on a global scale, as RNA-Seq analysis revealed increased intron retention rates. Surprisingly, we identified in a screen for Num1 interacting proteins not only NTC core components as Prp19 and Cef1, but several proteins with putative functions during vesicle-mediated transport processes. Among others, Num1 interacts with the motor protein Kin1 in the cytoplasm. Similar phenotypes with respect to filamentous and polar growth, vacuolar morphology, as well as the motility of early endosomes corroborate the genetic interaction between Num1 and Kin1. Our data implicate a previously unidentified connection between a component of the splicing machinery and cytoplasmic transport processes. As the num1 deletion also affects cytoplasmic mRNA transport, the protein may constitute a novel functional interconnection between the two disparate processes of splicing and trafficking.

  16. Activation of the cell wall integrity pathway promotes escape from G2 in the fungus Ustilago maydis.

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    Natalia Carbó

    2010-07-01

    Full Text Available It is widely accepted that MAPK activation in budding and fission yeasts is often associated with negative effects on cell cycle progression, resulting in delay or arrest at a specific stage in the cell cycle, thereby enabling cells to adapt to changing environmental conditions. For instance, activation of the Cell Wall Integrity (CWI pathway in the budding yeast Saccharomyces cerevisiae signals an increase in CDK inhibitory phosphorylation, which leads cells to remain in the G2 phase. Here we characterized the CWI pathway of Ustilago maydis, a fungus evolutionarily distant from budding and fission yeasts, and show that activation of the CWI pathway forces cells to escape from G2 phase. In spite of these disparate cell cycle responses in S. cerevisiae and U. maydis, the CWI pathway in both organisms appears to respond to the same class cell wall stressors. To understand the basis of such a difference, we studied the mechanism behind the U. maydis response. We found that activation of CWI pathway in U. maydis results in a decrease in CDK inhibitory phosphorylation, which depends on the mitotic phosphatase Cdc25. Moreover, in response to activation of the CWI pathway, Cdc25 accumulates in the nucleus, providing a likely explanation for the increase in the unphosphorylated form of CDK. We also found that the extended N-terminal domain of Cdc25, which is dispensable under normal growth conditions, is required for this G2 escape as well as for resistance to cell wall stressors. We propose that the process of cell cycle adaptation to cell stress evolved differently in these two divergent organisms so that each can move towards a cell cycle phase most appropriate for responding to the environmental signals encountered.

  17. Mre11 and Blm-Dependent Formation of ALT-Like Telomeres in Ku-Deficient Ustilago maydis.

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    Eun Young Yu

    2015-10-01

    Full Text Available A subset of human cancer cells uses a specialized, aberrant recombination pathway known as ALT to maintain telomeres, which in these cells are characterized by complex aberrations including length heterogeneity, high levels of unpaired C-strand, and accumulation of extra-chromosomal telomere repeats (ECTR. These phenotypes have not been recapitulated in any standard budding or fission yeast mutant. We found that eliminating Ku70 or Ku80 in the yeast-like fungus Ustilago maydis results initially in all the characteristic telomere aberrations of ALT cancer cells, including C-circles, a highly specific marker of ALT. Subsequently the ku mutants experience permanent G2 cell cycle arrest, accompanied by loss of telomere repeats from chromosome ends and even more drastic accumulation of very short ECTRs (vsECTRs. The deletion of atr1 or chk1 rescued the lethality of the ku mutant, and "trapped" the telomere aberrations in the early ALT-like stage. Telomere abnormalities are telomerase-independent, but dramatically suppressed by deletion of mre11 or blm, suggesting major roles for these factors in the induction of the ALT pathway. In contrast, removal of other DNA damage response and repair factors such as Rad51 has disparate effects on the ALT phenotypes, suggesting that these factors process ALT intermediates or products. Notably, the antagonism of Ku and Mre11 in the induction of ALT is reminiscent of their roles in DSB resection, in which Blm is also known to play a key role. We suggest that an aberrant resection reaction may constitute an early trigger for ALT telomeres, and that the outcomes of ALT are distinct from DSB because of the unique telomere nucleoprotein structure.

  18. Susceptibilidad y resistencia del maíz al hongo comestible huitlacoche (Ustilago maydis Cda. mejorando su virulencia

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    L. Martínez

    2000-01-01

    Full Text Available El huitlacoche es un patógeno del maíz, muy apreciado como alimento humano en la región central de México. Actualmente seis industrias lo comercializan enlatado. El total de la producción industrial se abastece de la recolección espontánea del hongo en campos de cultivo de maíz para producción de grano. Debido a lo anterior, los objetivos planteados en este estudio fueron: evaluar y seleccionar patotipos de Ustilago maydis con una alta virulencia sobre maíz; evaluar y seleccionar familias de medios hermanos maternos de maíz de reacción susceptible y resistente al huitlacoche. En 1997, se evaluaron 100 aislamientos del hongo en un híbrido experimental, seleccionando 12 de ellos por su vigor, presentando en promedio 190 g del hongo por planta infectada, y 135.24 g por planta inoculada (8.11 t×ha-1, 60 000 plantas×ha-1, índice de severidad de 36.82 y una incidencia de 70.64%. De las 300 familias de medios hermanos maternos evaluadas (1998 por inoculación con la mezcla de los 12 aislamientos seleccionados (1997, se eligieron 16 familias susceptibles, que presentaron en promedio 154.97 g del hongo por planta infectada y 112.88 g por planta inoculada (6.67 t×ha-1, 76.67 % de incidencia y 34.82 de índice de severidad; así como 14 familias resistentes (0 % de incidencia al ataque del hongo.

  19. Potential of Using Maize Cobs in Pig Diets — A Review

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    A. T. Kanengoni

    2015-12-01

    Full Text Available The quest to broaden the narrow range of feed ingredients available to pig producers has prompted research on the use of low cost, unconventional feedstuffs, which are typically fibrous and abundant. Maize cobs, a by-product of a major cereal grown worldwide, have potential to be used as a pig feed ingredient. Presently, maize cobs are either dumped or burnt for fuel. The major challenge in using maize cobs in pig diets is their lignocellulosic nature (45% to 55% cellulose, 25% to 35% hemicellulose, and 20% to 30% lignin which is resistant to pigs’ digestive enzymes. The high fiber in maize cobs (930 g neutral detergent fiber/kg dry matter [DM]; 573 g acid detergent fiber/kg DM increases rate of passage and sequestration of nutrients in the fiber reducing their digestion. However, grinding, heating and fermentation can modify the structure of the fibrous components in the maize cobs and improve their utilization. Pigs can also extract up to 25% of energy maintenance requirements from fermentation products. In addition, dietary fiber improves pig intestinal health by promoting the growth of lactic acid bacteria, which suppress proliferation of pathogenic bacteria in the intestines. This paper reviews maize cob composition and the effect on digestibility of nutrients, intestinal microflora and growth performance and proposes the use of ensiling using exogenous enzymes to enhance utilization in diets of pigs.

  20. Maize Prolamins Could Induce a Gluten-Like Cellular Immune Response in Some Celiac Disease Patients

    Science.gov (United States)

    Ortiz-Sánchez, Juan P.; Cabrera-Chávez, Francisco; Calderón de la Barca, Ana M.

    2013-01-01

    Celiac disease (CD) is an autoimmune-mediated enteropathy triggered by dietary gluten in genetically prone individuals. The current treatment for CD is a strict lifelong gluten-free diet. However, in some CD patients following a strict gluten-free diet, the symptoms do not remit. These cases may be refractory CD or due to gluten contamination; however, the lack of response could be related to other dietary ingredients, such as maize, which is one of the most common alternatives to wheat used in the gluten-free diet. In some CD patients, as a rare event, peptides from maize prolamins could induce a celiac-like immune response by similar or alternative pathogenic mechanisms to those used by wheat gluten peptides. This is supported by several shared features between wheat and maize prolamins and by some experimental results. Given that gluten peptides induce an immune response of the intestinal mucosa both in vivo and in vitro, peptides from maize prolamins could also be tested to determine whether they also induce a cellular immune response. Hypothetically, maize prolamins could be harmful for a very limited subgroup of CD patients, especially those that are non-responsive, and if it is confirmed, they should follow, in addition to a gluten-free, a maize-free diet. PMID:24152750

  1. Thc6 protein, isolated from Trichoderma harzianum, can induce maize defense response against Curvularia lunata.

    Science.gov (United States)

    Fan, Lili; Fu, Kehe; Yu, Chuanjin; Li, Yingying; Li, Yaqian; Chen, Jie

    2015-05-01

    Mutant T66 was isolated from 450 mutants (constructed with Agrobacterium tumefaciens-mediated transformation method) of Trichoderma harzianum. Maize seeds coated with T66 were more susceptible to Curvularia lunata when compared with those coated with wild-type (WT) strain. The disease index of maize treated with T66 and WT were 62.5 and 42.1%, respectively. Further research showed T-DNA has inserted into the ORF of one gene, which resulted in the functional difference between WT and T66. The gene was cloned and named Thc6, which encodes a novel 327 amino acid protein. To investigate its function, we obtained knockout, complementation, and overexpression mutants of Thc6. Challenge inoculation studies suggested that the Thc6 overexpression mutant can reduce the disease index of maize inbred line Huangzao 4 against the leaf spot pathogen (C. lunata). Meanwhile, The Thc6 mutants were found to affect the resistance of maize inbred line Huangzao 4 against C. lunata by enhancing the activation of jasmonate-responsive genes expression. Liquid chromatography-mass spectrometry (LC-MS) data further confirmed that the concentration of jasmonate in the induced maize exhibits a parallel change tendency with the expression level of defense-related genes. Hence, the Thc6 gene could be participated in the induced resistance of maize inbred line Huangzao 4 against C. lunata infection through a jasmonic acid-dependent pathway. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. IMAZAPYR-RESISTANT MAIZE TECHNOLOGY ADOPTION FOR ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    decisions by protecting maize (Zea mays L.) crop in western Kenya from Striga. Key Words: Adopters, Zea ... Africa, efficient and profitable production of maize is severely constrained by ..... gap by understanding its source. African. Journal of ...

  3. Phytohormone Involvement in the Ustilago maydis- Zea mays Pathosystem: Relationships between Abscisic Acid and Cytokinin Levels and Strain Virulence in Infected Cob Tissue.

    Directory of Open Access Journals (Sweden)

    Erin N Morrison

    Full Text Available Ustilago maydis is the causative agent of common smut of corn. Early studies noted its ability to synthesize phytohormones and, more recently these growth promoting substances were confirmed as cytokinins (CKs. Cytokinins comprise a group of phytohormones commonly associated with actively dividing tissues. Lab analyses identified variation in virulence between U. maydis dikaryon and solopathogen infections of corn cob tissue. Samples from infected cob tissue were taken at sequential time points post infection and biochemical profiling was performed using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI MS/MS. This hormone profiling revealed that there were altered levels of ABA and major CKs, with a marked reduction in CK glucosides, increases in methylthiol CKs and a particularly dramatic increase in cisZ CK forms, in U. maydis infected tissue. These changes were more pronounced in the more virulent dikaryon relative to the solopathogenic strain suggesting a role for cytokinins in moderating virulence during biotrophic infection. These findings highlight the fact that U. maydis does not simply mimic a fertilized seed but instead reprograms the host tissue. Results underscore the suitability of the Ustilago maydis- Zea mays model as a basis for investigating the control of phytohormone dynamics during biotrophic infection of plants.

  4. Technical feasibility for electron beam application on maize seeds disinfection for maize cultivation in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Zago, Claudia [Proenco Brasil Ltda. (Brazil)]. E-mail: clauzago@uol.com.br; Rela, Paulo Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (brazil). Centro de Tecnologia das Radiacoes]. E-mail: prela@ipen.br

    2007-07-01

    Among the man made activities agriculture plays a fundamental rule on the interference with environment; new alternatives for clean technologies are being searched in order to reduce the impact and degradation of the environment. This work presents a feasibility study to implement in Brazil a technology using electron beam treatment to disinfect maize seeds avoiding the spoilage from pathogens microorganisms. This technology was developed in Germany by Fraunhofer Institut FEP (Dresden) and the private company Schmidt-Seeger AG. It was patented as 'e-ventus'. Concerning to the technical feasibility it shows to be quite useful due to the results of the experiments performed in other countries with maize seeds and properly for the large amount to be treated in the country. Under the environmental management it is quite advantageous when compared with the traditional technology that uses chemical seed dressing agents. Nevertheless for a large scale commercial application it is necessary a cost analyse comparison study between the traditional technology and the alternative using electron beam. (author)

  5. Technical feasibility for electron beam application on maize seeds disinfection for maize cultivation in Brazil

    International Nuclear Information System (INIS)

    Zago, Claudia; Rela, Paulo Roberto

    2007-01-01

    Among the man made activities agriculture plays a fundamental rule on the interference with environment; new alternatives for clean technologies are being searched in order to reduce the impact and degradation of the environment. This work presents a feasibility study to implement in Brazil a technology using electron beam treatment to disinfect maize seeds avoiding the spoilage from pathogens microorganisms. This technology was developed in Germany by Fraunhofer Institut FEP (Dresden) and the private company Schmidt-Seeger AG. It was patented as 'e-ventus'. Concerning to the technical feasibility it shows to be quite useful due to the results of the experiments performed in other countries with maize seeds and properly for the large amount to be treated in the country. Under the environmental management it is quite advantageous when compared with the traditional technology that uses chemical seed dressing agents. Nevertheless for a large scale commercial application it is necessary a cost analyse comparison study between the traditional technology and the alternative using electron beam. (author)

  6. RNA interference in a maize pathogen reduces toxin production

    Science.gov (United States)

    The fungus Fusarium verticillioides can produce fumonisin mycotoxins in ears under certain environmental conditions. Because fumonisins are unhealthy for humans and livestock, control strategies with nominal risk to the environment are needed to reduce fumonisin exposure. Host-induced gene silencing...

  7. The Top 10 fungal pathogens in molecular plant pathology.

    Science.gov (United States)

    Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D

    2012-05-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  8. Maize, tropical (Zea mays L.).

    Science.gov (United States)

    Assem, Shireen K

    2015-01-01

    Maize (Zea mays L.) is the third most important food crop globally after wheat and rice. In sub-Saharan Africa, tropical maize has traditionally been the main staple of the diet; 95 % of the maize grown is consumed directly as human food and as an important source of income for the resource-poor rural population. The biotechnological approach to engineer biotic and abiotic traits implies the availability of an efficient plant transformation method. The production of genetically transformed plants depends both on the ability to integrate foreign genes into target cells and the efficiency with which plants are regenerated. Maize transformation and regeneration through immature embryo culture is the most efficient system to regenerate normal transgenic plants. However, this system is highly genotype dependent. Genotypes adapted to tropic areas are difficult to regenerate. Therefore, transformation methods used with model genotypes adapted to temperate areas are not necessarily efficient with tropical lines. Agrobacterium-mediated transformation is the method of choice since it has been first achieved in 1996. In this report, we describe a transformation method used successfully with several tropical maize lines. All the steps of transformation and regeneration are described in details. This protocol can be used with a wide variety of tropical lines. However, some modifications may be needed with recalcitrant lines.

  9. Maize Bioactive Peptides against Cancer

    Science.gov (United States)

    Díaz-Gómez, Jorge L.; Castorena-Torres, Fabiola; Preciado-Ortiz, Ricardo E.; García-Lara, Silverio

    2017-06-01

    Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derived food products has been associated with reduction risks of various types of cancer. Cereals main biomolecules includes proteins, peptides, and amino acids present in different quantities within the grain. The nutraceutical properties associated with peptides exerts biological functions that promote health and prevent this disease. In this review, we report the current status and advances on maize peptides regarding bioactive properties that have been reported such as antioxidant, antihypertensive, hepatoprotective, and anti-tumour activities. We also highlighted its biological potential through which maize bioactive peptides exert anti-cancer activity. Finally, we analyse and emphasize the possible areas of application for maize peptides.

  10. Putting the Function in Maize Genomics

    Directory of Open Access Journals (Sweden)

    Stephen P. Moose

    2009-07-01

    Full Text Available The 51st Maize Genetics Conference was held March 12–15, 2009 at Pheasant Run Resort in St. Charles, Illinois. Nearly 500 attendees participated in a scientific program (available at covering a wide range of topics which integrate the rich biology of maize with recent discoveries in our understanding of the highly dynamic maize genome. Among the many research themes highlighted at the conference, the historical emphasis on studying the tremendous phenotypic diversity of maize now serves as the foundation for maize as a leading experimental system to characterize the mechanisms that generate variation in complex plant genomes and associate evolutionary change with phenotypes of interest.

  11. Global maize production, utilization, and consumption.

    Science.gov (United States)

    Ranum, Peter; Peña-Rosas, Juan Pablo; Garcia-Casal, Maria Nieves

    2014-04-01

    Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification. © 2014 New York Academy of Sciences. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

  12. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens

    DEFF Research Database (Denmark)

    Nayaka, Siddaiah Chandra; Shankar, Akarere C. Udaya; Reddy, Munagala S.

    2009-01-01

    Abstract BACKGROUND: Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have...... disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars....... verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. CONCLUSION: The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize...

  13. Pathogen intelligence

    Directory of Open Access Journals (Sweden)

    Michael eSteinert

    2014-01-01

    Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

  14. A climate profile indicator based comparative analysis of climate change scenarios with regard to maize (Zea mays L.) cultures

    Energy Technology Data Exchange (ETDEWEB)

    Dios, N.; Szenteleki, K.; Ferenczy, A.; Petranyl, G. [Corvinus Univ. of Budapest (Hungary). Dept. of Mathematics and Informatics; Hufnagel, L. [Hungarian Academy of Sciences, Budapest (Hungary). Adaptation to Climate Change Research Group

    2009-07-01

    Recent research results let us conclude that climate change might have a significant effect on the yield of wheat, barley, rye, potato and maize, and the borderlines of their area of cultivation might shift 100--150 kilometers to the north. The possible mass occurrence of new aggressive pest, pathogen and weed species in Hungary might also create a problem from plant protection. Maize is one of the most important fodder-plants. Hungary has close to the largest total cultivating area in Europe. Maize is used in many ways, thus being of outstanding economic importance. In Hungary the conditions of maize cultivation are -- except for dry years -- quite favorable in most cultural regions and complex cultivating technologies are available. It also might gain a significant role in the line of new environment-friendly alternative sources of energy. For these reasons, it is important to examine the influence of meteorological factors on maize ecosystems and this examination should include as many climate change scenarios and as long a time series as possible. Using ecological data compiled from scientific literature on pest, pathogen and weed species characteristic in maize cultures in Hungary, we defined monthly climate profile indicators and applied them to complete a comparative analysis of the historical and modelled climate change scenario meteorological data of the city of Debrecen. Our results call attention to a drastic decline of the competitive ability of maize as compared to several C{sub 4} and especially C{sub 3} plants. According to the stricter scenarios, the frequency of potential pest and pathogen damage emergency situations will grow significantly by the end of the century.

  15. Maize starch biphasic pasting curves

    CSIR Research Space (South Africa)

    Nelles, EM

    2000-05-01

    Full Text Available (150–500 rev/min). The second pasting peak is attributed to the formation of complexes between amylose and low levels of lipid present in maize starch. When lipid was partially removed by extraction with methanol-chloroform (1: 3 v/v), the second...

  16. The 14-3-3 homolog, ArtA, regulates development and secondary metabolism in the opportunistic plant pathogen Aspergillus flavus

    Science.gov (United States)

    The opportunistic plant pathogenic fungus Aspergillus flavus produces carcinogenic mycotoxins denominated aflatoxins (AFs). Aflatoxin contamination of agriculturally important crops such as maize, peanut, sorghum and tree nuts is responsible for serious adverse health and economic impacts worldwide....

  17. Caractéristiques des souches d'Ustilago nuda, agent du charbon nu de l'orge, résistantes à la carboxine

    OpenAIRE

    Leroux , Pierre

    1986-01-01

    Des souches d’Ustilago nuda, agent du charbon nu de l’orge, résistantes à la carboxine ont été détectées en France et dans d’autres pays européens. Une résistance croisée positive s’observe entre ce fongicide, le fenfuram, la pyracarbolide et divers autres analogues structuraux ; le mépronil se singularise car il est plus toxique pour les isolats résistants à la carboxine que pour les isolats sensibles. Toutes les souches sont affectées de la même manière par l’antimycine A, l’azide de so...

  18. Extraction and characterization of natural cellulose fibers from maize tassel

    CSIR Research Space (South Africa)

    Maepa, CE

    2015-04-01

    Full Text Available This article reports on the extraction and characterization of novel natural cellulose fibers obtained from the maize (tassel) plant. Cellulose was extracted from the agricultural residue (waste biomaterial) of maize tassel. The maize tassel fibers...

  19. Aflatoxin levels in maize and maize products during the 2004 food ...

    African Journals Online (AJOL)

    Aflatoxin levels in maize and maize products during the 2004 food poisoning ... district were received at the National Public Health Laboratory Services (NPHLS). On analysis, they were found to be highly contaminated with aflatoxin B1.

  20. EVALUATION OF THE DEVELOPMENT OF MAIZE PLANTS (Zea mays L.) AFTER COLONIZATION BY ENDOPHYTE FUNGUS Fusarium verticillioides

    OpenAIRE

    Gomes, Ulisses de Deus; Orlandelli, Ravely Casarotti; Santos, Mariana Sanches; Polonio, Julio Cesar; Pamphile, João Alencar; Rubin Filho, Celso João

    2013-01-01

    Endophyte fungi inhabit the inside of plants without causing any damage. Benefits from endophyte-plant interactivities include vegetal growth and the plant´s defense against insects and other pathogens. Some endophytes, however, may act as latent pathogens which cause physiological changes and disease symptoms in the host. Current analysis evaluates the development of maize plants colonizer (treatment) and non-colonized (control) with the frequently found endophyte Fusarium verticillioides an...

  1. Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants

    Science.gov (United States)

    Aspergillus niger and A. carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspe...

  2. Responses to recurrent index selection for reduced fusarium ear rot and lodging and for increased yield in maize

    Science.gov (United States)

    Fusarium ear rot caused by the pathogen Fusarium verticillioides (Sacc.) Nirenberg damages maize (Zea mays L.) grain production and is associated with contamination of grain by fumonisin, a mycotoxin harmful to both humans and animals. Recurrent selection may be an effective way to combine improveme...

  3. Potential of fungal antagonists for biocontrol of toxigenic Fusarium spp. in wheat and maize through competition in crop debris

    NARCIS (Netherlands)

    Luongo, L.; Galli, M.; Corazza, L.; Meekes, E.T.M.; Haas, de B.H.; Lombaers-van der Plas, C.H.; Köhl, J.

    2005-01-01

    Pathogenic Fusarium spp. cause head blight in wheat or ear rot in maize leading to yield losses and also a reduction in quality due to mycotoxin contamination of the grain. Infected crop residues are the main inoculum source for epidemics. Saprophytic fungi, obtained from cereal tissues or necrotic

  4. Metabolic engineering of geranic acid in maize to achieve fungal resistance is compromised by novel glycosylation patterns

    NARCIS (Netherlands)

    Yang, T.; Stoopen, G.; Yalpani, N.; Vervoort, J.J.M.; Vos, de R.; Voster, A.; Verstappen, F.W.A.; Bouwmeester, H.J.; Jongsma, M.A.

    2011-01-01

    Many terpenoids are known to have antifungal properties and overexpression of these compounds in crops is a potential tool in disease control. In this study, 15 different mono- and sesquiterpenoids were tested in vitro against two major pathogenic fungi of maize (Zea mays), Colletotrichum

  5. Assessment of maize stem borer damage on hybrid maize varieties in Chitwan, Nepal

    OpenAIRE

    Buddhi Bahadur Achhami; Santa Bahadur BK; Ghana Shyam Bhandari

    2015-01-01

    Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage per...

  6. "Achieving Mexico’s Maize Potential"

    OpenAIRE

    Antonio Turrent Fernández; Timothy A. Wise; Elise Garvey

    2012-01-01

    Rising agricultural prices, combined with growing import dependence, have driven Mexico’s food import bill over $20 billion per year and increased its agricultural trade deficit. Mexico imports one-third of its maize, overwhelmingly from the United States, but three million producers grow most of the country’s white maize, which is used primarily for tortillas and many other pluricultural products for human consumption. Yield gaps are large among the country’s small to medium-scale maize farm...

  7. Disseminating genetically modified (GM) maize technology to ...

    African Journals Online (AJOL)

    Disseminating genetically modified (GM) maize technology to smallholder farmers in the Eastern Cape province of South Africa: extension personnel's awareness of stewardship requirements and dissemination practices.

  8. Ustilago maydis: ascenso de un hongo mexicano de la gastronomía local al mundo científico

    Directory of Open Access Journals (Sweden)

    José Ruiz Herrera

    2008-01-01

    Full Text Available En el presente trabajo se describe la naturaleza del hongo Ustilago maydis, su papel como causante de una enfermedad del maíz, su uso en la cocina mexicana y las condiciones que lo llevaron a convertirse en material de estudio científico, además de algunas características descollantes de su fisiología, genética y bioquímica. U. maydis es un hongo patógeno biotrófico específico del maíz, y el teozintle, siendo el agente causal del "huitlacoche" o carbón común, una enfermedad de distribución mundial que bajo ciertas condiciones puede causar severos daños económicos. Sin embargo, en México, las mazorcas infectadas han sido un alimento usado en la cocina tradicional desde la época pre-colombina, y actualmente también en la alta gastronomía del país y el extranjero. El hongo y sus huéspedes son nativos de la parte central de México, y fueron introducidos en Europa por los españoles, donde la enfermedad fue considerada como una alteración fisiológica de la planta. Su naturaleza como infección fúngica fue reconocida solo hasta la segunda mitad del siglo XIX. U. maydis se introdujo a los laboratorios de investigación a principios del Siglo XX, convirtiéndose en un modelo clásico para el estudio de las bases de la patogénesis fúngica en plantas, de la especificidad en el apareamiento y de la recombinación genética, entre otras. Esto fue debido a su facilidad de manejo, su corto ciclo de vida, y el ser posible su análisis mediante métodos de genética clásica y molecular. El ciclo de vida del hongo es complicado alternando formas de levadura haploide saprofítica y micelio dicariótico infeccioso. Este ciclo sexual solo se completa en su huésped natural, estando bajo el control de dos loci de apareamiento que controlan la fusión celular y la patogénesis. En condiciones de cultivo axénico, hemos demostrado que el hongo es capaz de infectar plantas filogenéticamente distantes del maíz; y hemos desarrollado

  9. The iojap gene in maize

    Energy Technology Data Exchange (ETDEWEB)

    Martienssen, Robert

    2001-12-01

    The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

  10. Proteomics of Maize Root Development.

    Science.gov (United States)

    Hochholdinger, Frank; Marcon, Caroline; Baldauf, Jutta A; Yu, Peng; Frey, Felix P

    2018-01-01

    Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  11. Proteomics of Maize Root Development

    Directory of Open Access Journals (Sweden)

    Frank Hochholdinger

    2018-03-01

    Full Text Available Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  12. Biological Control of Fusarium Stalk Rot of Maize Using Bacillus spp

    Directory of Open Access Journals (Sweden)

    Joon-Hee Han

    2015-12-01

    Full Text Available Maize (Zea mays L. is an economically important crop in worldwide. While the consumption of the maize is steadily increasing, the yield is decreasing due to continuous mono-cultivation and infection of soil-borne fungal pathogens such as Fusarium species. Recently, stalk rot disease in maize, caused by F. subglutinans and F. temperatum has been reported in Korea. In this study, we isolated bacterial isolates in rhizosphere soil of maize and subsequently tested for antagonistic activities against F. subglutinans and F. temperatum. A total of 1,357 bacterial strains were isolated from rhizosphere. Among them three bacterial isolates (GC02, GC07, GC08 were selected, based on antagonistic effects against Fusarium species. The isolates GC02 and GC07 were most efficient in inhibiting the mycelium growth of the pathogens. The three isolates GC02, GC07 and GC08 were identified as Bacillus methylotrophicus, B. amyloliquefaciens and B. thuringiensis using 16S rRNA sequence analysis, respectively. GC02 and GC07 bacterial suspensions were able to suppress over 80% conidial germination of the pathogens. GC02, GC07 and GC08 were capable of producing large quantities of protease enzymes, whereas the isolates GC07 and GC08 produced cellulase enzymes. The isolates GC02 and GC07 were more efficient in phosphate solubilization and siderophore production than GC08. Analysis of disease suppression revealed that GC07 was most effective in suppressing the disease development of stalk rot. It was also found that B. methylotrophicus GC02 and B. amyloliquefaciens GC07 have an ability to inhibit the growth of other plant pathogenic fungi. This study indicated B. methylotrophicus GC02 and B. amyloliquefaciens GC07 has potential for being used for the development of a biological control agent.

  13. A maize resistance gene functions against bacterial streak disease in rice

    OpenAIRE

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-01-01

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, wh...

  14. Decomposition and fertilizing effects of maize stover and chromolaena odorata on maize yield

    International Nuclear Information System (INIS)

    Tetteh, F.M.; Safo, E.Y.; Quansah, C.

    2008-01-01

    The quality, rates of decomposition and the fertilizing effect of chromolaena odorata, and maize stover were determined in field experiments as surface application or buried in litter bags. Studies on the effect of plant materials of contrasting qualities (maize stover and C. odorata) applied sole (10 Mg ha -1 ) and mixed, on maize grain and biomass yield were also conducted on the Asuansi (Ferric Acrisol) soil series. Total nitrogen content of the residues ranged from 0.85% in maize stover to 3.50% in C. odorata. Organic carbon ranged from 34.90% in C. odorata to 48.50% in maize stover. Phosphorus ranged from 0.10% in maize stover to 0.76% in C. odorata. In the wet season, the decomposition rate constants (k) were 0.0319 day -1 for C. odorata, and 0.0081 for maize stover. In the dry season, the k values were 0.0083 for C. odorata, and 0.0072 day -1 for maize stover. Burying of the plant materials reduced the half-life (t 50 ) periods from 18 to 10 days for C. odorata, and 45 to 20 days for maize stover. Maize grain yield of 2556 kg ha -1 was obtained in sole C. odorata (10 Mg ha -1 ) compared with 2167 kg ha -1 for maize stover. Mixing of maize stover and C. odorata residues improved the nutrient content as well as nutrient release by the mixtures resulting in greater maize grain yields in the mixtures than the sole maize stover treatment. It is recommended that C. odorata be used as green manure, mulching or composting material to improve fertility. (au)

  15. Foodborne pathogens

    Directory of Open Access Journals (Sweden)

    Thomas Bintsis

    2017-06-01

    Full Text Available Foodborne pathogens are causing a great number of diseases with significant effects on human health and economy. The characteristics of the most common pathogenic bacteria (Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Cronobacter sakazakii, Esherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Staphylococccus aureus, Vibrio spp. and Yersinia enterocolitica, viruses (Hepatitis A and Noroviruses and parasites (Cyclospora cayetanensis, Toxoplasma gondii and Trichinella spiralis, together with some important outbreaks, are reviewed. Food safety management systems based on to classical hazard-based approach has been proved to be inefficient, and risk-based food safety approach is now suggested from leading researchers and organizations. In this context, a food safety management system should be designed in a way to estimate the risks to human health from food consumption and to identify, select and implement mitigation strategies in order to control and reduce these risks. In addition, the application of suitable food safety education programs for all involved people in the production and consumption of foods is suggested.

  16. PERFORMANCE OF MAIZE (ZEA MAYS) CULTIVARS AS ...

    African Journals Online (AJOL)

    IBUKUN

    reported to have low remobilisation efficiency and reduced plasticity of seed weight to assimilate availability ... have indicated that the use of organo-mineral fertiliser in maize and melon gave high relative .... The soil physical and chemical characteristics of ..... yield in maize by examining genetic improvement and heterosis.

  17. (SSR) markers for drought tolerance in maize

    African Journals Online (AJOL)

    Maize is moderately sensitive to drought. Drought affects virtually all aspects of maize growth in varying degrees at all stages, from germination to maturity. Tolerance to drought is genetically and physiologically complicated and inherited quantitatively. Application of molecular-marker aided selection technique for ...

  18. Identification of multiple ear-colonizing insect and disease resistance in CIMMYT maize inbred lines with varying levels of silk maysin.

    Science.gov (United States)

    Ni, Xinzhi; Krakowsky, Matthew D; Buntin, G David; Rector, Brian G; Guo, Baozhu; Snook, Maurice E

    2008-08-01

    Ninety four corn inbred lines selected from International Center for the Improvement of Maize and Wheat (CIMMYT) in Mexico were evaluated for levels of silk maysin in 2001 and 2002. Damage by major ear-feeding insects [i.e., corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae); maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae); brown stink bug, Euschistus servus (Say); southern green stink bugs, Nezara viridula (L.) (Heteroptera: Pentatomidae)], and common smut [Ustilago maydis DC (Corda)] infection on these inbred lines were evaluated in 2005 and 2006 under subtropical conditions at Tifton, GA. Ten inbred lines possessing good agronomic traits were also resistant to the corn earworm. The correlation between ear-feeding insect damage or smut infection and three phenotypic traits (silk maysin level, husk extension, and husk tightness of corn ears) was also examined. Corn earworm and stink bug damage was negatively correlated to husk extension, but not to either silk maysin levels or husk tightness. In combination with the best agronomic trait ratings that show the least corn earworm and stink bug damage, lowest smut infection rate, and good insect-resistant phenotypic traits (i.e., high maysin and good husk coverage and husk tightness), 10 best inbred lines (CML90, CML92, CML94, CML99, CML104, CML108, CML114, CML128, CML137, and CML373) were identified from the 94 lines examined. These selected inbred lines will be used for further examination of their resistance mechanisms and development of new corn germplasm that confers multiple ear-colonizing pest resistance.

  19. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens.

    Science.gov (United States)

    Nayaka, Siddaiah Chandra; Shankar, Arakere C Udaya; Reddy, Munagala S; Niranjana, Siddapura R; Prakash, Harishchandra S; Shetty, Hunthrike S; Mortensen, Carmen N

    2009-07-01

    Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have elicited considerable attention over the past decade owing to their association with animal disease syndromes. Hence, the present study was conducted to evaluate ecofriendly approaches by using a maize rhizosphere isolate of Pseudomonas fluorescens (Trev.) Mig. and its formulation to control ear rot disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars. The field trials included both seed treatment and foliar spray. For all the experiments, P. fluorescens was formulated using corn starch, wheat bran and talc powder. In each case there were three different treatments of P. fluorescens, a non-treated control and chemical control. Pure culture and the formulations, in comparison with the control, increased plant growth and vigour as measured by seed germination, seedling vigour, plant height, 1000 seed weight and yield. P. fluorescens pure culture used as seed treatment and as spray treatment enhanced the growth parameters and reduced the incidence of F. verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize kernels intended for human and animal feed. (c) 2009 Society of Chemical Industry.

  20. Characterization of Indian and exotic quality protein maize (QPM ...

    African Journals Online (AJOL)

    Polymorphism analysis and genetic diversity of normal maize and quality protein maize (QPM) inbreds among locally well adapted germplasm is a prerequisite for hybrid maize breeding program. The diversity analyses of 48 maize accessions including Indian and exotic germplasm using 75 simple sequence repeat (SSR) ...

  1. Exploring maize-legume intercropping systems in Southwest Mexico

    NARCIS (Netherlands)

    Flores-Sanchez, D.; Pastor, A.V.; Lantinga, E.A.; Rossing, W.A.H.; Kropff, M.J.

    2013-01-01

    Maize yields in continuous maize production systems of smallholders in the Costa Chica, a region in Southwest Mexico, are low despite consistent inputs of fertilizers and herbicides. This study was aimed at investigating the prospects of intercropping maize (Zea mays L.) and maize-roselle (Hibiscus

  2. Selection for drought tolerance in two tropical maize populations ...

    African Journals Online (AJOL)

    Drought is a major factor limiting maize (Zea mays L.) yield in much of the world. The need to breed maize cultivars with improved drought tolerance is apparent. This study compared two maize populations, ZM601 and ZM607 for drought tolerance during flowering, the most drought-vulnerable period for the maize plant.

  3. Consumer preferences for maize products in urban Kenya.

    Science.gov (United States)

    De Groote, Hugo; Kimenju, Simon Chege

    2012-06-01

    New maize varieties have been biofortified with provitamin A, mainly a-carotene, which renders the grain yellow or orange. Unfortunately, many African consumers prefer white maize. The maize consumption patterns in Africa are, however, not known. To determine which maize products African consumers prefer to purchase and which maize preparations they prefer to eat. A survey of 600 consumers was conducted in Nairobi, Kenya, at three types of maize outlets: posho mills (small hammer mills), kiosks, and supermarkets. Clients of posho mills had lower incomes and less education than those of kiosks and supermarkets. The preferred maize product of the posho-mill clients was artisanal maize meal; the preferred product of the others was industrial maize meal. Maize is the preferred staple for lunch and dinner, eaten as a stiff porridge (ugali), followed by boiled maize and beans (githeri), regardless of socioeconomic background. For breakfast, only half the consumers prefer maize, mostly as a soft porridge (uji). This proportion is higher in low-income groups. Consumers show a strong preference for white maize over yellow, mostly for its organoleptic characteristics, and show less interest in biofortified maize. Maize is the major food staple in Nairobi, mostly eaten in a few distinct preparations. For biofortified yellow maize to be accepted, a strong public awareness campaign to inform consumers is needed, based on a sensory evaluation and the mass media, in particular on radio in the local language.

  4. Risk Adjusted Production Efficiency of Maize Farmers in Ethiopia: Implication for Improved Maize Varieties Adoption

    Directory of Open Access Journals (Sweden)

    Sisay Diriba Lemessa

    2017-09-01

    Full Text Available This study analyzes the technical efficiency and production risk of 862 maize farmers in major maize producing regions of Ethiopia. It employs the stochastic frontier approach (SFA to estimate the level of technical efficiencies of stallholder farmers. The stochastic frontier approach (SFA uses flexible risk properties to account for production risk. Thus, maize production variability is assessed from two perspectives, the production risk and the technical efficiency. The study also attempts to determine the socio-economic and farm characteristics that influence technical efficiency of maize production in the study area. The findings of the study showed the existence of both production risk and technical inefficiency in maize production process. Input variables (amounts per hectare such as fertilizer and labor positively influence maize output. The findings also show that farms in the study area exhibit decreasing returns to scale. Fertilizer and ox plough days reduce output risk while labor and improved seed increase output risk. The mean technical efficiency for maize farms is 48 percent. This study concludes that production risk and technical inefficiency prevents the maize farmers from realizing their frontier output. The best factors that improve the efficiency of the maize farmers in the study area include: frequency of extension contact, access to credit and use of intercropping. It was also realized that altitude and terracing in maize farms had influence on farmer efficiency.

  5. INTEGRATED WEED CONTROL IN MAIZE.

    Science.gov (United States)

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

  6. Carbaryl residues in maize products

    International Nuclear Information System (INIS)

    Zayed, S.M.A.D.; Mansour, S.A.; Mostafa, I.Y.; Hassan, A.

    1976-01-01

    The 14 C-labelled insecticide carbaryl was synthesized from [1- 14 C]-1-naphthol at a specific activity of 3.18mCig -1 . Maize plants were treated with the labelled insecticide under simulated conditions of agricultural practice. Mature plants were harvested and studied for distribution of total residues in untreated grains as popularly roasted and consumed, and in the corn oil and corn germ products. Total residues found under these conditions in the respective products were 0.2, 0.1, 0.45 and 0.16ppm. (author)

  7. Effects of maize planting patterns on the performance of cassava ...

    African Journals Online (AJOL)

    sola

    The design was a split-plot arrangement, laid out in a randomized ... significant differences (P<0.05) between the treatments in the growth and yield parameters of maize. The mean effects of companion crops on maize leaf area were 0.61, 0.60, 0.60 and 0.52 m2/plant for sole maize, maize / melon, maize / cassava and.

  8. QTL mapping of resistance to gray leaf spot in maize.

    Science.gov (United States)

    Zhang, Yan; Xu, Ling; Fan, Xingming; Tan, Jing; Chen, Wei; Xu, Mingliang

    2012-12-01

    Gray leaf spot (GLS), caused by the causal fungal pathogen Cercospora zeae-maydis, is one of the most serious foliar diseases of maize worldwide. In the current study, a highly resistant inbred line Y32 and a susceptible line Q11 were used to produce segregating populations for both genetic analysis and QTL mapping. The broad-sense heritability (H (2)) for GLS resistance was estimated to be as high as 0.85, indicating that genetic factors played key roles in phenotypic variation. In initial QTL analysis, four QTL, located on chromosomes 1, 2, 5, and 8, were detected to confer GLS resistance. Each QTL could explain 2.53-23.90 % of the total phenotypic variation, predominantly due to additive genetic effects. Two major QTL, qRgls1 and qRgls2 on chromosomes 8 and 5, were consistently detected across different locations and replicates. Compared to the previous results, qRgls2 is located in a 'hotspot' for GLS resistance; while, qRgls1 does not overlap with any other known resistance QTL. Furthermore, the major QTL-qRgls1 was fine-mapped into an interval of 1.4 Mb, flanked by the markers GZ204 and IDP5. The QTL-qRgls1 could enhance the resistance percentages by 19.70-61.28 %, suggesting its usefulness to improve maize resistance to GLS.

  9. The Mechanisms of Maize Resistance to Fusarium verticillioides by comprehensive analysis of RNA-seq Data

    Directory of Open Access Journals (Sweden)

    Yanping Wang

    2016-11-01

    Full Text Available Fusarium verticillioides is the most commonly reported fungal species responsible for ear rot of maize which substantially reduces grain yield. It also results in a substantial accumulation of mycotoxins that give rise to toxic response when ingested by animals and humans. For inefficient control by chemical and agronomic measures, it thus becomes more desirable to select more resistant varieties. However, the molecular mechanisms underlying the infection process remain poorly understood, which hampers the application of quantitative resistance in breeding programs. Here, we reveal the disease-resistance mechanism of the maize inbred line of BT-1 which displays high resistance to ear rot using RNA high throughput sequencing. By analyzing RNA-seq data from the BT-1 kernels before and after F. verticillioides inoculation, we found that transcript levels of genes associated with key pathways are dramatically changed compared with the control treatment. Differential gene expression in ear rot resistant and susceptible maize was confirmed by RNA microarray and qRT-PCR analyses. Further investigation suggests that the small heat shock protein family, some secondary metabolites, and the signaling pathways of abscisic acid (ABA, jasmonic acid (JA or salicylic acids (SA may be involved in the pathogen-associated molecular pattern-triggered immunity against F. verticillioides. These data will not only provide new insights into the molecular resistant mechanisms against fungi invading, but may also result in the identification of key molecular factors associated with ear rot resistance in maize.

  10. Essential oils on the control of stem and ear rot in maize

    Directory of Open Access Journals (Sweden)

    Glauco Antonio Teixeira

    2013-11-01

    Full Text Available Stem and ear rot caused by Stenocarpella maydis are responsible for severe losses in maize production. Treatment of seeds with fungicides may induce environmental damage. Hence, this study aimed to evaluate the effects of essential oils extracted from Cymbopogon winterianus, Thymus vulgaris, Cymbopogon citratus, Corymbia citriodora, Cinnamomum zeylanicum, and Syzygium aromaticum on the development of in vitro S. maydis. In addition, maize seeds were treated with these essential oils to determine their possible mode of action and effects. The oils from S. aromaticum, C. zeylanicum, and T. vulgaris inhibited fungal development at concentrations higher than 0.025%. The oils from S. aromaticum and C. zeylanicum showed seed germination rates of 89.0% and 84.5%, which were higher than that of the control. The oils from S. aromaticum and C. zeylanicum reduced the pathogen incidence in the seeds to 39.0% and 28.0%, respectively. Further, these oils as well as that from T. vulgaris produced lower reduction of maize stand. Scanning electron microscopy examination revealed that essential oils from S. aromaticum and T. vulgaris acted directly on the conidia, impeding germination. The findings suggest that the oils from S. aromaticum, C. zeylanicum, and T. vulgaris are potential alternatives for maize seed treatment in the control of S. maydis.

  11. A review on threat of gray leaf spot disease of maize in Asia

    Directory of Open Access Journals (Sweden)

    Narayan Bahadur Dhami

    2015-12-01

    Full Text Available Biotic and biotic constraints are yield limiting factors in maize producing regions. Among these gray leaf spot is a yield limiting foliar disease of maize in high land regions of Asia. This review is done from related different national and international journals, thesis, books, research papers etc. The objectives of this review are to become familiar with genetics and inheritance, epidemiology, symptoms and disease management strategies etc. High relative humidity, temperature, minimum tillage and maize monoculture are important factors responsible for disease development. The sibling species of Cercospora zeae-maydis (Tehon and Daniels, 1925 Group I and Group II and Cercospora sorghai var. maydis (Chupp, 1954 are associated with this disease. Pathogens colonize in maize debris. Conidia are the source of inoculums for disease spread. Severe blighting of leaves reduces sugars, stalk lodging and causes premature death of plants resulting in yield losses of up to 100%. Disease management through cultural practices is provisional. The use of fungicides for emergencies is effective however; their prohibitive cost and detrimental effects on the environment are negative consequences. The inheritance of tolerance is quantitative with small additive effects. The introgression of resistant genes among the crosses of resistant germplasm enhances the resistance. The crosses of resistant and susceptible germplasm possess greater stability than the crosses of susceptible and resistant germplasm. The development of gray leaf spot tolerant populations through tolerance breeding principle is an economical and sustainable approach to manage the disease.

  12. Fusarium diseases of maize associated with mycotoxin contamination of agricultural products intended to be used for food and feed.

    Science.gov (United States)

    Oldenburg, Elisabeth; Höppner, Frank; Ellner, Frank; Weinert, Joachim

    2017-08-01

    Infections of maize with phytopathogenic and toxinogenic Fusarium spp. may occur throughout the cultivation period. This can cause different types of diseases in vegetative and generative organs of the plant. Along with these infections, mycotoxins are often produced and accumulated in affected tissues, which could pose a significant risk on human and animal health when entering the food and feed chain. Most important fungal species infecting European maize belong to the Fusarium sections Discolour and Liseola, the first being more prevalent in cooler and humid climate regions than the second predominating in warmer and dryer areas. Coexistence of several Fusarium spp. pathogens in growing maize under field conditions is the usual case and may lead to multi-contamination with mycotoxins like trichothecenes, zearalenone and fumonisins. The pathways how the fungi gain access to the target organs of the plant are extensively described in relation to specific symptoms of typical rot diseases regarding ears, kernels, rudimentary ears, roots, stem, leaves, seed and seedlings. Both Gibberella and Fusarium ear rots are of major importance in affecting the toxinogenic quality of grain or ear-based products as well as forage maize used for human or animal nutrition. Although rudimentary ears may contain high amounts of Fusarium toxins, the contribution to the contamination of forage maize is minor due to their small proportion on the whole plant dry matter yield. The impact of foliar diseases on forage maize contamination is regarded to be low, as Fusarium infections are restricted to some parts on the leaf sheaths and husks. Mycotoxins produced in rotted basal part of the stem may contribute to forage maize contamination, but usually remain in the stubbles after harvest. As the probability of a more severe disease progression is increasing with a prolonged cultivation period, maize should be harvested at the appropriate maturity stage to keep Fusarium toxin contamination as

  13. Screening of promising maize genotypes against maize weevil (Sitophilus zeamais Motschulky) in storage condition

    OpenAIRE

    Ram B Paneru; Resham B Thapa

    2017-01-01

    The maize weevil (Sitophilus zeamais Motschulsky) is a serious pest of economic importance in stored grains. It causes major damage to stored maize grain thereby reducing its weight, quality and germination. An experiment was conducted in randomized complete block design (RCBD) with 3 replications to screen 32 maize genotypes against maize weevil in no-choice and free-choice conditions at Entomology Division, Khumaltar, Lalitpur (Room temperature: Maximum 24-32°C and Minimum 18-27°C). The fin...

  14. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides.

    Directory of Open Access Journals (Sweden)

    Martha M Vaughan

    Full Text Available Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2] are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.

  15. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides

    Science.gov (United States)

    Vaughan, Martha M.; Huffaker, Alisa; Schmelz, Eric A.; Dafoe, Nicole J.; Christensen, Shawn A.; McAuslane, Heather J.; Alborn, Hans T.; Allen, Leon Hartwell; Teal, Peter E. A.

    2016-01-01

    Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots. PMID:27410032

  16. A survey of pre-harvest ear rot diseases of maize and associated mycotoxins in south and central Zambia.

    Science.gov (United States)

    Mukanga, Mweshi; Derera, John; Tongoona, Pangirayi; Laing, Mark D

    2010-07-15

    Maize ear rots reduce grain yield and quality with implication on food security and health. Some of the pathogenic fungi produce mycotoxins in maize grain posing a health risk to humans and livestock. Unfortunately, the levels of ear rot and mycotoxin infection in grain produced by subsistence farmers in sub-Saharan countries are not known. A survey was thus conducted to determine the prevalence of the ear rot problem and levels of mycotoxins in maize grain. A total of 114 farmsteads were randomly sampled from 11 districts in Lusaka and southern provinces in Zambia during 2006. Ten randomly picked cobs were examined per farmstead and the ear rot disease incidence and severity were estimated on site. This was followed by the standard seed health testing procedures for fungal isolation in the laboratory. Results indicated that the dominant ear rots were caused by Fusarium and Stenocarpella. Incidence of Fusarium verticillioides ranged from 2 to 21%, whereas that of Stenocarpella maydis reached 37% on ear rot diseased maize grain. In addition, 2-7% F. verticillioides, and 3-18% Aspergillus flavus, respectively, were recovered from seemingly healthy maize grain. The mean rank of fungal species, from highest to lowest, was F. verticillioides, S. maydis, A. flavus, Fusarium graminearum, Aspergillus niger, Penicillium spp., Botrydiplodia spp., and Cladosporium spp. The direct competitive ELISA-test indicated higher levels of fumonisins than aflatoxins in pre-harvest maize grain samples. The concentration of fumonisins from six districts, and aflatoxin from two districts, was 10-fold higher than 2 ppm and far higher than 2 ppb maximum daily intake recommended by the FAO/WHO. The study therefore suggested that subsistence farmers and consumers in this part of Zambia, and maybe also in similar environments in sub-Saharan Africa, might be exposed to dangerous levels of mycotoxins due to the high levels of ear rot infections in maize grain. 2010 Elsevier B.V. All rights

  17. The Aspergillus flavus spermidine synthase (spds) gene, is required for normal development, aflatoxin production, and pathogenesis during infection of maize kernels

    Science.gov (United States)

    Aspergillus flavus is a soil-borne saprophyte and an opportunistic pathogen of both humans and plants. This fungus not only causes disease in several important food and feed crops such as maize, peanut, cottonseed and tree nuts but also produces the toxic and carcinogenic secondary metabolites (SMs)...

  18. Emerging Pathogens Initiative (EPI)

    Data.gov (United States)

    Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

  19. Maize cob losses and their effects on the poverty status of maize

    African Journals Online (AJOL)

    This study analysed fresh maize cob losses and its effect on the poverty status of maize farmers in Edo State,. Nigeria. The specific .... is the poverty gap for ... Total cost. 162,367.48. 100.00. Returns. Total expected yield (N). 327,966.63. _.

  20. Identification of resistance to Maize rayado fino virus in maize inbred lines

    Science.gov (United States)

    Maize rayado fino virus (MRFV) is one of the most important virus diseases of maize in America. Severe yield losses, ranging from 10 to 50% in landraces to nearly 100% in contemporary cultivars, have been reported. Resistance has been reported in populations, but few inbred lines have been identifie...

  1. Exploring karyotype diversity of Argentinian Guaraní maize landraces: Relationship among South American maize.

    Directory of Open Access Journals (Sweden)

    María Florencia Realini

    Full Text Available In Argentina there are two different centers of maize diversity, the Northeastern (NEA and the Northwestern (NWA regions of the country. In NEA, morphological studies identified 15 landraces cultivated by the Guaraní communities in Misiones Province. In the present study we analyzed the karyotype diversity of 20 populations of Guaraní maize landraces through classical and molecular cytogenetic analyses. Our results demonstrate significant intra and inter-populational variation in the percentage, number, size, chromosome position and frequencies of the heterochromatic blocks, which are called knobs. Knob sequence analysis (180-bp and TR-1 did not show significant differences among Guaraní populations. B chromosomes were not detected, and abnormal 10 (AB10 chromosomes were found with low frequency (0.1≥f ≤0.40 in six populations. Our results allowed karyotypic characterization of each analyzed population, defining for the first time the chromosomal constitution of maize germplasm from NEA. The multivariate analysis (PCoA and UPGMA of karyotype parameters allowed the distinction between two populations groups: the Popcorn and the Floury maize populations. These results are in agreement with previously published microsatellite and morphological/phenological studies. Finally, we compared our karyotype results with those previously reported for NWA and Central Region of South America maize. Our data suggest that there are important differences between maize from NEA and NWA at the karyotype level, supporting the hypothesis that there are two pathways of input of South America maize. Our results also confirm the existence of two centers of diversification of Argentinian native maize, NWA and NEA. This work contributes new knowledge about maize diversity, which is relevant for future plans to improve commercial maize, and for conservation of agrobiodiversity.

  2. Isolation, structural analysis, and expression characteristics of the maize nuclear factor Y gene families

    International Nuclear Information System (INIS)

    Zhang, Zhongbao; Li, Xianglong; Zhang, Chun; Zou, Huawen; Wu, Zhongyi

    2016-01-01

    NUCLEAR FACTOR-Y (NF-Y) has been shown to play an important role in growth, development, and response to environmental stress. A NF-Y complex, which consists of three subunits, NF-YA, NF-YB, and, NF-YC, binds to CCAAT sequences in a promoter to control the expression of target genes. Although NF-Y proteins have been reported in Arabidopsis and rice, a comprehensive and systematic analysis of ZmNF-Y genes has not yet been performed. To examine the functions of ZmNF-Y genes in this family, we isolated and characterized 50 ZmNF-Y (14 ZmNF-YA, 18 ZmNF-YB, and 18 ZmNF-YC) genes in an analysis of the maize genome. The 50 ZmNF-Y genes were distributed on all 10 maize chromosomes, and 12 paralogs were identified. Multiple alignments showed that maize ZmNF-Y family proteins had conserved regions and relatively variable N-terminal or C-terminal domains. The comparative syntenic map illustrated 40 paralogous NF-Y gene pairs among the 10 maize chromosomes. Microarray data showed that the ZmNF-Y genes had tissue-specific expression patterns in various maize developmental stages and in response to biotic and abiotic stresses. The results suggested that ZmNF-YB2, 4, 8, 10, 13, and 16 and ZmNF-YC6, 8, and 15 were induced, while ZmNF-YA1, 3, 4, 6, 7, 10, 12, and 13, ZmNF-YB15, and ZmNF-YC3 and 9 were suppressed by drought stress. ZmNF-YA3, ZmNF-YA8 and ZmNF-YA12 were upregulated after infection by the three pathogens, while ZmNF-YA1 and ZmNF-YB2 were suppressed. These results indicate that the ZmNF-Ys may have significant roles in the response to abiotic and biotic stresses. - Highlights: • We indicated a total of 50 members of ZmNF-Y gene family in maize genome. • We analyzed gene structure, protein architecture of ZmNF-Y genes. • Evolution pattern and phylogenic relationships were analyzed among 50 ZmNF-Y genes. • Expression pattern of ZmNF-Ys were detected in various maize tissues. • Transcript levels of ZmNF-Ys were measured under various abiotic and biotic stresses.

  3. Locally processed roasted-maize-based weaning foods fortified with ...

    African Journals Online (AJOL)

    Locally processed roasted-maize-based weaning foods fortified with legumes: factors ... African Journal of Food, Agriculture, Nutrition and Development ... Tom Brown (roasted-maize porridge) is one of the traditional weaning foods in Ghana.

  4. Aflatoxin variations in maize flour and grains collected from various ...

    African Journals Online (AJOL)

    In Kenya, maize remains an important staple food in every household. ... upper limit is 10ppb, indicating good manufacturing practices (GMP) by the millers. ... In summary, the study found aflatoxin contamination in maize grains especially in ...

  5. the influence of farmers' adoption behaviour on maize production ...

    African Journals Online (AJOL)

    p2333147

    The main cash crops grown in the country include coffee, sisal, cashew, cotton, tobacco ... Among these food crops, maize is the most important cereal food crop, and ... promoting recommended maize production practices in a package form.

  6. Diversity in global maize germplasm: Characterization and utilization

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... maize farmers as well as to the scientific community are depicted in figure 1, and ..... best practices for maintaining the original genetic diversity of the gene bank ..... maize; in Studies in the neolithic and urban revolution: V.

  7. Importance of husk covering on field infestation of maize by ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... An experiment was conducted to determine the importance of husk covering on field infestation of maize by the maize ... high yielding plants with no consideration for resistance ..... provided financial support for the study.

  8. Factors Affecting the Efficiency of Maize Marketing in Vandeikya ...

    African Journals Online (AJOL)

    Factors Affecting the Efficiency of Maize Marketing in Vandeikya Local Government Area of Benue State, Nigeria. ... Two hundred maize marketers were selected from Vandeikya Local Area (LGA) of ... EMAIL FULL TEXT EMAIL FULL TEXT

  9. participatory evaluation of drought tolerant maize varieties in the ...

    African Journals Online (AJOL)

    User

    ). Maize production provides livelihoods for millions of subsistence farmers in WCA, thus, increasing the productivity of maize-based cropping sys- tems could increase and stabilize rural incomes, alleviate poverty and reduce food insecurity in.

  10. Leaf transpiration efficiency of some drought-resistant maize lines

    Science.gov (United States)

    Field measurements of leaf gas exchange in maize often indicate stomatal conductances higher than required to provide substomatal carbon dioxide concentrations saturating to photosynthesis. Thus maize leaves often operate at lower transpiration efficiency (TE) than potentially achievable for specie...

  11. The mitochondrial LSU rRNA group II intron of Ustilago maydis encodes an active homing endonuclease likely involved in intron mobility.

    Directory of Open Access Journals (Sweden)

    Anja Pfeifer

    Full Text Available BACKGROUND: The a2 mating type locus gene lga2 is critical for uniparental mitochondrial DNA inheritance during sexual development of Ustilago maydis. Specifically, the absence of lga2 results in biparental inheritance, along with efficient transfer of intronic regions in the large subunit rRNA gene between parental molecules. However, the underlying role of the predicted LAGLIDADG homing endonuclease gene I-UmaI located within the group II intron LRII1 has remained unresolved. METHODOLOGY/PRINCIPAL FINDINGS: We have investigated the enzymatic activity of I-UmaI in vitro based on expression of a tagged full-length and a naturally occurring mutant derivative, which harbors only the N-terminal LAGLIDADG domain. This confirmed Mg²⁺-dependent endonuclease activity and cleavage at the LRII1 insertion site to generate four base pair extensions with 3' overhangs. Specifically, I-UmaI recognizes an asymmetric DNA sequence with a minimum length of 14 base pairs (5'-GACGGGAAGACCCT-3' and tolerates subtle base pair substitutions within the homing site. Enzymatic analysis of the mutant variant indicated a correlation between the activity in vitro and intron homing. Bioinformatic analyses revealed that putatively functional or former functional I-UmaI homologs are confined to a few members within the Ustilaginales and Agaricales, including the phylogenetically distant species Lentinula edodes, and are linked to group II introns inserted into homologous positions in the LSU rDNA. CONCLUSIONS/SIGNIFICANCE: The present data provide strong evidence that intron homing efficiently operates under conditions of biparental inheritance in U. maydis. Conversely, uniparental inheritance may be critical to restrict the transmission of mobile introns. Bioinformatic analyses suggest that I-UmaI-associated introns have been acquired independently in distant taxa and are more widespread than anticipated from available genomic data.

  12. MRN- and 9-1-1-Independent Activation of the ATR-Chk1 Pathway during the Induction of the Virulence Program in the Phytopathogen Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    María Tenorio-Gómez

    Full Text Available DNA damage response (DDR leads to DNA repair, and depending on the extent of the damage, to further events, including cell death. Evidence suggests that cell differentiation may also be a consequence of the DDR. During the formation of the infective hypha in the phytopathogenic fungus Ustilago maydis, two DDR kinases, Atr1 and Chk1, are required to induce a G2 cell cycle arrest, which in turn is essential to display the virulence program. However, the triggering factor of DDR in this process has remained elusive. In this report we provide data suggesting that no DNA damage is associated with the activation of the DDR during the formation of the infective filament in U. maydis. We have analyzed bulk DNA replication during the formation of the infective filament, and we found no signs of impaired DNA replication. Furthermore, using RPA-GFP fusion as a surrogate marker of the presence of DNA damage, we were unable to detect any sign of DNA damage at the cellular level. In addition, neither MRN nor 9-1-1 complexes, both instrumental to transmit the DNA damage signal, are required for the induction of the above mentioned cell cycle arrest, as well as for virulence. In contrast, we have found that the claspin-like protein Mrc1, which in other systems serves as scaffold for Atr1 and Chk1, was required for both processes. We discuss possible alternative ways to trigger the DDR, independent of DNA damage, in U. maydis during virulence program activation.

  13. Mutation avoidance and DNA repair proficiency in Ustilago maydis are differentially lost with progressive truncation of the REC1 gene product

    Energy Technology Data Exchange (ETDEWEB)

    Onel, K.; Thelen, M.P.; Ferguson, D.O.; Bennett, R.L.; Holloman, W.K. [Cornell Univ. Medical College, NY, NY (United States)

    1995-10-01

    The REC1 gene of Ustilago maydis has an uninterrupted open reading frame, predicted from the genomic sequence to encode a protein of 522 amino acid residues. Nevertheless, an intron is present, and functional activity of the gene in mitotic cells requires an RNA processing event to remove the intron. This results in a change in reading frame and production of a protein of 463 amino acid residues. The 3{prime}{r_arrow}5{prime} exonuclease activity of proteins derived form the REC1 genomic open reading frame, the intronless open reading frame, and several mutants was investigated. The mutants included a series of deletions constructed by removing restriction fragments at the 3{prime} end of the cloned REC1 gene and a set of mutant alleles previously isolated in screens for radiation sensitivity. The results indicated that elimination of the C-terminal third of the protein did not result in a serious reduction in 3{prime}{r_arrow}5{prime} exonuclease activity, but deletion into the midsection caused a severe loss of activity. The biological activity of the rec1-1 allele, which encodes a truncated polypeptide with full 3{prime}{r_arrow}5{prime} exonuclease activity, and the rec1-5 allele, which encodes a more severely truncated polypeptide with no exonuclease activity, was investigated. The two mutants were equally sensitive to the lethal effect of UV light, but the spontaneous mutation rate was elevated 10-fold over the wild-type rate in the rec1-1 mutant and 100-fold in the rec1-5 mutant. The elevated spontaneous mutation rate correlated with the ablation of exonuclease activity, but the radiation sensitivity did not. These results indicate that the C-terminal portion of the Rec1 protein is not essential for exonuclease activity but is crucial in the role of REC1 in DNA damage repair. 49 refs., 3 figs., 1 tab.

  14. Strategic Marketing Problems in the Uganda Maize Seed Industry

    OpenAIRE

    Larson, Donald W.; Mbowa, Swaibu

    2004-01-01

    Strategic marketing issues and challenges face maize seed marketing firms as farmers increasingly adopt hybrid varieties in a modernizing third world country such as Uganda. The maize seed industry of Uganda has changed dramatically from a government owned, controlled, and operated industry to a competitive market oriented industry with substantial private firm investment and participation. The new maize seed industry is young, dynamic, growing and very competitive. The small maize seed marke...

  15. A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development.

    Science.gov (United States)

    Vargas, Walter A; Sanz-Martín, José M; Rech, Gabriel E; Armijos-Jaramillo, Vinicio D; Rivera, Lina P; Echeverria, María Mercedes; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

    2016-02-01

    Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host's nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host's nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.

  16. Comparison of species composition and fumonisin production in Aspergillus section Nigri populations in maize kernels from USA and Italy.

    Science.gov (United States)

    Susca, Antonia; Moretti, Antonio; Stea, Gaetano; Villani, Alessandra; Haidukowski, Miriam; Logrieco, Antonio; Munkvold, Gary

    2014-10-01

    Fumonisin contamination of maize is considered a serious problem in most maize-growing regions of the world, due to the widespread occurrence of these mycotoxins and their association with toxicosis in livestock and humans. Fumonisins are produced primarily by species of Fusarium that are common in maize grain, but also by some species of Aspergillus sect. Nigri, which can also occur on maize kernels as opportunistic pathogens. Understanding the origin of fumonisin contamination in maize is a key component in developing effective management strategies. Although some fungi in Aspergillus sect. Nigri are known to produce fumonisins, little is known about the species which are common in maize and whether they make a measurable contribution to fumonisin contamination of maize grain. In this work, we evaluated populations of Aspergillus sect. Nigri isolated from maize in USA and Italy, focusing on analysis of housekeeping genes, the fum8 gene and in vitro capability of producing fumonisins. DNA sequencing was used to identify Aspergillus strains belonging to sect. Nigri, in order to compare species composition between the two populations, which might influence specific mycotoxicological risks. Combined beta-tubulin/calmodulin sequences were used to genetically characterize 300 strains (199 from Italy and 101 from USA) which grouped into 4 clades: Aspergillus welwitschiae (syn. Aspergillus awamori, 14.7%), Aspergillus tubingensis (37.0%) and Aspergillus niger group 1 (6.7%) and group 2 (41.3%). Only one strain was identified as Aspergillus carbonarius. Species composition differed between the two populations; A. niger predominated among the USA isolates (69%), but comprised a smaller percentage (38%) of Italian isolates. Conversely, A. tubingensis and A. welwitschiae occurred at higher frequencies in the Italian population (42% and 20%, respectively) than in the USA population (27% and 5%). The evaluation of FB2 production on CY20S agar revealed 118 FB2 producing and 84

  17. Nitrogen effects on maize yield following groundnut in rotation on ...

    African Journals Online (AJOL)

    Rotating maize (Zea mays L.) with groundnut (Arachis hypogaea L.) has been proposed as a way to maintain soil fertility and prevent maize productivity declines in the smallholder cropping systems of sub-humid Zimbabwe. Field experiments with fertilizer-N on maize in rotation with groundnut were conducted at three ...

  18. Intercropping maize with cassava or cowpea in Ghana | Ennin ...

    African Journals Online (AJOL)

    Maize/cassava and maize/cowpea intercrops were evaluated in southern Ghana, over a 5-year period to determine the optimum combination of component crop varieties and component plant population densities to optimize productivity of maize-based intercropping systems. Results indicated that some cowpea varieties ...

  19. The economic implication of substituting cocoa pod husk for maize ...

    African Journals Online (AJOL)

    This saving was found to bridge the deficit between demand and supply as given by supplementation done by importing maize. The study concluded that by utilizing CPH in compounding various livestock feed rations, the high price of maize arising from excessive demand can be reduced. The limiting role of maize in ...

  20. Developing a database for maize variety in Nigeria | Daniel | Moor ...

    African Journals Online (AJOL)

    Performance data of maize varieties at different locations needs to be accurate and accessible to stimulate the improvement of the Nigerian maize seed system. This paper describes a database model to implement a simple computerized information system for maize varieties and their performance at various locations in ...

  1. Review: Maize research and production in Nigeria | Iken | African ...

    African Journals Online (AJOL)

    Maize (Zea mays) is a major important cereal being cultivated in the rainforest and the derived Savannah zones of Nigeria. Land races, improved high yielding and pest and diseases resistant varieties of maize have been developed. Key words: Maize, Zea mays, Nigeria. African Journal of Biotechnology Vol.3(6) 2004: 302- ...

  2. quixotic coupling between irrigation system and maize-cowpea

    African Journals Online (AJOL)

    ACSS

    number row-1 and maize grain yield, respectively. The ridge ... Key Words: Furrow irrigation, water use efficiency, Zea mays. RÉSUMÉ ... important in arid and semi-arid regions, with ... as maize) canopy is not able to intercept all the solar radiation during the growth period. ... Intercropping maize and legumes considerably ...

  3. Quantitative trait loci for resistance to Maize rayado fino virus

    Science.gov (United States)

    Maize rayado fino virus (MRFV) causes one of the most important virus diseases of maize in regions of Mexico, Central and South America, where it causes moderate to severe yield losses. The virus is found from the southern United States. to northern Argentina where its vector, the maize leafhopper D...

  4. Oven-drying reduces ruminal starch degradation in maize kernels

    NARCIS (Netherlands)

    Ali, M.; Cone, J.W.; Hendriks, W.H.; Struik, P.C.

    2014-01-01

    The degradation of starch largely determines the feeding value of maize (Zea mays L.) for dairy cows. Normally, maize kernels are dried and ground before chemical analysis and determining degradation characteristics, whereas cows eat and digest fresh material. Drying the moist maize kernels

  5. Mixed cropping of groundnuts and maize in East Java

    NARCIS (Netherlands)

    Hoof, van W.C.H.

    1987-01-01

    Mixed cropping of groundnuts and maize in East Java was studied by means of a survey of farming practice and by field experiments. The influence of different sowing times and plant density of maize on the development and yield of groundnuts and maize were the main topics in this thesis. Plant

  6. Maize and the Malnutrition Conundrum in South Africa | BOOYENS ...

    African Journals Online (AJOL)

    In this paper, the author gives an overview of the factors leading to maize becoming a staple food among black people in South Africa. The purported relationship between maize consumption and malnutrition, proposals as well as experimental and practical efforts to correct the dietary deficiencies of maize are briefly ...

  7. The Black Aspergillus Species of Maize and Peanuts and Their Potential for Mycotoxin Production

    Science.gov (United States)

    Palencia, Edwin R.; Hinton, Dorothy M.; Bacon, Charles W.

    2010-01-01

    The black spored fungi of the subgenera Circumdata, the section Nigri (=Aspergillus niger group) is reviewed relative to their production of mycotoxins and their effects on plants as pathogens. Molecular methods have revealed more than 18 cryptic species, of which several have been characterized as potential mycotoxin producers. Others are defined as benign relative to their ability to produce mycotoxins. However, these characterizations are based on in vitro culture and toxins production. Several can produce the ochratoxins that are toxic to livestock, poultry, and humans. The black aspergilli produce rots of grapes, maize, and numerous other fruits and grain and they are generally viewed as post-harvest pathogens. Data are review to suggest that black aspergilli, as so many others, are symptomless endophytes. These fungi and their mycotoxins contaminate several major grains, foodstuffs, and products made from them such as wine, and coffee. Evidence is presented that the black aspergilli are producers of other classes of mycotoxins such as the fumonisins, which are known carcinogenic and known prior investigations as being produced by the Fusarium species. Three species are identified in U.S. maize and peanuts as symptomless endophytes, which suggests the potential for concern as pathogens and as food safety hazards. PMID:22069592

  8. Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean and sorghum.

    Science.gov (United States)

    Saleh, A A; Ahmed, H U; Todd, T C; Travers, S E; Zeller, K A; Leslie, J F; Garrett, K A

    2010-01-01

    Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58% among isolates in the tallgrass prairie, 71% in the maize fields, 75% in the sorghum fields and 80% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate 'hybrids' with novel genetic profiles and pathogenic capabilities.

  9. Maize production in mid hills of Nepal: from food to feed security

    OpenAIRE

    Krishna Prasad Timsina; Yuga Nath Ghimire; Jeevan Lamichhane

    2016-01-01

    This study was undertaken in 2016 to analyze the production and utilization of maize in Nepal. Sixty maize growers from Kavre and Lamjung districts were selected using purposive, cluster and simple random sampling techniques. Similarly, six feed industries and five maize experts from Chitwan district were also interviewed. Study shows 56% of the total areas were used for maize production and 50% of the maize areas were covered by hybrid maize. There was no practice of contract maize productio...

  10. The platelet-activating factor acetylhydrolase gene derived from Trichoderma harzianum induces maize resistance to Curvularia lunata through the jasmonic acid signaling pathway.

    Science.gov (United States)

    Yu, Chuanjin; Fan, Lili; Gao, Jinxin; Wang, Meng; Wu, Qiong; Tang, Jun; Li, Yaqian; Chen, Jie

    2015-01-01

    Platelet-activating factor acetylhydrolase (PAF-AH) derived from Trichoderma harzianum was upregulated by the interaction of T. harzianum with maize roots or the foliar pathogen Curvularia lunata. PAF-AH was associated with chitinase and cellulase expressions, but especially with chitinase, because its activity in the KO40 transformant (PAF-AH disruption transformant) was lower, compared with the wild-type strain T28. The result demonstrated that the colonization of maize roots by T. harzianum induced systemic protection of leaves inoculated with C. lunata. Such protection was associated with the expression of inducible jasmonic acid pathway-related genes. Moreover, the data from liquid chromatography-mass spectrometry confirmed that the concentration of jasmonic acid in maize leaves was associated with the expression level of defense-related genes, suggesting that PAF-AH induced resistance to the foliar pathogen. Our findings showed that PAF-AH had an important function in inducing systemic resistance to maize leaf spot pathogen.

  11. Resistance to Fusarium verticillioides and fumonisin accumulation in maize inbred lines involves an earlier and enhanced expression of lipoxygenase (LOX) genes.

    Science.gov (United States)

    Maschietto, Valentina; Marocco, Adriano; Malachova, Alexandra; Lanubile, Alessandra

    2015-09-01

    Fusarium verticillioides causes ear rot in maize and contaminates the kernels with the fumonisin mycotoxins. It is known that plant lipoxygenase (LOX)-derived oxylipins regulate defence against pathogens and that the host-pathogen lipid cross-talk influences the pathogenesis. The expression profiles of fifteen genes of the LOX pathway were studied in kernels of resistant and susceptible maize lines, grown in field condition, at 3, 7 and 14 days post inoculation (dpi) with F. verticillioides. Plant defence responses were correlated with the pathogen growth, the expression profiles of fungal FUM genes for fumonisin biosynthesis and fumonisin content in the kernels. The resistant genotype limited fungal growth and fumonisin accumulation between 7 and 14 dpi. Pathogen growth became exponential in the susceptible line after 7 dpi, in correspondence with massive transcription of FUM genes and fumonisins augmented exponentially at 14 dpi. LOX pathway genes resulted strongly induced after pathogen inoculation in the resistant line at 3 and 7 dpi, whilst in the susceptible line the induction was reduced or delayed at 14 dpi. In addition, all genes resulted overexpressed before infection in kernels of the resistant genotype already at 3 dpi. The results suggest that resistance in maize may depend on an earlier activation of LOX genes and genes for jasmonic acid biosynthesis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  12. Maize lethal necrosis (MLN), an emerging threat to maize-based food security in sub-Saharan Africa

    Science.gov (United States)

    In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on...

  13. Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants.

    Science.gov (United States)

    Palencia, Edwin Rene; Glenn, Anthony Elbie; Hinton, Dorothy Mae; Bacon, Charles Wilson

    2013-09-01

    Aspergillus niger and Aspergillus carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspergilli produce important mycotoxins, ochratoxins A, and the fumonisins. To facilitate the study of the black aspergilli-maize interactions with maize during the early stages of infections, we developed a method that used the enhanced yellow fluorescent protein (eYFP) and the monomeric red fluorescent protein (mRFP1) to transform A. niger and A. carbonarius, respectively. The results were constitutive expressions of the fluorescent genes that were stable in the cytoplasms of hyphae and conidia under natural environmental conditions. The hyphal in planta distribution in 21-day-old seedlings of maize were similar wild type and transformants of A. niger and A. carbonarius. The in planta studies indicated that both wild type and transformants internally colonized leaf, stem and root tissues of maize seedlings, without any visible disease symptoms. Yellow and red fluorescent strains were capable of invading epidermal cells of maize roots intercellularly within the first 3 days after inoculation, but intracellular hyphal growth was more evident after 7 days of inoculation. We also tested the capacity of fluorescent transformants to produce ochratoxin A and the results with A. carbonarius showed that this transgenic strain produced similar concentrations of this secondary metabolite. This is the first report on the in planta expression of fluorescent proteins that should be useful to study the internal plant colonization patterns of two ochratoxigenic species in the Aspergillus section Nigri. © 2013.

  14. MaizeGDB: The Maize Model Organism Database for Basic, Translational, and Applied Research

    OpenAIRE

    Lawrence, Carolyn J.; Harper, Lisa C.; Schaeffer, Mary L.; Sen, Taner Z.; Seigfried, Trent E.; Campbell, Darwin A.

    2008-01-01

    In 2001 maize became the number one production crop in the world with the Food and Agriculture Organization of the United Nations reporting over 614 million tonnes produced. Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses. Not only is maize an excellent source of food, feed, and fuel, but also its by-products are used in the production of various commercial products. Maize's unparalleled success in agriculture stems from basic research, th...

  15. Carbaryl residues in maize and processed products

    International Nuclear Information System (INIS)

    Qureshi, M.J.; Sattar, A. Jr.; Naqvi, M.H.

    1981-01-01

    Carbaryl residues in two local maize varieties were determined using a colorimetric method. No significant differences were observed for residues of the two varieties which ranged between 12.0 to 13.75 mg/kg in the crude oil, and averaged 1.04 and 0.67 mg/kg in the flour and cake respectively. In whole maize plants, carbaryl residues declined to approximately 2 mg/kg 35 days after treatment. Cooking in aqueous, oil or aqueous-oil media led to 63-83% loss of carbaryl residues, after 30 minutes. (author)

  16. Fusarium verticillioides and fumonisin contamination in Bt and non-Bt maize cultivated in Brazil.

    Science.gov (United States)

    Barroso, Vinícius M; Rocha, Liliana O; Reis, Tatiana A; Reis, Gabriela M; Duarte, Aildson P; Michelotto, Marcos D; Correa, Benedito

    2017-05-01

    Fusarium verticillioides is one of the main pathogens of maize, causing ear and stalk rots. This fungus is also able to produce high levels of fumonisins, which have been linked to various illnesses in humans and animals. Previous studies have shown that maize hybrids genetically modified with the cry genes from the bacterium Bacillus thuringiensis (Bt) presented lower incidence of F. verticillioides and fumonisin levels, presumably through the reduction of insects, which could act as vectors of fungi. The aim of this study was to assess the incidence of F. verticillioides and the concentration of fumonisins in Bt and isogenic non-Bt hybrids (2B710Hx, 30F35YG, 2B710, and 30F35, respectively). The samples of 2B710Hx and 30F35YG presented lower F. verticillioides frequency than 2B710 and 30F35 samples. However, there was no statistical difference between fumonisin contamination when Bt and non-Bt samples were compared (P > 0.05). The results suggest that other environmental parameters could possibly trigger fumonisin production during plant development in the field; consequently, other management strategies should be applied to aid controlling fumonisin contamination in maize.

  17. OUTBREAK OF MAIZE DOWNY MILDEW (Sclerophthora macrospora IN SLOVENIA IN 1999

    Directory of Open Access Journals (Sweden)

    Stanislav Trdan

    2000-12-01

    Full Text Available In 1999 a pronounced infection of maize with fungus Sclerophthora macrospora occurred in Slovenia, especially in its north-eastern and eastern regions. Symptoms, typical for infection with this fungus, were found on app. 1800 ha, which means on about 2.5 % of the acreage on which maize is grown. The infected plants were found only on those fields, or parts of those fields, which were flooded for some time soon after sowing or emergence of the crop. The percentage of the plants infected by the fungus was between 5 and 90 %, depending on the type of soil. This article presents different disease causing fungi, their taxonomy, and deals in detail with the species Sclerophthora macrospora, the only disease causing organism under our growing conditions. The article deals with hosts of the fungus, typical symptoms of the disease on maize (“crazy top”, pathogen biology, the mode of infection, its survival under unfavorable conditions, and possible protection against the infection. The article also describes the actual situation in Slovenia, and adds a comment on possible regular occurrences of this disease in future.

  18. A highly conserved metalloprotease effector enhances virulence in the maize anthracnose fungus Colletotrichum graminicola.

    Science.gov (United States)

    Sanz-Martín, José M; Pacheco-Arjona, José Ramón; Bello-Rico, Víctor; Vargas, Walter A; Monod, Michel; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

    2016-09-01

    Colletotrichum graminicola causes maize anthracnose, an agronomically important disease with a worldwide distribution. We have identified a fungalysin metalloprotease (Cgfl) with a role in virulence. Transcriptional profiling experiments and live cell imaging show that Cgfl is specifically expressed during the biotrophic stage of infection. To determine whether Cgfl has a role in virulence, we obtained null mutants lacking Cgfl and performed pathogenicity and live microscopy assays. The appressorium morphology of the null mutants is normal, but they exhibit delayed development during the infection process on maize leaves and roots, showing that Cgfl has a role in virulence. In vitro chitinase activity assays of leaves infected with wild-type and null mutant strains show that, in the absence of Cgfl, maize leaves exhibit increased chitinase activity. Phylogenetic analyses show that Cgfl is highly conserved in fungi. Similarity searches, phylogenetic analysis and transcriptional profiling show that C. graminicola encodes two LysM domain-containing homologues of Ecp6, suggesting that this fungus employs both Cgfl-mediated and LysM protein-mediated strategies to control chitin signalling. © 2015 BSPP and John Wiley & Sons Ltd.

  19. Resistance to Aspergillus flavus in maize and peanut: Molecular biology, breeding, environmental stress, and future perspectives

    Directory of Open Access Journals (Sweden)

    Jake C. Fountain

    2015-06-01

    Full Text Available The colonization of maize (Zea mays L. and peanut (Arachis hypogaea L. by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species (ROS within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A. flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  20. Septation of infectious hyphae is critical for appressoria formation and virulence in the smut fungus Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Johannes Freitag

    2011-05-01

    Full Text Available Differentiation of hyphae into specialized infection structures, known as appressoria, is a common feature of plant pathogenic fungi that penetrate the plant cuticle. Appressorium formation in U. maydis is triggered by environmental signals but the molecular mechanism of this hyphal differentiation is largely unknown. Infectious hyphae grow on the leaf surface by inserting regularly spaced retraction septa at the distal end of the tip cell leaving empty sections of collapsed hyphae behind. Here we show that formation of retraction septa is critical for appressorium formation and virulence in U. maydis. We demonstrate that the diaphanous-related formin Drf1 is necessary for actomyosin ring formation during septation of infectious hyphae. Drf1 acts as an effector of a Cdc42 GTPase signaling module, which also consists of the Cdc42-specific guanine nucleotide exchange factor Don1 and the Ste20-like kinase Don3. Deletion of drf1, don1 or don3 abolished formation of retraction septa resulting in reduced virulence. Appressorium formation in these mutants was not completely blocked but infection structures were found only at the tip of short filaments indicating that retraction septa are necessary for appressorium formation in extended infectious hyphae. In addition, appressoria of drf1 mutants penetrated the plant tissue less frequently.

  1. Septation of infectious hyphae is critical for appressoria formation and virulence in the smut fungus Ustilago maydis.

    Science.gov (United States)

    Freitag, Johannes; Lanver, Daniel; Böhmer, Christian; Schink, Kay Oliver; Bölker, Michael; Sandrock, Björn

    2011-05-01

    Differentiation of hyphae into specialized infection structures, known as appressoria, is a common feature of plant pathogenic fungi that penetrate the plant cuticle. Appressorium formation in U. maydis is triggered by environmental signals but the molecular mechanism of this hyphal differentiation is largely unknown. Infectious hyphae grow on the leaf surface by inserting regularly spaced retraction septa at the distal end of the tip cell leaving empty sections of collapsed hyphae behind. Here we show that formation of retraction septa is critical for appressorium formation and virulence in U. maydis. We demonstrate that the diaphanous-related formin Drf1 is necessary for actomyosin ring formation during septation of infectious hyphae. Drf1 acts as an effector of a Cdc42 GTPase signaling module, which also consists of the Cdc42-specific guanine nucleotide exchange factor Don1 and the Ste20-like kinase Don3. Deletion of drf1, don1 or don3 abolished formation of retraction septa resulting in reduced virulence. Appressorium formation in these mutants was not completely blocked but infection structures were found only at the tip of short filaments indicating that retraction septa are necessary for appressorium formation in extended infectious hyphae. In addition, appressoria of drf1 mutants penetrated the plant tissue less frequently.

  2. Calcium homeostasis and signaling in fungi and their relevance for pathogenicity of yeasts and filamentous fungi

    Directory of Open Access Journals (Sweden)

    Renata Tisi

    2016-09-01

    Full Text Available Though fungi show peculiarities in the purposes and specific traits of calcium signaling pathways, the general scheme and the most important players are well conserved if compared to higher eukaryotes. This provides a powerful opportunity either to investigate shared features using yeast as a model or to exploit fungal specificities as potential targets for antifungal therapies. The sequenced genomes from yeast Saccharomyces cerevisiae, Schizosaccharomyces pombe and the filamentous fungus Neurospora crassa were already published more than ten years ago. More recently the genome sequences of filamentous fungi of Aspergillus genus, some of which threatening pathogens, and dimorphic fungi Ustilago maydis were published, giving the chance to identify several proteins involved in calcium signaling based on their homology to yeast or mammalian counterparts. Nonetheless, unidentified calcium transporters are still present in these organisms which await to be molecularly characterized. Despite the relative simplicity in yeast calcium machinery and the availability of sophisticated molecular tools, in the last years, a number of new actors have been identified, albeit not yet fully characterized. This review will try to describe the state of the art in calcium channels and calcium signaling knowledge in yeast, with particular attention to the relevance of this knowledge with respect to pathological fungi.

  3. Sequencing, assembly, and annotation of Maize B104 : A maize transformation resource

    Science.gov (United States)

    Maize transformation is complicated. Most lines are not readily cultured and transformed, making the germplasm available for genome engineering extremely limited. Developing a better understanding of the genomic regions responsible for differences in culturability and transformability would be a goo...

  4. AMPK in Pathogens

    OpenAIRE

    Mesquita, Inês Morais; Moreira, Diana; Marques, Belém Sampaio; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo Jorge Leal

    2016-01-01

    During host–pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recogn...

  5. Developing Inset Resistant Maize Varieties for Food Security in Kenya

    International Nuclear Information System (INIS)

    Mugo, S.

    2002-01-01

    The Insect Resistant Maize for Africa (IRMA) project aims at increasing maize production and food security through development and deployment of stem borer resistant maize germplasm developed using conventional and through biotechnology methods such as Bt maize. Bt maize offers farmers an effective and practical option for controlling stem borers. It was recognized that the development and routine use of Bt maize will require addressing relevant bio-safety, environmental, and community concerns and research and information gathering activities are in place to address these concerns and research and information gathering activities are in place to address these concerns. Suitable Bt gene have been acquired or synthesized and back-crossed into elite maize germplasm at CIMMYT-Mexico, and the effective Cry-proteins against the major maize stem borers in Kenya were identified to better target pests. Stem borer resistant maize germplasm is being developed through conventional breeding, using locally adapted and exotic germplasm. for safe and effective deployment of Bt maize,studies on its impacts on target and non-target arthropods as well as studies on the effects of Bt maize on key non-target arthropods as well as studies on gene flow are underway. Insect resistance management strategies are being developed through quantifying the effectiveness, ???. Socioeconomic impact studies are revealing factors in the society that may influence the adoption of Bt maize in Kenya. Also, baseline data, essential for the monitoring and evaluation of the Bt maize technology in Kenya, has been established. Technology transfer and capacity building, creating awareness and communications have received attention in the project. This paper describes the major research activities as they relate to development of the stem bore resistant maize germplasm

  6. Occurrence of toxigenic fungi in maize and maize-gluten meal from Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Kashif SALEEMI

    2012-05-01

    Full Text Available The present study was designed to isolate and identify toxigenic mycoflora of maize and maize-gluten meal. A total of 82 samples of maize and 8 samples of maize-gluten meal were collected from Faisalabad district of Pakistan over a period of two years. These samples were inoculated on different culture media. Fungal contamination of maize and maize-gluten was 56% and 75% of samples, respectively. Isolation frequencies of different genera isolated from maize were Aspergillus 33%; Penicillium 28%; Fusarium 10%; and Alternaria 1%. Isolation frequency among species was maximum for P. verrucosum, followed by A. niger aggregates, A. ochraceous, A. flavus, P. chrysogenum, A. parasiticus, A. carbonarius, Fusarium spp. and Alternaria spp. Relative density of Aspergillus isolates was maximum for A. niger aggregates and A. ochraceous (30% each followed by A. flavus (26%, A. parasiticus (11% and A. carbonarius (3%. Percentage of toxigenic fungi among Aspergillus isolates was 52%. Aflatoxigenic isolates of A. flavus and A. parasiticus were 43 and 67% and ochratoxigenic isolates of A. carbonarius, A. ochraceous and A. niger aggregates were 100, 63 and 38%, respectively. Aspergillus parasiticus produced higher concentrations of AFB1 (maximum 1374.23 ng g-1 than A. flavus (maximum 635.50 ng g-1. Ochratoxin A production potential of A. ochraceous ranged from 1.81 to 9523.1 ng g-1, while in A. niger aggregates it was 1.30 to 1758.6 ng g-1. Isolation frequencies of fungal genera from maize-gluten meal were Aspergillus (63% and Penicillium (50%. A. flavus was the most frequently isolated species. Percentage of toxigenic fungi among Aspergillus isolates was 40%. Aflatoxigenic isolates of A. flavus were 33% and ochratoxigenic isolates of A. ochraceous were 100%.

  7. The Dent Stage of Maize Kernels Is the Most Conducive for Fumonisin Biosynthesis under Field Conditions ▿

    Science.gov (United States)

    Picot, Adeline; Barreau, Christian; Pinson-Gadais, Laëtitia; Piraux, François; Caron, Daniel; Lannou, Christian; Richard-Forget, Florence

    2011-01-01

    The fungal pathogen Fusarium verticillioides infects maize ears and produces fumonisins, known for their adverse effects on human and animal health. Basic questions remain unanswered regarding the kernel stage(s) associated with fumonisin biosynthesis and the kernel components involved in fumonisin regulation during F. verticillioides-maize interaction under field conditions. In this 2-year field study, the time course of F. verticillioides growth and fumonisin accumulation in developing maize kernels, along with the variations in kernel pH and amylopectin content, were monitored using relevant and accurate analytical tools. In all experiments, the most significant increase in fumonisin accumulation or in fumonisin productivity (i.e., fumonisin production per unit of fungus) was shown to occur within a very short period of time, between 22/32 and 42 days after inoculation and corresponding to the dent stage. This stage was also characterized by acidification in the kernel pH and a maximum level of amylopectin content. Our data clearly support published results based on in vitro experiments suggesting that the physiological stages of the maize kernel play a major role in regulating fumonisin production. Here we have validated this result for in planta and field conditions, and we demonstrate that under such conditions the dent stage is the most conducive for fumonisin accumulation. PMID:21984235

  8. Screening of promising maize genotypes against maize weevil (Sitophilus zeamais Motschulky in storage condition

    Directory of Open Access Journals (Sweden)

    Ram B Paneru

    2017-12-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky is a serious pest of economic importance in stored grains. It causes major damage to stored maize grain thereby reducing its weight, quality and germination. An experiment was conducted in randomized complete block design (RCBD with 3 replications to screen 32 maize genotypes against maize weevil in no-choice and free-choice conditions at Entomology Division, Khumaltar, Lalitpur (Room temperature: Maximum 24-32°C and Minimum 18-27°C. The findings showed that the maize genotypes had different response to maize weevil damage ranging from susceptible to tolerance. The genotypes Manakamana-3, Lumle White POP Corn and Ganesh-2 showed their tolerance to S. zeamais as evidenced by lower number of weevil emerged/attracted, lower amount of grain debris release and lower proportion of bored grains, while the genotype ZM-627 was the most susceptible to weevil damage in both tests. The other remaining genotypes were intermediate types. This information is useful to improve grain protection in storage and varietal improvement/release program.

  9. An immunity-triggering effector from the Barley smut fungus Ustilago hordei resides in an Ustilaginaceae-specific cluster bearing signs of transposable element-assisted evolution.

    Directory of Open Access Journals (Sweden)

    Shawkat Ali

    2014-07-01

    Full Text Available The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE, interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity

  10. An Immunity-Triggering Effector from the Barley Smut Fungus Ustilago hordei Resides in an Ustilaginaceae-Specific Cluster Bearing Signs of Transposable Element-Assisted Evolution

    KAUST Repository

    Ali, Shawkat

    2014-07-03

    The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE), interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity in its corn host.

  11. An Immunity-Triggering Effector from the Barley Smut Fungus Ustilago hordei Resides in an Ustilaginaceae-Specific Cluster Bearing Signs of Transposable Element-Assisted Evolution

    KAUST Repository

    Ali, Shawkat; Laurie, John D.; Linning, Rob; Cervantes-Chá vez, José Antonio; Gaudet, Denis; Bakkeren, Guus

    2014-01-01

    The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE), interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity in its corn host.

  12. Integrated database for identifying candidate genes for Aspergillus flavus resistance in maize.

    Science.gov (United States)

    Kelley, Rowena Y; Gresham, Cathy; Harper, Jonathan; Bridges, Susan M; Warburton, Marilyn L; Hawkins, Leigh K; Pechanova, Olga; Peethambaran, Bela; Pechan, Tibor; Luthe, Dawn S; Mylroie, J E; Ankala, Arunkanth; Ozkan, Seval; Henry, W B; Williams, W P

    2010-10-07

    Aspergillus flavus Link:Fr, an opportunistic fungus that produces aflatoxin, is pathogenic to maize and other oilseed crops. Aflatoxin is a potent carcinogen, and its presence markedly reduces the value of grain. Understanding and enhancing host resistance to A. flavus infection and/or subsequent aflatoxin accumulation is generally considered an efficient means of reducing grain losses to aflatoxin. Different proteomic, genomic and genetic studies of maize (Zea mays L.) have generated large data sets with the goal of identifying genes responsible for conferring resistance to A. flavus, or aflatoxin. In order to maximize the usage of different data sets in new studies, including association mapping, we have constructed a relational database with web interface integrating the results of gene expression, proteomic (both gel-based and shotgun), Quantitative Trait Loci (QTL) genetic mapping studies, and sequence data from the literature to facilitate selection of candidate genes for continued investigation. The Corn Fungal Resistance Associated Sequences Database (CFRAS-DB) (http://agbase.msstate.edu/) was created with the main goal of identifying genes important to aflatoxin resistance. CFRAS-DB is implemented using MySQL as the relational database management system running on a Linux server, using an Apache web server, and Perl CGI scripts as the web interface. The database and the associated web-based interface allow researchers to examine many lines of evidence (e.g. microarray, proteomics, QTL studies, SNP data) to assess the potential role of a gene or group of genes in the response of different maize lines to A. flavus infection and subsequent production of aflatoxin by the fungus. CFRAS-DB provides the first opportunity to integrate data pertaining to the problem of A. flavus and aflatoxin resistance in maize in one resource and to support queries across different datasets. The web-based interface gives researchers different query options for mining the database

  13. Historical genomics of North American maize

    NARCIS (Netherlands)

    Heerwaarden, van J.; Hufford, M.B.; Ross-Ibarra, J.

    2012-01-01

    Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density

  14. Hormonal responses during early embryogenesis in maize.

    Science.gov (United States)

    Chen, Junyi; Lausser, Andreas; Dresselhaus, Thomas

    2014-04-01

    Plant hormones have been shown to regulate key processes during embryogenesis in the model plant Arabidopsis thaliana, but the mechanisms that determine the peculiar embryo pattern formation of monocots are largely unknown. Using the auxin and cytokinin response markers DR5 and TCSv2 (two-component system, cytokinin-responsive promoter version #2), as well as the auxin efflux carrier protein PIN1a (PINFORMED1a), we have studied the hormonal response during early embryogenesis (zygote towards transition stage) in the model and crop plant maize. Compared with the hormonal response in Arabidopsis, we found that detectable hormone activities inside the developing maize embryo appeared much later. Our observations indicate further an important role of auxin, PIN1a and cytokinin in endosperm formation shortly after fertilization. Apparent auxin signals within adaxial endosperm cells and cytokinin responses in the basal endosperm transfer layer as well as chalazal endosperm are characteristic for early seed development in maize. Moreover, auxin signalling in endosperm cells is likely to be involved in exogenous embryo patterning as auxin responses in the endosperm located around the embryo proper correlate with adaxial embryo differentiation and outgrowth. Overall, the comparison between Arabidopsis and maize hormone response and flux suggests intriguing mechanisms in monocots that are used to direct their embryo patterning, which is significantly different from that of eudicots.

  15. INSECT AND MYCOFLORA INTERACTIONS IN MAIZE FLOUR ...

    African Journals Online (AJOL)

    Fusarium moniliforme had the highest occurrence of 36.7%, 28.1% and 33.3% while Aspergillus flavus/parasiticus had a frequency of 3.2%, 3.1% and 3% on primary isolation media of czapek dox agar (CDA), potato dextrose agar (PDA) and sabouraud dextrose agar (SDA) respectively, in maize flour without T. castaneum.

  16. The transcriptome landscape of early maize meiosis

    Science.gov (United States)

    Meiosis, particularly meiotic recombination, is a major factor affecting yield and breeding of plants. To gain insight into the transcriptome landscape during early initiation steps of meiotic recombination, we profiled early prophase I meiocytes from maize using RNA-seq. Our analyses of genes prefe...

  17. Zealactones. Novel natural strigolactones from maize

    NARCIS (Netherlands)

    Charnikhova, Tatsiana V.; Gaus, Katharina; Lumbroso, Alexandre; Sanders, Mark; Vincken, Jean Paul; Mesmaeker, de Alain; Ruyter-Spira, Carolien P.; Screpanti, Claudio; Bouwmeester, Harro J.

    2017-01-01

    In the root exudate and root extracts of maize hybrid cv NK Falkone seven putative strigolactones were detected using UPLC-TQ-MS-MS. All seven compounds displayed MS-MS-fragmentation common for strigolactones and particularly the presence of a fragment of m/z 97 Da, which may indicate the

  18. RESOURCE UTILISATION IN SOYBEAN/MAIZE INTERCROPS ...

    African Journals Online (AJOL)

    Soybean and maize may be planted as intercrops in alternating single rows in forage production systems to take advantage of available solar radiation and greater dry matter yields. Key Words: Nitrogen, row arrangement, photosynthetic active radiation, productivity. Résumé Des études des champs étaient conduites en ...

  19. Estimation of leaf area in tropical maize

    NARCIS (Netherlands)

    Elings, A.

    2000-01-01

    Leaf area development of six tropical maize cultivars grown in 1995 and 1996 in several tropical environments in Mexico (both favourable and moisture-and N-limited) was observed and analysed. First, the validity of a bell-shaped curve describing the area of individual leaves as a function of leaf

  20. The 50th Annual Maize Genetics Conference

    Energy Technology Data Exchange (ETDEWEB)

    Cone, Karen

    2014-03-26

    The 50th Annual Maize Genetics Conference was held February 27 - March 2, 2008 at the Marriott Wardman Park Hotel in Washington, D.C. As the golden anniversary of the Conference and coinciding with the release of a draft of the maize genome sequence, this was a special meeting. To publicize this unique occasion, meeting organizers hosted a press conference, which was attended by members of the press representing science and non-science publications, and an evening reception at the Smithsonian National Museum of Natural History, where the draft sequence was announced and awards were presented to Dr. Mary Clutter and Senator Kit Bond to thank them for their outstanding contributions to maize genetics and genomics research. As usual, the Conference provided an invigorating forum for exchange of recent research results in many areas of maize genetics, e.g., cytogenetics, development, molecular genetics, transposable element biology, biochemical genetics, and genomics. Results were shared via both oral and poster presentations. Invited talks were given by four distinguished geneticists: Vicki Chandler, University of Arizona; John Doebley, University of Wisconsin; Susan Wessler, University of Georgia; and Richard Wilson, Washington University. There were 46 short talks and 241 poster presentations. The Conference was attended by over 500 participants. This included a large number of first-time participants in the meeting and an increasingly visible presence by individuals from underrepresented groups. Although we do not have concrete counts, there seem to be more African American, African and Hispanic/Latino attendees coming to the meeting than in years past. In addition, this meeting attracted many participants from outside the U.S. Student participation continues to be hallmark of the spirit of free exchange and cooperation characteristic of the maize genetics community. With the generous support provided by DOE, USDA NSF, and corporate/private donors, organizers were

  1. Effect of organic fertilizers on maize production in Eastern Georgia

    Science.gov (United States)

    Jolokhava, Tamar; Kenchiashvili, Naira; Tarkhnishvili, Maia; Ghambashidze, Giorgi

    2016-04-01

    Maize remains to be the most important cereal crop in Georgia. Total area of arable land under cereal crops production equals to 184 thousands hectares (FAO statistical yearbook, 2014), from which maize takes the biggest share. Leading position of maize among other cereal crops is caused by its dual purpose as food and feed product. In Spite of a relatively high production of maize to other cereals there is still a high demand on it, especially as feed for animal husbandry. The same tendency is seen in organic production, where producers of livestock and poultry products require organically grown maize, the average yield of which is much less than those produced conventionally. Therefore, it is important to increase productivity of maize in organic farms. Current study aimed to improve maize yield using locally produced organic fertilizers and to compare them to the effect of mineral fertilizers. The study was carried out in Eastern Georgia under dry subtropical climate conditions on local hybrid of maize. This is the first attempt to use hybrid maize (developed with organic plant breeding method) in organic field trials in Georgia. The results shown, that grain yield from two different types of organic fertilizers reached 70% of the yields achieved with industrial mineral fertilizers. As on farm level differences between organic and conventional maize production are much severe, the results from the field trials seems to be promising for future improvement of organic cereal crop production.

  2. Characterization of genetic diversity and linkage disequilibrium of ZmLOX4 and ZmLOX5 loci in maize.

    Directory of Open Access Journals (Sweden)

    Gerald N De La Fuente

    Full Text Available Maize (Zea mays L. lipoxygenases (ZmLOXs are well recognized as important players in plant defense against pathogens, especially in cross kingdom lipid communication with pathogenic fungi. This study is among the first to investigate genetic diversity at important gene paralogs ZmLOX4 and ZmLOX5. Sequencing of these genes in 400 diverse maize lines showed little genetic diversity and low linkage disequilibrium in the two genes. Importantly, we identified one inbred line in which ZmLOX5 has a disrupted open reading frame, a line missing ZmLOX5, and five lines with a duplication of ZmLOX5. Tajima's D test suggests that both ZmLOX4 and ZmLOX5 have been under neutral selection. Further investigation of haplotype data revealed that within the ZmLOX family members only ZmLOX12, a monocot specific ZmLOX, showed strong linkage disequilibrium that extends further than expected in maize. Linkage disequilibrium patterns at these loci of interest are crucial for future candidate gene association mapping studies. ZmLOX4 and ZmLOX5 mutations and copy number variants are under further investigation for crop improvement.

  3. Identificación de las proteínas secretadas por el hongo Ustilago maydis (DeCandole Corda (Basidiomiceto cultivado en condiciones in vitro

    Directory of Open Access Journals (Sweden)

    Andrés Adolfo Estrada-Luna

    2010-01-01

    Full Text Available Introducción: Ustilago maydis es un hongo basidiomiceto que infecta al maíz y teozintle produciendo una enfermedad conocida como carbón común o huitlacoche. Actualmente no existen reportes acerca del secretoma del hongo cultivado bajo condiciones in vitro. Un estudio de esta naturaleza permitiría caracterizar los genes involucrados en varios procesos importantes, entre los que se tienen aquellos relacionados con la nutrición, la patogenicidad y la diferenciación del hongo. El objetivo de esta investigación fue identificar las proteínas secretadas al medio de cultivo por las formas de levadura o micelio de este hongo cultivado en dos condiciones de pH. Método: Se generaron las formas de micelio o levadura de Ustilago maydis (cepa FB2¿a2b2 a través del cultivo en medios mínimos con pH 3 y 7 respectivamente y se determinó su cinética de crecimiento. Las proteínas secretadas al medio se concentraron en una columna de fase reversa Sep-Pak Plus C18 y se eluyeron con una solución de acetonitrilo (60 % + ácido trifluoroacético (0.1 %, seguida de su liofilización parcial, y precipitación con ácido tricloroacético-acetona. Posteriormente las muestras fueron sometidas a electroforesis en poliacrilamida (SDS-PAGE y los geles teñidos con azul de Coomassie. Las bandas de proteína se cortaron del gel y se digirieron con tripsina. Las mezclas de péptidos fueron inyectados para su análisis en un espectrómetro de masas y el espectro MS/MS obtenido fue procesado en Masslynx 4.0 antes de someterlo al programa MASCOT (Matrix Science para realizar las búsquedas no-redundantes en la base de datos del National Center for Biotechnology Information. Resultados: El crecimiento de U. maydis a pH 7 fue mayor que a pH 3 (D.O. a 600 nm= 1.35 y 0.85, respectivamente a las 30 h de incubación. El proceso dimórfico de levadura a micelio a pH 3 se inició a las 8 h después de iniciados los cultivos. A las 30 h de cultivo se observó que el 100 % de

  4. Studies on the traditional methods of production of maize tuwo (a ...

    African Journals Online (AJOL)

    African Journal of Food, Agriculture, Nutrition and Development ... on the quality characteristics of maize tuwo (a Nigerian nonfermented maize dumpling) ... The sequential mixing of flour and water during maize tuwo preparation should also ...

  5. The Efficiency of Noni (Morinda citrifolia L.) Essential Oil on the Control of Leaf Spot Caused by Exserohilum turcicum in Maize Culture.

    Science.gov (United States)

    Silva, Janaina Costa E; Mourão, Dalmarcia de Sousa Carlos; Lima, Fabia Silva de Oliveira; Sarmento, Renato de Almeida; Dalcin, Mateus Sunti; Aguiar, Raimundo Wagner de Souza; Santos, Gil Rodrigues Dos

    2017-08-14

    The objective of this work was to evaluate the efficiency of noni essential oil on the control of Exserohilum turcicum , a causative agent of Exserohilum spot in maize culture. In the sanitary test 400 seeds were incubated using the blotter test method. For the transmissibility test, the fragments of damaged leaves of seedlings were removed and put into a potato, dextrose and agar (PDA) culture environment. To verify the pathogenicity, Koch´s postulates were performed. In the phytotoxicity test different concentrations of noni oil were applied in maize seedlings. E. turcicum conidia were submitted to different concentrations of noni oil. In the preventive and curative tests noni essential oils were applied before and after the conidia inoculation, respectively. The results revealed the presence of fungi of the genres Aspergillus , Penicillium , Rhizopus , Fusarium , and Exserohilum in the maize seeds. The pathogenicity of E. turcicum and also the transmission of this fungus from the seeds to the maize seedlings was confirmed. The inhibition of conidia germination was proportional to the concentration increase. The preventive application of noni essential oil was the most efficient on the control of Exserohilum spot.

  6. Seed biopriming with novel strain of Trichoderma harzianum for the control of toxigenic Fusarium verticillioides and fumonisins in maize

    DEFF Research Database (Denmark)

    Nayaka, S.Chandra; Niranjana, S.R.; Shankar, A.C. Uday

    2010-01-01

    Fusarium verticillioides is one of the most important fungal pathogens in maize causing both pre- and post-harvest losses and also capable of producing Fumonisins. In the present study attempts have been made for screening potential T. harzianum from native rhizosphere and to study its effect...... on Fusarium ear rot disease, fumonisin accumulation in different maize cultivars grown in India. Eight isolates of T. harzianum were isolated and T. harzianum isolate Th-8 exhibited better antifungal activity than carbendizim. Th-8 was formulated in different solid substrates like wheat bran, paddy husk...... of 10 g/kg. Treated seeds were subjected to evaluate F. verticillioides incidence, seed germination, seedling vigour and field emergence, yield, thousand seed weight and fumonisin production. It was found that the pure culture of T. harzianum was more effective in reducing the F. verticillioides...

  7. Isolation and characterization of subgenomic DNAs encapsidated in 'single' T = 1 isometric particles of Maize streak virus

    International Nuclear Information System (INIS)

    Casado, Carolina G.; Javier Ortiz, G.; Padron, Eric; Bean, Samantha J.; McKenna, Robert; Agbandje-McKenna, Mavis; Boulton, Margaret I.

    2004-01-01

    'Single' T = 1 isometric particles of Maize streak virus (MSV) have been isolated from infected maize leaves. Biochemical and genetic characterizations show that these particles contain subgenomic (sg) MSV DNA encapsidated by the MSV coat protein. The largest sg DNA is 1.56 kb, slightly larger than half genome size, although sg DNAs as small as 0.2 kb were also cloned. The sg DNAs are not infectious, and they do not appear to play a role in the pathogenicity of MSV. This is the first report of sg DNAs for MSV and, to our knowledge, the first time that encapsidated sg DNAs have been characterized at the sequence level for any geminivirus. These data will assist in our investigations into the role of genomic DNA in the formation of the unique geminate capsid architecture of the Geminiviridae

  8. Effects of intercropping on maize stemborers and their natural enemies

    DEFF Research Database (Denmark)

    Skovgård, Henrik; Päts, Peeter

    1996-01-01

    The effects of maize-cowpea intercropping on three lepidopteran stemborers (Chilo partellus (Swinhoe) C. orichalcociliellus (Strand) and Sesamia calamistis Hampson) and their natural enemies were studied in Kenya. Oviposition was not affected by intercropping, but significantly fewer larvae...... and wandering spiders, were not augmented by intercropping, but an inverse relationship in abundance was found between these two predator groups. It is concluded that maize intercropped with cowpea has only limited potential as a method of controlling the key pests in maize....

  9. Effect and fate of lindane in maize plant

    International Nuclear Information System (INIS)

    Bennaceur, M.; Ghezal, F.; Klaa, K.

    1992-10-01

    The fate and effect of lindane in maize plant, soil and predators were studied following insecticide application under field conditions. Respectively 84,2% and 93,3% of lindane residues were lost after 2 and 4 months in soil after treatment. About 90% of the insecticide was lost after one month in maize plant. Lindane residues were present in maize grains (0,205ppm). Lindane decreases the density of many predators in soils such as species of collembola, coccinellidae, formicidae, coleoptera

  10. Combining Maize Base Germplasm for Cold Tolerance Breeding

    OpenAIRE

    Rodríguez Graña, Víctor Manuel; Butrón Gómez, Ana María; Sandoya Miranda, Germán; Ordás Pérez, Amando; Revilla Temiño, Pedro

    2007-01-01

    Early planting can contribute to increased grain yield of maize (Zea mays L.), but it requires cold tolerance. A limited number of cold-tolerant maize genotypes have been reported. The objectives of this study were to test a new strategy to improve cold tolerance in maize searching for broad x narrow genetic combinations that may be useful as base populations for breeding programs, to compare genotype performance under cold-controlled and field conditions, and to establish the major genetic e...

  11. Status and prospects of maize research in Nepal

    OpenAIRE

    Govind KC; Tika B. Karki; Jiban Shrestha; Buddhi B. Achhami

    2015-01-01

    Food and nutritional securities are the major threats coupled with declining factor productivity and climate change effects in Nepal. Maize being the principal food crops of the majority of the hill people and source of animal feed for ever growing livestock industries in Terai of Nepal. Despite the many efforts made to increase the maize productivity in the country, the results are not much encouraging. Many of the maize based technologies developed and recommended for the farmers to date ar...

  12. Mixing of maize and wheat genomic DNA by somatic hybridization in regenerated sterile maize plants.

    Science.gov (United States)

    Szarka, B.; Göntér, I.; Molnár-Láng, M.; Mórocz, S.; Dudits, D.

    2002-07-01

    Intergeneric somatic hybridization was performed between albino maize ( Zea mays L.) protoplasts and mesophyll protoplasts of wheat ( Triticum aestivum L.) by polyethylene glycol (PEG) treatments. None of the parental protoplasts were able to produce green plants without fusion. The maize cells regenerated only rudimentary albino plantlets of limited viability, and the wheat mesophyll protoplasts were unable to divide. PEG-mediated fusion treatments resulted in hybrid cells with mixed cytoplasm. Six months after fusion green embryogenic calli were selected as putative hybrids. The first-regenerates were discovered as aborted embryos. Regeneration of intact, green, maize-like plants needed 6 months of further subcultures on hormone-free medium. These plants were sterile, although had both male and female flowers. The cytological analysis of cells from callus tissues and root tips revealed 56 chromosomes, but intact wheat chromosomes were not observed. Using total DNA from hybrid plants, three RAPD primer combinations produced bands resembling the wheat profile. Genomic in situ hybridization (GISH) using total wheat DNA as a probe revealed the presence of wheat DNA islands in the maize chromosomal background. The increased viability and the restored green color were the most-significant new traits as compared to the original maize parent. Other intermediate morphological traits of plants with hybrid origin were not found.

  13. Assessment of maize stem borer damage on hybrid maize varieties in Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Buddhi Bahadur Achhami

    2015-12-01

    Full Text Available Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage percentage by stem borer was up to 18.11%. Length of the feeding tunnel in maize stem was significantly higher in January than July. In case of exit holes made by borer counted more than four holes per plant that were planted in the month of January. All in all, except the tunnel length measurement per plant, we observed similar pattern in other borer damage parameters such as exit whole counts and plant damage percentage within the tested varieties. Stem borer damage was not significantly affect on grain yield.

  14. Propanol in maize silage at Danish dairy farms

    DEFF Research Database (Denmark)

    Raun, Birgitte Marie Løvendahl; Kristensen, Niels Bastian

    2010-01-01

    The objective of the present study was to investigate the prevalence maize silage containing propanol, the seasonal variation in propanol content of maize silage, and correlations between propanol and other fermentation products in maize silage collected from 20 randomly selected Danish dairy farms...... farms, the maize silage had ≥5 g propanol/kg DM. The present study indicates that dairy cows in Denmark are commonly exposed to propanol and that approximately 20% of the dairy cows will have an intake in the range of 75-100 g propanol/d under common feeding conditions....

  15. MORPHOLOGICAL AND MOLECULAR IDENTIFICATION OF Fusarium SPECIES AND THEIR PATHOGENICITY FOR WHEAT

    Directory of Open Access Journals (Sweden)

    Jelena Poštić

    2012-12-01

    Full Text Available From the root and lower stem parts of weeds and plant debris of maize, wheat, oat and sunflower we isolated 300 isolates of Fusarium spp. and performed morphological and molecular identification. With molecular identification using AFLP method we determined 14 Fusarium species: F. acuminatum, F. avenaceum, F. concolor, F. crookwellense, F. equiseti, F. graminearum, F. oxysporum, F. proliferatum, F. semitectum, F. solani, F. sporotrichioides, F. subglutinans, F. venenatum and F. verticillioides.By comparing results of morphological and molecular identification we found out that determination of 16,7% isolates was incorrect. Out of 300 isolates identified with molecular methods, 50 did not belong to the species determined with morphological determination.With pathogenicity tests of 30 chosen Fusarium isolates we determined that many of them were pathogenic to wheat and maize seedlings and to wheat heads. The most pathogenic were isolates of F. graminearum from A. retroflexus, A. theophrasti and C. album, F. venenatum from maize debris and and A. theophrasti, F. crookwellense from A. lappa. Antifungal influence of 11 essential oils on mycelia growth and sporulation of chosen Fusarium isolates determined that essential oils of T. vulgaris, P. anisum and E. caryophyllus had the strongest effect on mycelial growth. Influence of essential oils on sporulation was not statistically significant.

  16. Distribution of azotobacter in rhizosphere of maize

    International Nuclear Information System (INIS)

    Tahir, M.B.; Baig, M.B.

    1998-01-01

    Azotobacter distribution and species composition were studied under maize rhizosphere at four growth stages and in the uncropped soil (control). The study was conducted in the glazed pots with 10 kg soil in each pot. Soil in the pots was enriched with 20 mg N/kg and 15 mg/P/kg in the form of urea and single super phosphate, respectively. Six plants of maize variety Akbar were grown in 32 pots. Four pots were used as control (check). Sampling was done at four growth stages of 20, 40, 60 and 80 days after the germination of the crop. Results indicated that Azotobacter population increased as the plant growth progressed, reached maximum (1320) cells g/sup -1/ of soil at flowering stage and then declined. A chroococcum was found to be the dominant species in the main rhizosphere. (author)

  17. Grain yield stability of early maize genotypes

    Directory of Open Access Journals (Sweden)

    Chitra Bahadur Kunwar

    2016-12-01

    Full Text Available The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer’s variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer’s fields. Genotype and genotype × environment (GGE biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments.

  18. Maize Arabinoxylan Gels as Protein Delivery Matrices

    Directory of Open Access Journals (Sweden)

    Ana Luisa Martínez-López

    2009-04-01

    Full Text Available The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v in the presence of insulin or β-lactoglobulin at 0.1% (w/v was investigated. Insulin and β-lacto-globulin did not modify either the gel elasticity (9 Pa or the cross-links content (0.03 and 0.015 mg di- and triferulic acids/mg arabinoxylan, respectively. The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 × 10-7 and 0.79 × 10-7 cm2/s for insulin (5 kDa and β-lactoglobulin (18 kDa, respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.

  19. RESPONSIVENESS OF SPATIAL PRICE VOLATILITY TO INCREASED GOVERNMENT PARTICIPATION IN MAIZE GRAIN AND MAIZE MEAL MARKETING IN ZAMBIA

    OpenAIRE

    Syampaku, E.M; Mafimisebi, Taiwo Ejiola

    2014-01-01

    The study analyzed the responsiveness of maize grain and maize meal spatial price volatilities to increased government participation in maize grain marketing in Zambia using descriptive statistics and vector auto-regression (VAR). This was achieved by comparing spatial price volatility means and spatial price means for the period under increased government participation with respective means for periods under limited government participation. Also, spatial price volatilities were regressed ag...

  20. Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

    Science.gov (United States)

    Truter, J; Van Hamburg, H; Van Den Berg, J

    2014-02-01

    The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance.

  1. Temperature sensing by primary roots of maize

    Science.gov (United States)

    Poff, K. L.

    1990-01-01

    Zea mays L. seedlings, grown on agar plates at 26 degrees C, reoriented the original vertical direction of their primary root when exposed to a thermal gradient applied perpendicular to the gravity vector. The magnitude and direction of curvature can not be explained simply by either a temperature or a humidity effect on root elongation. It is concluded that primary roots of maize sense temperature gradients in addition to sensing the gravitational force.

  2. Intraguild Competition of Three Noctuid Maize Pests.

    Science.gov (United States)

    Bentivenha, J P F; Baldin, E L L; Hunt, T E; Paula-Moraes, S V; Blankenship, E E

    2016-08-01

    The western bean cutworm Striacosta albicosta (Smith), the fall armyworm Spodoptera frugiperda (J. E. Smith), and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) are among the major lepidopteran pests of maize in the United States, belonging to the same guild and injuring the reproductive tissues of this crop. Here, intraguild competition of these lepidopterans on non-Bt maize was evaluated through survival analysis of each species under laboratory and field conditions. Competition scenarios were carried out in arenas containing maize silk or ear tissue, using larvae on different stadium of development. Fitness cost competition studies were conducted to examine the influence of intraguild competition and cannibalism and predation rates on larval development. The survival of S. albicosta competing with the other species was significantly lower than in intraspecific competition, even when the larvae were more developed than the competitor. For S. frugiperda, survival remained high in the different competition scenarios, except when competing in a smaller stadium with H. zea Larvae of H. zea had a high rate of cannibalism, higher survival when competing against S. albicosta than S. frugiperda, and reduced survival when the H. zea larvae were at the same development stadium or smaller than the competitors. Based on fitness cost results, the absence of a competitor for the feeding source may confer an advantage to the larval development of S. frugiperda and H. zea Our data suggest that S. frugiperda has a competitive advantage against the other species, while S. albicosta has the disadvantage in the intraguild competition on non-Bt maize. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Aflatoxin Accumulation in a Maize Diallel Cross

    Directory of Open Access Journals (Sweden)

    W. Paul Williams

    2015-06-01

    Full Text Available Aflatoxins, produced by the fungus Aspergillus flavus, occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimination of aflatoxin in maize grain. In this investigation, a diallel cross was produced by crossing 10 inbred lines with varying degrees of resistance to aflatoxin accumulation in all possible combinations. Three lines that previously developed and released as sources of resistance to aflatoxin accumulation were included as parents. The 10 parental inbred lines and the 45 single crosses making up the diallel cross were evaluated for aflatoxin accumulation in field tests conducted in 2013 and 2014. Plants were inoculated with an A. flavus spore suspension seven days after silk emergence. Ears were harvested approximately 60 days later and concentration of aflatoxin in the grain determined. Parental inbred lines Mp717, Mp313E, and Mp719 exhibited low levels (3–12 ng/g of aflatoxin accumulation. In the diallel analysis, both general and specific combining ability were significant sources of variation in the inheritance of resistance to aflatoxin accumulation. General combining ability effects for reduced aflatoxin accumulation were greatest for Mp494, Mp719, and Mp717. These lines should be especially useful in breeding for resistance to aflatoxin accumulation. Breeding strategies, such as reciprocal recurrent selection, would be appropriate.

  4. Transcriptome Dynamics during Maize Endosperm Development.

    Directory of Open Access Journals (Sweden)

    Jianzhou Qu

    Full Text Available The endosperm is a major organ of the seed that plays vital roles in determining seed weight and quality. However, genome-wide transcriptome patterns throughout maize endosperm development have not been comprehensively investigated to date. Accordingly, we performed a high-throughput RNA sequencing (RNA-seq analysis of the maize endosperm transcriptome at 5, 10, 15 and 20 days after pollination (DAP. We found that more than 11,000 protein-coding genes underwent alternative splicing (AS events during the four developmental stages studied. These genes were mainly involved in intracellular protein transport, signal transmission, cellular carbohydrate metabolism, cellular lipid metabolism, lipid biosynthesis, protein modification, histone modification, cellular amino acid metabolism, and DNA repair. Additionally, 7,633 genes, including 473 transcription factors (TFs, were differentially expressed among the four developmental stages. The differentially expressed TFs were from 50 families, including the bZIP, WRKY, GeBP and ARF families. Further analysis of the stage-specific TFs showed that binding, nucleus and ligand-dependent nuclear receptor activities might be important at 5 DAP, that immune responses, signalling, binding and lumen development are involved at 10 DAP, that protein metabolic processes and the cytoplasm might be important at 15 DAP, and that the responses to various stimuli are different at 20 DAP compared with the other developmental stages. This RNA-seq analysis provides novel, comprehensive insights into the transcriptome dynamics during early endosperm development in maize.

  5. Differential resistance reaction of maize genotypes to maize stem borer (Chilo partellus Swinhoe at Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Ghanashyam Bhandari

    2016-12-01

    Full Text Available Maize stem borer (MSB, Chilo partellus Swinhoe, Lepidoptera: Pyralidae is one of the most important insect pest of maize in Nepal. Host plant resistance is the cost-effective, ecologically sound and stable approach to reduce damage by stem borers. Forty four maize genotypes were screened for resistance to maize stem borer at the research field of National Maize Research Program, Rampur during spring seasons (March to June of two consecutive years 2013 and 2014. The maize genotypes were evaluated in randomized complete block design with three replications and data were collected on foliar damage rating, tunnel length and number of exit holes made by the borer. The foliar damage and tunnel length damage were significant for genotypes for both the years. The exit holes were not significant in 2013 but significant in 2014 ranging from 2-6 scale. The foliar rating ranged from 2 to 5.5 in 2013 and 1.1 to 4.5 in 2014 on a 1-9 rating scale. The highly resistant genotypes (10 cm scale. The least susceptible genotypes (<5 cm were RampurSO3F8, RampurSO3FQ02 and RampurS10F18. The genotypes having least exit holes (2.0 in 2014 were RampurSO3F8, RampurSO3FQ02, RampurS10F18. Thus less damage parameters were observed in R-POP-2, RML-5/RML-8, RampurSO3F8, RampurSO3FQ02 and RampurS10F18 and therefore they can be used as parents or as sources of resistance in breeding program.

  6. AMPK in Pathogens.

    Science.gov (United States)

    Mesquita, Inês; Moreira, Diana; Sampaio-Marques, Belém; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo

    2016-01-01

    During host-pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host-pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.

  7. Potatoes, pathogens and pests

    NARCIS (Netherlands)

    Lazebnik, Jenny

    2017-01-01

    Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into

  8. Food-borne pathogens

    International Nuclear Information System (INIS)

    Niemand, J.G.

    1985-01-01

    The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process

  9. Pathogen inactivation techniques.

    Science.gov (United States)

    Pelletier, J P R; Transue, S; Snyder, E L

    2006-01-01

    The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

  10. Processes for managing pathogens.

    Science.gov (United States)

    Godfree, Alan; Farrell, Joseph

    2005-01-01

    Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

  11. The response of maize production in Kenya to economic incentives

    Directory of Open Access Journals (Sweden)

    Onono, P.A.,

    2013-06-01

    Full Text Available Agricultural development policy in Kenya has emphasised the use of incentives towards increased production and therefore self-sufficiency in maize which is a basic staple for most households. The channels used to provide incentives to maize farmers over the years include setting higher producer prices; subsidisation of inputs; provision of agricultural credit, research and extension services; construction and maintenance of roads, development of irrigation and water systems; legislative, institutional and macroeconomic reforms. Despite these efforts outputof maize has remained below domestic requirements in most years and the country continues to rely on imports to meet the deficits. Studies have assessed the responsiveness of maize to output price and reported inelastic responses and have recommended policies targeting non-price incentives to complement prices for the required increased production of maize. The studies, however, did not analyse the influence of the non-price incentives on the production of the crop. The findings of those studies are therefore deficient in explaining the relative importance of different non-price incentives and how they complement prices in influencing maize production in Kenya. This study investigated the response of maize production to both price and non-price incentives. The aim of this study was to ascertain the relative importance of non-price factors in influencing production of the crops as well as complementarity between price and non-price incentives. The findings show that maize production responds positively to its output price, development expenditures in agriculture, maize sales to marketing boards, growth in per capita GDP, liberalisation and governance reforms. However, maize production responds negatively to fertiliser price and unfavourable weather conditions. The response of maize output to its price is lower with rising inflation and grain market liberalisation.

  12. Sibling species of cercospora associated with gray leaf spot of maize.

    Science.gov (United States)

    Wang, J; Levy, M; Dunkle, L D

    1998-12-01

    ABSTRACT Monoconidial isolates of the fungus causing gray leaf spot of maize were obtained from diseased leaves collected throughout the United States and analyzed for genetic variability at 111 amplified fragment length polymorphism (AFLP) loci. Cluster analysis revealed two very distinct groups of Cercospora zeae-maydis isolates. Both groups were found to be relatively uniform internally with an average genetic similarity among isolates of approximately 93 and 94%, respectively. The groups were separated from each other by a genetic distance of approximately 80%, a distance greater than that separating each group from the sorghum pathogen, C. sorghi (67 to 70%). Characteristics and dimensions of conidia and conid-iophores produced on infected plants or nutrient media were unreliable criteria for taxonomic differentiation of isolates composing the two groups of C. zeae-maydis. Nucleotide sequences of 5.8S ribosomal DNA (rDNA) and the internal transcribed spacer (ITS) regions were identical within each group but different between the two groups and different from C. sorghi. Restriction fragment length polymorphisms generated by digestion of the 5.8S rDNA and ITS regions with TaqI readily distinguished each group and C. sorghi. Isolates in one group were generally distributed throughout maize-producing regions of the United States; isolates in the other group were localized in the eastern third of the country. Both types were present in the same fields at some locations. The genetic distance based on AFLP profiles and different ITS nucleotide sequences between the two morphologically indistinguishable groups indicate that they are sibling species. Although it is unlikely that breeding for resistance to gray leaf spot will be confounded by local or regional variation in the pathogen, a vigilant approach is warranted, because two pathogenic species exist with unknown abilities to evolve new pathotypes.

  13. The influence of farmers\\' adoption behaviour on maize production ...

    African Journals Online (AJOL)

    This study was therefore designed to determine the contribution of farmers\\' adoption of recommended maize production practices, namely maize varieties, seed spacing, fertilization and weeding on production efficiency in order to assess the soundness of the advice given to farmers. The research was conducted in the ...

  14. Effects of interplanted legumes with maize on major soil nutrients ...

    African Journals Online (AJOL)

    A field experiment was carried out at the Teaching and Research Farm of the University of Ibadan, in early 2004 and 2005 to evaluate the effects of interplanted legumes with maize on major soil nutrients and performance of maize. The experiment laid out in a randomized complete block design, with four levels of crop ...

  15. Regeneration of tropical maize lines ( Zea mays l .) from mature ...

    African Journals Online (AJOL)

    The use of immature zygotic embryos as an explant for maize regeneration has been hampered by the strictly limited suitable duration of immature embryos for culture. In contrast, mature zygotic embryos harvested from dry seeds are ubiquitous. However, generally mature embryos and especially tropical maize genotypes ...

  16. Aflatoxin Levels in Locally Grown Maize from Makueni District, Kenya

    African Journals Online (AJOL)

    Objectives: Investigations were carried out to determine aflatoxin levels in household maize in Makueni District and to correlate aflatoxin levels to maize drying and storage practices. Also, aflatoxin exposure in villages that reported aflatoxicosis cases in 2005 was compared with that in villages that did not report cases to ...

  17. Combining ability for maize grain yield and other agronomic ...

    African Journals Online (AJOL)

    Field experiments were conducted at the University of Ilorin Teaching and Research Farm in 2005 and 2006 cropping seasons with the objective to evaluate the combining ability for maize grain yield and other agronomic characters in 10 open pollinated maize varieties, which have been selected for high yield and stress ...

  18. Evaluating Terra MODIS Satellite Sensor Data Products for Maize ...

    African Journals Online (AJOL)

    Evaluating Terra MODIS Satellite Sensor Data Products for Maize Yield Estimation in South Africa. C Frost, N Thiebaut, T Newby. Abstract. The Free State Province of the Republic of South Africa contains some of the most important maize-producing areas in South Africa. For this reason this province has also been selected ...

  19. Replacement Value of Palm Kernel Meal for Maize on Carcass ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the effect of replacing maize with palm kernel meal on nutrient composition, fatty acid profile and sensory qualities of the meat of turkeys fed the dietary treatments. Six dietary treatments were formulated using palm kernel meal to replace maize at 0, 20, 40, 60, 80 and 100 percent.

  20. Maize gene banks helps farmers adapt to new challenges | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-10-28

    Oct 28, 2010 ... English · Français ... The farmers use a multitude of maize (corn) varieties – landraces – that are “very well adapted to harsh environments and poor soils, and ... These varieties were then “frozen in time” in maize gene banks.

  1. A Technique for Identification of Intrinsic Resistance of Maize ...

    African Journals Online (AJOL)

    ... the insect fat body to determine the levels of fat body vitellogenin (FVg) in the vitellogenic S. zeamais females which were reared on different maize varieties. Results on levels of FVg varied and ranged from 83.33% to 43.33% in insects raised in different varieties ANOVA of FVg, maize weight loss and F1 numbers showed ...

  2. Sporophytic control of pollen tube growth and guidance in maize

    Science.gov (United States)

    Lausser, Andreas; Kliwer, Irina; Srilunchang, Kanok-orn; Dresselhaus, Thomas

    2010-01-01

    Pollen tube germination, growth, and guidance (progamic phase) culminating in sperm discharge is a multi-stage process including complex interactions between the male gametophyte as well as sporophytic tissues and the female gametophyte (embryo sac), respectively. Inter- and intra-specific crossing barriers in maize and Tripsacum have been studied and a precise description of progamic pollen tube development in maize is reported here. It was found that pollen germination and initial tube growth are rather unspecific, but an early, first crossing barrier was detected before arrival at the transmitting tract. Pollination of maize silks with Tripsacum pollen and incompatible pollination of Ga1s/Ga1s-maize silks with ga1-maize pollen revealed another two incompatibility barriers, namely transmitting tract mistargeting and insufficient growth support. Attraction and growth support by the transmitting tract seem to play key roles for progamic pollen tube growth. After leaving transmitting tracts, pollen tubes have to navigate across the ovule in the ovular cavity. Pollination of an embryo sac-less maize RNAi-line allowed the role of the female gametophyte for pollen tube guidance to be determined in maize. It was found that female gametophyte controlled guidance is restricted to a small region around the micropyle, approximately 50–100 μm in diameter. This area is comparable to the area of influence of previously described ZmEA1-based short-range female gametophyte signalling. In conclusion, the progamic phase is almost completely under sporophytic control in maize. PMID:19926683

  3. Net Farm Income Analysis of Maize Production in Gwagwalada Area ...

    African Journals Online (AJOL)

    Net Farm Income Analysis of Maize Production in Gwagwalada Area Council of Federal Capital Territory, Nigeria. OO Alabi, AAA Coker, ME Idegbesor. Abstract. This study examined net farm income of maize production in Gwagwalada Area Council of Federal Capital Territory. The specific objectives are to: identify the ...

  4. Sources of Technical Efficiency Among Smallholders Maize Farmers ...

    African Journals Online (AJOL)

    The results show that the mean technical efficiency score for famers in the study area is 62.3%. This implies that there is a significant room for increasing maize yield in the study area if farmers use the resources at their disposal efficiently. Moreover, the results show that the efficiency of maize farmers in the study area is ...

  5. Determinants of technical inefficiency among maize-based farming ...

    African Journals Online (AJOL)

    Examining the level of farm-specific technical inefficiency of maize-based farming households in Niger state of Nigeria, this study fitted cross-sectional data into a Cobb- Douglass production frontier. Data used for this study were obtained using structured questionnaire administered to 108 randomly selected maize-based ...

  6. design, construction and performance analysis of a maize thresher

    African Journals Online (AJOL)

    ES Obe

    and evaluate a low cost maize sheller for rural farmers in Nigeria. ... between the human performance index for shelling and the machine .... maize in a mechanized system is the size of the ... factors are the design of the power transmis- .... and reliability in line with [11]). .... PGD thesis, Department of Mechanical En-.

  7. Contributions of Zea mays subspecies mexicana haplotypes to modern maize.

    Science.gov (United States)

    Yang, Ning; Xu, Xi-Wen; Wang, Rui-Ru; Peng, Wen-Lei; Cai, Lichun; Song, Jia-Ming; Li, Wenqiang; Luo, Xin; Niu, Luyao; Wang, Yuebin; Jin, Min; Chen, Lu; Luo, Jingyun; Deng, Min; Wang, Long; Pan, Qingchun; Liu, Feng; Jackson, David; Yang, Xiaohong; Chen, Ling-Ling; Yan, Jianbing

    2017-11-30

    Maize was domesticated from lowland teosinte (Zea mays ssp. parviglumis), but the contribution of highland teosinte (Zea mays ssp. mexicana, hereafter mexicana) to modern maize is not clear. Here, two genomes for Mo17 (a modern maize inbred) and mexicana are assembled using a meta-assembly strategy after sequencing of 10 lines derived from a maize-teosinte cross. Comparative analyses reveal a high level of diversity between Mo17, B73, and mexicana, including three Mb-size structural rearrangements. The maize spontaneous mutation rate is estimated to be 2.17 × 10 -8 ~3.87 × 10 -8 per site per generation with a nonrandom distribution across the genome. A higher deleterious mutation rate is observed in the pericentromeric regions, and might be caused by differences in recombination frequency. Over 10% of the maize genome shows evidence of introgression from the mexicana genome, suggesting that mexicana contributed to maize adaptation and improvement. Our data offer a rich resource for constructing the pan-genome of Zea mays and genetic improvement of modern maize varieties.

  8. Analysis of the Supply Response of Maize Producers in Nigeria ...

    African Journals Online (AJOL)

    The research work analyzed the supply response of maize producers in Nigeria and its implication for agricultural trade. The period covered was 1987-2007 (20 years) and data were collected on import quantity and value, export quantity and value, price of maize, price of its substitute, output and hectarage within the time ...

  9. Exploring cost-effective maize integrated weed management ...

    African Journals Online (AJOL)

    Several production constraints have led to low yields (< 2.5 t ha-1) in maize (Zea mays L.) inUganda, among which are weeds. This study investigated the most cost-effective integrated weedmanagement (IWM) approach in maize in eastern Uganda. An experiment was conducted atIkulwe station, Mayuge in 2011 and 2012 ...

  10. Detection of genetically modified maize ( Zea mays L.) in seed ...

    African Journals Online (AJOL)

    Maize is the second major cereal in Nepal; its food biosafety and ecological conservation is an important concern. To address this issue, it is necessary to detect genetically modified (GM) maize and establish a monitoring and regulatory system in Nepal. Currently, Nepal does not have legal regulations or labeling directives ...

  11. Interaction of maize chromatin-associated HMG proteins with mononucleosomes

    DEFF Research Database (Denmark)

    Lichota, J.; Grasser, Klaus D.

    2003-01-01

    maize HMGA and five different HMGB proteins with mononucleosomes (containing approx. 165 bp of DNA) purified from micrococcal nuclease-digested maize chromatin. The HMGB proteins interacted with the nucleosomes independent of the presence of the linker histone H1, while the binding of HMGA...

  12. Genomic variation in recently collected maize landraces from Mexico

    Directory of Open Access Journals (Sweden)

    María Clara Arteaga

    2016-03-01

    Full Text Available The present dataset comprises 36,931 SNPs genotyped in 46 maize landraces native to Mexico as well as the teosinte subspecies Zea maiz ssp. parviglumis and ssp. mexicana. These landraces were collected directly from farmers mostly between 2006 and 2010. We accompany these data with a short description of the variation within each landrace, as well as maps, principal component analyses and neighbor joining trees showing the distribution of the genetic diversity relative to landrace, geographical features and maize biogeography. High levels of genetic variation were detected for the maize landraces (HE = 0.234 to 0.318 (mean 0.311, while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (HE = 0.262 and 0.234, respectively. The distribution of genetic variation was better explained by environmental variables given by the interaction of altitude and latitude than by landrace identity. This dataset is a follow up product of the Global Native Maize Project, an initiative to update the data on Mexican maize landraces and their wild relatives, and to generate information that is necessary for implementing the Mexican Biosafety Law. Keywords: Maize, Teosinte, Maize SNP50K BeadChip, Mexican landraces, Proyecto Global de Maíces Nativos

  13. Occurrence of aflatoxin contamination in maize kernels and ...

    African Journals Online (AJOL)

    Aflatoxins are toxic metabolites produced mainly by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin B1 (AFB1) is a potent carcinogen, teratogen and mutagen. 660 pre- and post- harvest maize samples were collected from major maize growing areas in Tamil Nadu, India. Aflatoxin contamination was observed in ...

  14. Ion beam biotechnology and its application to maize breeding

    International Nuclear Information System (INIS)

    Yu Lixia; Li Wenjian; Dong Xicun; Zhou Libin; Ma Shuang

    2008-01-01

    Since the mid of 1980's, ion beam had been widely used in mutagenic breeding of various crops. Ion beam biotechnology had provided a new way for improving corn variety and creating new germplasm resources, and had promoted the development of maize breeding. The ion beam characteristics, the mutagenic mechanism and its application in maize breeding were described. (authors)

  15. Detection of optimum maturity of maize using image processing and ...

    African Journals Online (AJOL)

    A CCD camera for image acquisition of the different green colorations of the maize leaves at maturity was used. Different color features were extracted from the image processing system (MATLAB) and used as inputs to the artificial neural network that classify different levels of maturity. Keywords: Maize, Maturity, CCD ...

  16. Inadvertent presence of genetically modified elements in maize food ...

    African Journals Online (AJOL)

    Kenya has a biosafety law and has tested genetically modified (GM) maize under confinement and containment, but has neither released nor commercialized any GM crop. This study assessed various maize food products from the Kenyan farms and markets for the inadvertent presence of GMOs. It assessed the possibility ...

  17. Diversity in global maize germplasm: Characterization and utilization

    Indian Academy of Sciences (India)

    Maize (Zea mays L.) is not only of worldwide importance as a food, feed and as a source of diverse industrially important products, but is also a model genetic organism with immense genetic diversity. Although it was first domesticated in Mexico, maize landraces are widely found across the continents. Several studies in ...

  18. Genetic diversity of Pakistani maize genotypes using chromosome ...

    African Journals Online (AJOL)

    For improvement of maize crop presence of genetic diversity in the germplasm is very important. This study was conducted to determine genetic diversity among 17 Pakistani maize genotypes using 10 simple sequence repeat (SSR) primer sets. All the amplification products were in the range of <250-750 bp. To estimate the ...

  19. Significance and transmission of maize streak virus disease in Africa ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... soil nutrients, altitude and temperature on the biology of maize streak virus (MSV) / vector populations is discussed. ... status of maize host plants and its effects on population dynamics of Cicadulina mbila Naudé. (Homoptera: ..... time necessary for the leafhopper to reach the mesophyll of the leaf and ingest ...

  20. Yield advantage and water saving in maize/pea intercrop

    NARCIS (Netherlands)

    Mao, L.; Zhang, L.; Li, W.; Werf, van der W.; Sun, J.; Spiertz, J.H.J.; Li, L.

    2012-01-01

    Intercropping is a well-established strategy for maximization of yield from limited land, but mixed results have been obtained as to its performance in terms of water use efficiency. Here, two maize/pea intercrop layouts were studied in comparison to sole maize and sole pea with and without plastic

  1. Status and prospects of maize research in Nepal

    Directory of Open Access Journals (Sweden)

    Govind KC

    2015-12-01

    Full Text Available Food and nutritional securities are the major threats coupled with declining factor productivity and climate change effects in Nepal. Maize being the principal food crops of the majority of the hill people and source of animal feed for ever growing livestock industries in Terai of Nepal. Despite the many efforts made to increase the maize productivity in the country, the results are not much encouraging. Many of the maize based technologies developed and recommended for the farmers to date are not fully adopted. Therefore, problem is either on technology development or on dissemination or on both. Considering the above facts, some of the innovative and modern approaches of plant breeding and crop management technologies to increase the maize yield need to be developed and disseminated. There is a need for location-specific maize production technologies, especially for lowland winter maize, marginal upland maize production system, and resource poor farmers. Research efforts can be targeted to address both yield potential and on-farm yields by reducing the impacts of abiotic and biotic constraints. Therefore, in order to streamline the future direction of maize research in Nepal, an attempt has been made in this article to highlight the present status and future prospects with few key pathways.

  2. Regeneration of Sudanese maize inbred lines and open pollinated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-03

    Jun 3, 2008 ... Keywords: Sudanese maize genotypes, embryogenic callus, regeneration, and tissue culture. INTRODUCTION. Maize is an important food and forage crop in the North- ern and Southern regions of ... Skoog, 1965) containing 60 g l-1 sucrose and lacking 2,4-D (referred to as maturation or RI medium) and ...

  3. Intraplant communication in maize contributes to defense against insects

    Science.gov (United States)

    The vasculature of plants act as a channel for transport of signal(s) that facilitate long-distance intraplant communication. In maize, Maize insect resistance1-Cysteine Protease (Mir1-CP), which has homology to papain-like proteases, provides defense to different feeding guilds of insect pests. Fur...

  4. Studies on biochemical changes in maize wastes fermented with ...

    African Journals Online (AJOL)

    In an attempt to transform the agricultural waste products of maize cobs and shafts into useful products such as animal feeds and reduce the pollution effects of these wastes during maize seasons, they were fermented using Aspergillus niger for 72 hours. The fermented residues were analyzed with regard to proximate ...

  5. Detection of genetically modified maize (Zea mays L.) in seed ...

    African Journals Online (AJOL)

    ONOS

    2010-08-23

    Aug 23, 2010 ... establish a monitoring and regulatory system in Nepal. Currently, Nepal does not ... maize lines in 46 maize seed samples from different locations in Nepal. Suspected samples .... seeds supplied by informal channels (Sthapit and San, 2001). ... rence Materials and Measurements (IRRM, Geel, Belgium;.

  6. Maize flour fortification in Africa: markets, feasibility, coverage, and costs.

    Science.gov (United States)

    Fiedler, John L; Afidra, Ronald; Mugambi, Gladys; Tehinse, John; Kabaghe, Gladys; Zulu, Rodah; Lividini, Keith; Smitz, Marc-Francois; Jallier, Vincent; Guyondet, Christophe; Bermudez, Odilia

    2014-04-01

    The economic feasibility of maize flour and maize meal fortification in Kenya, Uganda, and Zambia is assessed using information about the maize milling industry, households' purchases and consumption levels of maize flour, and the incremental cost and estimated price impacts of fortification. Premix costs comprise the overwhelming share of incremental fortification costs and vary by 50% in Kenya and by more than 100% across the three countries. The estimated incremental cost of maize flour fortification per metric ton varies from $3.19 in Zambia to $4.41 in Uganda. Assuming all incremental costs are passed onto the consumer, fortification in Zambia would result in at most a 0.9% increase in the price of maize flour, and would increase annual outlays of the average maize flour-consuming household by 0.2%. The increases for Kenyans and Ugandans would be even less. Although the coverage of maize flour fortification is not likely to be as high as some advocates have predicted, fortification is economically feasible, and would reduce deficiencies of multiple micronutrients, which are significant public health problems in each of these countries. © 2013 New York Academy of Sciences.

  7. A comparison between hominy chop and defatted maize germ meal ...

    African Journals Online (AJOL)

    Defatted maize germ meal (DMG) is arbitrarily rated at a lower economic value than maize meal or hominy chop (HC). Five treatments with 15 steers each were fed different inclusion levels of DMG (0%, 25%, 50%, 75% and 100%), replacing hominy chop during the fattening period. Slaughter data were collected for carcass ...

  8. Performance and Energy Metabolism by Broiler Chickens Fed Maize ...

    African Journals Online (AJOL)

    Studies were conducted to evaluate the effect of replacing maize grain with different dietary levels of maize and millet offals on performance and energy metabolism in broiler chickens. Proximate composition and metabolizable energy (ME) values were determined. Feeding trial was also conducted to comparemaize and ...

  9. Climate Change and Maize Production: Empirical Evidence from ...

    African Journals Online (AJOL)

    Michael Madukwe

    Time series data on aggregate maize production, fertilizer use, .... The maize response model (eqn 3) was estimated using the time series data for ... The R. 2 value obtained from the equation is 0.534. This further indicates that aggregate total.

  10. Sub-Saharan African maize-based foods

    NARCIS (Netherlands)

    Ekpa, Onu; Palacios-Rojas, Natalia; Kruseman, Gideon; Fogliano, Vincenzo; Linnemann, Anita R.

    2018-01-01

    The demand for maize in Sub-Saharan Africa will triple by 2050 due to rapid population growth, while challenges from climate change will threaten agricultural productivity. Most maize breeding programmes have focused on improving agronomic properties and have paid relatively little attention to

  11. Evaluating Terra MODIS Satellite Sensor Data Products for Maize ...

    African Journals Online (AJOL)

    Celeste

    Maize plants mature on average from 120 to 165 days after planting. ... is a maize yield estimation timing model, developed using data from the ... The objective yields were surveyed and randomly selected from results of the stratified point ... are used in formulae (Frost, 2006) to derive plant population and a predicted ...

  12. Determination of radioactivity in maize and mung beans grown in ...

    African Journals Online (AJOL)

    Two staple foods (maize and mung beans) which were cultivated in Minjingu village, where there is phosphate deposit in Tanzania, were collected directly from the farms. The activity concentrations of 226Ra, 228Th and 40K were determined in the maize and mung beans samples using γ ray spectrometry employing HPGe ...

  13. Insight into the evolution of a plant pathogen: Comparative genomic analysis of the fungal maize pathogen Colletotrichum graminicola

    OpenAIRE

    Rech, Gabriel Eduardo

    2014-01-01

    [ES] Uno de los mayores problemas para el desarrollo de estrategias efectivas frente a hongos fitopatógenos es que, al igual que la mayoría de los microorganismos, presentan una gran plasticidad fenotípica y una extraordinaria capacidad de adaptarse a nuevos ambientes y/o de infectar nuevos huéspedes. En este contexto, resulta imprescindible determinar qué genes (u otras regiones del genoma) muestran evidencias de evolución adaptativa con el objetivo de identificar secuencias involucradas en ...

  14. Estimating plant distance in maize using Unmanned Aerial Vehicle (UAV).

    Science.gov (United States)

    Zhang, Jinshui; Basso, Bruno; Price, Richard F; Putman, Gregory; Shuai, Guanyuan

    2018-01-01

    Distance between rows and plants are essential parameters that affect the final grain yield in row crops. This paper presents the results of research intended to develop a novel method to quantify the distance between maize plants at field scale using an Unmanned Aerial Vehicle (UAV). Using this method, we can recognize maize plants as objects and calculate the distance between plants. We initially developed our method by training an algorithm in an indoor facility with plastic corn plants. Then, the method was scaled up and tested in a farmer's field with maize plant spacing that exhibited natural variation. The results of this study demonstrate that it is possible to precisely quantify the distance between maize plants. We found that accuracy of the measurement of the distance between maize plants depended on the height above ground level at which UAV imagery was taken. This study provides an innovative approach to quantify plant-to-plant variability and, thereby final crop yield estimates.

  15. Fungal Diversity of Maize (Zea Mays L. Grains

    Directory of Open Access Journals (Sweden)

    Gulbis Kaspars

    2016-06-01

    Full Text Available Maize is becoming more and more important crop for dairy farming as forage and as substrate for biogas production. The mycotoxin producing fungi can spoil feed, reduce cattle productivity and cause health problems. The aim of this research was to study the mycoflora of maize grains in order to clarify the fungal composition and verify the presence of potential mycotoxin producing fungi. The grain samples were collected from different maize hybrid performance trial in Research and Study farm “Vecauce” of Latvia University of Agriculture in 2014. The fungi from 14 genera were isolated from surface sterilized grains. The most abundant were Alternaria, Fusarium and Penicillium spp. Mycotoxin producing fungi are present in maize grain mycoflora, and there is a risk that maize production can contain mycotoxins.

  16. Level of zinc in maize seeds and maize growing soils of central ...

    African Journals Online (AJOL)

    Ethiopia is one of the world countries with reported zinc deficiency or high probability of zinc deficiency. Zinc deficiency is an important soil constraint to crop production, food quality and human health. The aim of this study was to evaluate the zinc concentration of different cultivars of maize seeds and soil samples in central ...

  17. Evaluation of maize-soybean flour blends for sour maize bread ...

    African Journals Online (AJOL)

    Properties examined included amylose content, bulk density, dispersibility, swelling power, water absorption capacity and viscoelastic properties. The effect of the different flour/meal samples on the properties of sour maize bread were evaluated by baking bread samples with the different flours/meals using a mixed starter ...

  18. Responses by earthworms to reduced tillage in herbicide tolerant maize and Bt maize cropping systems

    DEFF Research Database (Denmark)

    Krogh, P. H.; Griffiths, B.; Demsar, D.

    2007-01-01

    -toxin producing transgenic maize line MON810 was studied for 1 year. At a Danish study site, Foulum (Jutland), one year of Bt corn was followed by 2 years of herbicide tolerant corn. At the French study site the most prominent effects observed were due to the tillage method where RT significantly reduced...

  19. First report of Maize chlorotic mottle virus and maize (corn) lethal necrosis in Kenya

    Science.gov (United States)

    In September 2011, high incidence of a new maize (Zea mays L.) disease was reported at lower elevations (1900 masl) in the Longisa division of Bomet County, Southern Rift Valley of Kenya. Later the disease was noted in Bomet Central division, spreading into the neighboring Chepalungu and Narok South...

  20. A comparative study on infestation of three varieties of maize ( Zea ...

    African Journals Online (AJOL)

    A study was carried out to study the infestation of three maize varieties (Maize suwan I–Y, Maize T2 USR – White single cross and Maize suwan 123) by Sitophilus zeamais Motsch. Infestation was assessed by counting the numbers of alive and dead adults and the number of infested and uninfested seeds. It was found out ...

  1. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

  2. The Combining Ability of Maize Inbred Lines for Grain Yield and ...

    African Journals Online (AJOL)

    The Combining Ability of Maize Inbred Lines for Grain Yield and Reaction to Grey ... East African Journal of Sciences ... (GLS) to maize production, the national maize research program of Ethiopia ... The information from this study will be useful for the development of high-yielding and GLS disease-resistant maize varieties.

  3. MaizeGDB: enabling access to basic, translational, and applied research information

    Science.gov (United States)

    MaizeGDB is the Maize Genetics and Genomics Database (available online at http://www.maizegdb.org). The MaizeGDB project is not simply an online database and website but rather an information service to maize researchers that supports customized data access and analysis needs to individual research...

  4. Defense Responses to Mycotoxin-Producing Fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in Kernels of Susceptible and Resistant Maize Genotypes.

    Science.gov (United States)

    Lanubile, Alessandra; Maschietto, Valentina; De Leonardis, Silvana; Battilani, Paola; Paciolla, Costantino; Marocco, Adriano

    2015-05-01

    Developing kernels of resistant and susceptible maize genotypes were inoculated with Fusarium proliferatum, F. subglutinans, and Aspergillus flavus. Selected defense systems were investigated using real-time reverse transcription-polymerase chain reaction to monitor the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes protective from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) at 72 h postinoculation. The study was also extended to the analysis of the ascorbate-glutathione cycle and catalase, superoxide dismutase, and cytosolic and wall peroxidases enzymes. Furthermore, the hydrogen peroxide and malondialdehyde contents were studied to evaluate the oxidation level. Higher gene expression and enzymatic activities were observed in uninoculated kernels of resistant line, conferring a major readiness to the pathogen attack. Moreover expression values of PR genes remained higher in the resistant line after inoculation, demonstrating a potentiated response to the pathogen invasions. In contrast, reactive oxygen species-scavenging genes were strongly induced in the susceptible line only after pathogen inoculation, although their enzymatic activity was higher in the resistant line. Our data provide an important basis for further investigation of defense gene functions in developing kernels in order to improve resistance to fungal pathogens. Maize genotypes with overexpressed resistance traits could be profitably utilized in breeding programs focused on resistance to pathogens and grain safety.

  5. Seed treatments enhance photosynthesis in maize seedlings by reducing infection with Fusarium spp. and consequent disease development in maize

    Science.gov (United States)

    The effects of a seed treatment on early season growth, seedling disease development, incidence Fusarium spp. infection, and photosynthetic performance of maize were evaluated at two locations in Iowa in 2007. Maize seed was either treated with Cruiser 2Extreme 250 ® (fludioxonil + azoxystrobin + me...

  6. Genomic-based-breeding tools for tropical maize improvement.

    Science.gov (United States)

    Chakradhar, Thammineni; Hindu, Vemuri; Reddy, Palakolanu Sudhakar

    2017-12-01

    Maize has traditionally been the main staple diet in the Southern Asia and Sub-Saharan Africa and widely grown by millions of resource poor small scale farmers. Approximately, 35.4 million hectares are sown to tropical maize, constituting around 59% of the developing worlds. Tropical maize encounters tremendous challenges besides poor agro-climatic situations with average yields recorded <3 tones/hectare that is far less than the average of developed countries. On the contrary to poor yields, the demand for maize as food, feed, and fuel is continuously increasing in these regions. Heterosis breeding introduced in early 90 s improved maize yields significantly, but genetic gains is still a mirage, particularly for crop growing under marginal environments. Application of molecular markers has accelerated the pace of maize breeding to some extent. The availability of array of sequencing and genotyping technologies offers unrivalled service to improve precision in maize-breeding programs through modern approaches such as genomic selection, genome-wide association studies, bulk segregant analysis-based sequencing approaches, etc. Superior alleles underlying complex traits can easily be identified and introgressed efficiently using these sequence-based approaches. Integration of genomic tools and techniques with advanced genetic resources such as nested association mapping and backcross nested association mapping could certainly address the genetic issues in maize improvement programs in developing countries. Huge diversity in tropical maize and its inherent capacity for doubled haploid technology offers advantage to apply the next generation genomic tools for accelerating production in marginal environments of tropical and subtropical world. Precision in phenotyping is the key for success of any molecular-breeding approach. This article reviews genomic technologies and their application to improve agronomic traits in tropical maize breeding has been reviewed in

  7. Extracts against Various Pathogens

    Directory of Open Access Journals (Sweden)

    Ritika Chauhan

    2013-07-01

    The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

  8. Evolution of microbial pathogens

    National Research Council Canada - National Science Library

    DiRita, Victor J; Seifert, H. Steven

    2006-01-01

    ... A. Hogan vvi ■ CONTENTS 8. Evolution of Pathogens in Soil Rachel Muir and Man-Wah Tan / 131 9. Experimental Models of Symbiotic Host-Microbial Relationships: Understanding the Underpinnings of ...

  9. Indicators for waterborne pathogens

    National Research Council Canada - National Science Library

    Committee on Indicators for Waterborne Pathogens, National Research Council

    2004-01-01

    ... not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples.Â...

  10. Host–Pathogen Interactions

    NARCIS (Netherlands)

    Smits, M.A.; Schokker, D.J.

    2011-01-01

    The outcome of an infection is determined by numerous interactions between hosts and pathogens occurring at many different biological levels, ranging from molecule to population. To develop new control strategies for infectious diseases in livestock species, appropriate methodologies are needed

  11. Effect of Spatial Arrangement on Growth and Yield of Cowpea in a Cowpea-maize Intercrop

    Directory of Open Access Journals (Sweden)

    Ocaya, CP.

    2001-01-01

    Full Text Available Cowpea growth and yield performance when intercropped with maize was studied for 3 consecutive seasons under three spatial arrangements, i. e., maize planted at 90 x 30, 100 x 27, and 120 x 22.5 cm, with 2 rows of cowpea between the maize rows. Growth and yield of cowpea was improved significantly by widening maize intra-row distances as compared to the 90 x 30 cm spacing. Hence, intercropped cowpea needs to be sown where maize rows are wide apart, but the maize rows should not be too wide as this would lower the grain yield of maize.

  12. Pathogenicity and diversity of vegetative compatibility of Fusarium verticillioides

    Directory of Open Access Journals (Sweden)

    Krnjaja Vesna S.

    2007-01-01

    Full Text Available Pathogenicity of 10 Fusarium verticillioides isolates, originated from grain of wheat (five isolates and maize (five isolates, were studied under greenhouse conditions. Based on different parameters of the pathogenicity estimate (a scale for % of nonemerged plants, % of survived plants, plant vigour - the growth and dry weight of roots and epicotyls and disease severity it was determined that all F. verticillioides isolates expressed a different degree of pathogenicity. According to % of nonemerged plants six three and one F. verticillioides isolates expressed low, moderate and high degree of pathogenicity, respectively. All F. verticillioides isolates reduced the plant survival rate and vigour, while the disease severity ranged from 2.0 to 3.54. Two types of nit mutants, nit1 and NitM, were obtained by the use of the method of vegetative compatibility. The frequency of nit1 mutants was greater (58.79% than the frequency of NitM mutants (5.77%. A total of 10 vegetative compatibility groups (VCGs of F. verticillioides were established in the complementation tests. These results point out to a high genetic diversity of F. verticillioides population.

  13. Genome-Wide Annotation and Comparative Analysis of Cytochrome P450 Monooxygenases in Basidiomycete Biotrophic Plant Pathogens.

    Directory of Open Access Journals (Sweden)

    Lehlohonolo Benedict Qhanya

    Full Text Available Fungi are an exceptional source of diverse and novel cytochrome P450 monooxygenases (P450s, heme-thiolate proteins, with catalytic versatility. Agaricomycotina saprophytes have yielded most of the available information on basidiomycete P450s. This resulted in observing similar P450 family types in basidiomycetes with few differences in P450 families among Agaricomycotina saprophytes. The present study demonstrated the presence of unique P450 family patterns in basidiomycete biotrophic plant pathogens that could possibly have originated from the adaptation of these species to different ecological niches (host influence. Systematic analysis of P450s in basidiomycete biotrophic plant pathogens belonging to three different orders, Agaricomycotina (Armillaria mellea, Pucciniomycotina (Melampsora laricis-populina, M. lini, Mixia osmundae and Puccinia graminis and Ustilaginomycotina (Ustilago maydis, Sporisorium reilianum and Tilletiaria anomala, revealed the presence of numerous putative P450s ranging from 267 (A. mellea to 14 (M. osmundae. Analysis of P450 families revealed the presence of 41 new P450 families and 27 new P450 subfamilies in these biotrophic plant pathogens. Order-level comparison of P450 families between biotrophic plant pathogens revealed the presence of unique P450 family patterns in these organisms, possibly reflecting the characteristics of their order. Further comparison of P450 families with basidiomycete non-pathogens confirmed that biotrophic plant pathogens harbour the unique P450 families in their genomes. The CYP63, CYP5037, CYP5136, CYP5137 and CYP5341 P450 families were expanded in A. mellea when compared to other Agaricomycotina saprophytes and the CYP5221 and CYP5233 P450 families in P. graminis and M. laricis-populina. The present study revealed that expansion of these P450 families is due to paralogous evolution of member P450s. The presence of unique P450 families in these organisms serves as evidence of how a host

  14. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding.

    Science.gov (United States)

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-08-20

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects.

  15. Climatic and non-climatic drivers of spatiotemporal maize-area dynamics across the northern limit for maize production

    DEFF Research Database (Denmark)

    Odgaard, Mette Vestergaard; Bøcher, Peder Klith; Dalgaard, Tommy

    2011-01-01

    It is expected that the ongoing anthropogenic climate change will drive changes in agricultural production and its geographic distribution. Here, we assess the extent to which climate change is already driving spatiotemporal dynamics in maize production in Denmark. We use advanced spatial...... regression modeling with multi-model averaging to assess the extent to which the recent spatiotemporal dynamics of the maize area in Denmark are driven by climate (temperature as represented by maize heating units [MHU] and growing-season precipitation), climate change and non-climatic factors (cattle...... cultivation and cattle farming, probably reflecting a change to a more favorable climate for maize cultivation: in the beginning of the study period, northern areas were mostly too cold for maize cultivation, irrespective of cattle density, but this limitation has been diminishing as climate has warmed...

  16. New inoculants on maize silage fermentation

    Directory of Open Access Journals (Sweden)

    Fábia Giovana do Val de Assis

    2014-08-01

    Full Text Available The objective of this study was to evaluate the effect of bacterial inoculants at two inoculation rates on chemical and biological characteristics of maize silage. The treatments consisted of two inoculating rates (5 and 6 log cfu g-1 of forage for each strain of lactic acid bacteria (LAB identified as Lactobacillus buchneri, L. hilgardii, or L. plantarum. The maize was ensiled in experimental PVC silos. Samples were taken for the determination of the contents of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF, water-soluble carbohydrates (WSC, organic acids and alcohols, for the evaluation of the populations of lactic acid bacteria, yeasts, filamentous fungi, and for the determination of pH values during ensilage and after 30 or 90 days of fermentation. The doses of inoculants did not promote significant differences on the evaluated characteristics. There was effect of inoculants on acetic acid, 1.2-propanediol, LAB population, filamentous fungi, and pH value. No significant influence of the treatments with inoculants was observed in the variables DM, WSC, CP, lactic acid concentrations, or ethanol. The maximum temperature, i.e., the time to achieve the maximum temperature (TMT and aerobic stability (AS, was not influencied by treatments. However, a decrease in maximum temperature, an increase in TMT, and improvement in the AS were observed after 90 days of fermentation. These results proved the advantage of microbial inoculation. The treatments influenced LAB populations and filamentous fungi, but no effect was observed on the yeast population. The best inoculation dose is 6 cfu g-1 of forage because it provides higher reduction of filamentous fungi in maize silage, thereby decreasing the aerobic deterioration by these microorganisms.

  17. Swelling Kinetics of Waxy Maize Starch

    Science.gov (United States)

    Desam, Gnana Prasuna Reddy

    Starch pasting behavior greatly influences the texture of a variety of food products such as canned soup, sauces, baby foods, batter mixes etc. The annual consumption of starch in the U.S. is 3 million metric tons. It is important to characterize the relationship between the structure, composition and architecture of the starch granules with its pasting behavior in order to arrive at a rational methodology to design modified starch of desirable digestion rate and texture. In this research, polymer solution theory was applied to predict the evolution of average granule size of starch at different heating temperatures in terms of its molecular weight, second virial coefficient and extent of cross-link. Evolution of granule size distribution of waxy native maize starch when subjected to heating at constant temperatures of 65, 70, 75, 80, 85 and 90 C was characterized using static laser light scattering. As expected, granule swelling was more pronounced at higher temperatures and resulted in a shift of granule size distribution to larger sizes with a corresponding increase in the average size by 100 to 120% from 13 mum to 25-28 mum. Most of the swelling occurred within the first 10 min of heating. Pasting behavior of waxy maize at different temperatures was also characterized from the measurements of G' and G" for different heating times. G' was found to increase with temperature at holding time of 2 min followed by its decrease at larger holding times. This behavior is believed to be due to the predominant effect of swelling at small times. However, G" was insensitive to temperature and holding times. The structure of waxy maize starch was characterized by cryoscanning electron microscopy. Experimental data of average granule size vs time at different temperatures were compared with model predictions. Also the Experimental data of particle size distribution vs particle size at different times and temperatures were compared with model predictions.

  18. Selected parameters of maize straw briquettes combustion

    Directory of Open Access Journals (Sweden)

    Kraszkiewicz Artur

    2018-01-01

    Full Text Available An analysis of the process of burning briquettes made of maize straw was performed. A number of traits have been evaluated, including physical characteristics of the fuel through parameters describing combustion kinetics as well as products and combustion efficiency. The study was conducted in a grate boiler, during which the differentiating factor was the air velocity flowing to the boiler. It was observed that the obtained values of the considered parameters were different, particularly temperature of the flue gas and the amount of CO and SO2 in the flue gas.

  19. Fatty acid composition of maize germ oil from high-oil hybrids wet-milling processing

    Directory of Open Access Journals (Sweden)

    Jovanović Petar Lj.

    2005-01-01

    Full Text Available Maize germ was obtained by wet-milling laboratory processing of domestic high-oil maize hybrids. After separation, the germ was subjected to extraction of maize oil. Fatty acid composition of maize germ oil was determined by gas chromatography. The results showed very high levels of unsaturated fatty acids and a constant sum of oleic and linoleic acids in oils of different maize hybrids.

  20. Air analysis in the assessment of fumonisin contamination risk in maize.

    Science.gov (United States)

    Torelli, Emanuela; Gubiani, Rino; Firrao, Giuseppe; Cividino, Sirio; Locci, Romano; Gobbi, Emanuela

    2010-03-15

    In maize-growing areas where fumonisin contamination is endemic, there is an urgent need for novel methods to assess the quality of grain lots before their delivery to common drying and storage collection centres. Aerobiological samples of fungal spores released during harvest were analysed to establish a relationship between fumonisin contamination and the abundance of pathogen propagules collected in the combine harvester using a cyclone and membrane filters. Filter-captured propagules were analysed by direct plating, immunoenzymatic assay of specific Fusarium extracellular polysaccharides and real time polymerase chain reaction of the extracted DNA using fum1, a gene involved in the biosynthesis of fumonisin, as a target. The results showed that time of harvest and environmental conditions strongly influenced the efficiency and performance of the collection system. The data obtained were informative in comparing individual samples collected under similar conditions. The immunoenzymatic assay provided the most reliable data, which improved the ability of a neural network to predict the fumonisin content of lots, when added to agronomic, environmental and phytosanitary data. This is the first attempt to evaluate the Fusarium propagules dispersed during harvesting as a predictive means to assess maize quality. A method based on cyclone/filter capture and immunological detection has been shown to be feasible and to have the potential for the development of a continuous monitoring system, but the prediction capabilities in the present implementation were limited.

  1. Biological control of phytopathogenic fungi by endophytic actinomycetes isolated from maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Francisco Gheler Costa

    2013-12-01

    Full Text Available This work aimed a survey on the biodiversity of maize endophytic actinomycete, and an evaluation of their potential to control the phytopathogenic fungi. From several regions of São Paulo state, 40 strains were isolated from the healthy maize plants. The identification of these strains, based on morphological properties and fatty acid methyl ester (FAME profile showed that most of them belonged to the Streptomyces genus. These isolates were first screened for the growth inhibition of phytopathogenic fungi and results showed that all the isolate were able to inhibit the development of at least one tested pathogen. Two selected isolates were then evaluated for the control of P. aphanidermatum in cucumber (Cucumis sativa L. under greenhouse conditions. Isolate 16R3B was able to reduce up to 71% damping-off incidence whereas isolate 14F1D/2 reduced the disease incidence by 36%. Damping- off control in cucumber, mainly for the isolate 16R3B, suggested for its use in greenhouse cucumber producing fields and to be tested in field trials.

  2. Effects of temperature changes on maize production in Mozambique

    Science.gov (United States)

    Harrison, L.; Michaelsen, J.; Funk, Chris; Husak, G.

    2011-01-01

    We examined intraseasonal changes in maize phenology and heat stress exposure over the 1979-2008 period, using Mozambique meteorological station data and maize growth requirements in a growing degree-day model. Identifying historical effects of warming on maize growth is particularly important in Mozambique because national food security is highly dependent on domestic food production, most of which is grown in already warm to hot environments. Warming temperatures speed plant development, shortening the length of growth periods necessary for optimum plant and grain size. This faster phenological development also alters the timing of maximum plant water demand. In hot growing environments, temperature increases during maize pollination threaten to make midseason crop failure the norm. In addition to creating a harsher thermal environment, we find that early season temperature increases have caused the maize reproductive period to start earlier, increasing the risk of heat and water stress. Declines in time to maize maturation suggest that, independent of effects to water availability, yield potential is becoming increasingly limited by warming itself. Regional variations in effects are a function of the timing and magnitude of temperature increases and growing season characteristics. Continuation of current climatic trends could induce substantial yield losses in some locations. Farmers could avoid some losses through simple changes to planting dates and maize varietal types.

  3. Growing sensitivity of maize to water scarcity under climate change.

    Science.gov (United States)

    Meng, Qingfeng; Chen, Xinping; Lobell, David B; Cui, Zhenling; Zhang, Yi; Yang, Haishun; Zhang, Fusuo

    2016-01-25

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.

  4. Vulnerability of Maize Yields to Droughts in Uganda

    Directory of Open Access Journals (Sweden)

    Terence Epule Epule

    2017-03-01

    Full Text Available Climate projections in Sub-Saharan Africa (SSA forecast an increase in the intensity and frequency of droughts with implications for maize production. While studies have examined how maize might be affected at the continental level, there have been few national or sub-national studies of vulnerability. We develop a vulnerability index that combines sensitivity, exposure and adaptive capacity and that integrates agroecological, climatic and socio-economic variables to evaluate the national and spatial pattern of maize yield vulnerability to droughts in Uganda. The results show that maize yields in the north of Uganda are more vulnerable to droughts than in the south and nationally. Adaptive capacity is higher in the south of the country than in the north. Maize yields also record higher levels of sensitivity and exposure in the north of Uganda than in the south. Latitudinally, it is observed that maize yields in Uganda tend to record higher levels of vulnerability, exposure and sensitivity towards higher latitudes, while in contrast, the adaptive capacity of maize yields is higher towards the lower latitudes. In addition to lower precipitation levels in the north of the country, these observations can also be explained by poor soil quality in most of the north and socio-economic proxies, such as, higher poverty and lower literacy rates in the north of Uganda.

  5. From many, one: genetic control of prolificacy during maize domestication.

    Directory of Open Access Journals (Sweden)

    David M Wills

    2013-06-01

    Full Text Available A reduction in number and an increase in size of inflorescences is a common aspect of plant domestication. When maize was domesticated from teosinte, the number and arrangement of ears changed dramatically. Teosinte has long lateral branches that bear multiple small ears at their nodes and tassels at their tips. Maize has much shorter lateral branches that are tipped by a single large ear with no additional ears at the branch nodes. To investigate the genetic basis of this difference in prolificacy (the number of ears on a plant, we performed a genome-wide QTL scan. A large effect QTL for prolificacy (prol1.1 was detected on the short arm of chromosome 1 in a location that has previously been shown to influence multiple domestication traits. We fine-mapped prol1.1 to a 2.7 kb "causative region" upstream of the grassy tillers1 (gt1 gene, which encodes a homeodomain leucine zipper transcription factor. Tissue in situ hybridizations reveal that the maize allele of prol1.1 is associated with up-regulation of gt1 expression in the nodal plexus. Given that maize does not initiate secondary ear buds, the expression of gt1 in the nodal plexus in maize may suppress their initiation. Population genetic analyses indicate positive selection on the maize allele of prol1.1, causing a partial sweep that fixed the maize allele throughout most of domesticated maize. This work shows how a subtle cis-regulatory change in tissue specific gene expression altered plant architecture in a way that improved the harvestability of maize.

  6. Multicollinearity in canonical correlation analysis in maize.

    Science.gov (United States)

    Alves, B M; Cargnelutti Filho, A; Burin, C

    2017-03-30

    The objective of this study was to evaluate the effects of multicollinearity under two methods of canonical correlation analysis (with and without elimination of variables) in maize (Zea mays L.) crop. Seventy-six maize genotypes were evaluated in three experiments, conducted in a randomized block design with three replications, during the 2009/2010 crop season. Eleven agronomic variables (number of days from sowing until female flowering, number of days from sowing until male flowering, plant height, ear insertion height, ear placement, number of plants, number of ears, ear index, ear weight, grain yield, and one thousand grain weight), 12 protein-nutritional variables (crude protein, lysine, methionine, cysteine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine, and arginine), and 6 energetic-nutritional variables (apparent metabolizable energy, apparent metabolizable energy corrected for nitrogen, ether extract, crude fiber, starch, and amylose) were measured. A phenotypic correlation matrix was first generated among the 29 variables for each of the experiments. A multicollinearity diagnosis was later performed within each group of variables using methodologies such as variance inflation factor and condition number. Canonical correlation analysis was then performed, with and without the elimination of variables, among groups of agronomic and protein-nutritional, and agronomic and energetic-nutritional variables. The canonical correlation analysis in the presence of multicollinearity (without elimination of variables) overestimates the variability of canonical coefficients. The elimination of variables is an efficient method to circumvent multicollinearity in canonical correlation analysis.

  7. Iron and zinc availability in maize lines

    Directory of Open Access Journals (Sweden)

    Valéria Aparecida Vieira Queiroz

    2011-09-01

    Full Text Available The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to 42 mg.kg-1, iron (12.2 to 36.7 mg.kg-1, phosphorus (230 to 400 mg.100 g-1, phytic acid (484 to 1056 mg.100 g-1, phytic acid P (140 to 293 mg.100 g-1 and available-P (43.5 to 199.5 mg.100 g-1, and in the available-P/total-P ratio (0.14 to 0.50, Phy/Zn (18.0 to 43.5 and Phy/Fe (16.3 to 45.5 molar ratios. Lines 560977, 560978 and 560982 had greater availability of Zn and lines 560975, 560977, 561010 and 5610111 showed better Fe availability. Lines 560975, 560977 and 560978 also showed better available-P/total-P ratio. Thus, the lines 560975, 560977 and 560978 were considered to have the potential for the development of cultivars of maize with high availability of Fe and/or Zn.

  8. Temperature affects radiation use efficiency in maize

    International Nuclear Information System (INIS)

    Andrade, F.H.; Uhart, S.A.; Cirilo, A.

    1993-01-01

    The objective of this work was to study, under field conditions, the effect of temperature on radiation use efficiency (RUE) of maize. Field evidence of the negative effect of low temperature on this variable is lacking. Experiments with different sowing dates and five years of experimentation with October plantings provided a range of average temperatures during the vegetative period from 15.8 to 20.9°C. Delaying the sowing time from September to November produced a highly significant increase in RUE. There was a positive association between RUE and mean temperature from emergence to flowering. Efficiencies varied from 2.27 to 3.17 g of dry matter per MJ of intercepted photosynthetically active radiation for October plantings of five different years. With these data, a positive and significant association between RUE and mean temperature during the November–December vegetative period was found. Across years and planting dates, RUE and mean temperature during the vegetative period were closely correlated (r = 0.87). The regression equation was RUE = −1.8 + 0.07 T. Based on this evidence, it was concluded that low temperatures reduce RUE in maize. (author)

  9. Chlordecone Transfer and Distribution in Maize Shoots.

    Science.gov (United States)

    Pascal-Lorber, Sophie; Létondor, Clarisse; Liber, Yohan; Jamin, Emilien L; Laurent, François

    2016-01-20

    Chlordecone (CLD) is a persistent organic pollutant (POP) that was mainly used as an insecticide against banana weevils in the French West Indies (1972-1993). Transfer of CLD via the food chain is now the major mechanism for exposure of the population to CLD. The uptake and the transfer of CLD were investigated in shoots of maize, a C4 model plant growing under tropical climates, to estimate the exposure of livestock via feed. Maize plants were grown on soils contaminated with [(14)C]CLD under controlled conditions. The greatest part of the radioactivity was associated with roots, nearly 95%, but CLD was detected in whole shoots, concentrations in old leaves being higher than those in young ones. CLD was thus transferred from the base toward the plant top, forming an acropetal gradient of contaminant. In contrast, results evidenced the existence of a basipetal gradient of CLD concentration within leaves whose extremities accumulated larger amounts of CLD because of evapotranspiration localization. Extractable residues accounted for two-thirds of total residues both in roots and in shoots. This study highlighted the fact that the distribution of CLD contamination within grasses resulted from a conjunction between the age and evapotranspiration rate of tissues. CLD accumulation in fodder may be the main route of exposure for livestock.

  10. Morphological variation in maize inbred lines

    Directory of Open Access Journals (Sweden)

    Jiban Shrestha

    2014-05-01

    Full Text Available In order to identify morphological variation in maize inbred lines, one hundred five inbred lines were planted under randomized complete block design with two replications at research field of National Maize Research Program, Rampur, Chitwan, Nepal during summer season (March to June, 2010. Descriptive statistics and cluster analysis were done. The results revealed a wide range of morphological variation among the tested inbred lines. The inbred lines grouped in cluster 4 namely PUTU-13, L-9, RL-105, RL-197, RL-103, RML-9, RML-41, RL-165, RL-36, RL-76, RL-125, RL-30-3, L-6, RL-107, RL-174, RL-41, L-13, RML-76 and L-5 had 0.833 days anthesis-silking interval and earlier in flowering (tasseling in 54.50 days and silking in 55.33 days. Moreover they consisted of 1.16 plant aspect, 1.25 ear aspect, 33.08 cm tassel length and 13.5 tassel branch number. Among tested lines, the above inbred lines had better morphological traits, so it was concluded that they were good candidates for development of hybrids and synthetic varieties. DOI: http://dx.doi.org/10.3126/ije.v3i2.10521 International Journal of the Environment Vol.3(2 2014: 98-107

  11. Effects of maize maturity at harvest and dietary proportion of maize silage on intake and performance of growing/finishing bulls

    DEFF Research Database (Denmark)

    Zaralis, K.; Nørgaard, P.; Helander, C.

    2014-01-01

    Whole-crop maize silage as forage in diets of finishing cattle can promote high intakes and thus, enhances animal performance. In the present study we evaluated the effect of whole-crop maize maturity at harvest and the proportion of maize-silage in diets of finishing bulls, on feed intake...... of treatments, involving two maturity stages of maize at harvest (i.e. dough stage or dent stage) and two maize silage proportions (i.e. 100% maize silage or 50% maize and 50% grass silage). The diets were offered ad libitum as total mixed rations (TMRs) with inclusion of concentrates (i.e. rolled barley; dried...... distillers’ grain plus soluble; cold-pressed rapeseed cake) in a 40% proportion on DM basis. All animals were slaughtered at a target body weight of 630 kg. Bulls fed on diets containing maize silage as sole forage achieved higher live-weight gain (P

  12. Toxin distribution and sphingoid base imbalances in Fusarium verticillioides-infected and fumonisin B1-watered maize seedlings.

    Science.gov (United States)

    Arias, Silvina L; Mary, Verónica S; Otaiza, Santiago N; Wunderlin, Daniel A; Rubinstein, Héctor R; Theumer, Martín G

    2016-05-01

    Fusarium verticillioides is a major maize pathogen and there are susceptible and resistant cultivars to this fungal infection. Recent studies suggest that its main mycotoxin fumonisin B1 (FB1) may be involved in phytopathogenicity, but the underlying mechanisms are mostly still unknown. This work was aimed at assessing whether FB1 disseminates inside the plants, as well as identifying possible correlations between the maize resistant/susceptible phenotype and the unbalances of the FB1-structurally-related sphingoid base sphinganine (Sa) and phytosphingosine (Pso) due to toxin accumulation. Resistant (RH) and susceptible hybrid (SH) maize seedlings grown from seeds inoculated with a FB1-producer F. verticillioides and from uninoculated ones irrigated with FB1 (20 ppm), were harvested at 7, 14 and 21 days after planting (dap), and the FB1, Sa and Pso levels were quantified in roots and aerial parts. The toxin was detected in roots and aerial parts for inoculated and FB1-irrigated plants of both hybrids. However, FB1 levels were overall higher in SH seedlings regardless of the treatment (infection or watering). Sa levels increased substantially in RH lines, peaking at 54-fold in infected roots at 14 dap. In contrast, the main change observed in SH seedlings was an increase of Pso in infected roots at 7 dap. Here, it was found that FB1 disseminates inside seedlings in the absence of FB1-producer fungal infections, perhaps indicating this might condition the fungus-plant interaction before the first contact. Furthermore, the results strongly suggest the existence of at least two ceramide synthase isoforms in maize with different substrate specificities, whose differential expression after FB1 exposure could be closely related to the susceptibility/resistance to F. verticillioides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Belowground Interactions Impact the Soil Bacterial Community, Soil Fertility, and Crop Yield in Maize/Peanut Intercropping Systems

    Directory of Open Access Journals (Sweden)

    Qisong Li

    2018-02-01

    Full Text Available Intercropping has been widely used to control disease and improve yield in agriculture. In this study, maize and peanut were used for non-separation intercropping (NS, semi-separation intercropping (SS using a nylon net, and complete separation intercropping (CS using a plastic sheet. In field experiments, two-year land equivalent ratios (LERs showed yield advantages due to belowground interactions when using NS and SS patterns as compared to monoculture. In contrast, intercropping without belowground interactions (CS showed a yield disadvantage. Meanwhile, in pot experiments, belowground interactions (found in NS and SS improved levels of soil-available nutrients (nitrogen (N and phosphorus (P and enzymes (urease and acid phosphomonoesterase as compared to intercropping without belowground interactions (CS. Soil bacterial community assay showed that soil bacterial communities in the NS and SS crops clustered together and were considerably different from the CS crops. The diversity of bacterial communities was significantly improved in soils with NS and SS. The abundance of beneficial bacteria, which have the functions of P-solubilization, pathogen suppression, and N-cycling, was improved in maize and peanut soils due to belowground interactions through intercropping. Among these bacteria, numbers of Bacillus, Brevibacillus brevis, and Paenibacillus were mainly increased in the maize rhizosphere. Burkholderia, Pseudomonas, and Rhizobium were mainly increased in the peanut rhizosphere. In conclusion, using maize and peanut intercropping, belowground interactions increased the numbers of beneficial bacteria in the soil and improved the diversity of the bacterial community, which was conducive to improving soil nutrient (N and P supply capacity and soil microecosystem stability.

  14. Feasibility of Hydrothermal Pretreatment on Maize Silage for Bioethanol Production

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-01-01

    The potential of maize silage as a feedstock to produce bioethanol was evaluated in the present study. The hydrothermal pretreatment with five different pretreatment severity factors (PSF) was employed to pretreat the maize silage and compared in terms of sugar recovery, toxic test, and ethanol...... the liquors from the five conditions were not toxic to the Baker’s yeast. Pretreatment under 195°C for 7 min had the similar PSF with that of 185°C for 15 min, and both gave the higher ethanol concentration of 19.92 and 19.98 g/L, respectively. The ethanol concentration from untreated maize silage was only 7...

  15. Temperatures and the growth and development of maize and rice

    DEFF Research Database (Denmark)

    Sánchez, Berta; Rasmussen, Anton; Porter, John Roy

    2014-01-01

    and maize crop responses to temperature in different, but consistent, phenological phases and development stages. A literature review and data compilation of around 140 scientific articles have determined the key temperature thresholds and response to extreme temperature effects for rice and maize...... defined in all three crops. Anthesis and ripening are the most sensitive temperature stages in rice as well as in wheat and maize. We call for further experimental studies of the effects of transgressing threshold temperatures so such responses can be included into crop impact and adaptation models....

  16. Regulation of stomatal tropism and infection by light in Cercospora zeae-maydis: evidence for coordinated host/pathogen responses to photoperiod?

    OpenAIRE

    Hun Kim; John B Ridenour; Larry D Dunkle; Burton H Bluhm

    2011-01-01

    Cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. C. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. In this study, the discovery that light was required for C. zeae-maydis to perceive stomata and infect leaves led to the identification of CRP1, a gene encoding a putative blue-light photoreceptor ho...

  17. Viral pathogen discovery

    Science.gov (United States)

    Chiu, Charles Y

    2015-01-01

    Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

  18. Screening of different insecticides against maize shoot fly atherigona soccata (Rond.) and maize borer. chilo partellus (swinh.)

    International Nuclear Information System (INIS)

    Shahid, M.A.; Rana, Z.A.; Haq, I.; Tariq, H.

    2010-01-01

    Field studies were carried out in the research area of the Ayub Agricultural Research Institute, Faisalabad to determine the most effective maize seed treatment against maize shoot fly Atherigona soccata (Rond.) and insecticide against maize borer Chilo partellus (Swinh.) Trials were conducted following RCBD and replicated three times during 2005-2006. Two seed treatments Confider (imidacloprid) 70 WS and pensidor 72% WP (5 and 7 mg/kg seed) along with Confider (imidaclorid) 200 SC at the rate 40 ml/acre in the trial against maize shoot fly whereas, flubendiamide 48%, emamection 1.9 EC, spinosad 240 EC. carbofuran 3 G, indoxacarb 150 SC, alphacypermethrine 20 EC, monomehypo 5 G, bifenthrin 10 EC, cartap 4G, cyhalothrine 2.5 EC, cypermethrin 10 EC at the rate 20 ml, 150 ml, 40 ml, 8 kg, 150 ml, 200 ml, 5 kg, 150 ml, 6 kg. 250 ml and 300 ml per acre against maize borer were treated keeping one plo ast untreated check. Treatments were repeated as borer infestation reached above 5% level. All the seed treatments showed significant control of maize shoot fly in spite of dose 5 or 7 mg/kg seed along with foliar spray of confider 200 SC. The insecticides viz. flubendiamide 48% SC. emamectin 1.9 EC, spinosad 240 EC and carbofuran 3 G. indoxacarb 150 SC. alpha cypermethrin 20 EC, not only responded highest yield 5765, 5294, 5289, 5215, 5168 and 5025 kg/ha respectively but also manage the maize borer below ETL. (author)

  19. Highly pathogenic avian influenza.

    Science.gov (United States)

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  20. Mycoflora Of Maize Zea Maize At Different Locations In Hail Area-Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Elham S. Dawood

    2015-06-01

    Full Text Available Abstract Zea maize is one of the main cereals produced in Hail area Saudi Arabia. The risk of mycotoxin contamination is related to mycoflora associated with corn kernel. This paper reports on isolation and identification of external and internal mycoflora of maize harvested in Hail area in 2006 2008. A mycological survey was carried out on 200 samples from two agricultural companies . Comparison between frequency and relative density of the prevalent genera and species was carried out. Genus Fusarium was the most prevalent component of the internal seed - borne mycoflora in the two companies Aspergillus spp. was the most prevalent genus as external seed borne mycoflora. The predominant species of the different genera were Fusarium moniliforrme Aspergillus flavus A. niger and Alternaria alternate.

  1. ZmGns, a maize class I b-1,3-glucanase, is induced by biotic stresses and possesses strong antimicrobial activity

    Institute of Scientific and Technical Information of China (English)

    Yu-Rong Xie; Yenjit Raruang; Zhi-Yuan Chen; Robert L Brown; Thomas E Cleveland

    2015-01-01

    Plant b‐1,3‐glucanases are members of the patho-genesis‐related protein 2 (PR‐2) family, which is one of the 17 PR protein families and plays important roles in biotic and abiotic stress responses. One of the differential y expressed proteins (spot 842) identified in a recent proteomic comparison between five pairs of closely related maize (Zea mays L.) lines differing in aflatoxin resistance was further investigated in the present study. Here, the corresponding cDNA was cloned from maize and designated as ZmGns. ZmGns encodes a protein of 338 amino acids containing a potential signal peptide. The expression of ZmGns was detectible in al tissues studied with the highest level in silks. ZmGns was significantly induced by biotic stresses including three bacteria and the fungus Aspergillus flavus. ZmGns was also induced by most abiotic stresses tested and growth hormones including salicylic acid. In vivo, ZmGns showed a significant inhibitory activity against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and fungal pathogen Botrytis cinerea when it overexpressed in Arabidopsis. Its high level of expression in the silk tissue and its induced expression by phytohormone treatment, as wel as by bacterial and fungal infections, suggest it plays a complex role in maize growth, development, and defense.

  2. Do European Union Farmers Reject Genetically Modified Maize? Farmer preferences for Genetically Modified Maize in Greece

    OpenAIRE

    Skevas, T.; Kikulwe, E.M.; Papadopoulou, E.; Skevas, I.; Wesseler, J.H.H.

    2012-01-01

    The new EU proposal (IP/10/921) states that bans on genetically modified (GM) crops should not be based on environmental and health grounds, and it proposes a set of alternative reasons—including public order and morals—that can be cited by member states. This reveals the increasing importance of stakeholders’ attitudes in GM crops’ release decisions. This article analyzes farmers’ attitudes and perceptions toward GM maize based on a survey of large-area Greek farmers in Northeastern Greece. ...

  3. Cloning, sequencing and expression of a xylanase gene from the maize pathogen Helminthosporium turcicum

    DEFF Research Database (Denmark)

    Degefu, Y.; Paulin, L.; Lübeck, Peter Stephensen

    2001-01-01

    A gene encoding an endoxylanase from the phytopathogenic fungus Helminthosporium turcicum Pass. was cloned and sequenced. The entire nucleotide sequence of a 1991 bp genomic fragment containing an endoxylanase gene was determined. The xylanase gene of 795 bp, interrupted by two introns of 52 and ...

  4. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Barbara Manachini

    2009-03-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  5. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Anna Corsini

    2011-02-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  6. Pilot study of nitrogen utilisation in maize

    International Nuclear Information System (INIS)

    Futo, I.; Palcsu, L.; Vodila, G.

    2012-01-01

    Complete text of publication follows. In the cooperation between KITE Ltd., Nadudvar, Hungary and the Hertelendi Laboratory of Environmental Studies, the aim was to determine the ideal locations of fertilising, the ideal distance of rows for the ideal production yield. To track the nitrogen utilisation of maize (Zea mays) 15 N enriched NH 4 NO 3 fertiliser was introduced among the usual fertilisers in the maize field of KITE Ltd. Nadudvar, Hungary on 30 th March 2012, before sowing. Four maize samples were taken from different areas of different fertiliser treatment (non-fertilised and non-labelled, fertilised and non-labelled, fertilised and labelled between the rows and fertilised and labelled within the rows) and from different development stages of the plant on 22 nd May, 8 th June, 6 th July and 7 th September being sampling periods 1-4, respectively. The plant samples were subsampled based on organs: root, stem and leaf. Samples were dried to constant mass and pulverised. The 15 N measurements were made by a Thermo Finnigan Delta PLUS XP isotope ratio mass spectrometer coupled with an elemental analyser. In case of non-fertilised and non-labelled plants, all the three organs were getting 15 N depleted with time, most intensively the stem and the less intensively the root (Figure 1). For the leaves and stems of the fertilised and non-labelled plants, the tendency in time is very similar to the ones of the non-fertilised and non-labelled plants, however, the roots of the fertilised and non-labelled plants got significantly enriched in the sample of September. In case of the fertilised and labelled between-the-rows samples, labelling is slightly seen as the delta values are positive. These values are significantly lower than the ones for the fertilised and labelled-within-the-rows plants. It is seen that fertiliser got to the vegetation in the largest extent in this layout. Labelling showed its maximum intensity in the second sampling (8 th June) showing that

  7. (Allium sativum L.) Liliaceae as protectants against the maize weevil ...

    African Journals Online (AJOL)

    REV. FR. ANTHONY

    2014-03-05

    , was evaluated as a possible grain protectant against the maize weevil, Sitophilus zeamais (Motsch.). Each experiment was set out in completely randomized design (CRD) with four replications and a control treatment. Adult.

  8. Molecular analysis of quality protein (QPM) and normal maize ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... genetic variation among QPM and normal maize varieties is important for an efficient selection and .... olymerase chain reaction (PCR) amplifications of RAPD and ISSR ..... Genetic characterization of Malawian cowpea.

  9. Maize production in the central Kenya highlands using cattle ...

    African Journals Online (AJOL)

    Mo

    effective in the production of maize, compared to singular application of manures (5 t ha-1) and mineral fertilizer alone applied at rates below ...... A Handbook of Methods, 2nd. Edition. ... Manure management in the Kenya highlands: Practices.

  10. DYNAMICS OF Cercospora zeina POPULATIONS IN MAIZE-BASED ...

    African Journals Online (AJOL)

    ACSS

    DYNAMICS OFCercospora zeina POPULATIONS IN MAIZE-BASED AGRO- ..... Population differentiation of Cercospora zeina in three districts of Uganda based on analysis of molecular variance ..... interactions: The example of the Erysiphe.

  11. combustion properties of briquettes produced from maize cob

    African Journals Online (AJOL)

    joke

    2014-03-01

    Mar 1, 2014 ... were densified into briquettes using starch as binder. Combustion related ... Keywords: Briquette, maize cob, combustion properties, mesh sizes, binding agent ... smaller space requirement for storage (Yaman et al., 2000 and ...

  12. Inadvertent presence of genetically modified elements in maize food ...

    African Journals Online (AJOL)

    owner

    2013-07-31

    Jul 31, 2013 ... The maize imported into Kenya contained Bt genetic elements. Nevertheless, the .... obtained from various open air markets and retail shops located in ... Magic, Bokomo and Temmy) was not successful. Assessment of cry1Ab ...

  13. Evaluation of Conservation Tillage Techniques for Maize Production ...

    African Journals Online (AJOL)

    conservation tillage techniques and evaluate the impacts of the system on ... biological soil manipulation to optimize conditions for seed germination, emergence and ..... planting and weeding operations as total expense and sales from maize ...

  14. In vitro cytotoxicity of fungi spoiling maize silage

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Rasmussen, Peter Have; Larsen, Thomas Ostenfeld

    2011-01-01

    Penicillium roqueforti, Penicillium paneum, Monascus ruber, Alternaria tenuissima, Fusarium graminearum, Fusarium avenaceum, Byssochlamys nivea and Aspergillus fumigatus have previously been identified as major fungal contaminants of Danish maize silage. In the present study their metabolite....... roqueforti metabolites roquefortine C (48μg/mL), andrastin A (>50μg/mL), mycophenolic acid (>100μg/mL) and 1-hydroxyeremophil-7(11),9(10)-dien-8-one (>280μg/mL) were high. Fractionating of agar extracts identified PR-toxin as an important cytotoxic P. roqueforti metabolite, also detectable in maize silage....... The strongly cytotoxic B. nivea and P. paneum agar extracts contained patulin above the IC50 of 0.6μg/mL, however inoculated onto maize silage B. nivea and P. paneum did not produce patulin (>371μg/kg). Still B. nivea infected maize silage containing mycophenolic acid (∼50mg/kg), byssochlamic acid and other...

  15. (CultiAF) Reducing maize-based aflatoxin contamination

    International Development Research Centre (IDRC) Digital Library (Canada)

    In Zimbabwe, testing of harvested maize has revealed high levels of contamination by aflatoxins, ... and other private sector partners will increase the availability of improved grain storage containers. Researchers will work with the Ministry of ...

  16. Differential protein expression in maize (Zea mays) in response to ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... Accepted 25 May, 2011. Maize (Zea mays) is a major food stable in sub-Saharan Africa. .... has investigated differential expression at the proteome level, comparing this ..... GK, Jwa NS (2001). Characterization of rice (Oryza.

  17. traits and resistance to maize streak virus disease in kenya

    African Journals Online (AJOL)

    African Crop Science Journal, Vol. 14. No. 4, pp. ... Kenya Agricultural Research Institute, Muguga-South, P.O. Box 30148, Nairobi, Kenya .... streak disease has been identified in various maize recycling and development of pure-lines at.

  18. Biofortification of maize flour with grain amaranth for improved nutrition

    African Journals Online (AJOL)

    Biofortification of maize flour with grain amaranth for improved nutrition. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE ... African Journal of Food, Agriculture, Nutrition and Development. Journal Home ...

  19. Orange maize in Zambia: crop development and delivery experience

    African Journals Online (AJOL)

    Orange maize in Zambia: crop development and delivery experience. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE ... African Journal of Food, Agriculture, Nutrition and Development. Journal Home ...

  20. (MSV) resistant maize varieties for adaptation to a southern guinea

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... African Journal of Biotechnology Vol. 8 (19), pp. ... the development of superior maize varieties for the southern guinea savanna ecology. Key words: Zea ... tional agricultural research systems have succeeded in converting ...

  1. Screening of Plant Growth-Promoting Rhizobacteria from Maize ...

    African Journals Online (AJOL)

    Screening of Plant Growth-Promoting Rhizobacteria from Maize ( Zea Mays ) and Wheat ( Triticum Aestivum ) ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN ... African Journal of Food, Agriculture, Nutrition and Development.

  2. Genotypic variation for maize weevil resistance in eastern and ...

    African Journals Online (AJOL)

    ACSS

    Uganda Journal of Agricultural Sciences by National Agricultural Research Organisation ... damage, median development period, Dobie's index of susceptibility, and ... resistance and grain yield, suggesting that breeding for maize weevil ...

  3. Agronomic potentials of quality protein maize hybrids developed in ...

    African Journals Online (AJOL)

    Agronomic potentials of quality protein maize hybrids developed in Ghana. ... Ghana Journal of Agricultural Science ... and Wheat Improvement (CIMMYT) were evaluated on research stations and in farmers\\' fields in Ghana from 1995 to 1996.

  4. Studies on biochemical changes in maize wastes fermented with ...

    African Journals Online (AJOL)

    JTEkanem

    In an attempt to transform the agricultural waste products of maize cobs and shafts into useful products such as ... with transforming organic matter in the nature .... cerevisae Solid Media Fermentation. Food. Chemistry 82 (4) 599-602. 6.AOAC ...

  5. Reproductive performance of rabbits fed maize-milling waste based ...

    African Journals Online (AJOL)

    Owner

    The influence of maize-milling waste on the reproductive performance of rabbits was assessed. The .... stored in air-tight polythene bags prior to use in the experimental .... Nutrient digestibility and effect of heat treatment, J. Appl. Rabbit Res.

  6. Farmers' preferences for maize attributes in eastern and western

    African Journals Online (AJOL)

    ACSS

    African Crop Science Journal by African Crop Science Society is licensed ... Maize (Zea mays L.) is an important staple food crop in Uganda and is emerging as a cash crop for smallholder .... colour, grain size, pest and disease resistance.

  7. sources and use of extension information among maize farmers

    African Journals Online (AJOL)

    DR ADESOPE

    SOURCES AND USE OF EXTENSION INFORMATION AMONG MAIZE ... play one role or the other toward ensuring that research-based technologies ..... alternative means of controlling weeds (e.g. hoeing), high cost of herbicides and the risk.

  8. Drought tolerant tropical maize (Zea mays L.) developed through ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-26

    Oct 26, 2016 ... Seeds of the tropical maize inbred line CML216 were obtained from the International ... Infection, co-cultivation, resting, selection and maturation media ...... abscisic acid concentration does not induce kernel abortion in field-.

  9. Is there a strategy I iron uptake mechanism in maize?

    Science.gov (United States)

    Li, Suzhen; Zhou, Xiaojin; Chen, Jingtang; Chen, Rumei

    2018-04-03

    Iron is a metal micronutrient that is essential for plant growth and development. Graminaceous and nongraminaceous plants have evolved different mechanisms to mediate Fe uptake. Generally, strategy I is used by nongraminaceous plants like Arabidopsis, while graminaceous plants, such as rice, barley, and maize, are considered to use strategy II Fe uptake. Upon the functional characterization of OsIRT1 and OsIRT2 in rice, it was suggested that rice, as an exceptional graminaceous plant, utilizes both strategy I and strategy II Fe uptake systems. Similarly, ZmIRT1 and ZmZIP3 were identified as functional zinc and iron transporters in the maize genome, along with the determination of several genes encoding Zn and Fe transporters, raising the possibility that strategy I Fe uptake also occurs in maize. This mini-review integrates previous reports and recent evidence to obtain a better understanding of the mechanisms of Fe uptake in maize.

  10. Selenium concentration of maize grain in South Africa and possible ...

    African Journals Online (AJOL)

    Casey W

    reviewed paper: Proc. ... maize grain is a staple food for humans and a major ingredient in the diets of intensively fed livestock. Therefore, Se in ..... Dietary reference intakes for vitamin C, vitamin E, selenium and carotenoids. National Research.

  11. Researchers urge climate-resilience support for South African maize ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-20

    Apr 20, 2016 ... Researchers urge climate-resilience support for South African maize farmers ... They found that climate change is likely to hurt livelihoods and food security ... In Burkina Faso, local cultivation and livestock practices are losing ...

  12. Analysis of fresh maize marketing in Anambra state, Nigeria ...

    African Journals Online (AJOL)

    Analysis of fresh maize marketing in Anambra state, Nigeria. ... on marketing income in Anambra State, this study utilized descriptive statistic, Sherpherd-futrel model of determining marketing efficiency ... EMAIL FULL TEXT EMAIL FULL TEXT

  13. a study of technical inefficiencies of maize farmers within and ...

    African Journals Online (AJOL)

    p2333147

    frontier production functions were estimated for a sample of maize farmers within and outside the .... the normal distributions with the same variance, σ2, such that the mean,. µit, associated with the technical inefficiency effect, uit, is defined by.

  14. Impact of selection on maize root traits and rhizosphere interactions

    Science.gov (United States)

    Schmidt, J. E.; Gaudin, A. C. M.

    2017-12-01

    Effects of domestication and breeding on maize have been well-characterized aboveground, but impacts on root traits and rhizosphere processes remain unclear. Breeding in high-inorganic-input environments may have negatively affected the ability of modern maize to acquire nutrients through foraging and microbial interactions in marginal and/or organically managed soils. Twelve maize genotypes representing a selection gradient (teosintes, landraces, open-pollinated parents of modern elite germplasm, and modern hybrids released 1934-2015) were grown in three soils varying in intensity of long-term management (unfertilized, organic, conventional) in the greenhouse. Recruitment of rhizosphere microbial communities, nutrient acquisition, and plant productivity were affected by genotype-by-soil interactions. Maize genotypes exhibit significant variation in their ability to obtain nutrients from soils of different management history, indicating the potential for re-integration of beneficial root and rhizosphere traits to increase adaptation to low-input agroecosystems.

  15. Genetic diversity of maize genotypes on the basis of morpho ...

    African Journals Online (AJOL)

    Genetic diversity of maize genotypes on the basis of morpho-physiological and simple sequence repeat (SSR) markers. Ashish Kumar, Arunita Rakshit, Naresh K Mangilipelli, Y Varalaxmi, T Vijayalakshmi, Jainender M Vanaja, SK Yadav, B Venkateswarlu, M Maheswari ...

  16. Human pathogen avoidance adaptations

    NARCIS (Netherlands)

    Tybur, J.M.; Lieberman, D.

    2016-01-01

    Over the past few decades, researchers have become increasingly interested in the adaptations guiding the avoidance of disease-causing organisms. Here we discuss the latest developments in this area, including a recently developed information-processing model of the adaptations underlying pathogen

  17. Assessment of Climate Suitability of Maize in South Korea

    Science.gov (United States)

    Hyun, S.; Choi, D.; Seo, B.

    2017-12-01

    Assessing suitable areas for crops would be useful to design alternate cropping systems as an adaptation option to climate change adaptation. Although suitable areas could be identified by using a crop growth model, it would require a number of input parameters including cultivar and soil. Instead, a simple climate suitability model, e.g., EcoCrop model, could be used for an assessment of climate suitability for a major grain crop. The objective of this study was to assess of climate suitability for maize using the EcoCrop model under climate change conditions in Korea. A long term climate data from 2000 - 2100 were compiled from weather data source. The EcoCrop model implemented in R was used to determine climate suitability index at each grid cell. Overall, the EcoCrop model tended to identify suitable areas for maize production near the coastal areas whereas the actual major production areas located in inland areas. It is likely that the discrepancy between assessed and actual crop production areas would result from the socioeconomic aspects of maize production. Because the price of maize is considerably low, maize has been grown in an area where moisture and temperature conditions would be less than optimum. In part, a simple algorithm to predict climate suitability for maize would caused a relatively large error in climate suitability assessment under the present climate conditions. In 2050s, the climate suitability for maize increased in a large areas in southern and western part of Korea. In particular, the plain areas near the coastal region had considerably greater suitability index in the future compared with mountainous areas. The expansion of suitable areas for maize would help crop production policy making such as the allocation of rice production area for other crops due to considerably less demand for the rice in Korea.

  18. A Comprehensive Analysis of Alternative Splicing in Paleopolyploid Maize

    Directory of Open Access Journals (Sweden)

    Wenbin Mei

    2017-05-01

    Full Text Available Identifying and characterizing alternative splicing (AS enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level of alternatively spliced transcripts (intron retention and exon skipping do not solely reflect differences in total transcript abundance, and we present evidence that intron retention may act to fine-tune gene expression across seed development stages. Furthermore, we have identified temperature sensitive AS in maize and demonstrate that drought-induced changes in AS involve distinct sets of genes in reproductive and vegetative tissues. Examining our identified AS isoforms within B73 × Mo17 recombinant inbred lines (RILs identified splicing QTL (sQTL. The 43.3% of cis-sQTL regulated junctions are actually identified as alternatively spliced junctions in our analysis, while 10 Mb windows on each side of 48.2% of trans-sQTLs overlap with splicing related genes. Using sorghum as an out-group enabled direct examination of loss or conservation of AS between homeologous genes representing the two subgenomes of maize. We identify several instances where AS isoforms that are conserved between one maize homeolog and its sorghum ortholog are absent from the second maize homeolog, suggesting that these AS isoforms may have been lost after the maize whole genome duplication event. This comprehensive analysis provides new insights into the complexity of AS in maize.

  19. Classification of maize kernels using NIR hyperspectral imaging

    DEFF Research Database (Denmark)

    Williams, Paul; Kucheryavskiy, Sergey V.

    2016-01-01

    NIR hyperspectral imaging was evaluated to classify maize kernels of three hardness categories: hard, medium and soft. Two approaches, pixel-wise and object-wise, were investigated to group kernels according to hardness. The pixel-wise classification assigned a class to every pixel from individual...... and specificity of 0.95 and 0.93). Both feature extraction methods can be recommended for classification of maize kernels on production scale....

  20. Evaluation of the Effect of Replacing Maize with Cattle Rumen ...

    African Journals Online (AJOL)

    This study determined the nutritive values of cattle rumen waste (CRW) meal used for replacement of maize in the diets of Nile tilapia Oreochromis niloticus. CRW (20.9% CP) was used to replace maize (10.1 CP) at 0%, 25%, 50%, 75% and 100% making diets (D1-D5). The diets were fed to the fish (5.59±0.37g) to apparent ...

  1. Maize Endophytic Bacterial Diversity as Affected by Soil Cultivation History.

    Science.gov (United States)

    Correa-Galeote, David; Bedmar, Eulogio J; Arone, Gregorio J

    2018-01-01

    The bacterial endophytic communities residing within roots of maize ( Zea mays L.) plants cultivated by a sustainable management in soils from the Quechua maize belt (Peruvian Andes) were examined using tags pyrosequencing spanning the V4 and V5 hypervariable regions of the 16S rRNA. Across four replicate libraries, two corresponding to sequences of endophytic bacteria from long time maize-cultivated soils and the other two obtained from fallow soils, 793 bacterial sequences were found that grouped into 188 bacterial operational taxonomic units (OTUs, 97% genetic similarity). The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from fallow soils. A mean of 30 genera were found in the fallow soil libraries and 47 were in those from the maize-cultivated soils. Both alpha and beta diversity indexes showed clear differences between bacterial endophytic populations from plants with different soil cultivation history and that the soils cultivated for long time requires a higher diversity of endophytes. The number of sequences corresponding to main genera Sphingomonas, Herbaspirillum, Bradyrhizobium and Methylophilus in the maize-cultivated libraries were statistically more abundant than those from the fallow soils. Sequences of genera Dyella and Sreptococcus were significantly more abundant in the libraries from the fallow soils. Relative abundance of genera Burkholderia, candidatus Glomeribacter, Staphylococcus, Variovorax, Bacillus and Chitinophaga were similar among libraries. A canonical correspondence analysis of the relative abundance of the main genera showed that the four libraries distributed in two clearly separated groups. Our results suggest that cultivation history is an important driver of endophytic colonization of maize and that after a long time of cultivation of the soil the maize plants need to increase the richness of the bacterial endophytes communities.

  2. Euplectrus furnius parasitizing Spodoptera frugiperda in maize in Brazil

    Directory of Open Access Journals (Sweden)

    Vinícius Soares Sturza

    2013-11-01

    Full Text Available Brazil is among the world's biggest maize producers and fall armyworm, Spodoptera frugiperda (Smith (Lepidoptera: Noctuidae, is the main insect pest on this crop in the country. Despite the importance of its natural enemies, there still is a lack of information about parasitoids species that attack this insect-pest, such as larval parasitoids. This research reports Euplectrus furnius Walker (Hymenoptera: Eulophidae parasitizing S. fugiperda larvae on maize crop in Brazil.

  3. Genetic effects of heavy ion irradiation in maize and soybean

    International Nuclear Information System (INIS)

    Yatou, Osamu; Amano, Etsuo; Takahashi, Tan.

    1992-01-01

    Somatic mutation on leaves of maize and soybean were observed to investigate genetic effects of heavy ion irradiation. Maize seeds were irradiated with N, Fe and U ions and soybean seeds were irradiated with N ions. This is a preliminary report of the experiment, 1) to examine the mutagenic effects of the heavy ion irradiation, and 2) to evaluate the genetic effects of cosmic ray exposure in a space ship outside the earth. (author)

  4. Intercropping soybean and maize in a derived savanna ecology ...

    African Journals Online (AJOL)

    Compared to sole soybean, intercropping soybean and maize on flat and ridge reduced yields by 1.0 –29.1% and 29.4 - 40.2% respectively. In maize, intercropping on flat and ridge reduced yields by 13.2 - 25.2% and 24.8 - 43.5% respectively. Planting sole soybean on ridge enhanced mean yield by 18.6% as compared to ...

  5. Comparison of Milk and Maize Based Diets in Kwashiorkor ...

    African Journals Online (AJOL)

    Permeability ratios (95% confidence interval) on the milk diet improved by a mean of 6.4 (1.7 to 11.1) compared with - 6.8 (-16.8 to 5.0) in the maize group. The improved permeability on milk occurred despite more diarrhoea, which constituted 34.8% of hospital days compared to 24.3% in the maize group. Case fatality rates ...

  6. Effect of Spatial Arrangement on Growth and Yield of Cowpea in a Cowpea-maize Intercrop

    OpenAIRE

    Ocaya, CP.; Adipala, E.; Osiru, DSO.

    2001-01-01

    Cowpea growth and yield performance when intercropped with maize was studied for 3 consecutive seasons under three spatial arrangements, i. e., maize planted at 90 x 30, 100 x 27, and 120 x 22.5 cm, with 2 rows of cowpea between the maize rows. Growth and yield of cowpea was improved significantly by widening maize intra-row distances as compared to the 90 x 30 cm spacing. Hence, intercropped cowpea needs to be sown where maize rows are wide apart, but the maize rows should not be too wide as...

  7. Examination of injection moulded thermoplastic maize starch

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available This paper focuses on the effect of the different injection moulding parameters and storing methods on injection moulded thermoplastic maize starch (TPS. The glycerol and water plasticized starch was processed in a twin screw extruder and then with an injection moulding machine to produce TPS dumbbell specimens. Different injection moulding set-ups and storing conditions were used to analyse the effects on the properties of thermoplastic starch. Investigated parameters were injection moulding pressure, holding pressure, and for the storage: storage at 50% relative humidity, and under ambient conditions. After processing the mechanical and shrinkage properties of the manufactured TPS were determined as a function of the ageing time. While conditioning, the characteristics of the TPS changed from a soft material to a rigid material. Although this main behaviour remained, the different injection moulding parameters changed the characteristics of TPS. Scanning electron microscope observations revealed the changes in the material on ageing.

  8. Dynamic epigenetic states of maize centromeres

    Directory of Open Access Journals (Sweden)

    Yalin eLiu

    2015-10-01

    Full Text Available The centromere is a specialized chromosomal region identified as the major constriction, upon which the kinetochore complex is formed, ensuring accurate chromosome orientation and segregation during cell division. The rapid evolution of centromere DNA sequence and the conserved centromere function are two contradictory aspects of centromere biology. Indeed, the sole presence of genetic sequence is not sufficient for centromere formation. Various dicentric chromosomes with one inactive centromere have been recognized. It has also been found that de novo centromere formation is common on fragments in which centromeric DNA sequences are lost. Epigenetic factors play important roles in centromeric chromatin assembly and maintenance. Nondisjunction of the supernumerary B chromosome early prophase of meiosis I requires an active centromere. This review discusses recent studies in maize about genetic and epigenetic elements regulating formation and maintenance of centromere chromatin, as well as centromere behavior in meiosis.

  9. Cluster Analysis of Maize Inbred Lines

    Directory of Open Access Journals (Sweden)

    Jiban Shrestha

    2016-12-01

    Full Text Available The determination of diversity among inbred lines is important for heterosis breeding. Sixty maize inbred lines were evaluated for their eight agro morphological traits during winter season of 2011 to analyze their genetic diversity. Clustering was done by average linkage method. The inbred lines were grouped into six clusters. Inbred lines grouped into Clusters II had taller plants with maximum number of leaves. The cluster III was characterized with shorter plants with minimum number of leaves. The inbred lines categorized into cluster V had early flowering whereas the group into cluster VI had late flowering time. The inbred lines grouped into the cluster III were characterized by higher value of anthesis silking interval (ASI and those of cluster VI had lower value of ASI. These results showed that the inbred lines having widely divergent clusters can be utilized in hybrid breeding programme.

  10. Uptake, translocation, and debromination of polybrominated diphenyl ethers in maize

    Institute of Scientific and Technical Information of China (English)

    Moming Zhao; Shuzhen Zhang; Sen Wang; Honglin Huang

    2012-01-01

    Uptake,translocation and debromination of three polybrominated diphenyl ethers(PBDEs),BDE-28,-47 and-99,in maize were studied in a hydroponic experiment.Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability.PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants.Furthermore,PBDE concentrations decreased from roots to stems and then to leaves,and a very clear decreasing gradient was found in segments upwards along the stem.These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize.More highly brominated PBDEs were translocated with more difficulty.Radial translocation of PBDEs from nodes to sheath inside maize was also observed.Both acropetal and radial translocations were enhanced at higher transpiration rates,suggesting that PBDE transport was probably driven by the transpiration stream.Debromination of PBDEs occurred in all parts of the maize,and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences.This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants,elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.

  11. Multiple Pesticides Detoxification Function of Maize (Zea mays) GST34.

    Science.gov (United States)

    Li, Dongzhi; Xu, Li; Pang, Sen; Liu, Zhiqian; Zhao, Weisong; Wang, Chengju

    2017-03-08

    ZmGST34 is a maize Tau class GST gene and was found to be differently expressed between two maize cultivars differing in tolerance to herbicide metolachlor. To explore the possible role of ZmGST34 in maize development, the expression pattern and substrate specificity of ZmGST34 were characterized by quantitative RT-PCR and heterologous expression system, respectively. The results indicated that the expression level of ZmGST34 was increased ∼2-5-fold per day during the second-leaf stage of maize seedling. Chloroacetanilide herbicides or phytohormone treatments had no influence on the expression level of ZmGST34, suggesting that ZmGST34 is a constitutively expressed gene in maize seedling. Heterologous expression in Escherichia coli and in Arabidopsis thaliana proved that ZmGST34 can metabolize most chloroacetanilide herbicides and increase tolerance to these herbicides in transgenic Arabidopsis thaliana. The constitutive expression pattern and broad substrate activity of ZmGST34 suggested that this gene may play an important role in maize development in addition to the detoxification of pesticides.

  12. Water transfer in an alfalfa/maize association

    International Nuclear Information System (INIS)

    Corak, S.J.; Blevins, D.G.; Pallardy, S.G.

    1987-01-01

    The authors investigated the possibility of interspecific water transfer in an alfalfa (Medicago sativa L.) and maize (Zea mays L.) association. An alfalfa plant was grown through two vertically stacked plastic tubes. A 5 centimeter air gap between tubes was bridged by alfalfa roots. Five-week old maize plants with roots confined to the top tube were not watered, while associated alfalfa roots had free access to water in the bottom tube (the -/+ treatment). Additional treatments included: top and bottom tubes watered (+/+), top and bottom tubes droughted (-/-), and top tube droughted after removal of alfalfa root bridges and routine removal of alfalfa tillers (-*). Predawn leaf water potential of maize in the -/+ treatment fell to -1.5 megapascals 13 days after the start of drought; thereafter, predawn and midday potentials were maintained near -1.9 megapascals. Leaf water potentials of maize in the -/- and -* treatments declined steadily; all plants in these treatments were completely desiccated before day 50. High levels of tritium activity were detected in water extracted from both alfalfa and maize leaves after 3 H 2 O was injected into the bottom -/+ tube at day 70 or later. Maize in the -/+ treatment was able to survive an otherwise lethal period of drought by utilizing water lost by alfalfa roots

  13. Genomic variation in recently collected maize landraces from Mexico

    Science.gov (United States)

    Arteaga, María Clara; Moreno-Letelier, Alejandra; Mastretta-Yanes, Alicia; Vázquez-Lobo, Alejandra; Breña-Ochoa, Alejandra; Moreno-Estrada, Andrés; Eguiarte, Luis E.; Piñero, Daniel

    2015-01-01

    The present dataset comprises 36,931 SNPs genotyped in 46 maize landraces native to Mexico as well as the teosinte subspecies Zea maiz ssp. parviglumis and ssp. mexicana. These landraces were collected directly from farmers mostly between 2006 and 2010. We accompany these data with a short description of the variation within each landrace, as well as maps, principal component analyses and neighbor joining trees showing the distribution of the genetic diversity relative to landrace, geographical features and maize biogeography. High levels of genetic variation were detected for the maize landraces (HE = 0.234 to 0.318 (mean 0.311), while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (HE = 0.262 and 0.234, respectively). The distribution of genetic variation was better explained by environmental variables given by the interaction of altitude and latitude than by landrace identity. This dataset is a follow up product of the Global Native Maize Project, an initiative to update the data on Mexican maize landraces and their wild relatives, and to generate information that is necessary for implementing the Mexican Biosafety Law. PMID:26981357

  14. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Zealactones. Novel natural strigolactones from maize.

    Science.gov (United States)

    Charnikhova, Tatsiana V; Gaus, Katharina; Lumbroso, Alexandre; Sanders, Mark; Vincken, Jean-Paul; De Mesmaeker, Alain; Ruyter-Spira, Carolien P; Screpanti, Claudio; Bouwmeester, Harro J

    2017-05-01

    In the root exudate and root extracts of maize hybrid cv NK Falkone seven putative strigolactones were detected using UPLC-TQ-MS-MS. All seven compounds displayed MS-MS-fragmentation common for strigolactones and particularly the presence of a fragment of m/z 97 Da, which may indicate the presence of the so-called D-ring, suggests they are strigolactones. The levels of all these putative strigolactones increased upon phosphate starvation and decreased upon fluridone (carotenoid biosynthesis inhibitor) treatment, both of which are a common response for strigolactones. All seven compounds were subsequently isolated with prep-HPLC-MS. They all exhibited Striga hermonthica seed germination inducing activity just as the synthetic strigolactone analog GR24. The structure of two of the seven compounds was elucidated by NMR spectroscopy as: methyl (2E,3E)-4-(3,3-dimethyl-5-oxo-2-(prop-1-en-2-yl)tetrahydrofuran-2-yl)-2-(((4-methyl-5-oxo-2,5-dihydrofuran-2-yl)oxy)methylene)but-3-enoate (two diastereomers 1a and 1b). Strigolactones (1a/b) are closely related to the methyl ester of carlactonoic acid (MeCLA) and heliolactone. However, they contain a unique 4,4-dimethyltetrahydrofuran-2-one motif as the "A-ring" instead of the classical (di)methylcyclohexene. Because these compounds were isolated from maize (Zea mays) we called them "zealactone 1a and 1b". The implications of this discovery for our view on strigolactones and their biosynthesis are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. TAXONOMY OF FUSARIUM SPECIES ISOLATED FROM CULTIVATED PLANTS, WEEDS AND THEIR PATHOGENICITY FOR WHEAT

    Directory of Open Access Journals (Sweden)

    Jasenka Ćosić

    2002-06-01

    Full Text Available Fusarium species are wide-spread and known to be pathogenic agents to cultivated plants in various agroclimatic areas. During a four year investigation 10 Fusarium species and Microdochium nivale were isolated from wheat, barley, maize and soybean as well as from 10 weeds collected from 10 locations in Slavonia and Baranya. Fusarium graminearum was dominant on wheat and barley, F. moniliforme on maize and F. oxysporum on soybean. Regarding weeds, the presence of the following Fusarium species was established: F. graminearum on Amaranthus hybridus, Capsella bursa-pastoris, Lamium purpureum, Sorghum halepense and Urtica dioica, F. moniliforme on Abutilon theophrasti, F. subglutinans on Polygonum aviculare, F. avenaceum on Capsella bursa-pastoris, Rumex crispus and Matricaria sp., F. culmorum on Abutilon theophrasti, F. sporotrichioides on Polygonum aviculare, F. proliferatum and F. poae on Artemisia vulgaris. Pathogenicity test to wheat seedlings was done in our laboratory on winter wheat cultivars Slavonija and Demetra (totally 146 isolates. The most pathogenic species to wheat seedilings were F. graminearum, F. culmorum and F. sporotrichioides and the least pathogenic F. moniliforme, F. solani, F. oxysporum and F. poae. Pathogenicity test for wheat ears was done on genotypes Osk.8c9/3-94 and Osk.6.11/2 (totally 25 isolates. The results obtained by our investigation showed that there were no significant differences in pathogenicity of Fusarium species isolated from both cultivated plants and weeds. Weeds represent a constant source of inoculum of F. species for cultivated plants and they serve as epidemiologic bridges among vegetations.

  17. Leaves from banana (Musa nana) and maize (Zea mays) have no phyto-prophylactic effects on the susceptibility of grass carp (Ctenopharyngodon idella) to Aeromonas hydrophila infection.

    Science.gov (United States)

    Mayrhofer, Richard; Menanteau-Ledouble, Simon; Pucher, Johannes; Focken, Ulfert; El-Matbouli, Mansour

    2017-11-10

    The ubiquitous and opportunistic bacterial pathogen Aeromonas hydrophila has been associated with ulcerative dermatitis in fish, especially under stressful conditions. It can cause severe losses in fresh water aquaculture and is particularly prevalent in tropical and subtropical regions. Fresh leaves from maize and bananas have been used as feed supplement by fish farmers in Vietnam and it has been reported that they may have phyto-prophylactic benefits. In the present study, a feeding trial was conducted to investigate the benefits of providing maize and banana leaves as feed supplement: to determine if they were taken up and digested by grass carp (Ctenopharyngodon idella), if this uptake resulted in improved growth performance, and if leaf supplementation protected fish when challenged with A. hydrophila by intramuscular injection. All fish were fed an identical ratio of commercial pelleted feed relative to biomass. However, in 12/18 tanks, this diet was supplemented with either fresh banana leaves or fresh maize leaves; offered ad libitum. Addition of leaves increased the overall feed conversion ratio (FCR) significantly. However, if only the pellet were taken into account, then no difference was found between treatments. Changes to the isotopic composition of the fish showed leaf nutrient uptake occurred. No prophylactic effects of feeding banana or maize leaves were detected against infection with A. hydrophila, and the diet did not induce changes in the fish haematocrit. However, addition of the maize leaves was associated with significantly reduced severity of the skin lesions, which could improve the market value of the fish. Addition of the leaf supplement did not result in significantly improved growth performance. Similarly, the effect of the supplement on the fish survival to infection was not significant.

  18. Reacción de 100 variedades de caña de azúcar (saccharum officinarum) del banco de germoplasma del cincae, al carbón (ustilago scitaminea sydow), roya (puccinia melanocephala sydow) y mosaico (sugarcane mosaic virus) en la zona del cantón el triunfo

    OpenAIRE

    Fiallos Encalada, Freddy Fabian; Quilambaqui Jara, Miguel

    2009-01-01

    El presente trabajo tuvo como objetivo determinar la reacción de 100 variedades de Caña de Azúcar del Banco de Germoplasma del CINCAE inoculadas, al Carbón (Ustilago scitaminea Sydow), Roya (Puccinia melanocephala Sydow) y Mosaico (Sugarcane Mosaic Virus), las cuales son enfermedades que han causado enormes pérdidas en la producción del cultivo. El ensayo se realizó en el Centro de Investigación de la Caña de Azúcar del Ecuador (CINCAE), ubicado en el cantón El Triunfo, provincia del Guayas. ...

  19. Iron and manganese oxides modified maize straw to remove tylosin from aqueous solutions.

    Science.gov (United States)

    Yin, Yongyuan; Guo, Xuetao; Peng, Dan

    2018-08-01

    Maize straw modified by iron and manganese oxides was synthesized via a simple and environmentally friendly method. Three maize straw materials, the original maize straw, maize straw modified by manganese oxides and maize straw modified by iron and manganese oxides, were detected by SEM, BET, XPS, XRD and FTIR. The results showed that maize straw was successfully modified and maize straw modified by iron and manganese oxides has a larger surface area than MS. According to the experimental data, the sorption trend could conform to the pseudo-second-order kinetic model well, and the sorption ability of tylosin on sorbents followed the order of original maize straw oxides iron and manganese oxides. The study indicated that manganese oxides and iron-manganese oxides could significantly enhance the sorption capacity of original maize straw. The sorption isotherm data of tylosin on original maize straw fit a linear model well, while Freundlich models were more suitable for maize straw modified by manganese oxides and maize straw modified by iron and manganese oxides. The pH, ionic strength and temperature can affect the sorption process. The sorption mechanisms of tylosin on iron and manganese oxides modified maize straw were attribute to the surface complexes, electrostatic interactions, H bonding and hydrophobic interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Comparative transcriptome proifling of two maize near-isogenic lines differing in the allelic state for bacterial brown spot disease resistance

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-jun; Xu Li; ZHAO Pan-feng; LI Na; WU Lei; HE Yan; WANG Shou-cai

    2015-01-01

    The bacterial brown spot disease (BBS), caused primarily by Pseudomonas syringae pv. syringae van Hal (Pss), reduces plant vigor, yield and quality in maize. To reveal the nature of the defense mechanisms and identify genes involved in the effective host resistance, the dynamic changes of defense transcriptome triggered by the infection of Pss were investigated and compared between two maize near-isogenic lines (NILs). We found that Pss infection resulted in a sophisticated tran-scriptional reprogramming of several biological processes and the resistant NIL employed much faster defense responses than the susceptible NIL. Numerous genes encoding essential components of plant basal resistance would be able to be activated in the susceptible NIL, such as PEN1, PEN2, PEN3, and EDR1, however, in a basic manner, such resistance might not be sufifcient for suppressing Pss pathogenesis. In addition, the expressions of a large number of PTI-, ETI-, PR-, and WRKY-related genes were pronouncedly activated in the resistant NIL, suggesting that maize employ a multitude of defense pathways to defend Pss infection. Six R-gene homologs were identiifed to have signiifcantly higher expression levels in the resistant NIL at early time point, indicating that a robust surveil ance system (gene-to-gene model) might operate in maize during Pss attacks, and these homolog genes are likely to be potential candidate resistance genes involved in BBS disease resistance. Furthermore, a holistic group of novel pathogen-responsive genes were deifned, providing the repertoire of candidate genes for further functional characterization and identiifcation of their regulation patterns during pathogen infection.

  1. The mechanisms of root exudates of maize in improvement of iron nutrition of peanut in peanut/maize intercropping system by 14C tracer technique

    International Nuclear Information System (INIS)

    Zuo Yuanmei; Chen Qing; Zhang Fusuo

    2004-01-01

    The related mechanisms of root exudates of maize in improvement iron nutrition of peanut intercropped with maize was investigated by 14 C tracer technique. Neighboring roots between maize and peanut were separated by a 30 μm nylon net, the iron nutrition of peanut was also improved just like normal intercropping of maize and peanut. The results proved that root exudates of maize played an important role in improvement iron nutrition of peanut. The photosynthesis carbohydrate of maize could exuded into the rhizosphere of peanut and transfer into shoot and root of peanut in intercropping system. Root exudates of maize could increased efficiency of iron in soil and improved iron utilization of peanut

  2. Evolution of microbial pathogens.

    OpenAIRE

    Morschhäuser, J; Köhler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

    2000-01-01

    Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic micr...

  3. Cloning and molecular characterization of the glyceraldehyde-3-phosphate dehydrogenase-encoding gene and cDNA from the plant pathogenic fungus Glomerella cingulata.

    Science.gov (United States)

    Templeton, M D; Rikkerink, E H; Solon, S L; Crowhurst, R N

    1992-12-01

    The glyceraldehyde-3-phosphate dehydrogenase gene (gpdA) has been identified from a genomic DNA library prepared from the plant pathogenic fungus Glomerella cingulata. Nucleotide sequence data revealed that this gene codes for a putative 338-amino-acid protein encoded by two exons of 129 and 885 bp, separated by an intron 216 bp long. The 5' leader sequence is also spliced by an intron of 156 bp. A cDNA clone was prepared using the polymerase chain reaction, the sequence of which was used to confirm the presence of the intron in the coding sequence and the splicing of the 5' leader sequence. The transcriptional start point (tsp) was mapped at -253 nt from the site of the initiation of translation by primer extension and is adjacent to a 42-bp pyrimidine-rich region. The general structure of the 5' flanking region shows similarities to gpdA from Aspergillus nidulans. The putative protein product is 71-86% identical at the aa level to GPDs from Aspergillus nidulans, Cryphonectria parasitica, Curvularia lunata, Podospora anserina and Ustilago maydis.

  4. Effect of Bambara nut and cowpea intercropped with maize at different times on nutritive quality of maize for ruminant feeding

    Directory of Open Access Journals (Sweden)

    Olanite, J. A.

    2017-06-01

    Full Text Available Effects of Bambara nut and cowpea planted with maize at different times on nutritive quality of maize forage were investigated. The study was laid out in a Completely Randomized Design and the treatments were combination of crop types (Bambara nut-maize (MB and Cowpea-maize (MC and planting times of legumes (2 wks before planting maize, 2WBPM and 2 wks after planting maize, 2WAPM, and sole maize (as control. An experimental field measuring 19 m � 11 m was divided into 3 replicates; each replicate was sub-divided into 5 plots of dimension 3 m2 each, with 1 m and 2 m inter-plots and inter-blocks spacing respectively. Maize forage samples were harvested on each plot at 10 wks after planting, oven-dried, milled and analyzed to evaluate the chemical composition, mineral composition, in vitro gas production and post-incubation characteristics. Results revealed significant differences (P<0.05 among treatments with the highest (95.00% and least DM (92.12% values were recorded for MB 2WBPM and MC 2WAPM, respectively. CP values ranged from 10.36% in MB 2WBPM to 15.67% in MC 2WBPM but not significantly different from 14.19 % recorded for sole maize. Ash ranged from 7.00% in MB 2WAPM to 10.00% in sole maize. MC 2WBPM and sole maize had the highest (50.63% and least (38.40% in ADF content (P<0.05. ADL value (7.25% observed in MB 2WBPM was the highest, compared to the least (5.00% in sole maize. Sole maize recorded the least (40.40% and highest (25.91% cellulose and hemicellulose contents, respectively while MC 2WAPM had the highest (50.88% and lowest (15.80% values for cellulose and hemicellulose, respectively. Ca content (4.55g/kg of MB 2WAPM was lower than the other treatments. P content ranged from 3.54 g/kg in MB 2WAPM to 12.02 g/kg in MC 2WAPM. Gas production rates only varied (P<0.05 at the 3rd, 6th, 24th and 48th hours of incubation. MB 2WBPM yielded highest values of short chain fatty acids (0.09 �mol and metabolizable energy (3.08 MJ/kg while MB

  5. Natural incidence of Fusarium species and fumonisins B1 and B2 associated with maize kernels from nine provinces in China in 2012.

    Science.gov (United States)

    Fu, Meng; Li, Renjie; Guo, Congcong; Pang, Minhao; Liu, Yingchao; Dong, Jingao

    2015-01-01

    Fusarium species, which can produce mycotoxins, are the predominant pathogens causing maize ear rot, a disease that results in severe economic losses and serves as a potential health risk for humans and animals. A survey was conducted in 2012 to investigate the contamination of maize by Fusarium species and fumonisins B1 and B2. A total of 250 maize samples were randomly collected from nine provinces (Hebei, Shanxi, Inner Mongolia, Yunnan, Sichuan, Guizhou, Heilongjiang, Liaoning and Ningxia) in China. Fusarium species were isolated and identified using morphological (electron microscope) and molecular methods (polymerase chain reaction (PCR) and sequencing). Fumonisins B1 and B2 were analysed using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) with OPA (2-Mercaptoethanol, o-phthaldialdehyde) post-column derivatisation. A total of 2321 Fusarium isolates (20.7%) were obtained from all the samples. These isolates included nine Fusarium species, namely, F. graminearum, F. verticillioides, F. subglutinans, F. proliferatum, F. temperatum, F. oxysporum, F. equiseti, F. meridionale and F. chlamydosporum. The incidence of occurrence of Fusarium species in Guizhou was the highest, while in Inner Mongolia it was the lowest. F. verticillioides was the dominant species of maize ear rot in Liaoning, Sichuan, Hebei and Ningxia. F. graminearum was the dominant species in Yunnan, Guizhou and Shanxi. F. subglutinans was the dominant species in Heilongjiang. F. verticillioides and F. graminearum percentages were the same in Inner Mongolia. The incidence of fumonisins in Liaoning was high (up to 81.0%) and in Heilongjiang low (up to 10.3%). Except Shanxi, more than 50% of maize samples from other provinces were contaminated with fumonisins, with concentrations less than 500 ng g(-1). About 33% of maize samples from Yunnan were contaminated with high levels of fumonisins, and average of fumonisin levels were 5191 ng g(-1). Fusarium species causing maize

  6. Comparative histological and transcriptional analysis of maize kernels infected with Aspergillus flavus and Fusarium verticillioides

    Science.gov (United States)

    Aspergillus flavus and Fusarium verticillioides infect maize kernels and contaminate them with the mycotoxins aflatoxin and fumonisin, respectively. Combined histological examination of fungal colonization and transcriptional changes in maize kernels at 4, 12, 24, 48, and 72 hours post inoculation (...

  7. Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

    KAUST Repository

    Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Saharoui

    2016-01-01

    High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa

  8. Quantitative trait loci for resistance to maize streak virus disease in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... African Journal of Biotechnology Vol. ... development ... Biotechnology Center, Kenya Agricultural Research Institute, P.O. Box 58711-00200, Nairobi, ... Maize streak virus disease is an important disease of maize in Kenya.

  9. Effect of Some Agronomic Practices to Increase Maize Yield in Ghana

    African Journals Online (AJOL)

    Effect of Some Agronomic Practices to Increase Maize Yield in Ghana. ... Journal of Science and Technology (Ghana) ... With the increasing population and consumption of maize in the country, research must be directed to solve this problem ...

  10. Maize-common bean/lupine intercrop productivity and profitability in ...

    African Journals Online (AJOL)

    Phaseolus vulgaris L.), narrow-leaf lupine (Lupinus angustifolius L.), and white lupine (Lupinus albus L.) with maize (Zea mays L.) were conducted under two intercrop planting arrangements (IPA), single row of legume in between maize rows and ...

  11. Narrowing Maize Yield Gaps Under Rain-fed conditions in Tanzania ...

    African Journals Online (AJOL)

    Abstract. The wide gap between potential and actual yields of maize in Tanzania, due low productivity is the major constraint to ... An International Journal of Basic and Applied Research ... for determining maize grain yield followed by water.

  12. THE IMPORTANCE OF WESTERN CORN ROOTWORM IN CONTINUOUS MAIZE

    Directory of Open Access Journals (Sweden)

    Marija Ivezić

    2006-06-01

    Full Text Available Western Corn Rootworm (Diabrotica virgifera virgifera LeConte is considered to be one of the most important and potentially most severe pest of maize worldwide. The pest was detected in Croatia for the first time in 1995. Since then it has been spread over all areas with maize production in Croatia. The economically most efficient and preventive control measure is crop rotation and growing maize hybrids that show tolerance to WCR. The trials were settled in the area near Dubosevica where in 2002 and 2003 the economic damages caused by WCR were up to 80%. The aim of this investigation is to determine damages on maize root caused by WCR and loss in grain yield on commercial maize hybrids in continuous farming. Pheromone traps, type Csal♀m♂N®, were used in order to monitor WCR population dynamics. In the period of two months, 366 WCR adult beetles in total were captured. Root damage was evaluated according to Iowa Node Injury Scale and grain yield was measured and corrected to 14% moisture. Furthermore, the plant lodging, as a consequence of larval feeding, was assessed. The results have shown that root damage for hybrid Bc 5982 was 1.15, and 0.73 damage was on Pr 35p 12 roots. The grain yield obtained from hybrid Bc 5982 was 11.7 t/ha, and Pr 35p 12 had 12.3 t/ha. Statistical analyses showed that there were no significant differences in root damage and losses in grain yield between the two investigated hybrids. Results of this investigation indicate that growing maize for 2 to 3 years in continuous farming, in the same field, would not cause economically significant loss in maize gain yield.

  13. Biofuel, land and water: maize, switchgrass or Miscanthus?

    International Nuclear Information System (INIS)

    Zhuang Qianlai; Qin Zhangcai; Chen Min

    2013-01-01

    The productive cellulosic crops switchgrass and Miscanthus are considered as viable biofuel sources. To meet the 2022 national biofuel target mandate, actions must be taken, e.g., maize cultivation must be intensified and expanded, and other biofuel crops (switchgrass and Miscanthus) must be cultivated. This raises questions on the use efficiencies of land and water; to date, the demand on these resources to meet the national biofuel target has rarely been analyzed. Here, we present a data-model assimilation analysis, assuming that maize, switchgrass and Miscanthus will be grown on currently available croplands in the US. Model simulations suggest that maize can produce 3.0–5.4 kiloliters (kl) of ethanol for every hectare of land, depending on the feedstock to ethanol conversion efficiency; Miscanthus has more than twice the biofuel production capacity relative to maize, and switchgrass is the least productive of the three potential sources of ethanol. To meet the biofuel target, about 26.5 million hectares of land and over 90 km 3 of water (of evapotranspiration) are needed if maize grain alone is used. If Miscanthus was substituted for maize, the process would save half of the land and one third of the water. With more advanced biofuel conversion technology for Miscanthus, only nine million hectares of land and 45 km 3 of water would probably meet the national target. Miscanthus could be a good alternative biofuel crop to maize due to its significantly lower demand for land and water on a per unit of ethanol basis. (letter)

  14. Coordination of the maize transcriptome by a conserved circadian clock

    Directory of Open Access Journals (Sweden)

    Harmon Frank G

    2010-06-01

    Full Text Available Abstract Background The plant circadian clock orchestrates 24-hour rhythms in internal physiological processes to coordinate these activities with daily and seasonal changes in the environment. The circadian clock has a profound impact on many aspects of plant growth and development, including biomass accumulation and flowering time. Despite recent advances in understanding the circadian system of the model plant Arabidopsis thaliana, the contribution of the circadian oscillator to important agronomic traits in Zea mays and other cereals remains poorly defined. To address this deficit, this study investigated the transcriptional landscape of the maize circadian system. Results Since transcriptional regulation is a fundamental aspect of circadian systems, genes exhibiting circadian expression were identified in the sequenced maize inbred B73. Of the over 13,000 transcripts examined, approximately 10 percent displayed circadian expression patterns. The majority of cycling genes had peak expression at subjective dawn and dusk, similar to other plant circadian systems. The maize circadian clock organized co-regulation of genes participating in fundamental physiological processes, including photosynthesis, carbohydrate metabolism, cell wall biogenesis, and phytohormone biosynthesis pathways. Conclusions Circadian regulation of the maize genome was widespread and key genes in several major metabolic pathways had circadian expression waveforms. The maize circadian clock coordinated transcription to be coincident with oncoming day or night, which was consistent with the circadian oscillator acting to prepare the plant for these major recurring environmental changes. These findings highlighted the multiple processes in maize plants under circadian regulation and, as a result, provided insight into the important contribution this regulatory system makes to agronomic traits in maize and potentially other C4 plant species.

  15. Predicting weed problems in maize cropping by species distribution modelling

    Directory of Open Access Journals (Sweden)

    Bürger, Jana

    2014-02-01

    Full Text Available Increasing maize cultivation and changed cropping practices promote the selection of typical maize weeds that may also profit strongly from climate change. Predicting potential weed problems is of high interest for plant production. Within the project KLIFF, experiments were combined with species distribution modelling for this task in the region of Lower Saxony, Germany. For our study, we modelled ecological and damage niches of nine weed species that are significant and wide spread in maize cropping in a number of European countries. Species distribution models describe the ecological niche of a species, these are the environmental conditions under which a species can maintain a vital population. It is also possible to estimate a damage niche, i.e. the conditions under which a species causes damage in agricultural crops. For this, we combined occurrence data of European national data bases with high resolution climate, soil and land use data. Models were also projected to simulated climate conditions for the time horizon 2070 - 2100 in order to estimate climate change effects. Modelling results indicate favourable conditions for typical maize weed occurrence virtually all over the study region, but only a few species are important in maize cropping. This is in good accordance with the findings of an earlier maize weed monitoring. Reaction to changing climate conditions is species-specific, for some species neutral (E. crus-galli, other species may gain (Polygonum persicaria or loose (Viola arvensis large areas of suitable habitats. All species with damage potential under present conditions will remain important in maize cropping, some more species will gain regional importance (Calystegia sepium, Setara viridis.

  16. Essential Oil of Cymbopogon citratus on the Control of the Curvularia Leaf Spot Disease on Maize

    Science.gov (United States)

    Mourão, Dalmarcia de Sousa Carlos; Ferreira de Souza Pereira, Talita; de Souza, Danival José; Chagas Júnior, Aloísio Freitas; Veloso, Ronice Alves; Leão, Evelynne Urzêdo

    2017-01-01

    The Curvularia Leaf Spot is becoming more common due to the culture expansion and the low resistance of the cultivated genotypes in tropical regions. Thus, the objective was to evaluate the fungitoxicity of the essential oil of Cymbopogon citratus upon the phytopathogen Curvularia lunata, causative agent of the Curvularia Leaf Spot. There was realized pathogenicity tests of C. lunata in maize plants, phytotoxicity of the essential oil of C. citratus and gas chromatography attached, germination tests of the conidia, and of in vitro inhibition of C. lunata. Also, there were realized tests aiming at verifying the phytopathogen control in vivo. In the pathogenicity tests, there were verified symptoms of the disease in all of the suspensions tested on plants. It was observed that the essential oil concentrations of 7.5 µL mL−1 to 50 µL mL−1 were phytotoxic. The majoritarian chemical components of the essential oil of C. citratus were Geranial (41.46%) and Neral (32.43%). The concentrations of 5 and 7.5 µL mL−1 inhibited 100% of conidia germination. None of the concentrations evaluated effectively inhibited C. lunata mycelial growth in in vitro tests. In the preventive control, the concentration of 7.5 µL mL−1 was sufficient for the reduction of the progress of the disease, however the curative control was not efficient on the tested dosages. PMID:28930276

  17. Determination of the Heterotic groups of Maize inbred lines and the ...

    African Journals Online (AJOL)

    Maize weevil (Sitophilus zeamais Motschulsky) is a major maize (Zea mays L) storage insect pest in the tropics. Fifty-two inbred lines developed for weevil resistance were crossed to two testers, A and B, to determine their heterotic groups and inheritance of resistance to maize weevil. For 10 testcrosses selected for ...

  18. Adapting maize production to drought in the Northeast Farming Region of China

    DEFF Research Database (Denmark)

    Yin, Xiaogang; Olesen, Jørgen Eivind; Wang, M.

    2016-01-01

    Maize (Zea mays L.) is the most prominent crop in the Northeast Farming Region of China (NFR), and drought has been the largest limitation for maize production in this area during recent decades. The question of how to adapt maize production to drought has received great attention from policy...

  19. The W22 genome: a foundation for maize functional genomics and transposon biology

    Science.gov (United States)

    The maize W22 inbred has served as a platform for maize genetics since the mid twentieth century. To streamline maize genome analyses, we have sequenced and de novo assembled a W22 reference genome using small-read sequencing technologies. We show that significant structural heterogeneity exists in ...

  20. Econometric analysis of improved maize varieties and sustainable agricultural practices (SAPs) in Eastern Zambia

    NARCIS (Netherlands)

    Manda, J.

    2016-01-01

    Maize is the principle food staple in Zambia, providing both food and income for most of the rural populace. It is estimated that over 50% of the daily caloric intake is derived from maize; with an average consumption of over 85kg per year. Because of the importance of maize, a number of improved

  1. Significant yield increases from control of leaf diseases in maize - an overlooked problem?!

    DEFF Research Database (Denmark)

    Jørgensen, Lise Nistrup

    2012-01-01

    The area of maize has increased in several European countries in recent years. In Denmark, the area has increased from 10,000 ha in 1980 to 185,000 ha in 2011. Initially only silage maize was cultivated in Denmark, but in more recent years the area of grain maize has also increased. Farms growing...

  2. The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments.

    Directory of Open Access Journals (Sweden)

    Renata Calixto Campos

    Full Text Available Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h, a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional associated with maize management techniques. In Southern Brazil's scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost.

  3. Use of Maize (Zea mays L.) for phytomanagement of Cd-contaminated soils: a critical review.

    Science.gov (United States)

    Rizwan, Muhammad; Ali, Shafaqat; Qayyum, Muhammad Farooq; Ok, Yong Sik; Zia-Ur-Rehman, Muhammad; Abbas, Zaheer; Hannan, Fakhir

    2017-04-01

    Maize (Zea mays L.) has been widely adopted for phytomanagement of cadmium (Cd)-contaminated soils due to its high biomass production and Cd accumulation capacity. This paper reviewed the toxic effects of Cd and its management by maize plants. Maize could tolerate a certain level of Cd in soil while higher Cd stress can decrease seed germination, mineral nutrition, photosynthesis and growth/yields. Toxicity response of maize to Cd varies with cultivar/varieties, growth medium and stress duration/extent. Exogenous application of organic and inorganic amendments has been used for enhancing Cd tolerance of maize. The selection of Cd-tolerant maize cultivar, crop rotation, soil type, and exogenous application of microbes is a representative agronomic practice to enhance Cd tolerance in maize. Proper selection of cultivar and agronomic practices combined with amendments might be successful for the remediation of Cd-contaminated soils with maize. However, there might be the risk of food chain contamination by maize grains obtained from the Cd-contaminated soils. Thus, maize cultivation could be an option for the management of low- and medium-grade Cd-contaminated soils if grain yield is required. On the other hand, maize can be grown on Cd-polluted soils only if biomass is required for energy production purposes. Long-term field trials are required, including risks and benefit analysis for various management strategies aiming Cd phytomanagement with maize.

  4. African maize porridge: a food with slow in vitro starch digestibility

    CSIR Research Space (South Africa)

    Van der Merwe, B

    2001-02-15

    Full Text Available maize porridge to bread. An in vitro method was used to determine the starch digestibility of African maize porridge compared to other cereal foods. Maize porridge had a much lower in vitro starch digestibility than white bread (P<0.001). There was a...

  5. Production of high-amylose maize lines using RNA interference in ...

    African Journals Online (AJOL)

    amylose maize lines with a low T-DNA copy number, demonstrating that RNAi is an efficient method for the production of high-amylose maize lines. Key words: Maize, high-amylose, RNA interference, starch branching enzyme gene sbe2a.

  6. [Contamination with genetically modified maize MON863 of processed foods on the market].

    Science.gov (United States)

    Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

    2009-06-01

    Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize.

  7. Effects of N application on agronomic and environmental parameters in silage maize production on sandy soils

    NARCIS (Netherlands)

    Schröder, J.J.; Neeteson, J.J.; Withagen, J.C.M.; Noy, I.G.A.M.

    1998-01-01

    The current nitrogen (N) use in silage maize production can lead to considerable N losses to the environment. Maize growers fear that a reduction of N inputs needed to minimize N losses might depress yields. The objective of this study was therefore to quantify: (1) the response of silage maize dry

  8. The water footprint of sweeteners and bio-ethanol from sugar cane, sugar beet and maize

    NARCIS (Netherlands)

    Gerbens-Leenes, Winnie; Hoekstra, Arjen Ysbert

    2009-01-01

    Sugar cane and sugar beet are used for sugar for human consumption. In the US, maize is used, amongst others, for the sweetener High Fructose Maize Syrup (HFMS). Sugar cane, sugar beet and maize are also important for bio-ethanol production. The growth of crops requires water, a scarce resource. The

  9. Physiological and molecular analysis of selected Kenyan maize lines for aluminum tolerance

    Science.gov (United States)

    Aluminum (Al) toxicity is an important limitation to maize production in many tropical and sub-tropical acid soil areas. The aim of this study was to survey the variation in Al tolerance in a panel of maize lines adapted for Kenya and look for novel sources of Al tolerance. 112 Kenyan maize accessio...

  10. Partial Placement of Maize with Cocoa Husks Meals in Layers Mash ...

    African Journals Online (AJOL)

    The partial replacement value of cocoa husk meals for maize in laying hen diets were assessed under an on-farm condition, Urea-treated and untreated cocoa husk meals were each incorporated into the farmer's layer mash (FLM) to replace 25% of the maize portion. FLM contained 40% maize. Six groups of 15 laying hens ...

  11. Testing public Bt maize events for control of stem borers in the first ...

    African Journals Online (AJOL)

    Transgenic maize (Zea mays L), developed using modified genes from the bacterium Bacillus thuringiensis (Bt), controls stem borers without observable negative effects to humans, livestock or the environment, and is now sown on 134 million hectares globally. Bt maize could contribute to increasing maize production in ...

  12. Genome-Wide Association Mapping of and Aspergillus flavus Aflatoxin Accumulation Resistance in Maize

    Science.gov (United States)

    Marilyn L. Warburton; Juliet D. Tang; Gary L. Windham; Leigh K. Hawkins; Seth C. Murray; Wenwei Xu; Debbie Boykin; Andy Perkins; W. Paul Williams

    2015-01-01

    Contamination of maize (Zea mays L.) with aflatoxin, produced by the fungus Aspergillus flavus Link, has severe health and economic consequences. Efforts to reduce aflatoxin accumulation in maize have focused on identifying and selecting germplasm with natural host resistance factors, and several maize lines with significantly...

  13. The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments.

    Science.gov (United States)

    Campos, Renata Calixto; Hernández, Malva Isabel Medina

    2015-01-01

    Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h), a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional) associated with maize management techniques. In Southern Brazil's scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost.

  14. A(maize)ing attraction: gravid Anopheles arabiensis are attracted and oviposit in response to maize pollen odours.

    Science.gov (United States)

    Wondwosen, Betelehem; Hill, Sharon R; Birgersson, Göran; Seyoum, Emiru; Tekie, Habte; Ignell, Rickard

    2017-01-23

    Maize cultivation contributes to the prevalence of malaria mosquitoes and exacerbates malaria transmission in sub-Saharan Africa. The pollen from maize serves as an important larval food source for Anopheles mosquitoes, and females that are able to detect breeding sites where maize pollen is abundant may provide their offspring with selective advantages. Anopheles mosquitoes are hypothesized to locate, discriminate among, and select such sites using olfactory cues, and that synthetic volatile blends can mimic these olfactory-guided behaviours. Two-port olfactometer and two-choice oviposition assays were used to assess the attraction and oviposition preference of gravid Anopheles arabiensis to the headspace of the pollen from two maize cultivars (BH-660 and ZM-521). Bioactive compounds were identified using combined gas chromatography and electroantennographic detection from the headspace of the cultivar found to be most attractive (BH-660). Synthetic blends of the volatile compounds were then assessed for attraction and oviposition preference of gravid An. arabiensis, as above. Here the collected headspace volatiles from the pollen of two maize cultivars was shown to differentially attract and stimulate oviposition in gravid An. arabiensis. Furthermore, a five-component synthetic maize pollen odour blend was identified, which elicited the full oviposition behavioural repertoire of the gravid mosquitoes. The cues identified from maize pollen provide important substrates for the development of novel control measures that modulate gravid female behaviour. Such measures are irrespective of indoor or outdoor feeding and resting patterns, thus providing a much-needed addition to the arsenal of tools that currently target indoor biting mosquitoes.

  15. Maize transformation technology development for commercial event generation

    Science.gov (United States)

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M.

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed. PMID:25140170

  16. Preceramic maize from Paredones and Huaca Prieta, Peru.

    Science.gov (United States)

    Grobman, Alexander; Bonavia, Duccio; Dillehay, Tom D; Piperno, Dolores R; Iriarte, José; Holst, Irene

    2012-01-31

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, important problems remain. Among them is the paucity of information on maize's early morphological evolution and racial diversification brought about in part by the poor preservation of macrofossils dating to the pre-5000 calibrated years before the present period from obligate dispersal routes located in the tropical forest. We report newly discovered macrobotanical and microbotanical remains of maize that shed significant light on the chronology, land race evolution, and cultural contexts associated with the crop's early movements into South America and adaptation to new environments. The evidence comes from the coastal Peruvian sites of Paredones and Huaca Prieta, Peru; dates from the middle and late preceramic and early ceramic periods (between ca. 6700 and 3000 calibrated years before the present); and constitutes some of the earliest known cobs, husks, stalks, and tassels. The macrobotanical record indicates that a diversity of racial complexes characteristic of the Andean region emerged during the preceramic era. In addition, accelerator mass spectrometry radiocarbon determinations carried out directly on different structures of preserved maize plants strongly suggest that assays on burned cobs are more reliable than those on unburned cobs. Our findings contribute to knowledge of the early diffusion of maize and agriculture and have broader implications for understanding the development of early preindustrial human societies.

  17. Studies on maize inbred lines susceptibility to herbicides

    Directory of Open Access Journals (Sweden)

    Stefanović Lidija

    2010-01-01

    Full Text Available This paper presents the analysis of results obtained during long- term studies on the response of maize inbred lines to herbicides. Under the agroecological conditions of Zemun Polje the response (reaction of maize inbred lines to herbicides of different classes was investigated. Biological tests were performed and some agronomic, morphological, physiological and biochemical parameters were determined when the response of maize inbred lines to herbicides was estimated. The use of active ingredients of herbicides from triazine, acetanilide, thiocarbamate to new chemical groups (sulfonylurea etc., have been resulted in changes in weed suppression and susceptibility of inbred lines. Obtained results show that effects of herbicides on susceptible maize genotypes can be different: they can slowdown the growth and development and affect the plant height; they can also affect the stages of the tassel and ear development and at the end they can reduced grain yield of the tested inbreds. Numerous studies confirmed the existence of differences in susceptibility level of maize genotypes in relation to herbicides. According to gained results the recommendations for growers are made on the possibility of the application of new herbicides in the hybrid seed production.

  18. Maize transformation technology development for commercial event generation.

    Science.gov (United States)

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed.

  19. Mapping the Diversity of Maize Races in Mexico

    Science.gov (United States)

    Perales, Hugo; Golicher, Duncan

    2014-01-01

    Traditional landraces of maize are cultivated throughout more than one-half of Mexico's cropland. Efforts to organize in situ conservation of this important genetic resource have been limited by the lack of knowledge of regional diversity patterns. We used recent and historic collections of maize classified for race type to determine biogeographic regions and centers of landrace diversity. We also analyzed how diversity has changed over the last sixty years. Based on racial composition of maize we found that Mexico can be divided into 11 biogeographic regions. Six of these biogeographic regions are in the center and west of the country and contain more than 90% of the reported samples for 38 of the 47 races studied; these six regions are also the most diverse. We found no evidence of rapid overall decline in landrace diversity for this period. However, several races are now less frequently reported and two regions seem to support lower diversity than in previous collection periods. Our results are consistent with a previous hypothesis for diversification centers and for migration routes of original maize populations merging in western central Mexico. We provide maps of regional diversity patterns and landrace based biogeographic regions that may guide efforts to conserve maize genetic resources. PMID:25486121

  20. Sugar transport by maize endosperm suspension cultures

    International Nuclear Information System (INIS)

    Felker, F.C.; Goodwin, J.C.

    1987-01-01

    To determine the mechanism of sugar uptake by suspension cultures derived from developing maize (Zea mays L.) endosperm, incorporation of radioactivity from 14 C-sugars by the tissue in the mid-log phase of growth was examined. Among the sugars tested was l'-deoxy-l'-fluorosucrose (FS), a derivative not hydrolyzed by invertase but recognized by sucrose carriers in other systems. At 40 mM, uptake of label from FS was 23% of that from sucrose, while uptake of label from L-glucose (used as a control for medium carry-over and adsorption) was 16% of that from sucrose. Uptake of label from sucrose did not increase at concentrations above 50 mM, possibly due to a rate-limiting requirement for extracellular hydrolysis. Kinetic analysis revealed both saturable and linear components of uptake for glucose and fructose. The rate of fructose uptake exceeded that of glucose at all concentrations. Fructose uptake at 20 mM was inhibited by NaN 3 , HgCl 2 , dinitrophenol, carbonyl cyanide m-chlorophenylhydrazone, and p-chloromercuribenzenesulfonic acid. Results suggest that sucrose is hydrolyzed prior to uptake, and that fructose is transported preferentially by a carrier sensitive to an external sulfhydryl group inhibitor. Metabolic activity is required for sugar uptake. The specificity of the hexose transporter is currently being investigated