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  1. Genetic analysis of central carbon metabolism unveils an amino acid substitution that alters maize NAD-dependent isocitrate dehydrogenase activity.

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    Nengyi Zhang

    Full Text Available BACKGROUND: Central carbon metabolism (CCM is a fundamental component of life. The participating genes and enzymes are thought to be structurally and functionally conserved across and within species. Association mapping utilizes a rich history of mutation and recombination to achieve high resolution mapping. Therefore, applying association mapping in maize (Zea mays ssp. mays, the most diverse model crop species, to study the genetics of CCM is a particularly attractive system. METHODOLOGY/PRINCIPAL FINDINGS: We used a maize diversity panel to test the CCM functional conservation. We found heritable variation in enzyme activity for every enzyme tested. One of these enzymes was the NAD-dependent isocitrate dehydrogenase (IDH, E.C. 1.1.1.41, in which we identified a novel amino-acid substitution in a phylogenetically conserved site. Using candidate gene association mapping, we identified that this non-synonymous polymorphism was associated with IDH activity variation. The proposed mechanism for the IDH activity variation includes additional components regulating protein level. With the comparison of sequences from maize and teosinte (Zea mays ssp. Parviglumis, the maize wild ancestor, we found that some CCM genes had also been targeted for selection during maize domestication. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate the efficacy of association mapping for dissecting natural variation in primary metabolic pathways. The considerable genetic diversity observed in maize CCM genes underlies heritable phenotypic variation in enzyme activities and can be useful to identify putative functional sites.

  2. Ultrastructural Alteration of Maize Plants Infected with the Maize Rough Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    LI Zhao-hui; GUO Xing-qi; YE Bao-hua; GUO Yan-kui

    2002-01-01

    The ultrastruetural alteration of maize plants infected with the maize rough dwarf virus (MRDV) was studied with transmission electron microscopy. The results revealed that aggregates of virus particles, with a diameter of 60nm, were found in the root cell, and always distributed near the vacuole membrane. However, no such particles were checked in leaf cells. Moreover, no virus was observed in choroplasts,mitochondria nuclei, plasmodesmata or intercellular canal of all kinds of infected cells of maize, either.Structures of various organelles changed in the infected leaf and root cells of maize. An inward collapse and localized splitting of the tonoplast were observed, the chloropoast structure was destroyed by MRDV, and the number of destroyed or dysplasia chloroplast in leaf cells with serious symptoms was more than that in leaves without symptoms. The matrix of mitochondria in cells infected by MRDV decreased and some of them expanded and destructed. Nuclei was abnormal and the nuclear membrane was broken, In addition, the infected cells were characterized by a voluminous cytoplasm containing hypertrophied endoplasmic reticulum, with rich ribosome content and lots of starch grain.

  3. NAD+-dependent deacetylase Hst1p controls biosynthesis and cellular NAD+ levels in Saccharomyces cerevisiae.

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    Bedalov, Antonio; Hirao, Maki; Posakony, Jeffrey; Nelson, Melisa; Simon, Julian A

    2003-10-01

    Nicotine adenine dinucleotide (NAD(+)) performs key roles in electron transport reactions, as a substrate for poly(ADP-ribose) polymerase and NAD(+)-dependent protein deacetylases. In the latter two processes, NAD(+) is consumed and converted to ADP-ribose and nicotinamide. NAD(+) levels can be maintained by regeneration of NAD(+) from nicotinamide via a salvage pathway or by de novo synthesis of NAD(+) from tryptophan. Both pathways are conserved from yeast to humans. We describe a critical role of the NAD(+)-dependent deacetylase Hst1p as a sensor of NAD(+) levels and regulator of NAD(+) biosynthesis. Using transcript arrays, we show that low NAD(+) states specifically induce the de novo NAD(+) biosynthesis genes while the genes in the salvage pathway remain unaffected. The NAD(+)-dependent deacetylase activity of Hst1p represses de novo NAD(+) biosynthesis genes in the absence of new protein synthesis, suggesting a direct effect. The known Hst1p binding partner, Sum1p, is present at promoters of highly inducible NAD(+) biosynthesis genes. The removal of HST1-mediated repression of the NAD(+) de novo biosynthesis pathway leads to increased cellular NAD(+) levels. Transcript array analysis shows that reduction in cellular NAD(+) levels preferentially affects Hst1p-regulated genes in comparison to genes regulated with other NAD(+)-dependent deacetylases (Sir2p, Hst2p, Hst3p, and Hst4p). In vitro experiments demonstrate that Hst1p has relatively low affinity toward NAD(+) in comparison to other NAD(+)-dependent enzymes. These findings suggest that Hst1p serves as a cellular NAD(+) sensor that monitors and regulates cellular NAD(+) levels. PMID:12972620

  4. Biochemical and molecular characterization of the NAD(+)-dependent isocitrate dehydrogenase from the chemolithotroph Acidithiobacillus thiooxidans.

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    Inoue, Hiroyuki; Tamura, Takashi; Ehara, Nagisa; Nishito, Akira; Nakayama, Yumi; Maekawa, Makiko; Imada, Katsumi; Tanaka, Hidehiko; Inagaki, Kenji

    2002-08-27

    An isocitrate dehydrogenase (ICDH) with an unique coenzyme specificity from Acidithiobacillus thiooxidans was purified and characterized, and its gene was cloned. The native enzyme was homodimeric with a subunit of M(r) 45000 and showed a 78-fold preference for NAD(+) over NADP(+). The cloned ICDH gene (icd) was expressed in an icd-deficient strain of Escherichia coli EB106; the activity was found in the cell extract. The gene encodes a 429-amino acid polypeptide and is located between open reading frames encoding a putative aconitase gene (upstream of icd) and a putative succinyl-CoA synthase beta-subunit gene (downstream of icd). A. thiooxidans ICDH showed high sequence similarity to bacterial NADP(+)-dependent ICDH rather than eukaryotic NAD(+)-dependent ICDH, but the NAD(+)-preference of the enzyme was suggested due to residues conserved in the coenzyme binding site of the NAD(+)-dependent decarboxylating dehydrogenase.

  5. NAD+-Dependent Deacetylase Hst1p Controls Biosynthesis and Cellular NAD+ Levels in Saccharomyces cerevisiae

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    Bedalov, Antonio; Hirao, Maki; Posakony, Jeffrey; Nelson, Melisa; Simon, Julian A.

    2003-01-01

    Nicotine adenine dinucleotide (NAD+) performs key roles in electron transport reactions, as a substrate for poly(ADP-ribose) polymerase and NAD+-dependent protein deacetylases. In the latter two processes, NAD+ is consumed and converted to ADP-ribose and nicotinamide. NAD+ levels can be maintained by regeneration of NAD+ from nicotinamide via a salvage pathway or by de novo synthesis of NAD+ from tryptophan. Both pathways are conserved from yeast to humans. We describe a critical role of the ...

  6. Ligation reaction specificities of an NAD+-dependent DNA ligase from the hyperthermophile Aquifex aeolicus

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    Tong, Jie; Barany, Francis; Cao, Weiguo

    2000-01-01

    An NAD+-dependent DNA ligase from the hyperthermophilic bacterium Aquifex aeolicus was cloned, expressed in Escherichia coli and purified to homogeneity. The enzyme is most active in slightly alkaline pH conditions with either Mg2+ or Mn2+ as the metal cofactor. Ca2+ and Ni2+ mainly support formation of DNA–adenylate intermediates. The catalytic cycle is characterized by a low kcat value of 2 min–1 with concomitant accumulation of the DNA–adenylate intermediate when Mg2+ is used as the metal ...

  7. Metabolic control of cell division in α-proteobacteria by a NAD-dependent glutamate dehydrogenase.

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    Beaufay, François; De Bolle, Xavier; Hallez, Régis

    2016-01-01

    Prior to initiate energy-consuming processes, such as DNA replication or cell division, cells need to evaluate their metabolic status. We have recently identified and characterized a new connection between metabolism and cell division in the α-proteobacterium Caulobacter crescentus. We showed that an NAD-dependent glutamate dehydrogenase (GdhZ) coordinates growth with cell division according to its enzymatic activity. Here we report the conserved role of GdhZ in controlling cell division in another α-proteobacterium, the facultative intracellular pathogen Brucella abortus. We also discuss the importance of amino acids as a main carbon source for α-proteobacteria.

  8. A NAD-dependent glutamate dehydrogenase coordinates metabolism with cell division in Caulobacter crescentus.

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    Beaufay, François; Coppine, Jérôme; Mayard, Aurélie; Laloux, Géraldine; De Bolle, Xavier; Hallez, Régis

    2015-07-01

    Coupling cell cycle with nutrient availability is a crucial process for all living cells. But how bacteria control cell division according to metabolic supplies remains poorly understood. Here, we describe a molecular mechanism that coordinates central metabolism with cell division in the α-proteobacterium Caulobacter crescentus. This mechanism involves the NAD-dependent glutamate dehydrogenase GdhZ and the oxidoreductase-like KidO. While enzymatically active GdhZ directly interferes with FtsZ polymerization by stimulating its GTPase activity, KidO bound to NADH destabilizes lateral interactions between FtsZ protofilaments. Both GdhZ and KidO share the same regulatory network to concomitantly stimulate the rapid disassembly of the Z-ring, necessary for the subsequent release of progeny cells. Thus, this mechanism illustrates how proteins initially dedicated to metabolism coordinate cell cycle progression with nutrient availability.

  9. Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration.

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    Parmentier, S; Arnaut, F; Soetaert, W; Vandamme, E J

    2003-01-01

    D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.

  10. Altered starch structure is associated with endosperm modification in Quality Protein Maize

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    Gibbon, Bryan C.; Wang, Xuelu; Larkins, Brian A

    2003-01-01

    The biochemical basis of modified kernel texture in Quality Protein Maize (QPM) is poorly understood. Proteomic analysis of several QPM lines indicated increased levels of granule-bound starch synthase I in the soluble nonzein protein fraction of these genotypes. Increased extraction of this enzyme reflected a change in starch structure, which was manifested as shorter amylopectin branches and increased starch-granule swelling. In mature kernels, these alterations in starch structure were ass...

  11. Phenotypic and genetic characterization of NAD-dependent Pasteurellaceae from the respiratory tract of pigs and their possible pathogenetic importance

    DEFF Research Database (Denmark)

    Kielstein, P.; Wuthe, H.H.; Angen, Øystein;

    2001-01-01

    . In the present study, 107 of these NAD-dependent isolates from the porcine respiratory tract, primarily from lungs with pathological changes, were investigated. On the basis of phenotypic criteria, such as haemolysis, urease, catalase, and indole formation as well as other fermentative activities, 50...

  12. Purification and characterization of the plastid-localized NAD-dependent malate dehydrogenase from Arabidopsis thaliana.

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    An, Yan; Cao, Youzhi; Xu, Yingwu

    2016-07-01

    Malate dehydrogenase (MDH) ubiquitously exists in living organisms and has many isoforms in a single species. MDHs from some classes have been characterized for their catalytic properties, which show significant variations despite that they share high sequence identity for the active sites. One class MDH, the plastid-localized NAD-dependent MDH (plNAD-MDH) is known to be important for plant survival in a dark environment, but its biochemical and enzymatic properties have not been well characterized. This study attempts to fill the gap. plNAD-MDH was expressed in an Escherichia coli system and purified using nickel-affinity chromatography followed by size exclusion chromatography. The N-terminal fusion his-tag was removed by protease cleavage. The gel filtration assay and glutaraldehyde cross-linking results showed that the active enzyme was a homodimer in solution. Further assay indicated that plNAD-MDH is most active at a neutral pH value. The Km values for oxaloacetate and NADH are found in the submillimolar order, a median range for most MDHs. The maximum reaction rate values, however, are dramatically different from other plant MDHs, indicating that plNAD-MDH has different substrate specificity. Moreover, we obtained crystals for this enzyme, which laid the groundwork for further analysis of the enzymatic mechanism from structural stand point. PMID:26095832

  13. Virulence of South African isolates of Haemophilus paragallinarum. Part 1: NAD-dependent field isolates.

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    Bragg, R R

    2002-06-01

    The virulence of four South African field isolates of NAD-dependent Haemophilus paragallinarum, representing the four serovars known to occur in that country, was investigated. During this study an alternative challenge model for infectious coryza was used, in which the infectivity as well the virulence of different isolates could be evaluated. The challenge model consisted of the direct challenge, via intrasinus injection of one chicken in a row of interconnected layer cages, containing 10 chickens, which are subsequently infected by natural routes. A scoring system of the clinical signs was established in which a score is given to the ability of the isolate to produce clinical signs in the challenge birds. The mean daily disease score for the flock can be calculated and plotted on a graph to give a graphic representation of the disease profile. A mean disease score, calculated over a 20-day examination period can be calculated. Isolates can then be compared to each other, either graphically or by a comparison of the mean disease scores. It has been demonstrated using this scoring system that the South African serogroup C isolates appear to be more virulent than the South African serogroup A or B isolates. It was further established that the serovar C-3 isolate appeared to be the most virulent.

  14. Soil microbial biomass alterations during the maize silage growing season relative to tillage method

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    Staley, T.E.

    1999-12-01

    Tillage method can significantly alter soil microbial populations and activities. Although considerable literature exists on microbial and soil chemical alterations under various tillage methods, little information exists on soil microbial biomass C (SMB) alterations during the growing season, and especially on the relationship of SMB to crop N use. The objective of this study was to determine the effect of notillage (NT) or conventional tillage (CT), and soil location, on SMB during the growing season. A maize (Zea mays L.) silage/{sup 15}N field experiment, under NT or CT for 3 yr before this study, was used during the fourth growing season. Averaged over sampling times and location (within-row or between-row), SMB in the 0- to 3.8-cm and 3.8- to 7.5-cm soil layers under NT was 87 and 33% greater, respectively, than under CT. Linear regression of soil surface layer (0--3.8 cm) SMB on day-of-year revealed a significant (P {le} 0.10) relationship only within-row and under NT, with a 29% SMB decrease during the growing season. Similar regressions for the other layers and treatments were significant (P > 0.10) or had small seasonal differences. SMB was consistently higher in the between-row locations under both tillage methods. Despite substantial tillage method-induced differences in SMB (50% overall, accompanied by small differential seasonal differences) in the more surficial layers, these alterations appear to have been of little practical consequence, since previous work on these plots revealed essentially no differences in silage utilization of either fertilizer N or soil N relative to tillage method. Thus, the importance of SMB in significantly affecting crop N use in this within-row, banded, maize silage system is questioned.

  15. Molecular characterization of NAD+-dependent DNA ligase from Wolbachia endosymbiont of lymphatic filarial parasite Brugia malayi.

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    Nidhi Shrivastava

    Full Text Available The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD(+-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD(+-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD(+-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies.

  16. Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia

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    Vitorino Patrícia Goulart

    2001-01-01

    Full Text Available This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR. The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively.

  17. Mutational Analysis of Bacterial NAD+-dependent DNA Ligase:Role of Motif Ⅳ in Ligation Catalysis

    Institute of Scientific and Technical Information of China (English)

    Hong FENG

    2007-01-01

    The bacterial DNA ligase as a multiple domain protein is involved in DNA replication, repair and recombination. Its catalysis of ligation can be divided into three steps. To delineate the roles of amino acid residues in motif Ⅳ in ligation catalysis, site-directed mutants were constructed in a bacterial NAD+-dependent DNA ligase from Thermus sp. TAK16D. It was shown that four conserved residues (D286, G287, V289 and K291) in motif Ⅳ had significant roles on the overall ligation. Under single turnover conditions, the observed apparent rates of D286E, G287A, V289I and K291R mutants were clearly reduced compared with that of WT ligase on both match and mismatch nicked substrates. The effects of D286E mutation on overall ligation may not only be ascribed to the third step. The G287A mutation has a major effect on the second step. The effects of V289I and K291R mutation on overall ligation are not on the third step, perhaps other aspects, such as conformation change of ligase protein in ligation catalysis, are involved. Moreover, the amino acid substitutions of above four residues were more sensitive on mismatch nicked substrate, indicating an enhanced ligation fidelity.

  18. Mitochondrial NAD+-dependent malic enzyme from Anopheles stephensi: a possible novel target for malaria mosquito control

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    Pon Jennifer

    2011-10-01

    Full Text Available Abstract Background Anopheles stephensi mitochondrial malic enzyme (ME emerged as having a relevant role in the provision of pyruvate for the Krebs' cycle because inhibition of this enzyme results in the complete abrogation of oxygen uptake by mitochondria. Therefore, the identification of ME in mitochondria from immortalized A. stephensi (ASE cells and the investigation of the stereoselectivity of malate analogues are relevant in understanding the physiological role of ME in cells of this important malaria parasite vector and its potential as a possible novel target for insecticide development. Methods To characterize the mitochondrial ME from immortalized ASE cells (Mos. 43; ASE, mass spectrometry analyses of trypsin fragments of ME, genomic sequence analysis and biochemical assays were performed to identify the enzyme and evaluate its activity in terms of cofactor dependency and inhibitor preference. Results The encoding gene sequence and primary sequences of several peptides from mitochondrial ME were found to be highly homologous to the mitochondrial ME from Anopheles gambiae (98% and 59% homologous to the mitochondrial NADP+-dependent ME isoform from Homo sapiens. Measurements of ME activity in mosquito mitochondria isolated from ASE cells showed that (i Vmax with NAD+ was 3-fold higher than that with NADP+, (ii addition of Mg2+ or Mn2+ increased the Vmax by 9- to 21-fold, with Mn2+ 2.3-fold more effective than Mg2+, (iii succinate and fumarate increased the activity by 2- and 5-fold, respectively, at sub-saturating concentrations of malate, (iv among the analogs of L-malate tested as inhibitors of the NAD+-dependent ME catalyzed reaction, small (2- to 3-carbons organic diacids carrying a 2-hydroxyl/keto group behaved as the most potent inhibitors of ME activity (e.g., oxaloacetate, tartronic acid and oxalate. Conclusions The biochemical characterization of Anopheles stephensi ME is of critical relevance given its important role in

  19. Tunneling of redox enzymes to design nano-probes for monitoring NAD(+) dependent bio-catalytic activity.

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    Akshath, Uchangi Satyaprasad; Bhatt, Praveena

    2016-11-15

    Monitoring of bio-catalytic events by using nano-probes is of immense interest due to unique optical properties of metal nanoparticles. In the present study, tunneling of enzyme activity was achieved using redox cofactors namely oxidized cytochrome-c (Cyt-c) and Co-enzyme-Q (Co-Q) immobilized on Quantum dots (QDs) which acted as a bio-probe for NAD(+) dependent dehydrogenase catalyzed reaction. We studied how electron transfer from substrate to non-native electron acceptors can differentially modify photoluminescence properties of CdTe QDs. Two probes were designed, QD-Ox-Cyt-c and QD-Ox-Co-Q, which were found to quench the fluorescence of QDs. However, formaldehyde dehydrogenase (FDH) catalyzed reduction of Cyt-c and Co-Q on the surface of QDs lead to fluorescence turn-on of CdTe QDs. This phenomenon was successfully used for the detection of HCHO in the range of 0.01-100,000ng/mL (LOD of 0.01ng/mL) using both QD-Ox-Cyt-c (R(2)=0.93) and QD-Ox-Co-Q (R(2)=0.96). Further probe performance and stability in samples like milk, wine and fruit juice matrix were studied and we could detect HCHO in range of 0.001-100,000ng/mL (LOD of 0.001ng/mL) with good stability and sensitivity of probe in real samples (R(2)=0.97). Appreciable recovery and detection sensitivity in the presence of metal ions suggests that the developed nano-probes can be used successfully for monitoring dehydrogenase based bio-catalytic events even in the absence of NAD(+). Proposed method is advantageous over classical methods as clean up/ derivatization of samples is not required for formaldehyde detection. PMID:27179565

  20. M. tuberculosis sliding β-clamp does not interact directly with the NAD+-dependent DNA ligase.

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    Vandna Kukshal

    Full Text Available The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp to 3.0 Å resolution. The protein crystallized in the space group C222(1 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent K(d of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD(+-dependent DNA ligase (LigA and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria.

  1. Inhibition of the NAD-dependent protein deacetylase SIRT2 induces granulocytic differentiation in human leukemia cells.

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    Yoshitaka Sunami

    Full Text Available Sirtuins, NAD-dependent protein deacetylases, play important roles in cellular functions such as metabolism and differentiation. Whether sirtuins function in tumorigenesis is still controversial, but sirtuins are aberrantly expressed in tumors, which may keep cancerous cells undifferentiated. Therefore, we investigated whether the inhibition of sirtuin family proteins induces cellular differentiation in leukemic cells. The sirtuin inhibitors tenovin-6 and BML-266 induce granulocytic differentiation in the acute promyelocytic leukemia (APL cell line NB4. This differentiation is likely caused by an inhibition of SIRT2 deacetylase activity, judging from the accumulation of acetylated α-tubulin, a major SIRT2 substrate. Unlike the clinically used differentiation inducer all-trans retinoic acid, tenovin-6 shows limited effects on promyelocytic leukemia-retinoic acid receptor α (PML-RAR-α stability and promyelocytic leukemia nuclear body formation in NB4 cells, suggesting that tenovin-6 does not directly target PML-RAR-α activity. In agreement with this, tenovin-6 induces cellular differentiation in the non-APL cell line HL-60, where PML-RAR-α does not exist. Knocking down SIRT2 by shRNA induces granulocytic differentiation in NB4 cells, which demonstrates that the inhibition of SIRT2 activity is sufficient to induce cell differentiation in NB4 cells. The overexpression of SIRT2 in NB4 cells decreases the level of granulocytic differentiation induced by tenovin-6, which indicates that tenovin-6 induces granulocytic differentiation by inhibiting SIRT2 activity. Taken together, our data suggest that targeting SIRT2 is a viable strategy to induce leukemic cell differentiation.

  2. Amino acid residues involved in the catalytic mechanism of NAD-dependent glutamate dehydrogenase from Halobacterium salinarum.

    Science.gov (United States)

    Pérez-Pomares, F; Ferrer, J; Camacho, M; Pire, C; LLorca, F; Bonete, M J

    1999-02-01

    The pH dependence of kinetic parameters for a competitive inhibitor (glutarate) was determined in order to obtain information on the chemical mechanism for NAD-dependent glutamate dehydrogenase from Halobacterium salinarum. The maximum velocity is pH dependent, decreasing at low pHs giving a pK value of 7.19+/-0.13, while the V/K for l-glutamate at 30 degrees C decreases at low and high pHs, yielding pK values of 7.9+/-0.2 and 9.8+/-0.2, respectively. The glutarate pKis profile decreases at high pHs, yielding a pK of 9. 59+/-0.09 at 30 degrees C. The values of ionization heat calculated from the change in pK with temperature are: 1.19 x 10(4), 5.7 x 10(3), 7 x 10(3), 6.6 x 10(3) cal mol-1, for the residues involved. All these data suggest that the groups required for catalysis and/or binding are lysine, histidine and tyrosine. The enzyme shows a time-dependent loss in glutamate oxidation activity when incubated with diethyl pyrocarbonate (DEPC). Inactivation follows pseudo-first-order kinetics with a second-order rate constant of 53 M-1min-1. The pKa of the titratable group was pK1=6.6+/-0.6. Inactivation with ethyl acetimidate also shows pseudo-first-order kinetics as well as inactivation with TNM yielding second-order constants of 1.2 M-1min-1 and 2.8 M-1min-1, and pKas of 8.36 and 9.0, respectively. The proposed mechanism involves hydrogen binding of each of the two carboxylic groups to tyrosyl residues; histidine interacts with one of the N-hydrogens of the l-glutamate amino group. We also corroborate the presence of a conservative lysine that has a remarkable ability to coordinate a water molecule that would act as general base.

  3. Altered Lignin Biosynthesis Improves Cellulosic Bioethanol Production in Transgenic Maize Plants Down-Regulated for Cinnamyl Alcohol Dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    Silvia Fornalé; Pere Puigdomènech; Joan Rigau; David Caparrós-Ruiz; Montserrat Capellades; Antonio Encina; Kan Wang; Sami Irar; Catherine Lapierre; Katia Ruel; Jean-Paul Joseleau; Jordi Berenguer

    2012-01-01

    Cinnamyl alcohol dehydrogenase(CAD)is a key enzyme involved in the last step of monolignol biosynthesis.The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize.Transgenic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alterations in cell wall composition.Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content.In addition,these cell walls accumulate higher levels of cellulose and arabinoxylans.In contrast,cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides.In vitro degradability assays showed that,although to a different extent,the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants.CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass.Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type,making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.

  4. A "stripping" ligand tactic for use with the kinetic locking-on strategy: its use in the resolution and bioaffinity chromatographic purification of NAD(+)-dependent dehydrogenases.

    Science.gov (United States)

    O'Flaherty, M; O'Carra, P; McMahon, M; Mulcahy, P

    1999-08-01

    The kinetic locking-on strategy utilizes soluble analogues of the target enzymes' specific substrate to promote selective adsorption of individual NAD(+)-dependent dehydrogenases on their complementary immobilized cofactor derivative. Application of this strategy to the purification of NAD(+)-dependent dehydrogenases from crude extracts has proven that it can yield bioaffinity systems capable of producing one-chromatographic-step purifications with yields approaching 100%. However, in some cases the purified enzyme preparation was found to be contaminated with other proteins weakly bound to the immobilized cofactor derivative through binary complex formation and/or nonspecific interactions, which continuously "dribbled" off the matrix during the chromatographic procedure. The fact that this problem can be overcome by including a short pulse of 5'-AMP (stripping ligand) in the irrigant a couple of column volumes prior to the discontinuation of the specific substrate analogue (locking-on ligand) is clear from the results presented in this report. The general effectiveness of this auxiliary tactic has been assessed using model studies and through incorporation into an actual purification from a crude cellular extract. The results confirm the usefulness of the stripping-ligand tactic for the resolution and purification of NAD(+)-dependent dehydrogenases when using the locking-on strategy. These studies have been carried out using bovine liver glutamate dehydrogenase (GDH, EC 1.4.1.3), yeast alcohol dehydrogenase (YADH, EC 1.1.1.1), porcine heart mitochondrial malate dehydrogenase (mMDH, EC 1.1.1.37), and bovine heart L-lactate dehydrogenase (l-LDH, EC 1.1.1.27).

  5. A "stripping" ligand tactic for use with the kinetic locking-on strategy: its use in the resolution and bioaffinity chromatographic purification of NAD(+)-dependent dehydrogenases.

    Science.gov (United States)

    O'Flaherty, M; O'Carra, P; McMahon, M; Mulcahy, P

    1999-08-01

    The kinetic locking-on strategy utilizes soluble analogues of the target enzymes' specific substrate to promote selective adsorption of individual NAD(+)-dependent dehydrogenases on their complementary immobilized cofactor derivative. Application of this strategy to the purification of NAD(+)-dependent dehydrogenases from crude extracts has proven that it can yield bioaffinity systems capable of producing one-chromatographic-step purifications with yields approaching 100%. However, in some cases the purified enzyme preparation was found to be contaminated with other proteins weakly bound to the immobilized cofactor derivative through binary complex formation and/or nonspecific interactions, which continuously "dribbled" off the matrix during the chromatographic procedure. The fact that this problem can be overcome by including a short pulse of 5'-AMP (stripping ligand) in the irrigant a couple of column volumes prior to the discontinuation of the specific substrate analogue (locking-on ligand) is clear from the results presented in this report. The general effectiveness of this auxiliary tactic has been assessed using model studies and through incorporation into an actual purification from a crude cellular extract. The results confirm the usefulness of the stripping-ligand tactic for the resolution and purification of NAD(+)-dependent dehydrogenases when using the locking-on strategy. These studies have been carried out using bovine liver glutamate dehydrogenase (GDH, EC 1.4.1.3), yeast alcohol dehydrogenase (YADH, EC 1.1.1.1), porcine heart mitochondrial malate dehydrogenase (mMDH, EC 1.1.1.37), and bovine heart L-lactate dehydrogenase (l-LDH, EC 1.1.1.27). PMID:10425164

  6. Expression, purification, crystallization and preliminary X-ray analysis of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from Helicobacter pylori

    International Nuclear Information System (INIS)

    Glyceraldehyde-3-phosphate dehydrogenase B from H. pylori has been cloned, expressed, purified and crystallized in the presence of NAD. Crystals of GAPDHB diffracted to 2.8 Å resolution and belonged to space group P6522, with unit-cell parameters a = b = 166.1, c = 253.1 Å. Helicobacter pylori is a dangerous human pathogen that resides in the upper gastrointestinal tract. Little is known about its metabolism and with the onset of antibiotic resistance new treatments are required. In this study, the expression, purification, crystallization and preliminary X-ray diffraction of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from H. pylori are reported

  7. Methylotrophic Bacillus methanolicus encodes two chromosomal and one plasmid born NAD+ dependent methanol dehydrogenase paralogs with different catalytic and biochemical properties.

    Directory of Open Access Journals (Sweden)

    Anne Krog

    Full Text Available Bacillus methanolicus can utilize methanol as the sole carbon source for growth and it encodes an NAD(+-dependent methanol dehydrogenase (Mdh, catalyzing the oxidation of methanol to formaldehyde. Recently, the genomes of the B. methanolicus strains MGA3 (ATCC53907 and PB1 (NCIMB13113 were sequenced and found to harbor three different putative Mdh encoding genes, each belonging to the type III Fe-NAD(+-dependent alcohol dehydrogenases. In each strain, two of these genes are encoded on the chromosome and one on a plasmid; only one chromosomal act gene encoding the previously described activator protein ACT was found. The six Mdhs and the ACT proteins were produced recombinantly in Escherichia coli, purified, and characterized. All Mdhs required NAD(+ as cosubstrate, were catalytically stimulated by ACT, exhibited a broad and different substrate specificity range and displayed both dehydrogenase and reductase activities. All Mdhs catalyzed the oxidation of methanol; however the catalytic activity for methanol was considerably lower than for most other alcohols tested, suggesting that these enzymes represent a novel class of alcohol dehydrogenases. The kinetic constants for the Mdhs were comparable when acting as pure enzymes, but together with ACT the differences were more pronounced. Quantitative PCR experiments revealed major differences with respect to transcriptional regulation of the paralogous genes. Taken together our data indicate that the repertoire of methanol oxidizing enzymes in thermotolerant bacilli is larger than expected with complex mechanisms involved in their regulation.

  8. [Activity of liver mitochondrial NAD+-dependent dehydrogenases of the krebs cycle in rats with acetaminophen-induced hepatitis developed under conditions of alimentary protein deficiency].

    Science.gov (United States)

    Voloshchuk, O N; Kopylchuk, G P

    2016-01-01

    Activity of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, malate dehydrogenase, and the NAD(+)/NADН ratio were studied in the liver mitochondrial fraction of rats with toxic hepatitis induced by acetaminophen under conditions of alimentary protein deprivation. Acetaminophen-induced hepatitis was characterized by a decrease of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase and malate dehydrogenase activities, while the mitochondrial NAD(+)/NADН ratio remained at the control level. Modeling of acetaminophen-induced hepatitis in rats with alimentary protein caused a more pronounced decrease in the activity of NAD(+)-dependent dehydrogenases studied and a 2.2-fold increase of the mitochondrial NAD(+)/NADН ratio. This suggests that alimentary protein deprivation potentiated drug-induced liver damage.

  9. Expression, purification, crystallization and preliminary X-ray analysis of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Paul R.; Mohammad, Shabaz; Melrose, Helen J.; Moody, Peter C. E., E-mail: pcem1@leicester.ac.uk [Henry Wellcome Laboratories for Structural Biology, University of Leicester, Leicester LE1 9HN (United Kingdom)

    2008-08-01

    Glyceraldehyde-3-phosphate dehydrogenase B from H. pylori has been cloned, expressed, purified and crystallized in the presence of NAD. Crystals of GAPDHB diffracted to 2.8 Å resolution and belonged to space group P6{sub 5}22, with unit-cell parameters a = b = 166.1, c = 253.1 Å. Helicobacter pylori is a dangerous human pathogen that resides in the upper gastrointestinal tract. Little is known about its metabolism and with the onset of antibiotic resistance new treatments are required. In this study, the expression, purification, crystallization and preliminary X-ray diffraction of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from H. pylori are reported.

  10. Separation of cordycepin from Cordyceps militaris fermentation supernatant using preparative HPLC and evaluation of its antibacterial activity as an NAD+-dependent DNA ligase inhibitor

    Science.gov (United States)

    Zhou, Xiaofeng; Cai, Guoqiang; He, Yi; Tong, Guotong

    2016-01-01

    Cordycepin exhibits various bio-activities, including anticancer, antibacterial, antiviral and immune regulation activities, and is a significant focus of research. However, the preparation of high-purity cordycepin remains challenging. Also, the molecular target with which cordycepin interacts to cause an antibacterial effect remains unknown. In the present study, cordycepin was prepared by preparative high-performance liquid chromatography (prep-HPLC) and the purity obtained was 99.6%, indicating that this technique may be useful for the large-scale isolation of cordycepin in the future. The results of computational molecular docking analysis indicated that the interaction energy between cordycepin and NAD+-dependent DNA ligase (LigA) was lower than that between cordycepin and other common antibacterial targets. The highly pure cordycepin obtained by prep-HPLC demonstrated inhibitory activity against LigA from various bacteria in vitro. In conclusion, cordycepin may be useful as a broad-spectrum antibiotic targeting LigA in various bacteria. PMID:27588098

  11. Biochemical analysis of the NAD+-dependent malate dehydrogenase, a substrate of several serine/threonine protein kinases of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Xiao Ming Wang

    Full Text Available PknD is one of the eleven eukaryotic-like serine/threonine protein kinases (STPKs of Mycobacterium tuberculosis (Mtb. In vitro phosphorylation assays with the active recombinant PknD showed that the intracellular protein NAD+-dependent malate dehydrogenase (MDH is a substrate of this kinase. MDH, an energy-supplying enzyme, catalyzes the interconversion of malate and oxaloacetate and plays crucial roles in several metabolic pathways including the citric acid cycle. The phosphorylation site was identified on threonine residues and the phosphorylation inhibited the MDH activity. In vitro, the recombinant MDH could also be phosphorylated by at least five other STPKs, PknA, PknE, PknH, PknJ, and PknG. Immunoprecipitation analysis revealed that MDH was hyperphosphorylated in the bacteria at the beginning of the stationary and under oxygen-limited conditions by STPKs other than PknD. On the contrary, when PknD-deficient mutant mycobacteria were grown in a phosphate-depleted medium, MDH was not detectably phosphorylated. These results suggest that although the MDH is a substrate of several mycobacterial STPKs, the activity of these kinases can depend on the environment, as we identified PknD as a key element in the MDH phosphorylation assay under phosphate-poor conditions.

  12. Whole transcriptome profiling of maize during early somatic embryogenesis reveals altered expression of stress factors and embryogenesis-related genes.

    Directory of Open Access Journals (Sweden)

    Stella A G D Salvo

    Full Text Available Embryogenic tissue culture systems are utilized in propagation and genetic engineering of crop plants, but applications are limited by genotype-dependent culture response. To date, few genes necessary for embryogenic callus formation have been identified or characterized. The goal of this research was to enhance our understanding of gene expression during maize embryogenic tissue culture initiation. In this study, we highlight the expression of candidate genes that have been previously regarded in the literature as having important roles in somatic embryogenesis. We utilized RNA based sequencing (RNA-seq to characterize the transcriptome of immature embryo explants of the highly embryogenic and regenerable maize genotype A188 at 0, 24, 36, 48, and 72 hours after placement of explants on tissue culture initiation medium. Genes annotated as functioning in stress response, such as glutathione-S-transferases and germin-like proteins, and genes involved with hormone transport, such as PINFORMED, increased in expression over 8-fold in the study. Maize genes with high sequence similarity to genes previously described in the initiation of embryogenic cultures, such as transcription factors BABY BOOM, LEAFY COTYLEDON, and AGAMOUS, and important receptor-like kinases such as SOMATIC EMBRYOGENESIS RECEPTOR LIKE KINASES and CLAVATA, were also expressed in this time course study. By combining results from whole genome transcriptome analysis with an in depth review of key genes that play a role in the onset of embryogenesis, we propose a model of coordinated expression of somatic embryogenesis-related genes, providing an improved understanding of genomic factors involved in the early steps of embryogenic culture initiation in maize and other plant species.

  13. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development

    OpenAIRE

    Hongxia Wang; Jun Yang; Min Zhang; Weijuan Fan; Nurit Firon; Sitakanta Pattanaik; Ling Yuan; Peng Zhang

    2016-01-01

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosy...

  14. Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases.

    Science.gov (United States)

    Carrillo, Laura; Martinez, Manuel; Ramessar, Koreen; Cambra, Inés; Castañera, Pedro; Ortego, Felix; Díaz, Isabel

    2011-01-01

    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests.

  15. Deficiency of maize starch-branching enzyme i results in altered starch fine structure, decreased digestibility and reduced coleoptile growth during germination

    Directory of Open Access Journals (Sweden)

    Yandeau-Nelson Marna

    2011-05-01

    Full Text Available Abstract Background Two distinct starch branching enzyme (SBE isoforms predate the divergence of monocots and dicots and have been conserved in plants since then. This strongly suggests that both SBEI and SBEII provide unique selective advantages to plants. However, no phenotype for the SBEI mutation, sbe1a, had been previously observed. To explore this incongruity the objective of the present work was to characterize functional and molecular phenotypes of both sbe1a and wild-type (Wt in the W64A maize inbred line. Results Endosperm starch granules from the sbe1a mutant were more resistant to digestion by pancreatic α-amylase, and the sbe1a mutant starch had an altered branching pattern for amylopectin and amylose. When kernels were germinated, the sbe1a mutant was associated with shorter coleoptile length and higher residual starch content, suggesting that less efficient starch utilization may have impaired growth during germination. Conclusions The present report documents for the first time a molecular phenotype due to the absence of SBEI, and suggests strongly that it is associated with altered physiological function of the starch in vivo. We believe that these results provide a plausible rationale for the conservation of SBEI in plants in both monocots and dicots, as greater seedling vigor would provide an important survival advantage when resources are limited.

  16. Synthesis of a highly substituted N(6)-linked immobilized NAD(+) derivative using a rapid solid-phase modular approach: suitability for use with the kinetic locking-on tactic for bioaffinity purification of NAD(+)-dependent dehydrogenases.

    Science.gov (United States)

    Tynan, J; Forde, J; McMahon, M; Mulcahy, P

    2000-12-01

    This study is concerned with further development of the kinetic locking-on strategy for bioaffinity purification of NAD(+)-dependent dehydrogenases. Specifically, the synthesis of highly substituted N(6)-linked immobilized NAD(+) derivatives is described using a rapid solid-phase modular approach. Other modifications of the N(6)-linked immobilized NAD(+) derivative include substitution of the hydrophobic diaminohexane spacer arm with polar spacer arms (9 and 19.5 A) in an attempt to minimize nonbiospecific interactions. Analysis of the N(6)-linked NAD(+) derivatives confirm (i) retention of cofactor activity upon immobilization (up to 97%); (ii) high total substitution levels and high percentage accessibility levels when compared to S(6)-linked immobilized NAD(+) derivatives (also synthesized with polar spacer arms); (iii) short production times when compared to the preassembly approach to synthesis. Model locking-on bioaffinity chromatographic studies were carried out with bovine heart l-lactate dehydrogenase (l-LDH, EC 1.1.1.27), bakers yeast alcohol dehydrogenase (YADH, EC 1.1.1.1) and Sporosarcinia sp. l-phenylalanine dehydrogenase (l-PheDH, EC 1.4.1.20), using oxalate, hydroxylamine, and d-phenylalanine, respectively, as locking-on ligands. Surprisingly, two of these test NAD(+)-dependent dehydrogenases (lactate and alcohol dehydrogenase) were found to have a greater affinity for the more lowly substituted S(6)-linked immobilized cofactor derivatives than for the new N(6)-linked derivatives. In contrast, the NAD(+)-dependent phenylalanine dehydrogenase showed no affinity for the S(6)-linked immobilized NAD(+) derivative, but was locked-on strongly to the N(6)-linked immobilized derivative. That this locking-on is biospecific is confirmed by the observation that the enzyme failed to lock-on to an analogous N(6)-linked immobilized NADP(+) derivative in the presence of d-phenylalanine. This differential locking-on of NAD(+)-dependent dehydrogenases to N(6)-linked

  17. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development.

    Science.gov (United States)

    Wang, Hongxia; Yang, Jun; Zhang, Min; Fan, Weijuan; Firon, Nurit; Pattanaik, Sitakanta; Yuan, Ling; Zhang, Peng

    2016-01-01

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis. PMID:26727353

  18. The auxin-deficient defective kernel18 (dek18) mutation alters the expression of seed-specific biosynthethic genes in maize

    Science.gov (United States)

    The dek18 mutant of maize has decreased auxin content in kernels. Molecular and functional characterization of this mutant line offers the possibility to better understand auxin biology in maize seed development. Seeds of the dek18 mutants are smaller compared to wild type seeds and the vegetative d...

  19. Early Transcriptomic Adaptation to Na2CO3 Stress Altered the Expression of a Quarter of the Total Genes in the Maize Genome and Exhibited Shared and Distinctive Profiles with NaCl and High pH Stresses

    Institute of Scientific and Technical Information of China (English)

    LiMin Zhang; XiangGuo Liu; XinNing Qu; Ying Yu; SiPing Han; Yao Dou; YaoYao Xu; HaiChun Jing; DongYun Hao

    2013-01-01

    Sodium carbonate (Na2CO3) presents a huge challenge to plants by the combined damaging effects of Naþ, high pH, and CO32-. Little is known about the cellular responses to Na2CO3 stress. In this study, the transcriptome of maize (Zea mays L. cv. B73) roots exposed to Na2CO3 stress for 5 h was compared with those of NaCl and NaOH stresses. The expression of 8,319 genes, representing over a quarter of the total number of genes in the maize genome, was altered by Na2CO3 stress, and the downregulated genes (5,232) outnumbered the upregulated genes (3,087). The effects of Na2CO3 differed from those of NaCl and NaOH, primarily by downregulating different categories of genes. Pathways commonly altered by Na2CO3, NaCl, and NaOH were enriched in phenylpropanoid biosynthesis, oxidation of unsaturated fatty acids, ATP-binding cassette (ABC) transporters, as well as the metabolism of secondary metabolites. Genes for brassinosteroid biosynthesis were specifically upregulated by Na2CO3, while genes involved in ascorbate and aldarate metabolism, protein processing in the endoplasmic reticulum and by N-glycosylation, fatty acid biosynthesis, and the circadian rhythm were downregulated. This work provides the first holistic picture of early transcriptomic adaptation to Na2CO3 stress, and highlights potential molecular pathways that could be manipulated to improve tolerance in maize.

  20. A three-nucleotide mutation altering the Maize streak virus Rep pRBR-interaction motif reduces symptom severity in maize and partially reverts at high frequency without restoring pRBR-Rep binding.

    Science.gov (United States)

    Shepherd, Dionne N; Martin, Darren P; McGivern, David R; Boulton, Margaret I; Thomson, Jennifer A; Rybicki, Edward P

    2005-03-01

    Geminivirus infectivity is thought to depend on interactions between the virus replication-associated proteins Rep or RepA and host retinoblastoma-related proteins (pRBR), which control cell-cycle progression. It was determined that the substitution of two amino acids in the Maize streak virus (MSV) RepA pRBR-interaction motif (LLCNE to LLCLK) abolished detectable RepA-pRBR interaction in yeast without abolishing infectivity in maize. Although the mutant virus was infectious in maize, it induced less severe symptoms than the wild-type virus. Sequence analysis of progeny viral DNA isolated from infected maize enabled detection of a high-frequency single-nucleotide reversion of C(601)A in the 3 nt mutated sequence of the Rep gene. Although it did not restore RepA-pRBR interaction in yeast, sequence-specific PCR showed that, in five out of eight plants, the C(601)A reversion appeared by day 10 post-inoculation. In all plants, the C(601)A revertant eventually completely replaced the original mutant population, indicating a high selection pressure for the single-nucleotide reversion. Apart from potentially revealing an alternative or possibly additional function for the stretch of DNA that encodes the apparently non-essential pRBR-interaction motif of MSV Rep, the consistent emergence and eventual dominance of the C(601)A revertant population might provide a useful tool for investigating aspects of MSV biology, such as replication, mutation and evolution rates, and complex population phenomena, such as competition between quasispecies and population turnover. PMID:15722543

  1. Reshaping of the maize transcriptome by domestication.

    Science.gov (United States)

    Swanson-Wagner, Ruth; Briskine, Roman; Schaefer, Robert; Hufford, Matthew B; Ross-Ibarra, Jeffrey; Myers, Chad L; Tiffin, Peter; Springer, Nathan M

    2012-07-17

    Through domestication, humans have substantially altered the morphology of Zea mays ssp. parviglumis (teosinte) into the currently recognizable maize. This system serves as a model for studying adaptation, genome evolution, and the genetics and evolution of complex traits. To examine how domestication has reshaped the transcriptome of maize seedlings, we used expression profiling of 18,242 genes for 38 diverse maize genotypes and 24 teosinte genotypes. We detected evidence for more than 600 genes having significantly different expression levels in maize compared with teosinte. Moreover, more than 1,100 genes showed significantly altered coexpression profiles, reflective of substantial rewiring of the transcriptome since domestication. The genes with altered expression show a significant enrichment for genes previously identified through population genetic analyses as likely targets of selection during maize domestication and improvement; 46 genes previously identified as putative targets of selection also exhibit altered expression levels and coexpression relationships. We also identified 45 genes with altered, primarily higher, expression in inbred relative to outcrossed teosinte. These genes are enriched for functions related to biotic stress and may reflect responses to the effects of inbreeding. This study not only documents alterations in the maize transcriptome following domestication, identifying several genes that may have contributed to the evolution of maize, but highlights the complementary information that can be gained by combining gene expression with population genetic analyses.

  2. The NAD-Dependent Deacetylase Sirtuin-1 Regulates the Expression of Osteogenic Transcriptional Activator Runt-Related Transcription Factor 2 (Runx2 and Production of Matrix Metalloproteinase (MMP-13 in Chondrocytes in Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Koh Terauchi

    2016-06-01

    Full Text Available Aging is one of the major pathologic factors associated with osteoarthritis (OA. Recently, numerous reports have demonstrated the impact of sirtuin-1 (Sirt1, which is the NAD-dependent deacetylase, on human aging. It has been demonstrated that Sirt1 induces osteogenic and chondrogenic differentiation of mesenchymal stem cells. However, the role of Sirt1 in the OA chondrocytes still remains unknown. We postulated that Sirt1 regulates a hypertrophic chondrocyte lineage and degeneration of articular cartilage through the activation of osteogenic transcriptional activator Runx2 and matrix metalloproteinase (MMP-13 in OA chondrocytes. To verify whether sirtuin-1 (Sirt1 regulates chondrocyte activity in OA, we studied expressions of Sirt1, Runx2 and production of MMP-13, and their associations in human OA chondrocytes. The expression of Sirt1 was ubiquitously observed in osteoarthritic chondrocytes; in contrast, Runx2 expressed in the osteophyte region in patients with OA and OA model mice. OA relating catabolic factor IL-1βincreased the expression of Runx2 in OA chondrocytes. OA chondrocytes, which were pretreated with Sirt1 inhibitor, inhibited the IL-1β-induced expression of Runx2 compared to the control. Since the Runx2 is a promotor of MMP-13 expression, Sirt1 inactivation may inhibit the Runx2 expression and the resultant down-regulation of MMP-13 production in chondrocytes. Our findings suggest thatSirt1 may regulate the expression of Runx2, which is the osteogenic transcription factor, and the production of MMP-13 from chondrocytes in OA. Since Sirt1 activity is known to be affected by several stresses, including inflammation and oxidative stress, as well as aging, SIRT may be involved in the development of OA.

  3. Comparative population genomics of maize domestication and improvement.

    Science.gov (United States)

    Hufford, Matthew B; Xu, Xun; van Heerwaarden, Joost; Pyhäjärvi, Tanja; Chia, Jer-Ming; Cartwright, Reed A; Elshire, Robert J; Glaubitz, Jeffrey C; Guill, Kate E; Kaeppler, Shawn M; Lai, Jinsheng; Morrell, Peter L; Shannon, Laura M; Song, Chi; Springer, Nathan M; Swanson-Wagner, Ruth A; Tiffin, Peter; Wang, Jun; Zhang, Gengyun; Doebley, John; McMullen, Michael D; Ware, Doreen; Buckler, Edward S; Yang, Shuang; Ross-Ibarra, Jeffrey

    2012-06-03

    Domestication and plant breeding are ongoing 10,000-year-old evolutionary experiments that have radically altered wild species to meet human needs. Maize has undergone a particularly striking transformation. Researchers have sought for decades to identify the genes underlying maize evolution, but these efforts have been limited in scope. Here, we report a comprehensive assessment of the evolution of modern maize based on the genome-wide resequencing of 75 wild, landrace and improved maize lines. We find evidence of recovery of diversity after domestication, likely introgression from wild relatives, and evidence for stronger selection during domestication than improvement. We identify a number of genes with stronger signals of selection than those previously shown to underlie major morphological changes. Finally, through transcriptome-wide analysis of gene expression, we find evidence both consistent with removal of cis-acting variation during maize domestication and improvement and suggestive of modern breeding having increased dominance in expression while targeting highly expressed genes.

  4. Effects of temperature changes on maize production in Mozambique

    Science.gov (United States)

    Harrison, L.; Michaelsen, J.; Funk, C.; 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.

  5. Radiation preservation of maize

    International Nuclear Information System (INIS)

    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)

  6. IMPORTANCE OF MAIZE CROPPING

    OpenAIRE

    Mohammed Dhary Yousif EL-JUBOURI

    2012-01-01

    The Corn, wheat and rice together are the main crops. It is a plant that responds well to chemical and organic fertilization and the irrigation. But compliance is sensitive to optimum sowing time and integrated control of weeds, pests and diseases (2). The maize is the most important plant product, from the point of view commercially and is used primarily as fodder. The maize is an important source of vegetable oil and has many applications in industry, the manufacture of diverse items: cosme...

  7. 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.

  8. The Comparative Effects of Genetically Modified Maize and Conventional Maize on Wistar rats

    Directory of Open Access Journals (Sweden)

    Hasan Kýlýçgün

    2013-03-01

    Full Text Available       Aim: Genetically modified crops have a potential to solve many of the world’s  nutrition problems. On the other hand, the impact of these novel crops on environmental, animal and human health should be tested and their risk assessment is required. In this study, the aim of this study was to investigate the positive or possible negative effects of genetically modified maize on offspring rats which were between the start of dry food feeding and the time interval until they reached puberty. Material and Method: Thirty Wistar albino rats were used in this study. The rats were fed with transgenic Bacillus thuringiensis maize and conventional maize during 40 days. After the experimental period, the length, height and weight of organs and serum chemistry and hematology values were measured. Results: The length, height and weight of liver, spleen, lung and kidneys in Bacillus thuringiensis maize group of rats were different from those in control and conventional groups. When mean values of serum chemistry and hematology parameters, which were glucose, urea, total protein, cholesterol, triglyceride, very low-density lipoprotein, low-density lipoprotein, calcium, phosphorus, sodium, potassium, chlorine were examined, some obvious differences were found between the rats fed with transgenic maize and its conventional counterpart and control groups. Discussion: The results of this study showed that Bacillus  thuringiensis maize may not only have an effect on the length, height and weight of organs of the maturing term of rats but also lead to alterations in serum chemistry and hematology values.

  9. Changes in Cell Ultrastructure in Maize Leaves Infected by Maize Dwarf Mosaic Virus

    Institute of Scientific and Technical Information of China (English)

    GUO Xing-qi; ZHU Xiao-ping; ZHANG Jie-dao; GUO Yan-kui

    2003-01-01

    Ultrastructural alterations in foliar cells were studied in leaves of resistant maize varietyLuyu16 and susceptible maize inbred line Luyuan92 infected by maize dwarf mosaic virus Shandong isolate(MDMV-SD), respectively. The results showed that marked cytopathological alterations were observed both inresistant plants and in susceptible plants, compared with that in healthy plants. However, some ultrastructur-al alterations, which observed in resistant plants, were different from those in susceptible plants. In resistantplants, which infected with the virus, the main organelles, including chloroplasts and mitochondria, wereslightly destroyed, the amount of mitochondria and peroxisome were increased. A few or no plasmodesmatawere observed. There were three kinds of inclusions including pinwheel, bundle and laminated aggregate, andthe virus particles in the cytoplasm. In susceptible plants, which infected with the virus, the chloroplasts wereheavily disrupted, including thylakoid swelling and envelope broking. The virus particles were more than thosein the resistant variety. Four kinds of inclusions including pinwheel, bundle, laminated aggregate and highelecton-dense body appeared in cytoplasm. Plasmodesmata and plasma membrane were abundant, and therewere frequent invaginations of the plasma membrane that led to the formation of vesicles and myelin-likestructures.

  10. Insect Resistant Maize 5307

    OpenAIRE

    Directorate, Issued by Health Canada's Food

    2014-01-01

    Health Canada has notified Syngenta Seeds Canada Inc. that it has no objection to the sale of food derived from Insect Resistant Maize 5307. The Department conducted a comprehensive assessment of this corn event according to its Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits.

  11. Short-Term Treatment with the Urease Inhibitor N-(n-Butyl) Thiophosphoric Triamide (NBPT) Alters Urea Assimilation and Modulates Transcriptional Profiles of Genes Involved in Primary and Secondary Metabolism in Maize Seedlings

    Science.gov (United States)

    Zanin, Laura; Venuti, Silvia; Tomasi, Nicola; Zamboni, Anita; De Brito Francisco, Rita M.; Varanini, Zeno; Pinton, Roberto

    2016-01-01

    To limit nitrogen (N) losses from the soil, it has been suggested to provide urea to crops in conjunction with the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). However, recent studies reported that NBPT affects urea uptake and urease activity in plants. To shed light on these latter aspects, the effects of NBPT were studied analysing transcriptomic and metabolic changes occurring in urea-fed maize seedlings after a short-term exposure to the inhibitor. We provide evidence that NBPT treatment led to a wide reprogramming of plant metabolism. NBPT inhibited the activity of endogenous urease limiting the release and assimilation of ureic-ammonium, with a simultaneous accumulation of urea in plant tissues. Furthermore, NBPT determined changes in the glutamine, glutamate, and asparagine contents. Microarray data indicate that NBPT affects ureic-N assimilation and primary metabolism, such as glycolysis, TCA cycle, and electron transport chain, while activates the phenylalanine/tyrosine-derivative pathway. Moreover, the expression of genes relating to the transport and complexation of divalent metals was strongly modulated by NBPT. Data here presented suggest that when NBPT is provided in conjunction with urea an imbalance between C and N compounds might occur in plant cells. Under this condition, root cells also seem to activate a response to maintain the homeostasis of some micronutrients. PMID:27446099

  12. Interleukin-10 modifies the effects of interleukin-1beta and tumor necrosis factor-alpha on the activity and expression of prostaglandin H synthase-2 and the NAD+-dependent 15-hydroxyprostaglandin dehydrogenase in cultured term human villous trophoblast and chorion trophoblast cells.

    Science.gov (United States)

    Pomini, F; Caruso, A; Challis, J R

    1999-12-01

    The concentrations of tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta), two inflammatory cytokines in amniotic fluid, have been shown to rise during chorioamnionitis. This is probably related to activation of the immune system in order to intensify the inflammatory process and to protect the maternal and fetal organism from infectious agents. These cytokines activate the PG biosynthetic pathway in several tissues, but few studies have examined effects on PG-metabolizing enzymes. When PGs are produced by increased synthesis and/or decreased metabolism at the chorio-decidual interface, labor can be induced. Interleukin-10 (IL-10) is known to act as an antiinflammatory cytokine. The goals of this study were to evaluate the interaction of IL-10 with IL-1beta and TNFalpha on PG synthesis and to determine the effects of IL-10, IL-1beta, and TNFalpha on PG metabolism using purified cultures of villous trophoblast and chorion trophoblast cells prepared from placentas of patients at term. Cells were treated with IL-1beta and TNFalpha with or without IL-10 for various times up to 24 h. Levels of messenger ribonucleic acid (mRNA) encoding PGH synthase-2 (PGHS-2) and NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (PGDH) were quantified by Northern blotting, and PGE2 and 13,14-dihydro-15-keto-PGF2alpha (PGFM) output in the medium was measured by RIA. IL-1beta increased PGHS-2 mRNA and PGE2 output from villous and chorion trophoblasts and decreased PGDH mRNA in villous trophoblasts (all P < 0.05). These effects were reversed by IL-10. We found no change in PGHS-2 mRNA or PGE2 output in either trophoblast type treated with TNFalpha, but TNFalpha reduced PGDH mRNA in villous trophoblast, and this effect was reversed by IL-10 (both P < 0.05). We conclude that proinflammatory cytokines can influence PG output through effects on PG synthesis and metabolism and that these effects may be opposed by an antiinflammatory cytokine. These interactions may be

  13. Development of a Brazilian maize core collection

    Directory of Open Access Journals (Sweden)

    Ronaldo R. Coimbra

    2009-01-01

    Full Text Available The aim of this study was to evaluate methods for developing a Brazilian maize core collection. For an initial survey of the active collection, passport information, as well as characterization and evaluation of accessions, were taken into consideration, these then being divided according to geographic region and kernel-type. Multiple sampling methods were evaluated. The strategy of constant sampling generated extensive alterations in extract accession frequency. The multivariate strategy with dispersion graphs and principal components associated with the Tocher method was considered efficient for identifying the most divergent genotypes. The multivariate strategy generated greater alterations in the variance of traits. The average number of traits revealed few modifications with the various sampling strategies used. Therefore, the active collection could be considered as possessing a satisfactory amount of information for most of its accessions. Moreover, the multivariate strategy generated modifications in the variance of the traits, independent of sampling intensity.

  14. Maize variety and method of production

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Alterações morfológicas no sistema radicular do milho induzidas por fungos micorrízicos e fósforo Morphological alterations on root system of maize induced by mycorrhizal fungi and phosphorus

    Directory of Open Access Journals (Sweden)

    Wellington Bressan

    2002-04-01

    Full Text Available O objetivo deste trabalho, conduzido em casa de vegetação, foi avaliar os efeitos da inoculação de fungos micorrízicos arbusculares (Glomus etunicatum e Glomus clarum e da adição de níveis de P (0, 50, 100 e 200 mg/kg de solo sobre a morfologia do sistema radicular do milho (Zea mays L., cultivar BR 201, e a concentração de P na planta, em duas épocas de colheita (18 e 104 dias após semeadura em solo Latossolo Vermelho-Escuro distrófico desinfestado com Bromex. O experimento foi realizado na Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo, Sete Lagoas, MG. A inoculação de fungos micorrízicos aumentou o peso das raízes secas, o número de raízes laterais primárias e secundárias, e o teor de P na planta, porém reduziu a relação peso das raízes secas/peso da parte aérea seca e o número de pêlos radiculares. Esses efeitos foram dependentes das doses de P aplicadas ao solo e da espécie de fungo micorrízico. O peso das raízes secas das plantas micorrizadas mostrou correlação significativa (PThe objective of this research, carried out under greenhouse conditions was to evaluate the effect of mycorrhizal fungi (Glomus etunicatum and Glomus clarum inoculation and P levels (0, 50, 100 e 200 mg/kg of soil on maize (Zea mays L. root system morphology, cultivar BR 201, and P plant concentration in two harvest period (18 and 104 days after sowing in disinfested dystrophic Dark-Red Latosol. The experiment was carried out under greenhouse conditions at Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo, in Sete Lagoas, Minas Gerais, Brazil. Inoculation with mycorrhizal fungi increased root dry weight, number of first and second order lateral roots and P concentration in the plant, but decreased root/shoot dry weight ratio and number of root hairs. These effects were affected by P concentration in the soil and by mycorrhizal fungi species. Root dry weight of inoculated plants showed significative (P<=0.05 correlation to

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Soil microbial and faunal responses to herbicide tolerant maize and herbicide in two soils

    DEFF Research Database (Denmark)

    Griffiths, Bryan; Caul, Sandra; Thompson, J.;

    2008-01-01

    A glasshouse experiment was set up to compare processes and organisms in two soils planted with genetically modified (GM) herbicide tolerant (HT) maize treated with appropriate herbicides. This was part of a wider project (ECOGEN) looking at the consequences of GM cropping systems on soil biology...... of cotton strips and the nematode community; (3) herbicide application in general altered the community level physiological profile of the microbial community and reduced both soil basal respiration and the abundance of protozoa; and (4) the specific application of glufosinate-ammonium to T25 maize altered...

  18. Inbreeding drives maize centromere evolution.

    Science.gov (United States)

    Schneider, Kevin L; Xie, Zidian; Wolfgruber, Thomas K; Presting, Gernot G

    2016-02-23

    Functional centromeres, the chromosomal sites of spindle attachment during cell division, are marked epigenetically by the centromere-specific histone H3 variant cenH3 and typically contain long stretches of centromere-specific tandem DNA repeats (∼1.8 Mb in maize). In 23 inbreds of domesticated maize chosen to represent the genetic diversity of maize germplasm, partial or nearly complete loss of the tandem DNA repeat CentC precedes 57 independent cenH3 relocation events that result in neocentromere formation. Chromosomal regions with newly acquired cenH3 are colonized by the centromere-specific retrotransposon CR2 at a rate that would result in centromere-sized CR2 clusters in 20,000-95,000 y. Three lines of evidence indicate that CentC loss is linked to inbreeding, including (i) CEN10 of temperate lineages, presumed to have experienced a genetic bottleneck, contain less CentC than their tropical relatives; (ii) strong selection for centromere-linked genes in domesticated maize reduced diversity at seven of the ten maize centromeres to only one or two postdomestication haplotypes; and (iii) the centromere with the largest number of haplotypes in domesticated maize (CEN7) has the highest CentC levels in nearly all domesticated lines. Rare recombinations introduced one (CEN2) or more (CEN5) alternate CEN haplotypes while retaining a single haplotype at domestication loci linked to these centromeres. Taken together, this evidence strongly suggests that inbreeding, favored by postdomestication selection for centromere-linked genes affecting key domestication or agricultural traits, drives replacement of the tandem centromere repeats in maize and other crop plants. Similar forces may act during speciation in natural systems. PMID:26858403

  19. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment

    OpenAIRE

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J.; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt t...

  20. Identification and genetic characterization of maize cell wall variation for improved biorefinery feedstock characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, Markus [UC Berkeley; Hake, Sarah [USDA Albany

    2013-10-31

    The objectives of this program are to 1) characterize novel maize mutants with altered cell walls for enhanced biorefinery characteristics and 2) find quantitative trait loci (QTLs) related to biorefinery characteristics by taking advantage of the genetic diversity of maize. As a result a novel non-transgenic maize plant (cal1) has been identified, whose stover (leaves and stalk) contain more glucan in their walls leading to a higher saccharification yield, when subjected to a standard enzymatic digestion cocktail. Stacking this trait with altered lignin mutants yielded evene higher saccharification yields. Cal-1 mutants do not show a loss of kernel and or biomass yield when grown in the field . Hence, cal1 biomass provides an excellent feedstock for the biofuel industry.

  1. Intestinal and peripheral immune response to MON810 maize ingestion in weaning and old mice.

    Science.gov (United States)

    Finamore, Alberto; Roselli, Marianna; Britti, Serena; Monastra, Giovanni; Ambra, Roberto; Turrini, Aida; Mengheri, Elena

    2008-12-10

    This study evaluated the gut and peripheral immune response to genetically modified (GM) maize in mice in vulnerable conditions. Weaning and old mice were fed a diet containing MON810 or its parental control maize or a pellet diet containing a GM-free maize for 30 and 90 days. The immunophenotype of intestinal intraepithelial, spleen, and blood lymphocytes of control maize fed mice was similar to that of pellet fed mice. As compared to control maize, MON810 maize induced alterations in the percentage of T and B cells and of CD4(+), CD8(+), gammadeltaT, and alphabetaT subpopulations of weaning and old mice fed for 30 or 90 days, respectively, at the gut and peripheral sites. An increase of serum IL-6, IL-13, IL-12p70, and MIP-1beta after MON810 feeding was also found. These results suggest the importance of the gut and peripheral immune response to GM crop ingestion as well as the age of the consumer in the GMO safety evaluation. PMID:19007233

  2. MaizeGDB update: new tools, data and interface for the maize model organism database.

    Science.gov (United States)

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  3. Future carbon dioxide concentration decreases canopy evapotranspiration and soil water depletion by field-grown maize.

    Science.gov (United States)

    Hussain, Mir Zaman; Vanloocke, Andy; Siebers, Matthew H; Ruiz-Vera, Ursula M; Cody Markelz, R J; Leakey, Andrew D B; Ort, Donald R; Bernacchi, Carl J

    2013-05-01

    Maize, in rotation with soybean, forms the largest continuous ecosystem in temperate North America, therefore changes to the biosphere-atmosphere exchange of water vapor and energy of these crops are likely to have an impact on the Midwestern US climate and hydrological cycle. As a C4 crop, maize photosynthesis is already CO2 -saturated at current CO2 concentrations ([CO2 ]) and the primary response of maize to elevated [CO2 ] is decreased stomatal conductance (gs ). If maize photosynthesis is not stimulated in elevated [CO2 ], then reduced gs is not offset by greater canopy leaf area, which could potentially result in a greater ET reduction relative to that previously reported in soybean, a C3 species. The objective of this study is to quantify the impact of elevated [CO2 ] on canopy energy and water fluxes of maize (Zea mays). Maize was grown under ambient and elevated [CO2 ] (550 μmol mol(-1) during 2004 and 2006 and 585 μmol mol(-1) during 2010) using Free Air Concentration Enrichment (FACE) technology at the SoyFACE facility in Urbana, Illinois. Maize ET was determined using a residual energy balance approach based on measurements of sensible (H) and soil heat fluxes, and net radiation. Relative to control, elevated [CO2 ] decreased maize ET (7-11%; P < 0.01) along with lesser soil moisture depletion, while H increased (25-30 W m(-2) ; P < 0.01) along with higher canopy temperature (0.5-0.6 °C). This reduction in maize ET in elevated [CO2 ] is approximately half that previously reported for soybean. A partitioning analysis showed that transpiration contributed less to total ET for maize compared to soybean, indicating a smaller role of stomata in dictating the ET response to elevated [CO2 ]. Nonetheless, both maize and soybean had significantly decreased ET and increased H, highlighting the critical role of elevated [CO2 ] in altering future hydrology and climate of the region that is extensively cropped with these species. PMID:23505040

  4. ZEA MAIZE: A MODERN CRAZE

    Directory of Open Access Journals (Sweden)

    Dhamija Isha

    2013-06-01

    Full Text Available Zea stands for ‘sustaining life’ and Mays stands for ‘life giver’. Zea mays is one of the oldest and most dynamic crop species, which has gained popularity in modern world too, due to its applications in diverse dishes. Corn is produced in every continent of the world with the exception of Antarctica. It is an annual monoecious sunny plant, surviving perfectly in nutrient rich, well-drained soil. Each and every part of the corn, from husk to corn silk is beneficial for the society. There are more than 3,500 different uses for corn products. Corn does much more than feed people and livestock. The plant contains alkaloids, flavonoids, saponins, maizenic acid, vitamins B1, K and minerals like potassium, phosphorous and zinc. Traditionally, Maize is used as an analgesic, anti-diarrheal, anti-prostatitic, anti-lithiasis, anti-tumor, anti-hypertensive, anti-diabetic, anti-hyperlipidemic, anti-inflammatory and anti-oxidant. In this review article, we have narrated miscellaneous uses of corn varieties and described the pharmacological activities, phytoconstituents, nutritional value and traditional uses of maize. The maize has assorted uses like culinary, medicinal and industrial. Corn dishes like corn-meal, corn-flakes, popcorn, “makki ki roti” and corn soup highlight its dominance all over the world. Therefore, maize has become a craze among modern youth.

  5. Meiotic chromosomal variation resulting from irradiation of pollen in maize

    International Nuclear Information System (INIS)

    The objective of this study was to standardize an induction strategy of chromosome aberrations in maize inbred line L-869. Pollen grains irradiated with 0, 36 and 72 Gy were used for fertilization. Resulting seeds were planted in a greenhouse to assess the number of abnormal meiotic cells. Germination, height, sterility and mortality were verified. Cells with delayed separation of chromosomes, translocation, deficiency, abnormal pairing, later condensation and anaphase bridges were observed. The number of abnormalities increased as the dosage increased but chromosome aberration types were the same regardless of the dosages used. Various chromosome-altered plants were obtained without viability loss. (author)

  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. Ultrastructure of Maize Starch Granules. A Review

    OpenAIRE

    Gallant, Daniel J.; Bouchet, Brigitte

    1986-01-01

    History of starch granule ultrastructure and the principal data obtained on maize starch granules are analyzed. New results are developed: i) growth and development of the maize starch granules during maturation depend on the maize varieties and the tissue site in the kernel, especially the horny and flloury endosperms; ii) cytochemical studies of the starch granules differing from their amylose/amylopectin ratio show important differences in the distribution of their crystalline and amorph...

  8. The Paleobiolinguistics of Maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Cecil H. Brown

    2014-05-01

    Full Text Available Paleobiolinguistics is used to determine when and where maize (Zea mays developed significance for different prehistoric groups of Native America. Dates and locations of proto-languages for which maize terms reconstruct generally accord with crop-origin and dispersal information from plant genetics and archaeobotany. Paleobiolinguistic and other lines of evidence indicate that human interest in maize was extensive millennia before the widespread development of a village‐farming way of life in the New World.

  9. Comparative Genome Mapping of Sorghum and Maize

    OpenAIRE

    Whitkus, R; Doebley, J; Lee, M.

    1992-01-01

    Linkage relationships were determined among 85 maize low copy number nuclear DNA probes and seven isozyme loci in an F(2) population derived from a cross of Sorghum bicolor ssp. bicolor X S. bicolor ssp. arundinaceum. Thirteen linkage groups were defined, three more than the 10 chromosomes of sorghum. Use of maize DNA probes to produce the sorghum linkage map allowed us to make several inferences concerning processes involved in the evolutionary divergence of the maize and sorghum genomes. Th...

  10. Comparative proteomic analyses provide new insights into low phosphorus stress responses in maize leaves.

    Directory of Open Access Journals (Sweden)

    Kewei Zhang

    Full Text Available Phosphorus deficiency limits plant growth and development. To better understand the mechanisms behind how maize responds to phosphate stress, we compared the proteome analysis results of two groups of maize leaves that were treated separately with 1,000 µM (control, +P and 5 µM of KH2PO4 (intervention group, -P for 25 days. In total, 1,342 protein spots were detected on 2-DE maps and 15.43% had changed (P<0.05; ≥1.5-fold significantly in quantity between the +P and -P groups. These proteins are involved in several major metabolic pathways, including photosynthesis, carbohydrate metabolism, energy metabolism, secondary metabolism, signal transduction, protein synthesis, cell rescue and cell defense and virulence. The results showed that the reduction in photosynthesis under low phosphorus treatment was due to the down-regulation of the proteins involved in CO2 enrichment, the Calvin cycle and the electron transport system. Electron transport and photosynthesis restrictions resulted in a large accumulation of peroxides. Maize has developed many different reactive oxygen species (ROS scavenging mechanisms to cope with low phosphorus stress, including up-regulating its antioxidant content and antioxidase activity. After being subjected to phosphorus stress over a long period, maize may increase its internal phosphorus utilization efficiency by altering photorespiration, starch synthesis and lipid composition. These results provide important information about how maize responds to low phosphorus stress.

  11. 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.

  12. The role of maize root size in phosphorus uptake and productivity of maize/faba bean and maize/wheat intercropping systems.

    Science.gov (United States)

    Zhang, Yikai; Chen, Fanjun; Li, Long; Chen, Yanhua; Liu, Bingran; Zhou, Yuling; Yuan, Lixing; Zhang, Fusuo; Mi, Guohua

    2012-11-01

    Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulation of maize root growth could improve the productivity of the two intercropping systems. Two near isogenic maize hybrids (the larger-rooted T149 and smaller-rooted T222) were intercropped with faba bean and wheat, under conditions of high- and low-P availability. The larger-rooted T149 showed greater competitive ability than the smaller-rooted T222 in both maize/faba bean and maize/wheat intercropping systems. The higher competitive ability of T149 improved the productivity of the maize/faba bean intercropping system in P-sufficient conditions. In maize/wheat intercropping systems, root growth, shoot biomass, and P uptake of maize were inhibited by wheat, regardless of the P-supply. Compared with T222, the larger-rooted T149 suffered less in the intercropping systems. The total biomass of the maize/wheat intercropping system was higher for wheat/T149 than for wheat/T222 under low-P conditions. These data suggested that genetic improvement of maize root size could enhance maize growth and its ability to compete for P resources in maize/faba bean and maize/wheat intercropping systems. In addition, depending on the P availability, larger maize roots could increase the productivity of intercropping systems.

  13. Ustilago maydis reprograms cell proliferation in maize anthers.

    Science.gov (United States)

    Gao, Li; Kelliher, Timothy; Nguyen, Linda; Walbot, Virginia

    2013-09-01

    The basidiomycete Ustilago maydis is a ubiquitous pathogen of maize (Zea mays), one of the world's most important cereal crops. Infection by this smut fungus triggers tumor formation in aerial plant parts within which the fungus sporulates. Using confocal microscopy to track U. maydis infection on corn anthers for 7 days post-injection, we found that U. maydis is located on the epidermis during the first 2 days, and has reached all anther lobe cell types by 3 days post-injection. Fungal infection alters cell-fate specification events, cell division patterns, host cell expansion and host cell senescence, depending on the developmental stage and cell type. Fungal effects on tassel and plant growth were also quantified. Transcriptome profiling using a dual organism microarray identified thousands of anther genes affected by fungal infection at 3 days post-injection during the cell-fate specification and rapid cell proliferation phases of anther development. In total, 4147 (17%) of anther-expressed genes were altered by infection, 2018 fungal genes were expressed in anthers, and 206 fungal secretome genes may be anther-specific. The results confirm that U. maydis deploys distinct genes to cause disease in specific maize organs, and suggest mechanisms by which the host plant is manipulated to generate a tumor.

  14. Use of tropical maize for bioethanol production

    Science.gov (United States)

    Tropical maize is an alternative energy crop being considered as a feedstock for bioethanol production in the North Central and Midwest United States. Tropical maize is advantageous because it produces large amounts of soluble sugars in its stalks, creates a large amount of biomass, and requires lo...

  15. The genetic architecture of maize height

    Science.gov (United States)

    Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state (IBS) among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formida...

  16. ADVANCES IN TRANSGENIC MAIZE FOR QUALITY IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    M.Rajendar Reddy

    2015-12-01

    Full Text Available Maize (Zea mays is a major food and animal feed worldwide and occupies a relevant place in the world economy and trade as an industrial grain crop. Currently more than 70% of maize production is used for food and feed; therefore, knowledge of genes involved in grain structure and chemical is important for improving the nutritional and food-making properties of maize. It is a good source of carbohydrates, fats, proteins, vitamins and minerals but deficient in two essential amino acids, Viz., lysine and tryptophan. To overcome this problem and to improve the above quality characters the maize breeders have followed different strategies like opaque 2, QPM and development of transgenic maize with improved quality characters. Finally we can conclude that the conventional breeding techniques and now plant biotechnology are helping meet the growing demand for food production, nutrition security while preserving our environment for future generations

  17. Concentration and dissipation of chlorantraniliprole and thiamethoxam residues in maize straw, maize, and soil.

    Science.gov (United States)

    He, Min; Song, Dan; Jia, Hong C; Zheng, Yongquan

    2016-09-01

    To study the dissipation rates and final residual levels of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil, two independent field trials were conducted during the 2014 cropping season in Beijing and Anhui Provinces of China. A 40% wettable powder (20% chlorantraniliprole + 20% thiamethoxam) was sprayed onto maize straw and soil at an application rate of 118 g of active ingredient per hectare (g a.i.ha(-1)). The residual concentrations were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. The chlorantraniliprole half-lives in maize straw and soil were 9.0-10.8 and 9.5-21.7 days, respectively. The thiamethoxam half-lives in maize straw and soil were 8.4-9.8 and 4.3-11.7 days, respectively. The final residues of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil were measured after the pesticides had been sprayed two and three times with an interval of 7 days using 1 and 1.5 times the recommended rate (72 g a.i. ha(-1) and 108 g a.i. ha(-1), respectively). Representative maize straw, maize, and soil samples were collected after the last treatment at pre-harvest intervals of 7, 14, and 28 days. The chlorantraniliprole residue was below 0.01 mg kg(-1) in maize, between 0.01 and 0.31 mg kg(-1) in maize straw, and between 0.03 and 1.91 mg kg(-1) in soil. The thiamethoxam residue concentrations in maize, maize straw, and soil were a.i. ha(-1) was recommended, as it can be considered safe to human beings and animals. PMID:27192406

  18. The development dynamics of the maize root transcriptome responsive to heavy metal Pb pollution.

    Science.gov (United States)

    Gao, Jian; Zhang, Yongzhong; Lu, Chaolong; Peng, Hua; Luo, Mao; Li, Gaoke; Shen, Yaou; Ding, Haiping; Zhang, Zhiming; Pan, Guangtang; Lin, Haijian

    2015-03-01

    Lead (Pb), as a heavy metal element, has become the most important metal pollutant of the environment. With allocating a relatively higher proportion of its biomass in roots, maize could be a potential important model to study the phytoremediation of Pb-contaminated soil. Here we analyzed the maize root transcriptome of inbred lines 9782 under heavy metal lead (Pb) pollution, which was identified as a non-hyperaccumulator for Pb in roots. In the present study, more than 98 millions reads were mapped to define gene structure and detect polymorphism, thereby to qualify transcript abundance along roots development under Pb treatment. A total of 17,707, 17,440, 16,998 and 16,586 genes were identified in maize roots at four developmental stages (0, 12 h, 24 h and 48 h) respectively and 2,825, 2,626, 2161 and 2260 stage-specifically expressed genes were also identified respectively. In addition, based on our RNA-Seq data, transcriptomic changes during maize root development responsive to Pb were investigated. A total of 384 differentially expressed genes (DEGs) (log2Ratio ≥ 1, FDR ≤ 0.001) were identified, of which, 36 genes with significant alteration in expression were detected in four developmental stages; 12 DEGs were randomly selected and successful validated by qRT-PCR. Additionally, many transcription factor families might act as the important regulators at different developmental stages, such as bZIP, ERF and GARP et al. These results will expand our understanding of the complex molecular and cellular events in maize root development and provide a foundation for future study on root development in maize under heavy metal pollution and other cereal crops.

  19. Nutrient absorbtion of weeds in maize.

    Science.gov (United States)

    Lehoczky, E; Kismányoky, A; Nagy, P; Németh, T

    2008-01-01

    Our study was carried out in Hungary at Keszthely, in 2007. The effect of different cultivation methods: no-till drill, disk tillage, conventional tillage (ploughing) and five increasing N doses were studied on the weediness. The bi-factorial trial was arranged in split plot design with four replications. Crop rotation: winter wheat-winter wheat-maize-maize. The seeding of maize was 23rd of April in 2007. The weed survey was made with Balázs-Ujvárosi coenological method on the 17th of May. In the experiment were found 21 weed species. We collected all plants of every weed species by plots. The sample area was 1 m2. Furthermore five maize plants per plot were sampled on the 22nd of May. Maize was at 3-4 leaves stage. For reason of competition studies no herbicides were applied on sampling sites. The aerial parts of weeds and maize plants were collected, and the fresh and dry matter weight was measured. We analyzed in detail, the occurrence of weed species, and the biomass production of weeds in comparison with maize. The effect of different cultivation methods markedly demonstrated the weed cover, the number of perennial and annual weeds and the number of occurring weed species.

  20. Transposition of Ac from the P Locus of Maize into Unreplicated Chromosomal Sites

    OpenAIRE

    Chen, Jychian; Greenblatt, Irwin M.; Dellaporta, Stephen L.

    1987-01-01

    We have analyzed donor and target sites of the mobile element Activator (Ac) that are altered as a result of somatic transposition from the P locus in maize. Previous genetic analysis has indicated that the two mitotic daughter lineages which result from Ac transposition from P differ in their Ac constitution at the P locus. Both lineages, however, usually contain transposed Ac elements which map to the same genetic position. Using methylation-sensitive restriction enzymes and genomic blot a...

  1. Heterosis of maize photosynthetic performance

    Institute of Scientific and Technical Information of China (English)

    LI Xia; DING Zaisong; LI Lianlu; WANG Meiyun; ZHAO Ming

    2007-01-01

    Four maize inbred lines with different photosyn-thetic rates and their two hybrids were used as test materials,and the diurnal variations of their photosynthesis parameters in the silking stage were measured to study the heterosis of photosynthetic performance.Results showed that net photo-synthetic rate (In),transpiration rate (Tr) and stomatal conductance (Gs) all presented an obvious single-peaked curve in a day,with the peak values occurring at 10:00-12:00,12:00,10:00-12:00 a.m.,respectively,while water use efficiency (WUE) had a"V"type variant trend,with the lowest value appearing at 12:00.The diurnal variation of Pn and Tr was correlated markedly with Gs,suggesting that Gs played an important role in regulating the diurnal variation of Pn and Tr,and Pn,Tr and Gs had a higher heterosis in the afternoon than in the morning,while the WUE was in reverse,indicating that maize hybrid had higher resistance to the high temperature and dehydration in the afternoon,which provided a new path to select varieties with a high net photosynthetic rate.

  2. Cytotoxicity of Ustilago maydis isolated from maize

    Directory of Open Access Journals (Sweden)

    Magdalena Twarużek

    2013-03-01

    Full Text Available The main pathogen of maize are fungi of the genus Fusarium. Besides phytopathogenic Fusarium, Ustilago maydis is another fungal genus affecting maize yields, causing lesions, known as smut. The objective of the study was evaluation of the cytotoxicity of Ustilago maydis isolated from maize. Nine Ustilago maydis strains were selected to a detailed evaluation of their cytotoxicity using a 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT test. Ustilago maydis strains showed medium and high cytotoxicity compared to control. High levels of cytotoxicity of Ustilago maydis may be indicative of their toxigenic potential.

  3. Seed Development and Quality in Maize Cultivars

    Directory of Open Access Journals (Sweden)

    Kazem GHASSEMI-GOLEZANI

    2011-05-01

    Full Text Available In order to evaluate seed development and quality of maize (Zea mays cultivars (DC-370, SC-500, OSSK-602 and SC-604, a split plot experiment (using R.C.B. design with three replicates was conducted in 2009 at the Research Farm of the Faculty of Agriculture, University of Tabriz, Iran. Seeds were harvested at five day intervals in eight stages. Subsequently, the quality of seed samples was determined in the laboratory. Germination percentage and seedling dry weight were enhanced, but electrical conductivity of seed leachates was reduced with increasing seed weight on mother plant. Maximum seed quality of maize cultivars was attained at the end of seed filling phase. Seed quality at earlier harvests was low, because of immaturity. Differences in maximum seedling dry weight of maize cultivars were attributed to variation in genetic constitution. It was concluded that in maize cultivars, maximum seed quality could be achieved at physiological maturity.

  4. Maize RNA polymerase IV defines trans-generational epigenetic variation.

    Science.gov (United States)

    Erhard, Karl F; Parkinson, Susan E; Gross, Stephen M; Barbour, Joy-El R; Lim, Jana P; Hollick, Jay B

    2013-03-01

    The maize (Zea mays) RNA Polymerase IV (Pol IV) largest subunit, RNA Polymerase D1 (RPD1 or NRPD1), is required for facilitating paramutations, restricting expression patterns of genes required for normal development, and generating small interfering RNA (siRNAs). Despite this expanded role for maize Pol IV relative to Arabidopsis thaliana, neither the general characteristics of Pol IV-regulated haplotypes, nor their prevalence, are known. Here, we show that specific haplotypes of the purple plant1 locus, encoding an anthocyanin pigment regulator, acquire and retain an expanded expression domain following transmission from siRNA biogenesis mutants. This conditioned expression pattern is progressively enhanced over generations in Pol IV mutants and then remains heritable after restoration of Pol IV function. This unusual genetic behavior is associated with promoter-proximal transposon fragments but is independent of sequences required for paramutation. These results indicate that trans-generational Pol IV action defines the expression patterns of haplotypes using co-opted transposon-derived sequences as regulatory elements. Our results provide a molecular framework for the concept that induced changes to the heterochromatic component of the genome are coincident with heritable changes in gene regulation. Alterations of this Pol IV-based regulatory system can generate potentially desirable and adaptive traits for selection to act upon. PMID:23512852

  5. Global warming presents new challenges for maize pest management

    International Nuclear Information System (INIS)

    It has been conjectured that global warming will increase the prevalence of insect pests in many agro-ecosystems. In this paper, we quantitatively assess four of the key pests of maize, one of the most important systems in North American grain production. Using empirically generated estimates of pest overwintering thresholds and degree-day requirements, along with climate change projections from a high-resolution climate model, we project potential future ranges for each of these pests in the United States. Our analysis suggests the possibility of increased winter survival and greater degree-day accumulations for each of the pests surveyed. We find that relaxed cold limitation could expand the range of all four pest taxa, including a substantial range expansion in the case of corn earworm (H. zea), a migratory, cold-intolerant pest. Because the corn earworm is a cosmopolitan pest that has shown resistance to insecticides, our results suggest that this expansion could also threaten other crops, including those in high-value areas of the western United States. Because managing significant additional pressure from this suite of established pests would require additional pest management inputs, the projected decreases in cold limitation and increases in heat accumulation have the potential to significantly alter the pest management landscape for North American maize production. Further, these range expansions could have substantial economic impacts through increased seed and insecticide costs, decreased yields, and the downstream effects of changes in crop yield variability.

  6. Global warming presents new challenges for maize pest management

    Science.gov (United States)

    Diffenbaugh, Noah S.; Krupke, Christian H.; White, Michael A.; Alexander, Corinne E.

    2008-10-01

    It has been conjectured that global warming will increase the prevalence of insect pests in many agro-ecosystems. In this paper, we quantitatively assess four of the key pests of maize, one of the most important systems in North American grain production. Using empirically generated estimates of pest overwintering thresholds and degree-day requirements, along with climate change projections from a high-resolution climate model, we project potential future ranges for each of these pests in the United States. Our analysis suggests the possibility of increased winter survival and greater degree-day accumulations for each of the pests surveyed. We find that relaxed cold limitation could expand the range of all four pest taxa, including a substantial range expansion in the case of corn earworm (H. zea), a migratory, cold-intolerant pest. Because the corn earworm is a cosmopolitan pest that has shown resistance to insecticides, our results suggest that this expansion could also threaten other crops, including those in high-value areas of the western United States. Because managing significant additional pressure from this suite of established pests would require additional pest management inputs, the projected decreases in cold limitation and increases in heat accumulation have the potential to significantly alter the pest management landscape for North American maize production. Further, these range expansions could have substantial economic impacts through increased seed and insecticide costs, decreased yields, and the downstream effects of changes in crop yield variability.

  7. Global warming presents new challenges for maize pest management

    Energy Technology Data Exchange (ETDEWEB)

    Diffenbaugh, Noah S [Purdue Climate Change Research Center and Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Krupke, Christian H [Department of Entomology, Purdue University, 901 West State Street, West Lafayette, IN 47907 (United States); White, Michael A [Department of Watershed Sciences, Utah State University, 5210 Old Main Hall, Logan, UT 84322-5210 (United States); Alexander, Corinne E [Department of Agricultural Economics, Purdue University, 403 West State Street, West Lafayette, IN 47907-2056 (United States)], E-mail: diffenbaugh@purdue.edu

    2008-10-15

    It has been conjectured that global warming will increase the prevalence of insect pests in many agro-ecosystems. In this paper, we quantitatively assess four of the key pests of maize, one of the most important systems in North American grain production. Using empirically generated estimates of pest overwintering thresholds and degree-day requirements, along with climate change projections from a high-resolution climate model, we project potential future ranges for each of these pests in the United States. Our analysis suggests the possibility of increased winter survival and greater degree-day accumulations for each of the pests surveyed. We find that relaxed cold limitation could expand the range of all four pest taxa, including a substantial range expansion in the case of corn earworm (H. zea), a migratory, cold-intolerant pest. Because the corn earworm is a cosmopolitan pest that has shown resistance to insecticides, our results suggest that this expansion could also threaten other crops, including those in high-value areas of the western United States. Because managing significant additional pressure from this suite of established pests would require additional pest management inputs, the projected decreases in cold limitation and increases in heat accumulation have the potential to significantly alter the pest management landscape for North American maize production. Further, these range expansions could have substantial economic impacts through increased seed and insecticide costs, decreased yields, and the downstream effects of changes in crop yield variability.

  8. [Effects of nitrogen management on maize nitrogen utilization and residual nitrate nitrogen in soil under maize/soybean and maize/sweet potato relay strip intercropping systems].

    Science.gov (United States)

    Wang, Xiao-Chun; Yang, Wen-Yu; Deng, Xiao-Yan; Zhang, Qun; Yong, Tai-Wen; Liu, Wei-Guo; Yang, Feng; Mao, Shu-Ming

    2014-10-01

    A large amount of nitrogen (N) fertilizers poured into the fields severely pollute the environment. Reasonable application of N fertilizer has always been the research hotpot. The effects of N management on maize N utilization and residual nitrate N in soil under maize/soybean and maize/ sweet potato relay strip intercropping systems were reported in a field experiment in southwest China. It was found that maize N accumulation, N harvest index, N absorption efficiency, N contribution proportion after the anthesis stage in maize/soybean relay strip intercropping were increased by 6.1%, 5.4%, 4.3%, and 15.1% than under maize/sweet potato with an increase of 22.6% for maize yield after sustainable growing of maize/soybean intercropping system. Nitrate N accumulation in the 0-60 cm soil layer was 12.9% higher under maize/soybean intercropping than under maize/sweet potato intercropping. However, nitrate N concentration in the 60-120 cm soil layer when intercropped with soybean decreased by 10.3% than when intercropped with sweet potato, indicating a decrease of N leaching loss. Increasing of N application rate enhanced N accumulation of maize and decreased N use efficiency and significantly increased nitrate concentration in the soil profile except in the 60-100 cm soil layer, where no significant difference was observed with nitrogen application rate at 0 to 270 kg · hm(-2). Further application of N fertilizer significantly enhanced nitrate leaching loss. Postponing N application increased nitrate accumulation in the 60-100 cm soil layer. The results suggested that N application rates and ratio of base to top dressing had different influences on maize N concentration and nitrate N between maize/soybean and maize/sweet potato intercropping. Maize N concentration in the late growing stage, N harvest index and N use efficiency under maize/soybean intercropping increased (with N application rate at 180-270 kg · hm(-2) and ratio of base to top dressing = 3:2:5) and

  9. [Effects of nitrogen management on maize nitrogen utilization and residual nitrate nitrogen in soil under maize/soybean and maize/sweet potato relay strip intercropping systems].

    Science.gov (United States)

    Wang, Xiao-Chun; Yang, Wen-Yu; Deng, Xiao-Yan; Zhang, Qun; Yong, Tai-Wen; Liu, Wei-Guo; Yang, Feng; Mao, Shu-Ming

    2014-10-01

    A large amount of nitrogen (N) fertilizers poured into the fields severely pollute the environment. Reasonable application of N fertilizer has always been the research hotpot. The effects of N management on maize N utilization and residual nitrate N in soil under maize/soybean and maize/ sweet potato relay strip intercropping systems were reported in a field experiment in southwest China. It was found that maize N accumulation, N harvest index, N absorption efficiency, N contribution proportion after the anthesis stage in maize/soybean relay strip intercropping were increased by 6.1%, 5.4%, 4.3%, and 15.1% than under maize/sweet potato with an increase of 22.6% for maize yield after sustainable growing of maize/soybean intercropping system. Nitrate N accumulation in the 0-60 cm soil layer was 12.9% higher under maize/soybean intercropping than under maize/sweet potato intercropping. However, nitrate N concentration in the 60-120 cm soil layer when intercropped with soybean decreased by 10.3% than when intercropped with sweet potato, indicating a decrease of N leaching loss. Increasing of N application rate enhanced N accumulation of maize and decreased N use efficiency and significantly increased nitrate concentration in the soil profile except in the 60-100 cm soil layer, where no significant difference was observed with nitrogen application rate at 0 to 270 kg · hm(-2). Further application of N fertilizer significantly enhanced nitrate leaching loss. Postponing N application increased nitrate accumulation in the 60-100 cm soil layer. The results suggested that N application rates and ratio of base to top dressing had different influences on maize N concentration and nitrate N between maize/soybean and maize/sweet potato intercropping. Maize N concentration in the late growing stage, N harvest index and N use efficiency under maize/soybean intercropping increased (with N application rate at 180-270 kg · hm(-2) and ratio of base to top dressing = 3:2:5) and

  10. Can transgenic maize affect soil microbial communities?

    Science.gov (United States)

    Mulder, Christian; Wouterse, Marja; Raubuch, Markus; Roelofs, Willem; Rutgers, Michiel

    2006-09-29

    The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their cells. Litter placement is known for its strong influence on the soil decomposer communities. The effects of the addition of crop residues on respiration and catabolic activities of the bacterial community were examined in microcosm experiments. Four cultivars of Zea mays L. of two different isolines (each one including the conventional crop and its Bacillus thuringiensis cultivar) and one control of bulk soil were included in the experimental design. The growth models suggest a dichotomy between soils amended with either conventional or transgenic maize residues. The Cry1Ab protein appeared to influence the composition of the microbial community. The highly enhanced soil respiration observed during the first 72 h after the addition of Bt-maize residues can be interpreted as being related to the presence of the transgenic crop residues. This result was confirmed by agar plate counting, as the averages of the colony-forming units of soils in conventional treatments were about one-third of those treated with transgenic straw. Furthermore, the addition of Bt-maize appeared to induce increased microbial consumption of carbohydrates in BIOLOG EcoPlates. Three weeks after the addition of maize residues to the soils, no differences between the consumption rate of specific chemical guilds by bacteria in soils amended with transgenic maize and bacteria in soils amended with conventional maize were detectable. Reaped crop residues, comparable to post-harvest maize straw (a common practice in current agriculture), rapidly influence the soil bacterial cells at a functional level. Overall, these data support the existence of short

  11. MORPHOLOGICAL AND THERMAL PROPERTIES OF MAIZE STARCH

    OpenAIRE

    Elena Corina Popescu; Alexandru Stoica; Elena Bărăscu; Maria Iordan

    2010-01-01

    Maize, rice, wheat and potato are the main sources of starches which differ significantly in composition, morphology,thermal, rheological and retrogradation properties. Starch has unique thermal properties and functionality that havepermitted its wide use in food products and industrial applications.The structure of the starch granule results from the physical arrangement of amylose and amylopectin. Amylose contentof starches from different maize types ranged between 15.3% and 25.1%. Amylopec...

  12. Control of virus diseases in maize.

    Science.gov (United States)

    Redinbaugh, Margaret G; Zambrano, José L

    2014-01-01

    Diseases caused by viruses are found throughout the maize-growing regions of the world and can cause significant losses for producers. In this review, virus diseases of maize and the pathogens that cause them are discussed. Factors leading to the spread of disease and measures for disease control are reviewed, as is our current knowledge of the genetics of virus resistance in this important crop. PMID:25410107

  13. MEASUREMENT AND MODELLING AVERAGE PHOTOSYNTHESIS OF MAIZE

    OpenAIRE

    ZS LÕKE

    2005-01-01

    The photosynthesis of fully developed maize was investigated in the Agrometeorological Research Station Keszthely, in 2000. We used LI-6400 type measurement equipment to locate measurement points where the intensity of photosynthesis mostly nears the average. So later we could obtain average photosynthetic activities featuring the crop, with only one measurement. To check average photosynthesis of maize we used Goudriaan’s simulation model (CMSM) as well to calculate values on cloudless sampl...

  14. Possible involvement of maize Rop1 in the defence responses of plants to viral infection.

    Science.gov (United States)

    Cao, Yanyong; Shi, Yan; Li, Yongqiang; Cheng, Yuqin; Zhou, Tao; Fan, Zaifeng

    2012-09-01

    The expression of host genes can be altered during the process of viral infection. To investigate the viral infection-induced up-regulated gene expression changes of maize at different time intervals post-inoculation with Sugarcane mosaic virus (SCMV), a suppression subtractive hybridization cDNA library was constructed. A total of 454 cDNA clones were identified to be viral infection-induced up-regulated genes. The influence of Rop1 on the infection of maize by SCMV was investigated. The results showed that transient silencing of the ZmRop1 gene through virus-induced gene silencing enhanced the accumulation and systemic infection of SCMV and another potyvirus (Pennisetum mosaic virus) in maize plants, whereas transient over-expression of ZmRop1 in maize protoplasts reduced SCMV accumulation. Furthermore, it was demonstrated that the heterologous expression of ZmRop1 impaired Potato virus X infection in Nicotiana benthamiana plants. These data suggest that ZmRop1 may play a role in plant defence responses to viral infection.

  15. Maize leaf development under climate change scenarios

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2010-11-01

    Full Text Available The objective of this work was to simulate maize leaf development in climate change scenarios at Santa Maria, RS, Brazil, considering symmetric and asymmetric increases in air temperature. The model of Wang & Engel for leaf appearance rate (LAR, with genotype-specific coefficients for the maize variety BRS Missões, was used to simulate tip and expanded leaf accumulated number from emergence to flag leaf appearance and expansion, for nine emergence dates from August 15 to April 15. LAR model was run for each emergence date in 100-year climate scenarios: current climate, and +1, +2, +3, +4 and +5°C increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum air temperature. Maize crop failure due to frost decreased in elevated temperature scenarios, in the very early and very late emergence dates, indicating a lengthening in the maize growing season in warmer climates. The leaf development period in maize was shorter in elevated temperature scenarios, with greater shortening in asymmetric temperature increases, indicating that warmer nights accelerate vegetative development in maize.

  16. Pathogenicity of P. terrestris on Maize Seedlings

    Directory of Open Access Journals (Sweden)

    Jelena Lević

    2012-01-01

    Full Text Available Pathogenicity of P. terrestris was determined by the Knop’s medium slants method intest tubes. Isolates originated from the roots of maize (Zea mays L., barley (Hordeum vulgareL., Johnson grass (Sorghum halepense Pers., sorghum (Sorghum bicolour (L. Moench., garlic(Allium sativum L., onion (Allium cepa L., barnyard millet (Echinochloa crus-galli (L. P.Beauv.and green foxtail (Setaria viridis (L. P.B.. A fragment of a fungal colony, cultivated on PDA,was placed on the bottom of Knop’s medium slant in each test tube and then steriliseda maize seed was placed 2 cm away from the inoculum. After 21-day inoculation of seeds,the intensity of the development of symptoms on maize seedlings was estimated. The reddishor dark pigment on the root, mesocotyl and/or coleoptyl of seedlings was an indicatorfor the infection by the fungus under in vitro conditions. Based on the pathogenicity test,the isolates were classified into the following three groups: slightly (3 isolates, moderately(6 isolates and very pathogenic (6 isolates to maize seedlings. The obtained results showthat P. terrestris, originating from different hosts, can be a maize pathogen. These resultscan explain the high frequency and high incidence of this fungus on maize roots in Serbia.

  17. Climate Change and Maize Yield in Iowa.

    Science.gov (United States)

    Xu, Hong; Twine, Tracy E; Girvetz, Evan

    2016-01-01

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century.

  18. Smectite alteration

    International Nuclear Information System (INIS)

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  19. Study Progress on Tissue Culture of Maize Mature Embryo

    Science.gov (United States)

    Wang, Hongzhen; Cheng, Jun; Cheng, Yanping; Zhou, Xioafu

    It has been paid more and more attention on maize tissue culture as it is a basic work in maize genetic transformation, especially huge breakthrough has been made in maize tissue culture utilizing mature embryos as explants in the recent years. This paper reviewed the study progress on maize tissue culture and plant regeneration utilizing mature embryos as explants from callus induction, subculture, plant regeneration and browning reduction and so on.

  20. 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...

  1. A novel Snf2 protein maintains trans-generational regulatory states established by paramutation in maize.

    Directory of Open Access Journals (Sweden)

    Christopher J Hale

    2007-10-01

    Full Text Available Paramutations represent heritable epigenetic alterations that cause departures from Mendelian inheritance. While the mechanism responsible is largely unknown, recent results in both mouse and maize suggest paramutations are correlated with RNA molecules capable of affecting changes in gene expression patterns. In maize, multiple required to maintain repression (rmr loci stabilize these paramutant states. Here we show rmr1 encodes a novel Snf2 protein that affects both small RNA accumulation and cytosine methylation of a proximal transposon fragment at the Pl1-Rhoades allele. However, these cytosine methylation differences do not define the various epigenetic states associated with paramutations. Pedigree analyses also show RMR1 does not mediate the allelic interactions that typically establish paramutations. Strikingly, our mutant analyses show that Pl1-Rhoades RNA transcript levels are altered independently of transcription rates, implicating a post-transcriptional level of RMR1 action. These results suggest the RNA component of maize paramutation maintains small heterochromatic-like domains that can affect, via the activity of a Snf2 protein, the stability of nascent transcripts from adjacent genes by way of a cotranscriptional repression process. These findings highlight a mechanism by which alleles of endogenous loci can acquire novel expression patterns that are meiotically transmissible.

  2. 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 arrang

  3. 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 (consist

  4. Differential gene expression between cross-fertilized and self-fertilized kernels during the early stages of seed development in maize

    Institute of Scientific and Technical Information of China (English)

    FanrongMeng; ZhongfuNi; LiminWu; QixinSun

    2005-01-01

    In maize, cross-fertilization advantage was observed during the early stage of embryo development and grain filling. In this study, we performed screening of differentially expressed genes between maize cross-fertilized and self-fertilized kernels at 5, 10, and 15 days after pollination (DAP) by differential display technique. The results indicated that the patterns of gene expression altered obviously in crossfertilized kernels as compared to self-fertilized kernels. Both quantitative and qualitative differences were observed. Four differentially expressed cDNAs were cloned and sequenced, their expression patterns were confirmed by reverse-Northern blot. Sequence analysis and database search revealed that two of them were new sequences; the other two were methyl-binding domain protein (MBD) andphos phoenolpyruvate carboxylase (PEPC), respectively, and it is concluded that the altered gene expression may be responsible for theobserved maize heterosis.

  5. Soil Microbial and Faunal Community Responses to Bt-Maize and Insecticide in Two Soils

    DEFF Research Database (Denmark)

    Griffiths, B. S.; Caul, S.; Thompson, J.;

    2006-01-01

    The effects of maize (Zea mays L.), genetically modified to express the Cry1Ab protein (Bt), and an insecticide on soil microbial and faunal communities were assessed in a glasshouse experiment. Soil for the experiment was taken from field sites where the same maize cultivars were grown to allow...... comparison between results under glasshouse conditions with those from field trials. Plants were grown in contrasting sandy loam and clay loam soils, half were sprayed with a pyrethroid insecticide (deltamethrin) and soil samples taken at the five-leaf stage, flowering, and maturity. The main effect on all...... measured parameters was that of soil type and there were no effects of Bt trait or insecticide on plant growth. The Bt trait resulted in more soil nematodes and protozoa (amoebae), whereas insecticide application increased plant Bt concentration and altered nematode community structure. The only...

  6. Effect of high hydrostatic pressure treatment on conventional hydroxypropylation of maize starch.

    Science.gov (United States)

    Chun, Ei-Hyun; Oh, Seon-Min; Kim, Hui-Yun; Kim, Byung-Yong; Baik, Moo-Yeol

    2016-08-01

    Effect of high hydrostatic pressure (HHP) treatment on conventional hydroxypropylation of maize starch was investigated. Three groups, 'Con' group (conventional hydroxypropylation), 'HHP-Con' group (HHP treatment before conventional hydroxypropylation), and 'Con-HHP' group (HHP treatment after conventional hydroxypropylation), were used in this work. The degree of substitution (DS) increased over the reaction time in all groups. Swelling power and solubility were high in HHP treated groups compared to Con group because HHP treatment weakens the binding forces inside starch granule. In the results of RVA, the Con-HHP group showed a lower pasting temperature and a higher breakdown and viscosity than the other groups. Pre- and post HHP-treatments altered the physicochemical properties of hydroxypropylated maize starch. Hydrophilic and bulky hydroxypropyl groups may weaken the bindings in the granule, while the HHP treatment promoted the collapse of granules and accelerated the leaching of intra-soluble materials. PMID:27112881

  7. Household dietary exposure to aflatoxins from maize and maize products in Kenya.

    Science.gov (United States)

    Kilonzo, Robert M; Imungi, Jasper K; Muiru, William M; Lamuka, Peter O; Njage, Patrick M Kamau

    2014-01-01

    Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analysed for aflatoxin contamination. The samples were quantitatively analysed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modelled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18 and 480 μg kg⁻¹, 20% of muthokoi at between 12 and 123 μg kg⁻¹, and 35% of maize meal at between 6 and 30 μg kg⁻¹. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg⁻¹ body weight day⁻¹, while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 and 27 ± 154 ng kg⁻¹ body weight day⁻¹ respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.

  8. Genome-wide identification, expression analysis of auxin-responsive GH3 family genes in maize (Zea mays L.) under abiotic stresses

    Institute of Scientific and Technical Information of China (English)

    Shangguo Feng; Runqing Yue; Sun Tao Yanjun Yang; Lei Zhang; Mingfeng Xu; Huizhong Wang; Chenjia Shen

    2015-01-01

    Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The respon-siveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses.

  9. Substrates for Efficient Fluorometric Screening Employing the NAD-Dependent Sirtuin 5 Lysine Deacylase (KDAC) Enzyme

    DEFF Research Database (Denmark)

    Madsen, Andreas Stahl; Olsen, Christian Adam

    2012-01-01

    of individual isozymes has been a longstanding goal. Essential for the discovery of novel modulators, however, are good screening protocols and mechanistic insights with regard to the targets in question. We therefore evaluated the activities of the seven human sirtuin hydrolases against a panel of fluorogenic...

  10. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    OpenAIRE

    Vandna Kukshal; Taran Khanam; Deepti Chopra; Nidhi Singh; Sabyasachi Sanyal; Ravishankar Ramachandran

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C222(1) with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains...

  11. Getting domestication straight: ramosa1 in maize.

    Science.gov (United States)

    Dempewolf, Hannes

    2010-04-01

    Knowledge of the identities and characteristics of genes that govern the dramatic phenotypic differences between cultivated plants and their wild ancestors has greatly enhanced our understanding of the domestication process. In this issue of Molecular Ecology, Sigmon & Vollbrecht report the discovery of a new maize domestication gene, ramosa1, which encodes a putative transcription factor in the ramosa developmental pathway. Ramosa1 appears to be instrumental in determining the straightness of kernel rows on the maize cob. The key domestication alleles at ramosa1 are prevalent in landraces of maize. These results reinforce findings from previous studies of crop evolution by highlighting the importance of standing genetic variation and changes in transcriptional regulators in domestication. The evolutionary genetics of domestication also provides a framework for predicting the evolutionary response of organisms to strong human-induced selection pressures over limited time intervals.

  12. Economic efficiency of the maize grain

    Directory of Open Access Journals (Sweden)

    Ana Mariana Dincu

    2014-11-01

    Full Text Available In this work, was calculated and the level of profitability for several levels of production for grain maize cultivation. We chose corn because it is one of the most important forage crops, we could say even the largest, occupying third place among cultivated plants worldwide. Along with wheat and barley, the food is the biggest part of the population in the world, directly or converted to animal products. Maize can be used in animal feed in various forms. The most used is corn grain, which is characterized by a very high nutritional value, this product is properly regarded as a feed concentrate. Culture of maize have been designed two levels of production: 4000 kg / ha and 6000 kg / ha.

  13. MORPHOLOGICAL AND THERMAL PROPERTIES OF MAIZE STARCH

    Directory of Open Access Journals (Sweden)

    Elena Corina Popescu

    2010-01-01

    Full Text Available Maize, rice, wheat and potato are the main sources of starches which differ significantly in composition, morphology,thermal, rheological and retrogradation properties. Starch has unique thermal properties and functionality that havepermitted its wide use in food products and industrial applications.The structure of the starch granule results from the physical arrangement of amylose and amylopectin. Amylose contentof starches from different maize types ranged between 15.3% and 25.1%. Amylopectin is considered responsible for thecrystalline structure of starch granules.The morphological and physicochemical characteristics of maize starch are related to the enzymes involved in itsbiosynthesis.The surface of the starch granule plays a fundamental rôle as the first barrier to processes such as granule hydration,enzyme attack, and chemical reaction with modifying agents. Major parameters describing the solid surface are:specific surface area, total pore volume, mean pore radius (diameter and pore volume distribution in relation to poreradius (diameter.

  14. Evaluation of maize grain and polyunsaturated fatty acid (PUFA) as energy sources for breeding rams based on hormonal, sperm functional parameters and fertility.

    Science.gov (United States)

    Selvaraju, Sellappan; Raju, Priyadarshini; Rao, Somu Bala Nageswara; Raghavendra, Subbarao; Nandi, Sumantha; Dineshkumar, Dhanasekaran; Thayakumar, Allen; Parthipan, Shivashanmugam; Ravindra, Janivara Parameswaraiah

    2012-01-01

    The objective of the present study was to elucidate the effect of different sources of dietary energy (maize vs polyunsaturated fatty acid (PUFA) on semen functional parameters and fertility of adult rams. Eighteen adult rams were divided into two groups (maize and PUFA, n=9). The main energy source for the rams in the maize group was coarsely ground maize grain, whereas in the PUFA group it was sunflower oil (rich in 18:2 linoleic acid, an omega-6 acid). The ration was fed for a minimum period of 60 days and thereafter semen was collected for evaluation. The proportion of progressive forward motility was significantly (P<0.05) higher in the PUFA group compared with the maize group. Sperm lipid peroxidation as measured by malondialdehyde formation (µM per 1×10(9) spermatozoa) was significantly (P<0.05) higher in the PUFA group compared with the maize group. When the semen was diluted with Tris-egg yolk-citrate buffer and incubated for 24h at 4°C, the proportions of plasmalemma integrity, the sperm subpopulation positive for functional membrane and acrosomal integrities, and mitochondrial membrane potential were significantly (P<0.05) higher in PUFA-fed than in maize-fed animals. The different sources of energy did not influence the serum and seminal plasma IGF-I levels. The cleavage rate (percentage) did not differ significantly between PUFA- (45.4±4.91) and maize- (44.63±6.8) fed animals. In conclusion, PUFA feeding influenced sperm quality by altering or stabilising membrane integrity. The present study indicates that PUFA may improve semen quality but did not improve in vitro fertilisation.

  15. Evaluation of maize grain and polyunsaturated fatty acid (PUFA) as energy sources for breeding rams based on hormonal, sperm functional parameters and fertility.

    Science.gov (United States)

    Selvaraju, Sellappan; Raju, Priyadarshini; Rao, Somu Bala Nageswara; Raghavendra, Subbarao; Nandi, Sumantha; Dineshkumar, Dhanasekaran; Thayakumar, Allen; Parthipan, Shivashanmugam; Ravindra, Janivara Parameswaraiah

    2012-01-01

    The objective of the present study was to elucidate the effect of different sources of dietary energy (maize vs polyunsaturated fatty acid (PUFA) on semen functional parameters and fertility of adult rams. Eighteen adult rams were divided into two groups (maize and PUFA, n=9). The main energy source for the rams in the maize group was coarsely ground maize grain, whereas in the PUFA group it was sunflower oil (rich in 18:2 linoleic acid, an omega-6 acid). The ration was fed for a minimum period of 60 days and thereafter semen was collected for evaluation. The proportion of progressive forward motility was significantly (P<0.05) higher in the PUFA group compared with the maize group. Sperm lipid peroxidation as measured by malondialdehyde formation (µM per 1×10(9) spermatozoa) was significantly (P<0.05) higher in the PUFA group compared with the maize group. When the semen was diluted with Tris-egg yolk-citrate buffer and incubated for 24h at 4°C, the proportions of plasmalemma integrity, the sperm subpopulation positive for functional membrane and acrosomal integrities, and mitochondrial membrane potential were significantly (P<0.05) higher in PUFA-fed than in maize-fed animals. The different sources of energy did not influence the serum and seminal plasma IGF-I levels. The cleavage rate (percentage) did not differ significantly between PUFA- (45.4±4.91) and maize- (44.63±6.8) fed animals. In conclusion, PUFA feeding influenced sperm quality by altering or stabilising membrane integrity. The present study indicates that PUFA may improve semen quality but did not improve in vitro fertilisation. PMID:22697117

  16. Carbaryl residues in maize and processed products

    International Nuclear Information System (INIS)

    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)

  17. Immunochemical identification of gelsolin in maize pollen

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Gelsolin is a representative of a type of actin-binding proteins (ABPs) universally found in eukaryotes. It plays role in nucleation, capping and severing of actin filaments in vitro. In our experiment, gelsolin was purified from pig plasma and the polyclonal antibodies against it were prepared. The crude extracts of maize pollen were immunodetected by Western-blotting with polyclonal antibody and monoclonal antibody respectively. The immunodetection results show that gelsolin exists in maize pollen and its molecular weight is about 91 ku, similar to that of gelsolin found in animal tissues.

  18. 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.

  19. FINANCIAL AND RISK ANALYSIS OF MAIZE TECHNOLOGY IN ETHIOPIA, BASED ON CERES-MAIZE MODEL RESULTS

    OpenAIRE

    Crawford, Eric W.; Howard, Julie A.; Kelly, Valerie A.

    2000-01-01

    This paper presents a financial and risk analysis of improved versus traditional maize production technology in Ethiopia, based on yields simulated with the CERES-Maize crop growth model (Schulthess and Ward, 2000). The purpose is to analyze the potential performance of the SG2000/Ministry of Agriculture program technology under less favorable meteorological conditions (rainfall level and distribution), and in areas with lower agroecological potential than those covered by the SG2000/MOA prog...

  20. Dual transcriptome analysis reveals insights into the response to Rice black-streaked dwarf virus in maize

    Science.gov (United States)

    Zhou, Yu; Xu, Zhennan; Duan, Canxing; Chen, Yanping; Meng, Qingchang; Wu, Jirong; Hao, Zhuanfang; Wang, Zhenhua; Li, Mingshun; Yong, Hongjun; Zhang, Degui; Zhang, Shihuang; Weng, Jianfeng; Li, Xinhai

    2016-01-01

    Maize rough dwarf disease (MRDD) is a viral infection that results in heavy yield losses in maize worldwide, particularly in the summer maize-growing regions of China. MRDD is caused by the Rice black-streaked dwarf virus (RBSDV). In the present study, analyses of microRNAs (miRNAs), the degradome, and transcriptome sequences were used to elucidate the RBSDV-responsive pathway(s) in maize. Genomic analysis indicated that the expression of three non-conserved and 28 conserved miRNAs, representing 17 known miRNA families and 14 novel miRNAs, were significantly altered in response to RBSDV when maize was inoculated at the V3 (third leaf) stage. A total of 99 target transcripts from 48 genes of 10 known miRNAs were found to be responsive to RBSDV infection. The annotations of these target genes include a SQUAMOSA promoter binding (SPB) protein, a P450 reductase, an oxidoreductase, and a ubiquitin-related gene, among others. Characterization of the entire transcriptome suggested that a total of 28 and 1085 differentially expressed genes (DEGs) were detected at 1.5 and 3.0 d, respectively, after artificial inoculation with RBSDV. The expression patterns of cell wall- and chloroplast-related genes, and disease resistance- and stress-related genes changed significantly in response to RBSDV infection. The negatively regulated genes GRMZM2G069316 and GRMZM2G031169, which are the target genes for miR169i-p5 and miR8155, were identified as a nucleolin and a NAD(P)-binding Rossmann-fold superfamily protein in maize, respectively. The gene ontology term GO:0003824, including GRMZM2G031169 and other 51 DEGs, was designated as responsive to RBSDV. PMID:27493226

  1. Dual transcriptome analysis reveals insights into the response to Rice black-streaked dwarf virus in maize.

    Science.gov (United States)

    Zhou, Yu; Xu, Zhennan; Duan, Canxing; Chen, Yanping; Meng, Qingchang; Wu, Jirong; Hao, Zhuanfang; Wang, Zhenhua; Li, Mingshun; Yong, Hongjun; Zhang, Degui; Zhang, Shihuang; Weng, Jianfeng; Li, Xinhai

    2016-08-01

    Maize rough dwarf disease (MRDD) is a viral infection that results in heavy yield losses in maize worldwide, particularly in the summer maize-growing regions of China. MRDD is caused by the Rice black-streaked dwarf virus (RBSDV). In the present study, analyses of microRNAs (miRNAs), the degradome, and transcriptome sequences were used to elucidate the RBSDV-responsive pathway(s) in maize. Genomic analysis indicated that the expression of three non-conserved and 28 conserved miRNAs, representing 17 known miRNA families and 14 novel miRNAs, were significantly altered in response to RBSDV when maize was inoculated at the V3 (third leaf) stage. A total of 99 target transcripts from 48 genes of 10 known miRNAs were found to be responsive to RBSDV infection. The annotations of these target genes include a SQUAMOSA promoter binding (SPB) protein, a P450 reductase, an oxidoreductase, and a ubiquitin-related gene, among others. Characterization of the entire transcriptome suggested that a total of 28 and 1085 differentially expressed genes (DEGs) were detected at 1.5 and 3.0 d, respectively, after artificial inoculation with RBSDV. The expression patterns of cell wall- and chloroplast-related genes, and disease resistance- and stress-related genes changed significantly in response to RBSDV infection. The negatively regulated genes GRMZM2G069316 and GRMZM2G031169, which are the target genes for miR169i-p5 and miR8155, were identified as a nucleolin and a NAD(P)-binding Rossmann-fold superfamily protein in maize, respectively. The gene ontology term GO:0003824, including GRMZM2G031169 and other 51 DEGs, was designated as responsive to RBSDV. PMID:27493226

  2. Alterações químicas em solos e crescimento de milho e feijoeiro após aplicação de lodo de esgoto Soil chemical alterations and growth of maize and bean plants after sewage sludge application

    Directory of Open Access Journals (Sweden)

    C. W. A. Nascimento

    2004-04-01

    Full Text Available O lodo de esgoto obtido do tratamento das águas servidas contém considerável percentual de matéria orgânica e de elementos essenciais para as plantas, podendo desempenhar importante papel na produção agrícola e na manutenção da fertilidade do solo. O presente trabalho objetivou estudar o efeito da aplicação de doses crescentes de lodo produzido pela Companhia Pernambucana de Saneamento (COMPESA sobre as características químicas de dois solos, quantidades de metais pesados absorvidas e crescimento de plantas de milho e de feijoeiro cultivadas em casa de vegetação, visando à futura utilização do lodo em ensaios de campo. Foram utilizados dois tipos de solos com diferentes teores de argila aos quais foram adicionadas seis doses de lodo de esgoto (equivalentes a 0, 10, 20, 30, 40 e 60 Mg ha-1. As aplicações promoveram diminuição do pH e aumento dos teores de matéria orgânica, nitrogênio total, fósforo, potássio, sódio, cálcio e magnésio em ambos os solos, exceção feita aos teores de sódio e potássio de um deles. As doses de lodo de esgoto aumentaram a produção de matéria seca do milho e do feijoeiro. Os teores dos metais Zn, Cu, Mn, Fe e Pb no lodo, no solo e nas plantas estiveram abaixo dos limites estabelecidos para utilização agrícola, o que permite sua aplicação sem maiores riscos ao ambiente.Sewage sludge from wastewater treatments contains organic matter and plant nutrients that may play an important role in agricultural production and maintenance of soil fertility. The present study aimed to evaluate the effect of increasing sewage sludge rates on soil chemical properties, heavy metal concentration in soils and plants, and the growth of maize and bean plants cultivated in pots under greenhouse conditions. Two soil types with different clay contents were used for application of six sewage sludge rates (equivalent to 0, 10, 20, 30, 40, and 60 Mg ha-1. Sludge application led to a decrease of pH and

  3. 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 nu

  4. Use of tropical maize for bioethanol production.

    Science.gov (United States)

    Chen, Ming-Hsu; Kaur, Prabhjot; Dien, Bruce; Below, Frederick; Vincent, Michael L; Singh, Vijay

    2013-08-01

    Tropical maize is an alternative energy crop being considered as a feedstock for bioethanol production in the North Central and Midwest United States. Tropical maize is advantageous because it produces large amounts of soluble sugars in its stalks, creates a large amount of biomass, and requires lower inputs (e.g. nitrogen) than grain corn. Soluble sugars, including sucrose, glucose and fructose were extracted by pressing the stalks at dough stage (R4). The initial extracted syrup fermented faster than the control culture grown on a yeast extract/phosphate/sucrose medium. The syrup was subsequently concentrated 1.25-2.25 times, supplemented with urea, and fermented using Saccharomyces cerevisiae for up to 96 h. The final ethanol concentrations obtained were 8.1 % (v/v) to 15.6 % (v/v), equivalent to 90.3-92.2 % of the theoretical yields. However, fermentation productivity decreased with sugar concentration, suggesting that the yeast might be osmotically stressed at the increased sugar concentrations. These results provide in-depth information for utilizing tropical maize syrup for bioethanol production that will help in tropical maize breeding and development for use as another feedstock for the biofuel industry. PMID:23508398

  5. 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...

  6. Interaction between maize seed and Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is an opportunistic fungal pathogen that colonizes maize seeds and contaminates them with aflatoxin. The fungus is localized in the endosperm and aleurone. To investigate the plant microbe interaction, we conducted histological and molecular studies to characterize the internal co...

  7. Genetic Diversity and Molecular Evolution of Chinese Waxy Maize Germplasm

    Science.gov (United States)

    Zheng, Hongjian; Wang, Hui; Yang, Hua; Wu, Jinhong; Shi, Biao; Cai, Run; Xu, Yunbi; Wu, Aizhong; Luo, Lijun

    2013-01-01

    Waxy maize (Zea mays L. var. certaina Kulesh), with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection. PMID:23818949

  8. 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.

  9. 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

  10. A Systemic Proteomic Analysis of Maize Seedling during the Process of De-etiolation

    Institute of Scientific and Technical Information of China (English)

    Zhuo Shen; Yingchang Mei; Jie Shen; Qing Chao; Baichen Wang

    2012-01-01

    To better understand light regulation of C4 plant maize development,we investigated dynamic proteomic differences between etiolated seedlings and etiolated seedlings illuminated for 6 h,12 h,and 24 h respectively.The proteins extracted from these samples were analyzed by using a quantitative proteomic approach based on Isobaric tags for relative and absolute quantitation (iTRAQ).Among more than 4703 proteins identified,1712 were significantly altered during etiolated maize seedling greening.Of these 1351 proteins,108 were identified as membrane proteins that seldom had been identified with proteomic method,indicating the power of our method for membrane protein identification; These significantly changed proteins respectively involved in photosynthesis,metabolism,nitrogen assimilation,and components of chloroplastic translational machinery.These results thus define the differential regulation of distinct biological systems during greening in maize and demonstrate the usefulness of comprehensive and comparative proteome analysis for the characterization of biological processes in plant cells,particularly in C4 plant.

  11. Pullulanase and Starch Synthase III Are Associated with Formation of Vitreous Endosperm in Quality Protein Maize.

    Directory of Open Access Journals (Sweden)

    Hao Wu

    Full Text Available The opaque-2 (o2 mutation of maize increases lysine content, but the low seed density and soft texture of this type of mutant are undesirable. Lines with modifiers of the soft kernel phenotype (mo2 called "Quality Protein Maize" (QPM have high lysine and kernel phenotypes similar to normal maize. Prior research indicated that the formation of vitreous endosperm in QPM might involve changes in starch granule structure. In this study, we focused on analysis of two starch biosynthetic enzymes that may influence kernel vitreousness. Analysis of recombinant inbred lines derived from a cross of W64Ao2 and K0326Y revealed that pullulanase activity had significant positive correlation with kernel vitreousness. We also found that decreased Starch Synthase III abundance may decrease the pullulanase activity and average glucan chain length given the same Zpu1 genotype. Therefore, Starch Synthase III could indirectly influence the kernel vitreousness by affecting pullulanase activity and coordinating with pullulanase to alter the glucan chain length distribution of amylopectin, resulting in different starch structural properties. The glucan chain length distribution had strong positive correlation with the polydispersity index of glucan chains, which was positively associated with the kernel vitreousness based on nonlinear regression analysis. Therefore, we propose that pullulanase and Starch Synthase III are two important factors responsible for the formation of the vitreous phenotype of QPM endosperms.

  12. MYB31/MYB42 Syntelogs Exhibit Divergent Regulation of Phenylpropanoid Genes in Maize, Sorghum and Rice.

    Science.gov (United States)

    Agarwal, Tina; Grotewold, Erich; Doseff, Andrea I; Gray, John

    2016-01-01

    ZmMYB31 and ZmMYB42 are R2R3-MYB transcription factors implicated in the regulation of phenylpropanoid genes in maize. Here, we tested the hypothesis that the regulatory function of MYB31 and MYB42 is conserved in other monocots, specifically in sorghum and rice. We demonstrate that syntelogs of MYB31 and MYB42 do bind to phenylpropanoid genes that function in all stages of the pathway and in different tissues along the developmental gradient of seedling leaves. We found that caffeic acid O-methyltransferase (COMT1) is a common target of MYB31 and MYB42 in the mature leaf tissues of maize, sorghum and rice, as evidenced by Chromatin immunoprecipitation (ChIP) experiments. In contrast, 4-coumarate-CoA ligase (4CL2), ferulate-5-hydroxylase (F5H), and caffeoyl shikimate esterase (CSE), were targeted by MYB31 or MYB42, but in a more species-specific fashion. Our results revealed MYB31 and MYB42 participation in auto- and cross-regulation in all three species. Apart from a limited conservation of regulatory modules, MYB31 and MYB42 syntelogs appear to have undergone subfunctionalization following gene duplication and divergence of maize, sorghum, and rice. Elucidating the different regulatory roles of these syntelogs in the context of positive transcriptional activators may help guide attempts to alter the flux of intermediates towards lignin production in biofuel grasses. PMID:27328708

  13. Modulation of Soil Particle Size and Nutrient Availability in the Maize Rhizosheath

    Institute of Scientific and Technical Information of China (English)

    MA Wei; LI Xue-Xian; LI Chun-Jian

    2011-01-01

    Root exudates,microorganism colonization and soil aggregates together form the rhizosheath,a special cylinder of micro-ecosystem adhering to the root surface.To study how the rhizosheath affects soil structure and nutrient distribution,we analyzed the impact of maize rhizosheath on soil particle size and nutrient availability in pot and field experiments.The results showed that there was a significant size decrease of soil particles in the rhizosheath.Meanwhile,the soil mineral nitrogen in the rhizosheath was significantly higher than that in the rhizosphere or bulk soil at tasseling and maturity stages of maize.The contents of Fe and Mn were also differentially altered in the rhizosheath.Rhizosheath development,indicated by a dry weight ratio of rhizosheath soil to the root,was relatively independent of root development during the whole experimental period.The formation of maize rhizosheath contributed to the modulation of soil particle size and nutrient availability.The subtle local changes of soil physical and chemical properties may have profound influence on soil formation,rhizospheric ecosystem initiation,and mineral nutrient mobilization over the long history of plant evolution and domestication.

  14. Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

    Science.gov (United States)

    Devos, Yann; Cougnon, Mathias; Vergucht, Sofie; Bulcke, Robert; Haesaert, Geert; Steurbaut, Walter; Reheul, Dirk

    2008-12-01

    With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize. Impacts on human health and the environment were calculated through the pesticide occupational and environmental risk (POCER) indicator. Results showed that the environmental impact of herbicide regimes solely relying on the active ingredients glyphosate (GLY) or glufosinate-ammonium (GLU) is lower than that of herbicide regimes applied in non-GMHR maize. Due to the lower potential of GLY and GLU to contaminate ground water and their lower acute toxicity to aquatic organisms, the POCER exceedence factor values for the environment were reduced approximately by a sixth when GLY or GLU is used alone. However, the environmental impact of novel herbicide regimes tested may be underestimated due to the assumption that active ingredients used with GMHR maize would be used alone. Data retrieved from literature suggest that weed control efficacy is increased and resistance development delayed when GLY or GLU is used together with other herbicides in the GMHR system. Due to the partial instead of complete replacement of currently used herbicide regimes, the beneficial environmental impact of novel herbicide regimes might sometimes be reduced or counterbalanced. Despite the high weed control efficacy provided by the biotechnology-based weed management strategy, neither indirect harmful effects on farmland biodiversity through losses in food resources and shelter, nor shifts in weed communities have been

  15. A systematic proteomic analysis of NaCl-stressed germinating maize seeds.

    Science.gov (United States)

    Meng, Ling-Bo; Chen, Yi-Bo; Lu, Tian-Cong; Wang, Yue-Feng; Qian, Chun-Rong; Yu, Yang; Ge, Xuan-Liang; Li, Xiao-Hui; Wang, Bai-Chen

    2014-05-01

    Salt (NaCl) is a common physiological stressor of plants. To better understand how germinating seeds respond to salt stress, we examined the changes that occurred in the proteome of maize seeds during NaCl-treated germination. Phenotypically, salt concentrations less than 0.2 M appear to delay germination, while higher concentrations disrupt development completely, leading to seed death. The identities of 96 proteins with expression levels altered by NaCl-incubation were established using 2-DE-MALDI-TOF-MS and 2-DE-MALDI-TOF-MS/MS. Of these 96 proteins, 79 were altered greater than twofold when incubated with a 0.2 M salt solution, while 51 were altered when incubated with a 0.1 M salt solution. According to their functional annotations in the Swiss-Prot protein-sequence databases, these proteins are mainly involved in seed storage, energy metabolism, stress response, and protein metabolism. Notably, the expression of proteins that respond to abscisic acid signals increased in response to salt stress. The results of this study provide important clues as to how NaCl stresses the physiology of germinating maize seeds. PMID:24700167

  16. Comprehending smallholder maize enterprises’ profitability with the current maize marketing system in Zimbabwe: A case of Mazowe district

    Directory of Open Access Journals (Sweden)

    John Basera

    2016-06-01

    Full Text Available Maize enterprise profitability is essential for sustainable maize production in smallholder farming. In Zimbabwe a lot of factors including several policy measures implemented in the past are believed to be influencing current maize profitability trends. Literature to confirm some of the crucial factors is limited especially in the smallholder farming sector. In this study we analyze profitability of smallholder maize farmers in Mazowe District of Zimbabwe. We estimate maize enterprise profitability using gross margin analysis, factors driving profitability using linear regression analysis and the influence of tobacco farming adoption on maize enterprise profitability using propensity score matching. We relied on both primary and secondary data from the study area. Results did not show robust outcomes on maize enterprises profitability. Maize profitability was found to be influenced positively by age of household head and selling produce to private buyers and negatively by fertilizer, chemical, and transport costs. Tobacco farming adoption was found to have a positive influence on maize profitability. Based on the results the study recommends the government through its various programs targeting agricultural development and food security to focus on smallholder maize production and marketing with the aim of improving its profitability.

  17. Types of Maize Virus Diseases and Progress in Virus Identification Techniques in China

    Institute of Scientific and Technical Information of China (English)

    Cui Yu; Zhang Ai-hong; Ren Ai-jun; Miao Hong-qin

    2014-01-01

    There are a total of more than 40 reported maize viral diseases worldwide. Five of them have reportedly occurred in China. They are maize rough dwarf disease, maize dwarf mosaic disease, maize streak dwarf disease, maize crimson leaf disease, maize wallaby ear disease and corn lethal necrosis disease. This paper reviewed their occurrence and distribution as well as virus identification techniques in order to provide a basis for virus identification and diagnosis in corn production.

  18. SUPPLY RESPONSIVENESS OF MAIZE FARMERS IN KENYA: A FARM-LEVEL ANALYSIS

    OpenAIRE

    Olwande, John; Ngigi, Margaret; Nguyo, Wilson

    2009-01-01

    This study assessed how responsive maize output is to price and non-price factors and how sensitive fertilizer and labour demand are to prices and non-price factors using cross-sectional farm-level data for 334 maize producing households in the High Potential Maize Zone of Kenya. The study employed normalized restricted translog profit function to estimate maize supply and variable input demand elasticities. Results show that maize price support is an inadequate policy for expanding maize sup...

  19. Low dose gamma radiation on maize seed and its effect on plant growth and yield

    International Nuclear Information System (INIS)

    Seed or plant treatment with ionizing radiations, at certain doses can promote an increase and/or germination acceleration, greater plant development, an agricultural production increase, etc. Radiation doses used to obtain these stimuli do not provoke alteration on the genetic patrimony, because generally the dose level is very low. Low doses of gamma radiation have been reported to induce useful effects in rice, wheat, corn, tomato, radish, etc. which resulted in improved germination and higher yields. The present work is aimed to examine the effects of 60Co gamma radiation on maize seeds, on its development and crop production

  20. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment.

    Science.gov (United States)

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes.

  1. Processing maize flour and corn meal food products.

    Science.gov (United States)

    Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

    2014-04-01

    Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn.

  2. Processing maize flour and corn meal food products

    Science.gov (United States)

    Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

    2014-01-01

    Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn. PMID:24329576

  3. STRATEGY OF MAIZE'S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    JIANG Hui-ming; GU Li-li

    2003-01-01

    Jilin Province is one of the main grain-producing provinces of China, which has dominant position in maize production, by the view of its advantages in policy, location, breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize, analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages, carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province, cast the agricultural predicament off and promote the agricultural development into a new stage.

  4. How Do Various Maize Crop Models Vary in Their Responses to Climate Change Factors?

    Science.gov (United States)

    Bassu, Simona; Brisson, Nadine; Grassini, Patricio; Durand, Jean-Louis; Boote, Kenneth; Lizaso, Jon; Jones, James W.; Rosenzweig, Cynthia; Ruane, Alex C.; Adam, Myriam; Baron, Christian; Basso, Bruno; Biernath, Christian; Boogaard, Hendrik; Conijn, Sjaak; Corbeels, Marc; Deryng, Delphine; DeSanctis, Giacomo; Gayler, Sebastian; Grassini, Patricio; Hatfield, Jerry; Hoek, Steven; Izaurralde, Cesar; Jongschaap, Raymond; Kemanian, Armen R.; Kersebaum, K. Christian

    2014-01-01

    Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, growth, and yield. With the goal of analyzing the sensitivity of simulated yields to changes in temperature and atmospheric carbon dioxide concentrations [CO2], we present the largest maize crop model intercomparison to date, including 23 different models. These models were evaluated for four locations representing a wide range of maize production conditions in the world: Lusignan (France), Ames (USA), Rio Verde (Brazil) and Morogoro (Tanzania). While individual models differed considerably in absolute yield simulation at the four sites, an ensemble of a minimum number of models was able to simulate absolute yields accurately at the four sites even with low data for calibration, thus suggesting that using an ensemble of models has merit. Temperature increase had strong negative influence on modeled yield response of roughly -0.5 Mg ha(sup 1) per degC. Doubling [CO2] from 360 to 720 lmol mol 1 increased grain yield by 7.5% on average across models and the sites. That would therefore make temperature the main factor altering maize yields at the end of this century. Furthermore, there was a large uncertainty in the yield response to [CO2] among models. Model responses to temperature and [CO2] did not differ whether models were simulated with low calibration information or, simulated with high level of calibration information.

  5. The Dynamics of DNA Methylation in Maize Roots under Pb Stress

    Directory of Open Access Journals (Sweden)

    Haiping Ding

    2014-12-01

    Full Text Available Plants adapt to adverse conditions through a series of physiological, cellular, and molecular processes, culminating in stress tolerance. However, little is known about the associated regulatory mechanisms at the epigenetic level in maize under lead (Pb stress. Therefore, in this study, we aimed to compare DNA methylation profiles during the dynamic development of maize roots following Pb treatment to identify candidate genes involved in the response to Pb stress. Methylated DNA immunoprecipitation-sequencing (MeDIP-seq was used to investigate the genome-wide DNA methylation patterns in maize roots under normal condition (A1 and 3 mM Pb(NO32 stress for 12 h (K2, 24 h (K3 and 48 h (K4. The results showed that the average methylation density was the highest in CpG islands (CGIs, followed by the intergenic regions. Within the gene body, the methylation density of the introns was higher than those of the UTRs and exons. In total, 3857 methylated genes were found in 4 tested samples, including 1805 differentially methylated genes for K2 versus A1, 1508 for K3 versus A1, and 1660 for K4 versus A1. Further analysis showed that 140 genes exhibited altered DNA methylation in all three comparisons, including some well-known stress-responsive transcription factors and proteins, such as MYB, AP2/ERF, bZIP, serine-threonine/tyrosine-proteins, pentatricopeptide repeat proteins, RING zinc finger proteins, F-box proteins, leucine-rich repeat proteins and tetratricopeptide repeat proteins. This study revealed the genome-scale DNA methylation patterns of maize roots in response to Pb exposure and identified candidate genes that potentially regulate root dynamic development under Pb stress at the methylation level.

  6. TCUP: A novel hAT transposon active in maize tissue culture

    Directory of Open Access Journals (Sweden)

    Alan eSmith

    2012-01-01

    Full Text Available Transposable elements are capable of inducing heritable de novo genetic variation. The sequences capable of reactivation, and environmental factors that induce mobilization, remain poorly defined even in well-studied genomes such as maize. We treated maize tissue culture with the demethylating agent 5-aza-2-deoxcytidine and examined long-term tissue culture lines to discover silenced transposable elements that have the potential to induce heritable genetic variation. Through these screens we have identified a novel low copy number hAT transposon, Tissue Culture Up-Regulated (TCUP, which is transcribed at high levels in long-term maize Black Mexican Sweet (BMS tissue culture and up-regulated in response to treatment with 5-aza-2-deoxycytidine. Analysis of the TIGR Maize Gene Index revealed that this element is the most frequently represented EST from the BMS cell culture library and is not represented in other tissue libraries, which is the basis for its name. A full-length sequence was assembled in inbred B73 that contains the putative functional motifs required for autonomous movement of a hAT transposon. Transposon display detected movement of TCUP in two long-term tissue cultured cell lines of the genotype Hi-II AxB and BMS. This research implicates TCUP as a transposon that is capable of reactivation and which may also be particularly sensitive to the stress of the tissue culture environment. Our findings are consistent with the hypothesis that epigenetic alterations potentiate genomic responses to stress during clonal propagation of plants.

  7. Effects of nitrogen application and maize growth on N2O emission from soil

    Institute of Scientific and Technical Information of China (English)

    YANG Lanfang; CAI Zucong

    2007-01-01

    Using the pot experiment and closed static chamber-gas chromatography(GC)technique,this paper studied the effects of nitrogen application(150 and 300 mg/kg soil)and maize growth on N2O emission from soil.In maizeplanted soil,the N2O emission rate increased with increasing N application rate,its peak appeared at the seedling stage,and there was no significant correlation between N20 emission rate and air temperature.Contrarily,in exposed soil,the peak of N20 emission rate occurred at the later stages of the experiment,and there was a significant exponential correlation between soil N2O emission rate and air temperature,in which Q10(the value of soil N2O emission rate responding to temperature)was 4.4 and 3.2 in high and low N applications.The total amount of N2O emission increased remarkably with increased N application rate in both planted and un-planted soils.N2O emission inventory from exposed and maizeplanted soils in high N application was 2.5 and 1.6 times as high as that in low N application,respectively.In the same N application rate,N2O emission inventory in high and low N application from exposed soil was 12 and 7.5 times as high as that from maize-planted soil,respectively.As compared with exposed soil,maize growth reduced N2O emission by 92% and 87%,respectively,at high and low N application rates.In summary,maize growth and nitrogen application not only affected the seasonal variation and magnitude of N2O emission from soil,but also altered the relationship between air temperature and soil N2O emission.

  8. SNP-analysis in certification and identification of maize lines

    OpenAIRE

    Сатарова, Т. М.; Дзюбецький, Б. В.; Черчель, В. Ю.; Борисова, В. В.; Таганцова, М. М.

    2014-01-01

    Methodical aspects of using the analysis of DNA single-nucleotide polymorphism (SNP-analysis) for certification and identification of maize lines are considered. It is shown that SNP-genotyping is a method with high discriminatory potential that can differentiate maize lines among themselves and is recommended to use for certification of maize  lines and analysis of their homogeneity, stability and genotype differences.

  9. Impact of contour hedgerows on maize yields in the Philippines

    OpenAIRE

    Shively, Gerald E.

    1998-01-01

    Metadata only record This paper investigates the impact of contour hedgerows on maize yields. The author applies and agricultural production function to assess data from upland Philippine maize farms and hedgerows of double rows of the nitrogen-fixing species Desmodium rensonii and Flemengia macrophylla. Although the findings show a positive long term impact on maize yields, the short term impact of hedgerows is negative; they reduce land available for cultivation and decrease productivity...

  10. 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....

  11. Technical Efficiency Analysis of Maize Production: Evidence from Ghana

    OpenAIRE

    Bempomaa, Beatrice; Acquah, Henry de-Graft

    2014-01-01

    The study applies the single-stage modelling stochastic frontier approach to investigate the performance of maize farmers in the Ejura-Sekyedumase District of Ghana. It estimates the level of technical efficiency and its determinants for 306 maize farmers. Findings indicated that land, labour and fertilizer influenced output positively whilst agrochemicals and seeds affected output negatively. A wide variation in output was also found among producers of maize. The study further revealed that ...

  12. Index selection of tropical maize genotypes for nitrogen use efficiency

    OpenAIRE

    Ítalo Stefanine Correia Granato; Felipe Pereira Bermudez; Gabriel Gonçalves dos Reis; Julio César Dovale; Glauco Vieira Miranda; Roberto Fritsche-Neto

    2014-01-01

    Nitrogen (N) limitation in maize crops is related to the fact that the efficiency of nitrogen fertilization in maize does not exceed 50%, primarily due to volatilization, denitrification and soil leaching. Therefore, the development of new nitrogen use efficient (NUE) cultivars is necessary. The aim of the present study was to develop indices for the accurate selection of NUE maize genotypes for use in conditions of both high and low N availability. The experiment was conducted in a greenhous...

  13. 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. PMID:12582555

  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. Bt maize and integrated pest management--a European perspective.

    Science.gov (United States)

    Meissle, Michael; Romeis, Jörg; Bigler, Franz

    2011-09-01

    The European corn borer (Ostrinia nubilalis), the Mediterranean corn borer (Sesamia nonagrioides) and the western corn rootworm (Diabrotica virgifera virgifera) are the main arthropod pests in European maize production. Practised pest control includes chemical control, biological control and cultural control such as ploughing and crop rotation. A pest control option that is available since 1996 is maize varieties that are genetically engineered (GE) to produce insecticidal compounds. GE maize varieties available today express one or several genes from Bacillus thuringiensis (Bt) that target corn borers or corn rootworms. Incentives to growing Bt maize are simplified farm operations, high pest control efficiency, improved grain quality and ecological benefits. Limitations include the risk of resistance evolution in target pest populations, risk of secondary pest outbreaks and increased administration to comply with licence agreements. Growers willing to plant Bt maize in the European Union (EU) often face the problem that authorisation is denied. Only one Bt maize transformation event (MON810) is currently authorised for commercial cultivation, and some national authorities have banned cultivation. Spain is the only EU member state where Bt maize adoption levels are currently delivering farm income gains near full potential levels. In an integrated pest management (IPM) context, Bt maize can be regarded as a preventive (host plant resistance) or a responsive pest control measure. In any case, Bt maize is a highly specific tool that efficiently controls the main pests and allows combination with other preventive or responsive measures to solve other agricultural problems including those with secondary pests.

  16. Chemical composition and quality of sweet sorghum and maize silages

    OpenAIRE

    PODKÓWKA, Zbigniew; Lucyna PODKÓWKA

    2011-01-01

    Sweet sorghum (Sorghum saccharatum) silage, maize (Zea mays) silage, and sorghum and maize (1:1) silage were investigated. The silages were analysed for chemical composition, quality and aerobic stability. Dry matter was the lowest (20.88%) in sorghum silage and the highest (37.45%) in maize silage. In sorghum silage, the concentration of crude ash and crude fibre was higher, and that of crude protein, crude fat and N-free extractives lower compared to maize silage. Neutral detergent fibre an...

  17. 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.

  18. Does Land Use Patterns Matter for Bt-Maize: The Case of Maize Farming System in Kenya

    OpenAIRE

    Muhammad, Lutta; Owuor, George; De Groote , Hugo; Kimenju, Simon Chege

    2006-01-01

    Population pressures and the need to optimize the use of limited available land has led to increasing cropping affluence levels within the maize agro-ecologies in Kenya, and a shift from large to smallholder intensification and multiple cropping patterns. Using a geographic information system, this study relates cropping patterns, by area share, maize productivity and household incomes across maize agro-ecologies, with the purpose to establish a decision support system for optimizing land all...

  19. 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.

  20. The radiosensitizing effect of metronidazole in maize

    International Nuclear Information System (INIS)

    The identification of chemical substances which increase the efficiency of radiation is important to make easier the obtention of plants with structural chromosome aberrations which may be used in an alternative program for hybrid maize production. The present work was carried out to investigate the effect of the chemical substance metronidazole in maize seedlings submitted to gamma radiation. Several treatments were done, soaking the seeds in solutions with varied concentrations of the active substance combined with solution filtration and gamma radiation. On the third day of the experiment, germination percentage, root and stem lengths were evaluated. At a high concentration (1,250 mg/50 mL) metronidazole behaved as a radiosensibilizer in the presence of radiation. Even at a low concentration (250 mg/50 mL; 750 mg/50 mL) and in the absence of radiation, metronidazole behaved as toxic substance. (author)

  1. Distribution of azotobacter in rhizosphere of maize

    International Nuclear Information System (INIS)

    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)

  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.

  3. Effects of Selected Diazotrophs on Maize Growth

    Science.gov (United States)

    Kifle, Medhin H.; Laing, Mark D.

    2016-01-01

    Laboratory, greenhouse, and field experiments were conducted at the University of KwaZulu-Natal, Pietermaritzburg, South Africa in the 2010/2011 and 2011∖2012 seasons to study the effects of eight strains of diazotrophic bacteria on the growth and yield of maize. Maize seeds were treated with Bacillus megaterium (V16), Pseudomonas sp. (StB5, A3, A6, and A61), Burkholderia ambifaria (V9), Enterobacter cloacae (L1) and Pantoea ananatis (LB5), aiming to stimulate plant growth, and maintain or increase yields while reducing the need for N fertilization. All the diazotrophic bacteria increased germination of maize seed, and Pseudomonas sp. (StB5) and B. megaterium (V16) significantly increased shoot length. Pseudomonas sp. (StB5), B. megaterium (V16), E. cloacae (L1), B. ambifaria (V9), and Pseudomonas sp. (A3) very significantly increased root length and seed vigor index. Under greenhouse conditions, plants treated with diazotrophic bacteria developed more leaf chlorophyll and greater dry weight, albeit not significantly (n.s.). In a field trial in 2010/2011, application of the best five diazotrophic bacteria, with or without 33% N-fertilizer, had no significant effect on germination, grain yield, dry weight, plant height and leaf chlorophyll. In the 2011/2012 growing season, at 60 days after planting (DAP), all the diazotrophic bacteria increased plant dry weights to equal that of the fertilized control (33%N-fertilizer) (n.s.). After inoculation with the diazotrophs alone increased plant heights (n.s.), and chlorophyll contents (n.s.). With the addition of 33%N-fertilizer at planting, the diazotrophs still caused increases of chlorophyll content relative to the control with 33%N (n.s.). It may be concluded that the tested diazotrophs alone may be beneficial for use on maize growth. PMID:27713756

  4. 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. PMID:27330146

  5. [Nixtamalization cooking characteristics of 11 maize varieties].

    Science.gov (United States)

    Billeb de Sinibaldi, A C; Bressani, R

    2001-03-01

    In the present study, 11 maize varieties were analyzed for their nixtamalization cooking quality. The 11 varieties were grown in the same locality and in the same year. The samples were evaluated for their physical characteristics, such as moisture content averaging 13.3%, average 1000 kernel weight (312.5 g), grain hardness through density (1.28 g/ml) and percent floaters (9.5%). These data indicated that all maize varieties had a hard endosperm which is recommended for the nixtamalization cooking process. The 11 varieties were formed on the average by 5.7% seed coat, 11.5% germ and 82.8% endosperm. The low seed coat content suggest a low solids loss during processing. Cooking quality evaluation was done by applying a standard lime cooking procedure to all varieties. An average solid loss of 3.2% was measured, with 0.8% of seed coat still attached to the endosperm. Water absorption at the end of cooking was 40.8% without soaking and 46.9% at the end of soaking. Nixtamal moisture was 47.9% after soaking and only 41.5% at the end of cooking. Cooking time with soaking for 50% moisture in the grain varied from 69 to 122 minutes at 1500 meters over sea level. The cooked grain was dried with hot air and ground however, the particle size obtained was not as that in commercial nixtamalized maize flour. However, the cooking quality parameters to make dough and tortillas were acceptable, with a penetration index of hydrated flour of 178.6 mm, pH 7.97, water absorption index (WAI) of 3.23 g gel/g flour and 4.11% water solubility index (WSI). All flours from the 11 varieties of maize gave acceptable tortillas as evaluated by physical characteristics and sensory quality. However of the 11 varieties 7 including the control were superior for nixtamalization cooking quality. PMID:11515238

  6. Potassium leakage and maize seed physiological potential

    OpenAIRE

    Miguel Mariane Victorio de Carvalho; Marcos Filho Julio

    2002-01-01

    Seed production usually requires fast decisions to improve the efficacy of seed handling during harvesting, processing and storage. Seed technologists have focused on the development or improvement of procedures which allow rapid and consistent identification of higher quality seed lots. This research verified the effectiveness of the potassium leachate test on the evaluation of the physiological potential of maize seeds in comparison to recommended seed vigor tests. Five seed lots of the hyb...

  7. Seed Development and Quality in Maize Cultivars

    OpenAIRE

    Kazem GHASSEMI-GOLEZANI; Zahra TAJBAKHSH; Yaeghoob RAEY

    2011-01-01

    In order to evaluate seed development and quality of maize (Zea mays) cultivars (DC-370, SC-500, OSSK-602 and SC-604), a split plot experiment (using R.C.B. design) with three replicates was conducted in 2009 at the Research Farm of the Faculty of Agriculture, University of Tabriz, Iran. Seeds were harvested at five day intervals in eight stages. Subsequently, the quality of seed samples was determined in the laboratory. Germination percentage and seedling dry weight were enhanced, but...

  8. Taxonomy Icon Data: maize [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available maize Zea mays Zea_mays_L.png Zea_mays_NL.png Zea_mays_S.png Zea_mays_NS.png http://biosciencedbc.jp/taxonom...y_icon/icon.cgi?i=Zea+mays&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Zea...+mays&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Zea+mays&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Zea+mays&t=NS ...

  9. Genetically modified maize: exploring consumer acceptance

    OpenAIRE

    Batrinou, Anthimia M.; Sinanoglou, Vasilia; Gogkou, Antigoni; Sakellaris, George

    2006-01-01

    Recent EU regulations have imposed mandatory labelling of all food products that consist of or contain genetically modified organisms (GMOs). Labelling should state that "this product contains genetically modified organisms". This study examines how different label messages may affect the attitude of consumers in tasting a specific food product (corn chip) derived from maize presented with five different labels ("organic corn", "conventional corn", "product that contains genetically modified ...

  10. 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.

  11. Aflatoxin regulations in a network of global maize trade.

    Directory of Open Access Journals (Sweden)

    Felicia Wu

    Full Text Available Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1, B(2, G(1, and G(2 differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

  12. Aflatoxin regulations in a network of global maize trade.

    Science.gov (United States)

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1), B(2), G(1), and G(2)) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

  13. 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.

  14. Impact of Cinnamic Acid on Physiological and Anatomical Changes in Maize Plants (Zea mays L. Grown under Salinity Stress

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Singh

    2014-05-01

    Full Text Available The environmental contamination with high salt is the elementary intimidation to the agriculture. Maize plants were deeply affected due to salinity worldwide and a severe problem to scientists. A probable survival strategy of the plants under unpleasant environmental circumstances is to use of endogenous metabolites that could ameliorate the harsh effect of salinity. Current study was under taken to observe the effect of cinnamic acid (CA, a central molecule of phenylpropanoid pathway (Secondary metabolism on the growth and development of maize plants under NaCl stress conditions. CA is rapidly produced by plants in response to stressful condition. Response to maize seed to the presoaking treatment 0.05mM CA was deliberated under different concentration of NaCl stress such as 50, 100, 150, 200, mM NaCl for 14 days. The injurious effects of salinity on growth and development were manifested by decreased fresh weight, dry weight, and relative water content (RWC and chlorophyll pigment contents. Degree of lipid peroxidation turned down through the significant decrease in MDA content in maize seedlings. CA induced the anatomical properties under salinity .In present exploration. The cortical cells were induced in root in response to CA than stress. Here, the present study was undertaken with the aim of determining salt induced anatomical and morphological alteration in the presence of exogenous CA. The major reduction in dimension of cortical cells was observed which indicate that salt stress reduced the tolerance of cortical cell more than treatment in maize root. We conclude that CA is a potential phenylpyranoid for protecting crop plant under saline environment.

  15. Resistant starch alters gut microbiome and metabolomics profiles concurrent with amelioration of chronic kidney disease in rats

    Science.gov (United States)

    Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xeno-metabolites). The fermentable dietary fiber—high amylose maize...

  16. Characteristics and mechanisms of acrylate polymer damage to maize seedlings.

    Science.gov (United States)

    Chen, Xian; Mao, Xiaoyun; Lu, Qin; Liao, Zongwen; He, Zhenli

    2016-07-01

    Superabsorbent acrylate polymers (SAPs) have been widely used to maintain soil moisture in agricultural management, but they may cause damage to plants, and the mechanisms are not well understood. In this study, seed germination, soil pot culture, hydroponic experiments, and SAPs degradation were conducted to investigate damage characteristics and mechanisms associated with SAPs application. The Results showed that SAPs inhibited maize growth and altered root morphology (irregular and loose arrangement of cells and breakage of cortex parenchyma), and the inhibitory effects were enhanced at higher SAPs rates. After 1h SAP hydrogels treatment, root malondialdehyde (MDA) content was significantly increased, while superoxide dismutase (SOD) and catalase (CAT) content were significantly decreased. Hydroponics experiment indicated that root and shoot growth was inhibited at 2.5mgL(-1) acrylic acid (AA), and the inhibition was enhanced with increasing AA rates. This effect was exacerbated by the presence of Na(+) at a high concentration in the hydrogels. Release and degradation of AA were enhanced at higher soil moisture levels. A complete degradation of AA occurred between 15 and 20 days after incubation (DAI), but it took longer for Na(+) concentration to decrease to a safe level. These results indicate that high concentration of both AA and Na(+) present in the SAPs inhibits plant growth. The finding of this study may provide a guideline for appropriate application of SAPs in agriculture. PMID:27057990

  17. Climate change compromises the immune response of maize

    Science.gov (United States)

    Maize is by quantity the most important C4 cereal crop in the US; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2] is a driving force behind the warmer temperatures and drought, whi...

  18. Genetic, evoluntionary and plant breedinginsights from the domestication of maize

    Science.gov (United States)

    The natural history of maize began nine thousand years ago when Mexican farmers started to collect the seeds of the wild grass, teosinte. Invaluable as a food source, maize permeated Mexican culture and religion. Its domestication eventually led to its adoption as a model organism, aided in large pa...

  19. A single molecule scaffold for the maize genome

    Science.gov (United States)

    About 85% of the maize genome consists of highly repetitive Sequences that are interspersed by low copy, gene-coding sequences. The maize community has dealt with this genomic complexity by the Construction of an integrated genetic and physical map (iMap), but this resource alone was not sufficient ...

  20. Molecular and Ultrastructural Properties of Maize White Line Virus

    Science.gov (United States)

    This paper reports the complete nucleotide sequence of the genome of Maize white line mosaic virus (MWLMV) and describes the ultrastructural features of infected maize cells. The viral genome is an RNA molecule 4293 nt in size with the same structural organization of members of the Aureusvirus and ...

  1. 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...

  2. Chemical composition and quality of sweet sorghum and maize silages

    Directory of Open Access Journals (Sweden)

    Zbigniew PODKÓWKA

    2011-10-01

    Full Text Available Sweet sorghum (Sorghum saccharatum silage, maize (Zea mays silage, and sorghum and maize (1:1 silage were investigated. The silages were analysed for chemical composition, quality and aerobic stability. Dry matter was the lowest (20.88% in sorghum silage and the highest (37.45% in maize silage. In sorghum silage, the concentration of crude ash and crude fibre was higher, and that of crude protein, crude fat and N-free extractives lower compared to maize silage. Neutral detergent fibre and acid detergent fibre were the highest in sorghum silage and the lowest in maize silage. The silages were dominated by lactic acid, with trace amounts of butyric acid. Maize silage was higher lactic acid and higher total acids than others. All silages were of very good quality according to Flieg-Zimmer scale. Silage pH ranged from 4.20 to 4.31. Sorghum silage was characterized by higher aerobic stability (81h compared to the other silages from maize (74h and sorghum and maize 1:1 (69h.

  3. Influence of Seed Coating Formulations on Maize Production

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effects of four coating formulations on maize production were studied. The results showec that all coating formulations had some effects on improving maize seedlings, strengthening the resistance againt diseases and pests and increasing the yields in dtifferent degrees, especially Paxil which increased the com yield by 12.0%, significantly higher than the control.

  4. A Single Molecule Scaffold for the Maize Genome

    Science.gov (United States)

    About 80% of the maize genome consists of highly repetitive sequences that are interspersed by low copy, gene-coding sequences. The maize community has dealt with this genomic complexity by the construction of an integrated genetic and physical map (iMap), but this resource alone may not be sufficie...

  5. The art and design of genetic screens: maize

    Science.gov (United States)

    Maize (Zea mays) is an excellent model for basic research. Genetic screens have informed our understanding of developmental processes, meiosis, epigenetics and biochemical pathways--not only in maize but also in other cereal crops. We discuss the forward and reverse genetic screens that are possible...

  6. 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...

  7. Sequence Resources at MaizeGDB with Emphasis on POPcorn: A Project Portal for Corn

    Science.gov (United States)

    MaizeGDB is the maize research community’s centralized, long-term repository for genetic and genomic information about the crop plant and model organism Zea mays ssp. mays. The MaizeGDB team endeavors to meet the needs of the maize research community based on feedback and guidance. Recent work has f...

  8. Diversity in global maize germplasm: Characterization and utilization

    Indian Academy of Sciences (India)

    B M Prasanna

    2012-11-01

    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 Mexico and other countries highlighted the genetic variability in the maize germplasm. Applications of molecular markers, particularly in the last two decades, have led to new insights into the patterns of genetic diversity in maize globally, including landraces as well as wild relatives (especially teosintes) in Latin America, helping in tracking the migration routes of maize from the centers of origin, and understanding the fate of genetic diversity during maize domestication. The genome sequencing of B73 (a highly popular US Corn Belt inbred) and Palomero (a popcorn landrace in Mexico) in the recent years are important landmarks in maize research, with significant implications to our understanding of the maize genome organization and evolution. Next-generation sequencing and high-throughput genotyping platforms promise to further revolutionize our understanding of genetic diversity and for designing strategies to utilize the genomic information for maize improvement. However, the major limiting factor to exploit the genetic diversity in crops like maize is no longer genotyping, but high-throughput and precision phenotyping. There is an urgent need to establish a global phenotyping network for comprehensive and efficient characterization of maize germplasm for an array of target traits, particularly for biotic and abiotic stress tolerance and nutritional quality. ‘Seeds of Discovery’ (SeeD), a novel initiative by CIMMYT with financial support from the Mexican Government for generating international public goods, has initiated intensive exploration of phenotypic and molecular diversity of maize germplasm conserved in the CIMMYT Gene Bank; this

  9. Tolerance of Maize(Zea mays L. )to Chlorsulfuron

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Fourteen inbreds of maize were tested for the tolerance to chlorsulfuron with the method of seedling wa- ter culter. Significant difference existed in the tolerance of different type maize when tested with 1 and 2 μg/ kg of chlorsulfuron. The tolerance in different type maize wa dent>flint>sugar>midiem>super sugar pop. The tolerance of different inbred maize was negative correlated with the concentration concentration of chorsulfuron. The tolerance of hybrids might have some relation with their parent lines because in this test the hybrids response to chlorsulfuron showed significant positive correlation with that of tits female parent which suggented some maternal in inheritance and was not controlled by nuclear. It was possible that toler- ance of maize to chlorsulfuron was cytoplasm inheritance.

  10. 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.

  11. Maize Haploid Induction and Doubling – Recent Experience with Exotic and Elite Maize Populations

    Science.gov (United States)

    Experience from three maize research projects utilizing the haploid inducer RWS x RWK-76 from the University of Hohenheim will be summarized. These projects result from collaborations between Iowa State Doubled Haploid Facility (http://www.plantbreeding.iastate.edu/DHF/DHF.htm) researchers and USDA...

  12. 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.

  13. Targeted Sequencing Reveals Large-Scale Sequence Polymorphism in Maize Candidate Genes for Biomass Production and Composition.

    Directory of Open Access Journals (Sweden)

    Moses M Muraya

    Full Text Available A major goal of maize genomic research is to identify sequence polymorphisms responsible for phenotypic variation in traits of economic importance. Large-scale detection of sequence variation is critical for linking genes, or genomic regions, to phenotypes. However, due to its size and complexity, it remains expensive to generate whole genome sequences of sufficient coverage for divergent maize lines, even with access to next generation sequencing (NGS technology. Because methods involving reduction of genome complexity, such as genotyping-by-sequencing (GBS, assess only a limited fraction of sequence variation, targeted sequencing of selected genomic loci offers an attractive alternative. We therefore designed a sequence capture assay to target 29 Mb genomic regions and surveyed a total of 4,648 genes possibly affecting biomass production in 21 diverse inbred maize lines (7 flints, 14 dents. Captured and enriched genomic DNA was sequenced using the 454 NGS platform to 19.6-fold average depth coverage, and a broad evaluation of read alignment and variant calling methods was performed to select optimal procedures for variant discovery. Sequence alignment with the B73 reference and de novo assembly identified 383,145 putative single nucleotide polymorphisms (SNPs, of which 42,685 were non-synonymous alterations and 7,139 caused frameshifts. Presence/absence variation (PAV of genes was also detected. We found that substantial sequence variation exists among genomic regions targeted in this study, which was particularly evident within coding regions. This diversification has the potential to broaden functional diversity and generate phenotypic variation that may lead to new adaptations and the modification of important agronomic traits. Further, annotated SNPs identified here will serve as useful genetic tools and as candidates in searches for phenotype-altering DNA variation. In summary, we demonstrated that sequencing of captured DNA is a powerful

  14. Identification of a strain of maize dwarf mosaic virus, related to sugarcane mosaic virus isolated from maize in Burundi

    Directory of Open Access Journals (Sweden)

    Verhoyen, M.

    1983-01-01

    Full Text Available A strain of maize dwarf mosaic virus related to sugarcane mosaic virus has been isolated from maize in Burundi. The properties (including electron microscopy and serology of the virus are described, and elements for a control strategy are reviewed.

  15. 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

    2015-01-01

    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. PMID:26308050

  16. 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.

  17. Salt stress in maize: effects, resistance mechanisms, and management. A review

    OpenAIRE

    Farooq, Muhammad; Hussain, Mubshar; Wakeel, Abdul; Kadambot H M Siddique

    2015-01-01

    Maize is grown under a wide spectrum of soil and climatic conditions. Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Understanding maize response to salt stress and resistance mechanisms and overviewing management options may help to devise strategies for improved maize performance in saline environments. Here, we reviewed the effects, resistance mechanisms, and management of salt stress in maize. Our main conclusions ar...

  18. 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.

  19. Microsatellite-assisted backcross selection in maize

    Directory of Open Access Journals (Sweden)

    Luciana Lasry Benchimol

    2005-12-01

    Full Text Available A microsatellite marker (SSR was chosen to simulate a target allele and three criteria (02, 04 and 06 markers per chromosome were tested to evaluate the most efficient parameters for performing marker-assisted backcross (MAB selection. We used 53 polymorphic SSRs to genotype 186 BC1 maize (Zea mays L. plants produced by crossing the inbred maize lines L-08-05 (donor parent and L-14-4B (recurrent parent. The second backcross (BC2 generation was produced with 180 plants and screened with markers which were not recovered from the first backcross (BC1 generation. A total of 480 plants were evaluated in the third backcross (BC3 generation from which 48 plants were selected for parental genotype recovery. Recurrent genotype recovery averages in three backcross generations were compatible with those expected in BC4 or BC5, indicating genetic gain due to the marker-assisted backcrossing. The target marker (polymorphic microsatellite PHI037 was efficiently transferred. Six markers per chromosome showed a high level of precision for parental estimates at different levels of maize genome saturation and donor alleles were not present in the selected recovered pure lines. Phenotypically, the plants chosen based on this criterion (06 markers per chromosome were closer to the recurrent parent than any other selected by other criteria (02 or 04 markers per chromosome. This approach allowed the understanding that six microsatellites per chromosome is a more efficient parameter than 02 and 04 markers per chromosome for deriving a marker-assisted backcross (MAB experiment in three backcross generations.

  20. Lipids in Aspergillus flavus-maize interaction

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    Massimo eReverberi

    2014-02-01

    Full Text Available In sSome filamentous fungi, the pathways related to the oxidative stress and oxylipins production are involved both in the process of host-recognition of the host that and in the pathogenic phase. In fact, recent studies have shown that the production of oxylipins in filamentous fungi, yeasts and chromists is also related to the development of the organism itself and to mechanisms of communication with the host at the cellular level. The oxylipins, also involved produced in by the host during defense reactions, are able to induce sporulation and to modulate regulate the biosynthesis of mycotoxins in numerous several pathogenic fungi, apparently replacing the endogenous ones. In A. flavus, the oxylipins play a crucial role as signals for the regulation regulatingof the biosynthesis of aflatoxins, the conidiogenesis and the formation of sclerotia.To investigate the involvement of the an oxylipins based cross-talk into Z. mays and A. flavus interaction, we analyzed the oxylipins profile of the wild type strain and of three mutants of A. flavus that are deleted at the Aflox1 gene level also during maize kernel invasion; Aflox1 encodes for a manganese lipoxygenase.A lipidomic approach has been addressed through the use of LC-ToF-MS, followed by a statistical analysis of the principal components (PCA. The results showed the existence of a difference between the oxylipins profile generated by the WT and the mutants onto challenged maize. In relation to this, aflatoxin synthesis which is largely hampered in vitro, is intriguingly restored. These results highlight the important role of maize oxylipin in driving secondary metabolism in A. flavus.

  1. Iron and zinc availability in maize lines

    OpenAIRE

    Valéria Aparecida Vieira Queiroz; Paulo Evaristo de Oliveira Guimarães; Luciano Rodrigues Queiroz; Estefânia de Oliveira Guedes; Vanessa Diniz Barcelos Vasconcelos; Lauro José Guimarães; Paulo Eduardo de Aquino Ribeiro; Robert Eugene Schaffert

    2011-01-01

    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...

  2. Silicon Improves Maize Photosynthesis in Saline-Alkaline Soils

    Directory of Open Access Journals (Sweden)

    Zhiming Xie

    2015-01-01

    Full Text Available The research aimed to determine the effects of Si application on photosynthetic characteristics of maize on saline-alkaline soil, including photosynthetic rate (Pn, stomatal conductance (gs, transpiration rate (E, and intercellular CO2 concentration (Ci of maize in the field with five levels (0, 45, 90, 150, and 225 kg·ha−1 of Si supplying. Experimental results showed that the values of Pn, gs, and Ci of maize were significantly enhanced while the values of E of maize were dramatically decreased by certain doses of silicon fertilizers, which meant that Si application with proper doses significantly increased photosynthetic efficiency of maize in different growth stages under stressing environment of saline-alkaline soil. The optimal dose of Si application in this experiment was 150 kg·ha−1 Si. It indicated that increase in maize photosynthesis under saline-alkaline stress took place by Si application with proper doses, which is helpful to improve growth and yield of maize.

  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

    2016-01-01

    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. Viruses in maize and Johnsongrass in southern Ohio.

    Science.gov (United States)

    Stewart, L R; Teplier, R; Todd, J C; Jones, M W; Cassone, B J; Wijeratne, S; Wijeratne, A; Redinbaugh, M G

    2014-12-01

    The two major U.S. maize viruses, Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV), emerged in southern Ohio and surrounding regions in the 1960s and caused significant losses. Planting resistant varieties and changing cultural practices has dramatically reduced virus impact in subsequent decades. Current information on the distribution, diversity, and impact of known and potential U.S. maize disease-causing viruses is lacking. To assess the current reservoir of viruses present at the sites of past disease emergence, we used a combination of serological testing and next-generation RNA sequencing approaches. Here, we report enzyme-linked immunosorbent assay and RNA-Seq data from samples collected over 2 years to assess the presence of viruses in cultivated maize and an important weedy reservoir, Johnsongrass (Sorghum halepense). Results revealed a persistent reservoir of MDMV and two strains of MCDV in Ohio Johnsongrass. We identified sequences of several other grass-infecting viruses and confirmed the presence of Wheat mosaic virus in Ohio maize. Together, these results provide important data for managing virus disease in field corn and sweet corn maize crops, and identifying potential future virus threats.

  5. Transcriptional responses of maize seedling root to phosphorus starvation.

    Science.gov (United States)

    Lin, Hai-Jian; Gao, Jian; Zhang, Zhi-Ming; Shen, Ya-Ou; Lan, Hai; Liu, Li; Xiang, Kui; Zhao, Maojun; Zhou, Shufeng; Zhang, Yong-Zhong; Gao, Shi-Bin; Pan, Guang-Tang

    2013-09-01

    Maize (Zea mays) is the most widely cultivated crop around the world, however, it is commonly affected by phosphate (Pi) deficiency and the underlying molecular basis of responses mechanism is still unknown. In this study, the transcriptional response of maize roots to Pi starvation at 3 days after the onset of Pi deprivation was assessed. The investigation revealed a total of 283 Pi-responsive genes, of which 199 and 84 genes were found to be either up- or down-regulated respectively, by 2-fold or more. Pi-responsive genes were found to be involved in sugar and nitrogen metabolic pathways, ion transport, signal transduction, transcriptional regulation, and other processes related to growth and development. In addition, the expression patterns of maize inorganic phosphorus transporters, acid phosphatase, phytase, 2-deoxymugineic acid synthase1, POD and MYB transcription factor were validated in 178 roots response to low phosphorus stress. of which, two genes encoding phytase and acid phosphatase were significantly induced by Pi deficiency and may play a pivotal role in the process of absorption and re-utilization of Pi in Maize. These results not only enhance our knowledge about molecular processes associated with Pi deficiency, but also facilitate the identification of key molecular determinants for improving Pi use in maize. Moreover, this work sets a framework to produce Pi-specific maize microarrays to study the changes in global gene expression between Pi-efficient and Pi-inefficient maize genotypes. PMID:23670044

  6. 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, Peder; 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

  7. 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. PMID:26701746

  8. 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.

  9. RNA-directed DNA methylation enforces boundaries between heterochromatin and euchromatin in the maize genome.

    Science.gov (United States)

    Li, Qing; Gent, Jonathan I; Zynda, Greg; Song, Jawon; Makarevitch, Irina; Hirsch, Cory D; Hirsch, Candice N; Dawe, R Kelly; Madzima, Thelma F; McGinnis, Karen M; Lisch, Damon; Schmitz, Robert J; Vaughn, Matthew W; Springer, Nathan M

    2015-11-24

    The maize genome is relatively large (∼ 2.3 Gb) and has a complex organization of interspersed genes and transposable elements, which necessitates frequent boundaries between different types of chromatin. The examination of maize genes and conserved noncoding sequences revealed that many of these are flanked by regions of elevated asymmetric CHH (where H is A, C, or T) methylation (termed mCHH islands). These mCHH islands are quite short (∼ 100 bp), are enriched near active genes, and often occur at the edge of the transposon that is located nearest to genes. The analysis of DNA methylation in other sequence contexts and several chromatin modifications revealed that mCHH islands mark the transition from heterochromatin-associated modifications to euchromatin-associated modifications. The presence of an mCHH island is fairly consistent in several distinct tissues that were surveyed but shows some variation among different haplotypes. The presence of insertion/deletions in promoters often influences the presence and position of an mCHH island. The mCHH islands are dependent upon RNA-directed DNA methylation activities and are lost in mop1 and mop3 mutants, but the nearby genes rarely exhibit altered expression levels. Instead, loss of an mCHH island is often accompanied by additional loss of DNA methylation in CG and CHG contexts associated with heterochromatin in nearby transposons. This suggests that mCHH islands and RNA-directed DNA methylation near maize genes may act to preserve the silencing of transposons from activity of nearby genes.

  10. Maize mutants lacking chloroplast FtsY exhibit pleiotropic defects in the biogenesis of thylakoid membranes.

    Science.gov (United States)

    Asakura, Yukari; Hirohashi, Toshiya; Kikuchi, Shingo; Belcher, Susan; Osborne, Erin; Yano, Satoshi; Terashima, Ichiro; Barkan, Alice; Nakai, Masato

    2004-01-01

    A chloroplast signal recognition particle (SRP) that is related to the SRP involved in secretion in bacteria and eukaryotic cells is used for the insertion of light-harvesting chlorophyll proteins (LHCPs) into the thylakoid membranes. A conserved component of the SRP mechanism is a membrane-bound SRP receptor, denoted FtsY in bacteria. Plant genomes encode FtsY homologs that are targeted to the chloroplast (cpFtsY). To investigate the in vivo roles of cpFtsY, we characterized maize cpFtsY and maize mutants having a Mu transposon insertion in the corresponding gene (chloroplast SRP receptor1, or csr1). Maize cpFtsY accumulates to much higher levels in leaf tissue than in roots and stems. Interestingly, it is present at similar levels in etiolated and green leaf tissue and was found to bind the prolamellar bodies of etioplasts. A null cpFtsY mutant, csr1-1, showed a substantial loss of leaf chlorophyll, whereas a "leaky" allele, csr1-3, conditioned a more moderate chlorophyll deficiency. Both alleles caused the loss of various LHCPs and the thylakoid-bound photosynthetic enzyme complexes and were seedling lethal. By contrast, levels of the membrane-bound components of the thylakoid protein transport machineries were not altered. The thylakoid membranes in csr1-1 chloroplasts were unstacked and reduced in abundance, but the prolamellar bodies in mutant etioplasts appeared normal. These results demonstrate the essentiality of cpFtsY for the biogenesis not only of the LHCPs but also for the assembly of the other membrane-bound components of the photosynthetic apparatus. PMID:14688289

  11. [Characteristics of farmland eco-environment at the intercropping stage of maize intercropped with winter wheat and their effects on seedling growth of summer maize].

    Science.gov (United States)

    Zhu, Yuan-gang; Li, Hong-jie; Cui, Xin-yan; Jia, Chun-lan; Yang, Jin-sheng; Liu, Shao-kun; Zhang, Ji-wang; Dong, Shu-ting

    2015-07-01

    To study the farmland eco-environment of intercropping maize with wheat at the intercropping stage and its influence on maize seedling growth, two summer maize cultivars, Zhengdan 958 and Denghai 661, were either intercropped with wheat or directly seeded. The result demonstrated that there was little difference for the soil water content of the farmland between the two cultivation methods. The highest soil temperature of intercropped maize was 4.8-5.2 °C lower than the soil temperature of directly-seeded maize, and the lowest temperature of the intercropped maize was 1.4-1.7 °C lower. But, the temperatures for both planting methods met the requirement for seed germination. Light intensity on the ground surface of the intercropped maize was 4.4%-10.6% less than natural light, and insufficient light was the main reason for the weak and late seedling. Compared to the directly-seeded maize, the speeds of seed germination and accumulation of dry matters of the intercropped maize were relatively slow. On the whole, the seedling of intercropped maize was not strong, which presented small leaves, short height and low chlorophyll content. The restraint on the growth of intercropped maize was enhanced with the extension of intercropping period. For farm planting, direct-seeding could improve the seed germination and seedling growth of summer maize. PMID:26710624

  12. Physiological, Ultrastructural and Proteomic Responses in the Leaf of Maize Seedlings to Polyethylene Glycol-Stimulated Severe Water Deficiency

    Directory of Open Access Journals (Sweden)

    Ruixin Shao

    2015-09-01

    Full Text Available After maize seedlings grown in full-strength Hoagland solution for 20 days were exposed to 20% polyethylene glycol (PEG-stimulated water deficiency for two days, plant height, shoot fresh and dry weights, and pigment contents significantly decreased, whereas malondialdehyde (MDA content greatly increased. Using transmission electron microscopy, we observed that chloroplasts of mesophyll cells in PEG-treated maize seedlings were swollen, with a disintegrating envelope and disrupted grana thylakoid lamellae. Using two-dimensional gel electrophoresis (2-DE method, we were able to identify 22 protein spots with significantly altered abundance in the leaves of treated seedlings in response to water deficiency, 16 of which were successfully identified. These protein species were functionally classified into signal transduction, stress defense, carbohydrate metabolism, protein metabolism, and unknown categories. The change in the abundance of the identified protein species may be closely related to the phenotypic and physiological changes due to PEG-stimulated water deficiency. Most of the identified protein species were putatively located in chloroplasts, indicating that chloroplasts may be prone to damage by PEG stimulated-water deficiency in maize seedlings. Our results help clarify the molecular mechanisms of the responses of higher plants to severe water deficiency.

  13. Protein profiles reveal diverse responsive signaling pathways in kernels of two maize inbred lines with contrasting drought sensitivity.

    Science.gov (United States)

    Yang, Liming; Jiang, Tingbo; Fountain, Jake C; Scully, Brian T; Lee, Robert D; Kemerait, Robert C; Chen, Sixue; Guo, Baozhu

    2014-01-01

    Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964) with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP), and protein profiles were investigated in developing kernels (35 DAP) using iTRAQ (isobaric tags for relative and absolute quantitation). Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels.

  14. Protein Profiles Reveal Diverse Responsive Signaling Pathways in Kernels of Two Maize Inbred Lines with Contrasting Drought Sensitivity

    Directory of Open Access Journals (Sweden)

    Liming Yang

    2014-10-01

    Full Text Available Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964 with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP, and protein profiles were investigated in developing kernels (35 DAP using iTRAQ (isobaric tags for relative and absolute quantitation. Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels.

  15. Fine Root Patterning and Balanced Inorganic Phosphorus Distribution in the Soil Indicate Distinctive Adaptation of Maize Plants to Phosphorus Deficiency

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; YU Peng; PENG Yun-Feng; LI Xue-Xian; CHEN Fan-Jun; LI Chun-Jian

    2012-01-01

    Plants have diverse strategies to cope with phosphorus (P) deficiency.To better understand how maize responds to P deficiency,a field experiment with two P levels,0 and 100 kg P2O5 ha-1 (P0 and P100,respectively),was carried out as a part of a long-term Pfertilizer field trial.Plant and soil analyses showed that P-deficient maize reduced its growth rate,increased P use efficiency,and formed more thin roots with the diameter less than 0.6 mm at jointing and silking stages,compared to the plants treated with P100.Further,there were no differences in major inorganic P fractions (Ca2-P,Ca8-P,A1-P,Fe-P,occluded P and Ca10-P) between the rhizospheric and bulk soils at each harvest,even when soil Olsen-P was only 1.38 mg kg-1.These results suggested that maize responded to P deficiency by reducing the internal P demand for growth and increasing P acquisition ability by favorable root morphological alteration at low carbon cost.

  16. Breakage-fusion-bridge cycles and de novo telomere formation on broken chromosomes in maize callus cultures.

    Science.gov (United States)

    Santos-Serejo, Janay A; Aguiar-Perecin, Margarida L R

    2016-06-01

    Breakpoints involved in chromosome alterations associated with heterochromatin have been detected in maize plants regenerated from callus culture. A cytogenetic analysis of plants regenerated from a maize callus was performed aiming to analyze the stability of a chromosome 7 bearing a deficiency-duplication (Df-Dp), which was interpreted as derived from a chromatid type breakage-fusion-bridge (BFB) cycle. The Df-Dp chromosome 7 was stable in mitotic and meiotic cells of the regenerated plants. Fluorescence in situ hybridization showed signals of telomeric sequences on the broken chromosome arm and provided evidence of de novo telomere formation. The stability of two types of altered chromosome 7 was investigated in C-banded metaphases from samples of the original callus that were collected during a period of 30-42 months after culture initiation. New alterations involving heterochromatic knobs of chromosomes 7 and 9 were observed. The aberrant chromosomes were stable in the subcultures, thus providing evidence of broken chromosome healing. The examination of anaphases showed the presence of bridges, which was consistent with the occurrence of BFB cycles. De novo telomere formation occurred in euchromatic and heterochromatic chromosome termini. The results point to events of chromosomal evolution that might occur in plants. PMID:27203556

  17. 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.

  18. 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.

  19. Genome-wide genetic changes during modern breeding of maize.

    Science.gov (United States)

    Jiao, Yinping; Zhao, Hainan; Ren, Longhui; Song, Weibin; Zeng, Biao; Guo, Jinjie; Wang, Baobao; Liu, Zhipeng; Chen, Jing; Li, Wei; Zhang, Mei; Xie, Shaojun; Lai, Jinsheng

    2012-06-03

    The success of modern maize breeding has been demonstrated by remarkable increases in productivity over the last four decades. However, the underlying genetic changes correlated with these gains remain largely unknown. We report here the sequencing of 278 temperate maize inbred lines from different stages of breeding history, including deep resequencing of 4 lines with known pedigree information. The results show that modern breeding has introduced highly dynamic genetic changes into the maize genome. Artificial selection has affected thousands of targets, including genes and non-genic regions, leading to a reduction in nucleotide diversity and an increase in the proportion of rare alleles. Genetic changes during breeding happen rapidly, with extensive variation (SNPs, indels and copy-number variants (CNVs)) occurring, even within identity-by-descent regions. Our genome-wide assessment of genetic changes during modern maize breeding provides new strategies as well as practical targets for future crop breeding and biotechnology.

  20. Identification and role of plasma membrane aquaporin in maize root

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using antiserum against expressed aquaporin fusion protein, GST-RD28, the distribution of aquaporin in the plasma membrane of maize root protoplasts has been examined under confocal laser scanning microscopy by indirect fluorescence staining. Results indicate that there are abundant aquaporins in maize roots, which are distributed in plasma membrane unevenly. Western blotting analysis of total protein solubilized from maize root plasma membrane shows that antiserum against GST-RD28 can cross-react with one protein around 55 ku. Another 28 ku protein can also be detected when the concentration of SDS and DTT in SDS-PAGE sample buffer is increased. The 55 and 28 ku proteins may be dimeric and monomeric of aquaporin respectively. Functional experiments show that aquaporin blocker HgCl2 and aquaporin antiserum can suppress the swelling of maize root protoplasts in hypotonic solution, indicating that aquaporin in plasma membrane of protoplast facilitates rapid transmembrane water flow.

  1. Organization of the R chromosome region in maize

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Research is reported which seeks to analyze variations in anthocyanin pigmentation in maize attributable to the R region on chromosome 10. The emphasis is on the structure of the individual genic elements. (ACR)

  2. Molecular classification of Maize cytoplasms in a breeding program

    Directory of Open Access Journals (Sweden)

    Colombo. N * , Presello, D.A. , Kandus M. , G.E. Eyherabide and J.C. Salerno

    2012-06-01

    Full Text Available Cytoplasmic male sterility (CMS is maternally inherited in most of higher plants species. Together with nuclear restorer genes (Rf, CMS cytoplasms contribute significantly to the efficient production of hybrid seed. Three main types of male sterile cytoplasms are known in maize: T, S and C, which can be distinguished by crossing with specific restorer lines. Recently, PCR markers have been developed allowing the identification of different cytoplasms quickly and accurately. Our objective was to classify the cytoplasm type of maize inbred lines used in our breeding program and F1s obtained from crosses between CMS lines and elite maize lines using PCR multiplex. A multiplex PCR protocol was optimized for our conditions. We obtained the molecular classification of the analyzed cytoplasms. The optimized protocol is a valuable tool to trace male sterile cytoplasms and determine hybrid seed purity in our maize breeding program.

  3. Functional and structural analysis of maize hsp101 IRES.

    Directory of Open Access Journals (Sweden)

    Augusto Samuel Jiménez-González

    Full Text Available Maize heat shock protein of 101 KDa (HSP101 is essential for thermotolerance induction in this plant. The mRNA encoding this protein harbors an IRES element in the 5'UTR that mediates cap-independent translation initiation. In the current work it is demonstrated that hsp101 IRES comprises the entire 5'UTR sequence (150 nts, since deletion of 17 nucleotides from the 5' end decreased translation efficiency by 87% compared to the control sequence. RNA structure analysis of maize hsp101 IRES revealed the presence of three stem-loops toward its 5' end, whereas the remainder sequence contains a great proportion of unpaired nucleotides. Furthermore, HSP90 protein was identified by mass spectrometry as the protein preferentially associated with the maize hsp101 IRES. In addition, it has been found that eIFiso4G rather than eIF4G initiation factor mediates translation of the maize hsp101 mRNA.

  4. Effects of INH, DNP, 2,4-D and CMU on the photosynthetic activity of barley and maize plants

    International Nuclear Information System (INIS)

    Determinations of the rate of photosynthesis were made in barley and maize leaves treated with INH, DNP, 2,4-D or CMU. 1 ppm of the chemicals in nutritive solutions was absorbed by roots during 24 or 48 hours in both dark and light conditions. After this period, photosynthetic activity, compensation point and 14CO2 assimilation were determined. Results show that INH increases the rate of photosynthesis, DNP and 2,4-D do not alter it sensibly and CMU acts as a strong inhibitor of photosynthesis. Some possible applications for ths obtention of labelled compounds by biosynthesis are discussed. (Author) 87 refs

  5. Maize RNA Polymerase IV Defines trans-Generational Epigenetic Variation[W

    Science.gov (United States)

    Erhard, Karl F.; Parkinson, Susan E.; Gross, Stephen M.; Barbour, Joy-El R.; Lim, Jana P.; Hollick, Jay B.

    2013-01-01

    The maize (Zea mays) RNA Polymerase IV (Pol IV) largest subunit, RNA Polymerase D1 (RPD1 or NRPD1), is required for facilitating paramutations, restricting expression patterns of genes required for normal development, and generating small interfering RNA (siRNAs). Despite this expanded role for maize Pol IV relative to Arabidopsis thaliana, neither the general characteristics of Pol IV–regulated haplotypes, nor their prevalence, are known. Here, we show that specific haplotypes of the purple plant1 locus, encoding an anthocyanin pigment regulator, acquire and retain an expanded expression domain following transmission from siRNA biogenesis mutants. This conditioned expression pattern is progressively enhanced over generations in Pol IV mutants and then remains heritable after restoration of Pol IV function. This unusual genetic behavior is associated with promoter-proximal transposon fragments but is independent of sequences required for paramutation. These results indicate that trans-generational Pol IV action defines the expression patterns of haplotypes using co-opted transposon-derived sequences as regulatory elements. Our results provide a molecular framework for the concept that induced changes to the heterochromatic component of the genome are coincident with heritable changes in gene regulation. Alterations of this Pol IV–based regulatory system can generate potentially desirable and adaptive traits for selection to act upon. PMID:23512852

  6. Transcriptomic profiling of Bacillus amyloliquefaciens FZB42 in response to maize root exudates

    Directory of Open Access Journals (Sweden)

    Fan Ben

    2012-06-01

    Full Text Available Abstract Background Plant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates. Results Bacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261 was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides. Conclusions Here we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  7. Transcriptomic profiling of Bacillus amyloliquefaciens FZB42 in response to maize root exudates

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  8. Molecular adaptations of Herbaspirillum seropedicae during colonization of the maize rhizosphere.

    Science.gov (United States)

    Balsanelli, Eduardo; Tadra-Sfeir, Michelle Z; Faoro, Helisson; Pankievicz, Vânia Cs; de Baura, Valter A; Pedrosa, Fábio O; de Souza, Emanuel M; Dixon, Ray; Monteiro, Rose A

    2016-09-01

    Molecular mechanisms of plant recognition and colonization by diazotrophic bacteria are barely understood. Herbaspirillum seropedicae is a Betaproteobacterium capable of colonizing epiphytically and endophytically commercial grasses, to promote plant growth. In this study, we utilized RNA-seq to compare the transcriptional profiles of planktonic and maize root-attached H. seropedicae SmR1 recovered 1 and 3 days after inoculation. The results indicated that nitrogen metabolism was strongly activated in the rhizosphere and polyhydroxybutyrate storage was mobilized in order to assist the survival of H. seropedicae during the early stages of colonization. Epiphytic cells showed altered transcription levels of several genes associated with polysaccharide biosynthesis, peptidoglycan turnover and outer membrane protein biosynthesis, suggesting reorganization of cell wall envelope components. Specific methyl-accepting chemotaxis proteins and two-component systems were differentially expressed between populations over time, suggesting deployment of an extensive bacterial sensory system for adaptation to the plant environment. An insertion mutation inactivating a methyl-accepting chemosensor induced in planktonic bacteria, decreased chemotaxis towards the plant and attachment to roots. In summary, analysis of mutant strains combined with transcript profiling revealed several molecular adaptations that enable H. seropedicae to sense the plant environment, attach to the root surface and survive during the early stages of maize colonization. PMID:25923055

  9. The Root Cap Determines Ethylene-Dependent Growth and Development in Maize Roots

    Institute of Scientific and Technical Information of China (English)

    Achim Hahn; Roman Zimmermann; Dierk Wanke; Klaus Harter; Hans G.Edelmann

    2008-01-01

    Besides providing protection against mechanical damage to the root tip,the root cap is involved in the perception and processing of diverse external and internal stimuli resulting in altered growth and development.The transduction of these stimuli includes hormonal signaling pathways such as those of auxin,ethylene and cytokinin.Here,we show that the root cap is essential for the ethylene-induced regulation of elongation growth and root hair formation in maize.Exogenously applied ethylene is no longer able to inhibit elongation growth when the root cap has been surgically removed prior to hormone treatment.Reconstitution of the cap positively correlates with the developing capacity of the roots to respond to ethylene again.In contrast,the removal of the root cap does not per se affect growth inhibition controlled by auxin and cytokinin.Furthermore,our semi-quantitative RT-PCR results support earlier findings that the maize root cap is a site of high gene expression activity with respect to sensing and responding to hormones such as ethylene.From these data,we propose a novel function of the root cap which is the establishment of competence to respond to ethylene in the distal zones of the root.

  10. Ammonium sulphate on maize crops under no tillage

    Directory of Open Access Journals (Sweden)

    Maria Anita Gonçalves da Silva

    2012-01-01

    Full Text Available The objectives of this work were to evaluate the management of N and S (as ammonium sulphate fertilization under no-tillage system on the components of maize productivity and on N and S accumulation in the crop, as well as to evaluate the minimum value of the Nitrogen Sufficiency Index (NSI 0.95 as an indicator for side dressing requirements. The experiment had a completely randomized block design with six treatments and four replications carried out in Red Latosol dystrophic soil (Hapludox, in Campo Mourão, Paraná State, where the following treatments in summer growth maize were applied: T1- 120 kg ha-1 N in seeding; T2- 120 kg ha-1 N in side dressing; T3- 40 kg ha-1 N in seeding and 80 kg ha-1 N in side dressing; T4- 30 kg ha-1 N in seeding and 90 kg ha-1 N in side dressing, monitored by a chlorophyll meter using the Nitrogen Sufficiency Index (NSI; T5- 120 kg ha-1 N anticipated in wheat seeding; T6- without nitrogen fertilization. NSI was determined by the relationship between the leaf chlorophyll index (ICF average of T4 plants and that one in the plot fertilized with 120 kg ha-1 N at the maize seed sowing (T1. During two years, ammonium sulphate was applied to the maize crop after wheat under no tillage system. In the first year, with adequate rainfall, the maize yield was similar to the one in which the complete ammonium sulphate dose application was done in maize seeding and side dressing. The anticipated fertilization to wheat seed sowing resulted in maize yield without difference from the parceled form. In the second year, with irregular rainfall, all treatments with N were similar and they increased maize yield compared to that without N fertilization. NSI of 0.95 was not efficient to evaluate maize N requirements in side dressing, and resulted in lower maize yield. N was accumulated mainly in the grains unlike S that accumulated in the plant shoots; both were highly correlated to maize productivity.

  11. Comparative genome research between maize and rice using genomic in situ hybridization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using the genomic DNAs of maize and rice as probes respectively,the homology of maize and rice genomes was assessed by genomic in situ hybridization. When rice genomic DNAs were hybridized to maize, all chromosomes displayed many multiple discrete regions, while each rice chromosome delineated a single consecutive chromosomal region after they were hybridized with maize genomic DNAs. The results indicate that the genomes of maize and rice share high homology, and confirm the proposal that maize and rice are diverged from a common ancestor.

  12. Growing sensitivity of maize to water scarcity under climate change

    OpenAIRE

    Qingfeng Meng; Xinping Chen; Lobell, David B; Zhenling Cui; Yi Zhang; Haishun Yang; Fusuo Zhang

    2016-01-01

    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 moder...

  13. Use of Polish-bred maize hybrids for biogas production

    OpenAIRE

    Zbigniew PODKÓWKA; Lucyna PODKÓWKA

    2015-01-01

    The suitability for biogas production of silages from selected Polish-bred maize hybrids was investigated. Biogas and methane yield of silages was 513 – 703 and 339 – 443 Ndm3•kg-1 ODM. Hybrids were characterized by a high methane content in biogas (over 63%). Differences were found in biogas and methane production from different maize varieties. The highest-yielding hybrids were SMH 1785 and KBK 11149.

  14. Genetic Architecture of Domestication-Related Traits in Maize.

    Science.gov (United States)

    Xue, Shang; Bradbury, Peter J; Casstevens, Terry; Holland, James B

    2016-09-01

    Strong directional selection occurred during the domestication of maize from its wild ancestor teosinte, reducing its genetic diversity, particularly at genes controlling domestication-related traits. Nevertheless, variability for some domestication-related traits is maintained in maize. The genetic basis of this could be sequence variation at the same key genes controlling maize-teosinte differentiation (due to lack of fixation or arising as new mutations after domestication), distinct loci with large effects, or polygenic background variation. Previous studies permit annotation of maize genome regions associated with the major differences between maize and teosinte or that exhibit population genetic signals of selection during either domestication or postdomestication improvement. Genome-wide association studies and genetic variance partitioning analyses were performed in two diverse maize inbred line panels to compare the phenotypic effects and variances of sequence polymorphisms in regions involved in domestication and improvement to the rest of the genome. Additive polygenic models explained most of the genotypic variation for domestication-related traits; no large-effect loci were detected for any trait. Most trait variance was associated with background genomic regions lacking previous evidence for involvement in domestication. Improvement sweep regions were associated with more trait variation than expected based on the proportion of the genome they represent. Selection during domestication eliminated large-effect genetic variants that would revert maize toward a teosinte type. Small-effect polygenic variants (enriched in the improvement sweep regions of the genome) are responsible for most of the standing variation for domestication-related traits in maize.

  15. The role of cis regulatory evolution in maize domestication.

    Science.gov (United States)

    Lemmon, Zachary H; Bukowski, Robert; Sun, Qi; Doebley, John F

    2014-11-01

    Gene expression differences between divergent lineages caused by modification of cis regulatory elements are thought to be important in evolution. We assayed genome-wide cis and trans regulatory differences between maize and its wild progenitor, teosinte, using deep RNA sequencing in F1 hybrid and parent inbred lines for three tissue types (ear, leaf and stem). Pervasive regulatory variation was observed with approximately 70% of ∼17,000 genes showing evidence of regulatory divergence between maize and teosinte. However, many fewer genes (1,079 genes) show consistent cis differences with all sampled maize and teosinte lines. For ∼70% of these 1,079 genes, the cis differences are specific to a single tissue. The number of genes with cis regulatory differences is greatest for ear tissue, which underwent a drastic transformation in form during domestication. As expected from the domestication bottleneck, maize possesses less cis regulatory variation than teosinte with this deficit greatest for genes showing maize-teosinte cis regulatory divergence, suggesting selection on cis regulatory differences during domestication. Consistent with selection on cis regulatory elements, genes with cis effects correlated strongly with genes under positive selection during maize domestication and improvement, while genes with trans regulatory effects did not. We observed a directional bias such that genes with cis differences showed higher expression of the maize allele more often than the teosinte allele, suggesting domestication favored up-regulation of gene expression. Finally, this work documents the cis and trans regulatory changes between maize and teosinte in over 17,000 genes for three tissues.

  16. Approaches in breeding for high quality protein maize

    Directory of Open Access Journals (Sweden)

    Denić Miloje

    2008-01-01

    Full Text Available Maize is the principal crop and major staple food in the most African and South American countries. The main problem in human nutrition in developing countries, and in livestock feed in developed countries, is insufficient production and poor quality of cereal proteins. In the case of maize, due to the very low content of essential amino acids lysine and tryptophan in grain endosperm, biological value is very low, which is main limiting factor of common maize in human nutrition and feeding of monogastric animals. Quality protein maize (QPM can help in solving of this problem. Maize production also faces serious constraints caused by agro-ecological conditions and poor socio-economic situation. To alleviate the effect of the constraints, selected genotypes with more desirable traits and appropriate field-plot techniques to create multiple-stress conditions, were used. It was found that, in downy mildew nursery distance up to 35 m from spreader plot is providing sufficient down load of spores for plant infection, provided that the testing breeding materials are planted towards to down-stream direction of the dominant wind. Using these breeding approaches large number of early, white and flint synthetics, composites and inbred lines were created with resistance or tolerance to downy mildew (DMR, maize streak virus (SR and drought (DT. Created genotypes exhibited very good kernel modification and yield potential under low and normal inputs. In the case of synthetics and composites, besides tolerance to multiple stress factors, they were competing in yield with local QPM and normal maize checks. In the case of created inbred lines high combining ability was exhibited both in non-conventional and conventional maize hybrids. Trial data revealed that in the most cases the best entries were over-yielding the best checks.

  17. Adoption of Improved Maize Seed Varieties in Southern Zambia

    OpenAIRE

    Thomson Kalinda; Gelson Tembo; Elias Kuntashula

    2014-01-01

    Maize is the principal agricultural crop produced by Zambian smallholder farmers for household consumption and sale. Their production strategy is therefore important in meeting food security and income needs. This study uses data collected from a survey of a random sample of farm households in southern Zambia to develop a Tobit regression model. The model identifies farm and farmer characteristics important for adoption of improved maize seed varieties as well as to determine the role of farm...

  18. Maize breeding in East and Southern Africa, 1900–2000

    OpenAIRE

    Smale, Melinda; Jayne, T.S.

    2004-01-01

    "During the first half of the 20th century, African farmers transformed maize from a minor imported foodcrop into the continent's principal staple food. In the second half of the century, newly independent governments launched support programs that greatly expanded smallholder production, leading to substantial production surges of 10 to 20 years in duration. Today, after widespread adoption by both commercial farmers and smallholders, farmers now plant 58 percent of all maize area in East an...

  19. The role of cis regulatory evolution in maize domestication.

    Directory of Open Access Journals (Sweden)

    Zachary H Lemmon

    2014-11-01

    Full Text Available Gene expression differences between divergent lineages caused by modification of cis regulatory elements are thought to be important in evolution. We assayed genome-wide cis and trans regulatory differences between maize and its wild progenitor, teosinte, using deep RNA sequencing in F1 hybrid and parent inbred lines for three tissue types (ear, leaf and stem. Pervasive regulatory variation was observed with approximately 70% of ∼17,000 genes showing evidence of regulatory divergence between maize and teosinte. However, many fewer genes (1,079 genes show consistent cis differences with all sampled maize and teosinte lines. For ∼70% of these 1,079 genes, the cis differences are specific to a single tissue. The number of genes with cis regulatory differences is greatest for ear tissue, which underwent a drastic transformation in form during domestication. As expected from the domestication bottleneck, maize possesses less cis regulatory variation than teosinte with this deficit greatest for genes showing maize-teosinte cis regulatory divergence, suggesting selection on cis regulatory differences during domestication. Consistent with selection on cis regulatory elements, genes with cis effects correlated strongly with genes under positive selection during maize domestication and improvement, while genes with trans regulatory effects did not. We observed a directional bias such that genes with cis differences showed higher expression of the maize allele more often than the teosinte allele, suggesting domestication favored up-regulation of gene expression. Finally, this work documents the cis and trans regulatory changes between maize and teosinte in over 17,000 genes for three tissues.

  20. The Role of cis Regulatory Evolution in Maize Domestication

    Science.gov (United States)

    Lemmon, Zachary H.; Bukowski, Robert; Sun, Qi; Doebley, John F.

    2014-01-01

    Gene expression differences between divergent lineages caused by modification of cis regulatory elements are thought to be important in evolution. We assayed genome-wide cis and trans regulatory differences between maize and its wild progenitor, teosinte, using deep RNA sequencing in F1 hybrid and parent inbred lines for three tissue types (ear, leaf and stem). Pervasive regulatory variation was observed with approximately 70% of ∼17,000 genes showing evidence of regulatory divergence between maize and teosinte. However, many fewer genes (1,079 genes) show consistent cis differences with all sampled maize and teosinte lines. For ∼70% of these 1,079 genes, the cis differences are specific to a single tissue. The number of genes with cis regulatory differences is greatest for ear tissue, which underwent a drastic transformation in form during domestication. As expected from the domestication bottleneck, maize possesses less cis regulatory variation than teosinte with this deficit greatest for genes showing maize-teosinte cis regulatory divergence, suggesting selection on cis regulatory differences during domestication. Consistent with selection on cis regulatory elements, genes with cis effects correlated strongly with genes under positive selection during maize domestication and improvement, while genes with trans regulatory effects did not. We observed a directional bias such that genes with cis differences showed higher expression of the maize allele more often than the teosinte allele, suggesting domestication favored up-regulation of gene expression. Finally, this work documents the cis and trans regulatory changes between maize and teosinte in over 17,000 genes for three tissues. PMID:25375861

  1. Generating Novel Allelic Variation Through Activator Insertional Mutagenesis in Maize

    OpenAIRE

    Bai, Ling; Singh, Manjit; Pitt, Lauren; Sweeney, Meredith; Brutnell, Thomas P.

    2007-01-01

    The maize transposable element Activator (Ac) has been exploited as an insertional mutagen to disrupt, clone, and characterize genes in a number of plant species. To develop an Ac-based mutagenesis platform for maize, a large-scale mutagenesis was conducted targeting the pink scutellum1 locus. We selected 1092 Ac transposition events from a closely linked donor Ac, resulting in the recovery of 17 novel ps1 alleles. Multiple phenotypic classes were identified corresponding to Ac insertions in ...

  2. The Adoption of Bt-Maize - An Econometric Analysis

    OpenAIRE

    Consmuller, Nicola; Beckmann, Volker; Petrick, Martin

    2009-01-01

    In this study, we theoretically and empirically investigate the determinants of Bt maize adoption in German regions. Specifically, we ask how the regulatory framework, the farm structures as well as the socio-political environment of GM expansion in Germany have influenced regional adoption rates. Following a description of the relevant legal and economic framework in Germany, we develop theoretical hypotheses concerning regional variation in Bt-maize adoption and test them econometrically wi...

  3. Developmentally related responses of maize catalase genes to salicylic acid.

    OpenAIRE

    L. Guan; Scandalios, J G

    1995-01-01

    The response of the maize catalase genes (Cat1, Cat2, and Cat3) to salicylic acid (SA) was examined at two distinct developmental stages: embryogenesis and germination. A unique, germination-related differential response of each maize catalase gene to various doses of SA was observed. During late embryogenesis, total catalase activity in scutella increased dramatically with 1 mM SA treatment. The accumulation of Cat2 transcript and CAT-2 isozyme protein provided the major contribution to the ...

  4. Genetic effects of heavy ion irradiation in maize and soybean

    International Nuclear Information System (INIS)

    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)

  5. Polyphenolic Profile of Maize Seedlings Treated with 24-Epibrassinolide

    OpenAIRE

    Hadi Waisi; Aleksandra Kosović; Đurđa Krstić; Dušanka Milojković-Opsenica; Bogdan Nikolić; Vesna Dragičević; Jelena Trifković

    2015-01-01

    High-performance thin-layer chromatography (HPTLC) combined with image analysis and pattern recognition methods were used for fingerprinting of phenolic compounds present in seedlings of two maize genotypes ZP 434 (new generation hybrid, drought tolerant) and ZP 704 (older generation hybrid, drought sensitive) treated with different concentrations of 24-epibrassinolide. This is the first report of TLC chromatographic profile of phenolics’ mixtures in maize seed extracts influenced by brassino...

  6. Deciphering the role of NADPH oxidase in complex interactions between maize (Zea mays L.) genotypes and cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert

    2016-07-22

    Plant NADPH oxidases (NOXs) encompass a group of membrane-bound enzymes participating in formation of reactive oxygen species (ROS) under physiological conditions as well as in response to environmental stressors. The purpose of the survey was to unveil the role of NADPH oxidase in pro-oxidative responses of maize (Zea mays L.) seedling leaves exposed to cereal aphids' infestation. The impact of apteral females of bird cherry-oat aphid (Rhopalosiphum padi L.) and grain aphid (Sitobion avenae F.) feeding on expression levels of all four NADPH oxidase genes (rbohA, rbohB, rbohC, rbohD) and total activity of NOX enzyme in maize plants were investigated. In addition, inhibitory effect of diphenylene iodonium (DPI) pre-treatment on NOX activity and hydrogen peroxide content in aphid-stressed maize seedlings was studied. Leaf infestation biotests were accomplished on 14-day-old seedlings representing two aphid-resistant varieties (Ambrozja and Waza) and two aphid-susceptible ones (Tasty Sweet and Złota Karłowa). Insects' attack led to profound upregulation of rbohA and rbohD genes in tested host plants, lower elevations were noted in level of rbohB mRNA, whereas abundance of rbohC transcript was not significantly altered. It was uncovered aphid-induced enhancement of NOX activity in examined plants. Higher increases in expression of all investigated rboh genes and activity of NADPH oxidase occurred in tissues of more resistant maize cultivars than in susceptible ones. Furthermore, DPI treatment resulted in strong reduction of NOX activity and H2O2 accumulation in aphid-infested Z. mays plants, thus evidencing circumstantial role of the enzyme in insect-elicited ROS generation. PMID:27178208

  7. ABA Affects Brassinosteroid-Induced Antioxidant Defense via ZmMAP65-1a in Maize Plants.

    Science.gov (United States)

    Zhu, Yuan; Liu, Weijuan; Sheng, Yu; Zhang, Juan; Chiu, Tsanyu; Yan, Jingwei; Jiang, Mingyi; Tan, Mingpu; Zhang, Aying

    2015-07-01

    Brassinosteroids (BRs) and ABA co-ordinately regulate water deficit tolerance in maize leaves. ZmMAP65-1a, a maize microtubule-associated protein (MAP) which plays an essential role in BR-induced antioxidant defense, has been characterized previously. However, the interactions among BR, ABA and ZmMAP65-1a in water deficit tolerance remain unexplored. In this study, we demonstrated that ABA was required for BR-induced antioxidant defense via ZmMAP65-1a by using biochemical blocking and ABA biosynthetic mutants. The expression of ZmMAP65-1a in maize leaves and mesophyll protoplasts could be increased under polyethylene glycol- (PEG) stimulated water deficit and ABA treatments. Furthermore, the importance of ABA in the early pathway of BR-induced water deficit tolerance was demonstrated by limiting ABA availability. Blocking ABA biosynthesis biochemically or by a null mutation inhibited the downstream gene expression of ZmMAP65-1a and the activity of ZmMAPK5 in the pathway. It also affected the activities of BR-induced antioxidant defense-related enzymes, namely ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD) and NADPH oxidase. In addition, combining results from transiently overexpressed or silenced ZmMAP65-1a in mesophyll protoplasts, we discovered that ZmMAP65-1a mediated the ABA-induced gene expression and activities of APX and SOD. Surprisingly, silencing of ZmMAP65-1a in mesophyll protoplasts did not alter the gene expression of ZmCCaMK and vice versa in response to ABA. Taken together, our data indicate that water deficit-induced ABA is a key mediator in BR-induced antioxidant defense via ZmMAP65-1a in maize.

  8. Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

    Science.gov (United States)

    Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

    2014-05-01

    Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses.

  9. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

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    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  10. Physical Characteristics of Maize Cob Briquette under Moderate Die Pressure

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    Patomsok Wilaipon

    2007-01-01

    Full Text Available The potential energy content of maize cob available in Thailand was calculated based on maize productivity, the residue-to-product ratio and the heating value of maize cob. It was found that the computed value was about 74.2 PJ/year. Besides, the potential energy value exceed 1,000 TJ/year was also reported for the case of five provinces of Thailand. Concerning with maize cob briquette, the effect of molasses binder ratio and briquetting pressure on briquette density was experimentally investigated. It was found that the density of the briquettes was strongly influenced by the two factors. Moreover, a relationship between these factors over the studied range was also developed and validated. Thermogravimetric investigation was also carried out. The results showed that the maximum mass loss of maize cob occurred at the temperature of about 353oC. Finally, according to the ultimate analysis of the material, it was found that the maize cob used in the experiment is comprised of 40.50% carbon, 5.68% hydrogen and 0.37% hydrogen, respectively.

  11. Genomic variation in recently collected maize landraces from Mexico

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    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.

  12. 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

    2016-03-01

    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 (H E = 0.234 to 0.318 (mean 0.311), while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (H E = 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

  13. Mycoflora of commercial maize seed in 2010

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    Medić-Pap Slađana S.

    2011-01-01

    Full Text Available Ear and kernel rots can reduce yield, quality and feed value of grain. Toxins produced by the fungi in corn can also have serious implications on the end use of the grain. Various fungi cause ear and kernel rots. Fungi belonging to the genus Fusarium are the most significant fungi which can cause corn ear and kernel rots. The aim of this paper is to test health of mercantile maize seed belonging to different hybrids. Seed health testing was done using filter paper and nutritive media (PDA method. Fungi from genera Fusarium, Penicillium, Aspergillus and Alternaria were isolated from tested corn seed by both methods. Two species from the genus Fusarium were found in the tested corn samples F. graminearum and F. monilirome. Tested hybrids that belonged to different FAO maturity groups showed differences in susceptibility to ear and kernel rot.

  14. Screening Drought Tolerance Criteria in Maize

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    Masoud Kiani

    2013-05-01

    Full Text Available Six pure lines of maize were tested in a randomized complete block design with three replication under irrigated and rainfed conditions. Genetic variation was found between the genotypes for yield potential (Yp stress yield (Ys, tolerance index (TOL, geometric mean productivity (GMP, harmonic mean (HM and stress tolerance index (STI. Stress tolerance index was corrected using a correction coefficient (Ki and thus a modified stress tolerance index (MSTI was introduced as the optimal selection criterion for drought-tolerant genotypes. The results of three-D plotting indicated that the most desirable genotype for irrigated and rainfed conditions was the genotype K1515, for non-stressed conditions K18 and for stress conditions K104/3, K760/7 and K126/10.

  15. ATP-dependent protease in maize mitochondria

    International Nuclear Information System (INIS)

    ATP-dependent protease was identified in the matrix of Zea mays L. Sachara mitochondria. 14C-methylated casein has been used as a substrate, and the matrix ATP-dependent protease exhibited similar sensitivity towards specific inhibitors as the Lon protease from E. coli nd analogues from rat liver and yeast mitochondria. Here we report the existence of Lon like ATP-dependent protease in intact mitochondria prepared from 4-days-old epicotyls of Zea mays L. seedling. Enzyme has been purified from Lubrol treated mitochondria using ion exchange chromatography and gel filtration. The enzyme activity has been estimated using 14C-methylated casein as a substrate and sensitivity of the protease towards the specific inhibitors has been tested. ATP-dependent protease from the mitochondrial matrix of maize exhibit similar sensitivity to the above mentioned inhibitors like Lon protease from yeast and rat liver mitochondria as well as from E. coli. (authors)

  16. Heritable epigenetic variation among maize inbreds.

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    Steve R Eichten

    2011-11-01

    Full Text Available Epigenetic variation describes heritable differences that are not attributable to changes in DNA sequence. There is the potential for pure epigenetic variation that occurs in the absence of any genetic change or for more complex situations that involve both genetic and epigenetic differences. Methylation of cytosine residues provides one mechanism for the inheritance of epigenetic information. A genome-wide profiling of DNA methylation in two different genotypes of Zea mays (ssp. mays, an organism with a complex genome of interspersed genes and repetitive elements, allowed the identification and characterization of examples of natural epigenetic variation. The distribution of DNA methylation was profiled using immunoprecipitation of methylated DNA followed by hybridization to a high-density tiling microarray. The comparison of the DNA methylation levels in the two genotypes, B73 and Mo17, allowed for the identification of approximately 700 differentially methylated regions (DMRs. Several of these DMRs occur in genomic regions that are apparently identical by descent in B73 and Mo17 suggesting that they may be examples of pure epigenetic variation. The methylation levels of the DMRs were further studied in a panel of near-isogenic lines to evaluate the stable inheritance of the methylation levels and to assess the contribution of cis- and trans- acting information to natural epigenetic variation. The majority of DMRs that occur in genomic regions without genetic variation are controlled by cis-acting differences and exhibit relatively stable inheritance. This study provides evidence for naturally occurring epigenetic variation in maize, including examples of pure epigenetic variation that is not conditioned by genetic differences. The epigenetic differences are variable within maize populations and exhibit relatively stable trans-generational inheritance. The detected examples of epigenetic variation, including some without tightly linked genetic

  17. Maize Yield Response to Fertilizer and Profitability of Fertilizer Use Among Small-Scale Maize Producers in Zambia

    OpenAIRE

    Xu, Zhiying; Govereh, Jones; Black, J. Roy; Jayne, Thomas S.

    2006-01-01

    Multi-year nationwide survey data is used to estimate maize yield response functions and determine profitability of fertilizer use by small-scale farmers in Zambia. There has been a dearth of empirical studies on economics of fertilization in the context of Sub-Saharan Africa. In this paper we identify major methodological issues arising from using survey data and estimate maize yield response functions for small-scale rural households that have various management practices and soil condition...

  18. Stolbur phytoplasma transmission to maize by Reptalus panzeri and the disease cycle of maize redness in Serbia.

    Science.gov (United States)

    Jović, J; Cvrković, T; Mitrović, M; Krnjajić, S; Petrović, A; Redinbaugh, M G; Pratt, R C; Hogenhout, S A; Tosevski, I

    2009-09-01

    Maize redness (MR), induced by stolbur phytoplasma ('Candidatus Phytoplasma solani', subgroup 16SrXII-A), is characterized by midrib, leaf, and stalk reddening and abnormal ear development. MR has been reported from Serbia, Romania, and Bulgaria for 50 years, and recent epiphytotics reduced yields by 40 to 90% in South Banat District, Serbia. Potential vectors including leafhoppers and planthoppers in the order Hemiptera, suborder Auchenorrhyncha, were surveyed in MR-affected and low-MR-incidence fields, and 33 different species were identified. Only Reptalus panzeri populations displayed characteristics of a major MR vector. More R. panzeri individuals were present in MR-affected versus low-MR fields, higher populations were observed in maize plots than in field border areas, and peak population levels preceded the appearance of MR in late July. Stolbur phytoplasma was detected in 17% of R. panzeri adults using nested polymerase chain reaction but not in any other insects tested. Higher populations of R. panzeri nymphs were found on maize, Johnsongrass (Sorghum halepense), and wheat (Triticum aestivum) roots. Stolbur phytoplasma was detected in roots of these three plant species, as well as in R. panzeri L(3) and L(5) nymphs. When stolbur phytoplasma-infected R. panzeri L(3) nymphs were introduced into insect-free mesh cages containing healthy maize and wheat plants, 89 and 7%, respectively, became infected. These results suggest that the MR disease cycle in South Banat involves mid-July transmission of stolbur phytoplasma to maize by infected adult R. panzeri. The adult R. panzeri lay eggs on infected maize roots, and nymphs living on these roots acquire the phytoplasma from infected maize. The nymphs overwinter on the roots of wheat planted into maize fields in the autumn, allowing emergence of phytoplasma-infected vectors the following July.

  19. Diversity of Fusarium species isolated from UK forage maize and the population structure of F. graminearum from maize and wheat.

    Science.gov (United States)

    Basler, Ryan

    2016-01-01

    Pre-harvest contamination of forage maize by mycotoxin producing Fusarium species was investigated in the UK in 2011 and 2012. A total of 15 Fusarium species were identified from a collection of 1,761 Fusarium isolates recovered from maize stalks and kernels. This study characterized the diversity of Fusarium species present in forage maize in the UK. The predominant species detected were F. graminearum (32.9%) and F. culmorum (34.1%). Along with those species; F. avenacem, F. cerealis, F. equiseti, F. langsethiae, F. napiforme, F. oxysporum, F. poae, F. proliferatum, F. scripi, F. solani, F. subglutinans, F. tricinctum and, F. verticillioides were occasionally isolated. The trichothecene genotypes for F. graminearum were determined to be 84.9% deoxynivalenol (DON) and 15.0% nivalenol (NIV) while F. culmorum isolates were determined to have 24.9% DON and 75.1% NIV genotypes. A Bayesian model-based clustering method with nine variable number of tandem repeat markers was used to evaluate the population genetic structure of 277 F. graminearum isolates from the maize and wheat in the UK. There were three genetic clusters detected which were DON in maize, NIV in maize and DON in wheat. There were high admixture probabilities for 14.1% of the isolates in the populations. In conclusion, increased maize production in the UK and the high admixture rates in a significant portion of F. graminearum populations in maize and wheat will contribute to a new pathogen population which will further complicate breeding strategies for tolerance or resistance to this pathogen in both crops.

  20. Bt-maize (MON810 and non-GM soybean meal in diets for Atlantic salmon (Salmo salar L. juveniles--impact on survival, growth performance, development, digestive function, and transcriptional expression of intestinal immune and stress responses.

    Directory of Open Access Journals (Sweden)

    Jinni Gu

    Full Text Available Responses in Atlantic salmon (Salmo salar L. juveniles (fry fed diets containing genetically modified maize (Bt-maize, MON810 expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize. One pair was fishmeal-based while the other pair included standard (extracted soybean meal (SBM; 16.7% inclusion level, with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile

  1. Consequences for Protaphorura armata (Collembola: Onychiuridae) following exposure to genetically modified Bacillus thuringiensis (Bt) maize and non-Bt maize

    International Nuclear Information System (INIS)

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. - Protaphorura armata performed equally well when reared on two Bt and three non-Bt maize varieties

  2. Consequences for Protaphorura armata (Collembola: Onychiuridae) following exposure to genetically modified Bacillus thuringiensis (Bt) maize and non-Bt maize

    Energy Technology Data Exchange (ETDEWEB)

    Heckmann, Lars-Henrik [National Environmental Research Institute, Department of Terrestrial Ecology, Vejlsovej 25, PO Box 314, DK-8600 Silkeborg (Denmark); Griffiths, Bryan S. [Scottish Crop Research Institute, Department of Soil Plant Dynamics, Invergowrie, Dundee DD2 5DA (United Kingdom); Caul, Sandra [Scottish Crop Research Institute, Department of Soil Plant Dynamics, Invergowrie, Dundee DD2 5DA (United Kingdom); Thompson, Jacqueline [Scottish Crop Research Institute, Department of Soil Plant Dynamics, Invergowrie, Dundee DD2 5DA (United Kingdom); Pusztai-Carey, Marianne [Case Western Reserve University, Cleveland, OH 44106 (United States); Moar, William J. [Auburn University, Department of Entomology and Plant Pathology, Auburn, AL 36849 (United States); Andersen, Mathias N. [Danish Institute of Agricultural Sciences, Research Centre Foulum, PO Box 50, DK-8830 Tjele (Denmark); Krogh, Paul Henning [National Environmental Research Institute, Department of Terrestrial Ecology, Vejlsovej 25, PO Box 314, DK-8600 Silkeborg (Denmark)]. E-mail: phk@dmu.dk

    2006-07-15

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. - Protaphorura armata performed equally well when reared on two Bt and three non-Bt maize varieties.

  3. The growth of maize seedlings as function of free energy and redox potential

    Directory of Open Access Journals (Sweden)

    Dragičević Vesna D.

    2010-01-01

    Full Text Available The difference in the growth of maize seedlings originating from seeds injured by accelerated ageing, as well as those altered by restoring with low 2,4-D (2,4-dichlorophenoxyacetic acid concentrations was examined, from the point of view of free energy and redox potential. The ageing decreased germination ability, the seedling growth and free energy, with no remarkable influence on the redox capacity. Meanwhile, the 2,4-D treatment increased the germination percentage and the seedling growth, by better energy utilisation, with shifting of the redox balance to a reducing environment. From this point of view, the free energy and the redox potential are useful tools for the determination of biological vitality.

  4. A chemical pollen suppressant inhibits auxin-induced growth in maize coleoptile sections

    Energy Technology Data Exchange (ETDEWEB)

    Vesper, M.J. (Univ. of Dayton, OH (USA)); Cross, J.W. (Sogetal, Inc., Hayward, CA (USA))

    1990-05-01

    Chemical inhibitors of pollen development having a phenylcinnoline carboxylate structure were found to inhibit IAA- and 1-NAA-induced growth in maize coleoptile sections. The inhibitor (100 {mu}M) used in these experiments caused approx. 35% reduction in auxin-induced growth over the auxin concentration range of 0.3 to 100 {mu}M. Growth inhibition was noted as a lengthening of the latent period and a decrease in the rate of an auxin-induced growth response. An acid growth response to pH 5 buffer in abraded sections was not impaired. The velocity of basipetal transport of ({sup 3}H)IAA through the coleoptile sections also was not inhibited by the compound, nor was uptake of ({sup 3}H)IAA. Similarly, the inhibitor does not appear to alter auxin-induced H{sup +} secretion. We suggest that the agent targets some other process necessary for auxin-dependent growth.

  5. Morphological and Physiological Alteration of Maize Root Architectures on Drought Stress.

    Science.gov (United States)

    Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Research experiments were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought s...

  6. Morphological and biological alteration of maize root architectures on drought stress

    Science.gov (United States)

    Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Studies were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought stress in corn...

  7. Effect of Substitution of Wheat with Maize on Technological and Organoleptic Properties of Chapatties

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    Saeeda Raza

    2014-04-01

    Full Text Available Unleavened flat bread (chapatti was prepared from wheat (Tritium aestivum and maize (Zea mays composite flour. The wheat flours from mill and grindstone were collected from local market and blended with maize flour in 100:0, 90:10, 80:20 proportions. Technological and rheological studies revealed that gluten, falling number and water absorption values decreased with increased maize proportion. Increased dough development time by addition of 20% maize flour for either flour types was observed. Decrease in dough stability was observed by increased maize proportion in grindstone flour but in mill flour decrease with 10% maize and increase with 20% maize is noted. Overall Farinographic quality was highest in 20% blend of maize in grindstone flour. Chapatties were prepared and subjected to organoleptic tests by a panel of trained judges and 20% blend get maximum acceptability.

  8. 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.

  9. RESPONSE OF MAIZE GENOTYPES TO FERTILIZATION ON HYDROMORPHIC SOIL OF SAVA VALLEY

    Directory of Open Access Journals (Sweden)

    Branimir Šimić

    2003-06-01

    Full Text Available Growing seed-maize is more profitable than mercantile maize, but also riskier, especially under less favourable soil conditions because parents of maize hybrids are less tolerant than their progeny to environmental stress, including plant nutrition problems. For this reason, we conducted the field experiment with P and K fertilization and a range of maize genotypes (parents of seed-maize on soil with moderate P and K supplies. Following application of 382 kg P and 726 kg K ha-1 , maize grain yields increased from 1.93 t ha-1 to 2.86 t ha-1 (3-year means. High correlations were found between grain yields of maize genotypes and nutrient concentrations in ear-leaf at silking stage (r = 0.82** for P and r = 0.90** for K. Based on these results, we could recommend the higher P and K fertilization of seed-maize crops on soils of similar chemical properties.

  10. Alkaline Cooking Quality of Polyembryonic and Non-Polyembryonic Maize Populations

    Directory of Open Access Journals (Sweden)

    Marisol Cruz Requena

    2011-08-01

    Full Text Available Polyembryony is the formation of several embryos in a seed and is present in many plants, included maize. In the present study the chemical, physical and rheological properties of nixtamalized maize flour, masa and tortilla of maize kernel with high polyembryony levels and brachytic population were evaluated and compared to three control populations. The nixtamalized maize flour and tortillas of brachytic population were similar to the control population in most of the tests. The retrogradation in nixtamalized maize flour of brachytic population was lower than the control nixtamalized maize flour showed 191.77 RVU; the protein content of nixtamalized maize flour of brachytic population was greater and content of ash in tortilla was lower than the controls. The flour made from maize brachytic population is an option for the flour and tortilla industry.

  11. 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.

  12. Characterization of Maize Producing Households in Southern Zambia

    Directory of Open Access Journals (Sweden)

    Thomson Kalinda

    2014-01-01

    Full Text Available Maize is an important crop in the livelihood of Zambia’s most vulnerable populations. A huge challenge facing most of Sub-Saharan Africa (SSA countries like Zambia is to increase maize productivity of smallholder farmers, which has remained very low over the past decades. Through various breeding programmes, more than 50 new maize hybrids and open-pollinated varieties have been developed and provided to the farmers through seed companies and Non-Governmental Organizations (NGOs. However, the extent to which such varieties have been adopted remains unknown. The purpose of this study was to characterize the maize producing households and to assess adoption of improved maize varieties. Data were collected from randomly selected households in the maize-producing areas of Monze and Kalomo Districts in southern Zambia. Principal Components Analysis (PCA on asset ownership was used to generate a wealth index used to rank the survey households. The results confirm that poorly endowed households, most of whom are female-headed, are far less likely to adopt improved varieties than their well-off counterparts. Important maize variety attributes sought by farmers include early maturity (85% of households, tolerance to water stress (83%, yield potential (79%, pest/disease resistance (56%, better processing quality (56% and cob/grain size (50%. A larger proportion of well endowed households planted improved varieties, compared with their poorly endowed counterparts. These findings suggest that moving the poor households and female-headed households up the wealth ladder poses a considerable challenge and calls for targeting the key factors that could potentially improve their welfare.

  13. 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.

  14. 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.

  15. Impact of Improved Maize Adoption on Welfare of Farm Households in Malawi: A Panel Data Analysis

    OpenAIRE

    Bezu, Sosina; Kassie, Girma; Shiferaw, Bekele; Ricker-Gilbert, Jacob

    2013-01-01

    This paper assesses improved maize adoption in Malawi and examines the link between adoption and household welfare using a three-year household panel data. The distributional effect of maize technology adoption is also investigated by looking at impacts across wealth and gender groups. We applied control function approach and IV regression to control for endogeneity of input subsidy and improved maize adoption. We found that modern maize variety adoption is positively correlated with the hous...

  16. 10 Reasons to be Tantalized by the B73 Maize Genome

    OpenAIRE

    Fusheng Wei; Jianwei Zhang; Shiguo Zhou; Ruifeng He; Mary Schaeffer; Kristi Collura; David Kudrna; Faga, Ben P.; Marina Wissotski; Wolfgang Golser; Rock, Susan M.; Graves, Tina A.; Fulton, Robert S.; Ed Coe; Patrick S Schnable

    2009-01-01

    Maize is a major cereal crop and an important model system for basic biological research. Knowledge gained from maize research can also be used to genetically improve its grass relatives such as sorghum, wheat, and rice. The primary objective of the Maize Genome Sequencing Consortium (MGSC) was to generate a reference genome sequence that was integrated with both the physical and genetic maps. Using a previously published integrated genetic and physical map, combined with in-coming maize geno...

  17. Relation between endosperm and in vitro kinetic of starch digestibility in maize hybrids for broiler chickens

    Directory of Open Access Journals (Sweden)

    Goran Kis

    2010-01-01

    Full Text Available The objective of this study was to determine relationship between endosperm type of maize hybrids produced in Croatia and kinetic of starch digestibility provided by in vitro method. Proportion of endosperm type (horny and floury were used to classify hybrids into dents or flints maize. Flints had less rapidly digestible starch than dents. Maize hybrid kernel endosperm characteristics could be used for prediction of digestibility kinetics of maize grain.

  18. RELATIONS AMONG WESTERN CORN ROOTWORM RESISTANCE TRAITS AND ELEMENTS CONCENTRATION IN MAIZE GERMPLASM ROOTS

    OpenAIRE

    Andrija Brkić; Ivan Brkić; Emilija Raspudić; Mirjana Brmež; Josip Brkić; Domagoj Šimić

    2015-01-01

    Western corn rootworm – WCR (Diabrotica virgifera virgifera LeConte) is an important maize pest in Croatia. Using native resistance of maize germplasm could reduce chemical treatments and other costs in maize production. Objectives of this study were: i) to assess variability of WCR resistance traits (root injury, regrowth and size) and concentrations of nine elements in roots of 128 maize genotypes, and ii) to determine correlations among the traits and ion concentrations. Res...

  19. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize

    OpenAIRE

    Asters, Matthew C.; Williams, W. Paul; Perkins, Andy D; Mylroie, J. Erik; Windham, Gary L.; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimize...

  20. The impact of food aid on maize prices and production in Swaziland

    OpenAIRE

    Mabuza, Majola Lawrence; Hendriks, Sheryl L.; Ortmann, Gerald F.; Sithole, M.M.

    2009-01-01

    The objective of the study was to provide empirical evidence on whether food aid leads to depressed domestic maize prices and reduced maize production in subsequent years in Swaziland. The lack of empirical evidence has often resulted in premature negative conclusions about the impact of food aid on Swaziland’s maize industry. The study used secondary national data from 1985 to 2006. Variables used in the statistical analysis included quantity of cereal food aid; quantity of commercial maiz...

  1. Some aspects of cultivation and utilization of waxy maize (Zea mays L. ssp. ceratina)

    OpenAIRE

    Agnieszka Klimek-Kopyra; Aleksander Szmigiel; Tadeusz Zając; Agnieszka Kidacka

    2012-01-01

    This paper is a review of available literature on Zea mays L.ssp.ceratina. It contains information on the origin, cul- tivation and utilization of waxy maize in the world and can be a contribution to the development of new research on maize cultivation and starch processing technology. Maize, as an old and economically important cereal, played an enormous role in the ancient civilisations of the New World. Among the maize subspecies compared, Z. mays ssp. indurata and Z. mays ssp. indenta...

  2. Development of molecular biology techniques for the detection of genetically modified organisms in maize food products

    OpenAIRE

    Sousa, S.C.; Mafra, I; Silva, C.S. Ferreira da; Amaral, J S; Oliveira, M.B.P.P.

    2008-01-01

    In the last years, the increase in the cultivated area of genetically modified (GM) maize has become a reality. GA21, MON810 and MON 863 maize crops are some of the authorized maize events for food and feed under the European Union (EU) regulations. These crops of transgenic maize bring profit towards the conventional ones, as they confer resistence to some plagues and/or herbices. Concerning the raise of production and consumption of foodstuffs derived from genetically modified organisms (GM...

  3. The Comparative Effects of Genetically Modified Maize and Conventional Maize on Wistar rats

    OpenAIRE

    Hasan Kýlýçgün

    2013-01-01

          Aim: Genetically modified crops have a potential to solve many of the world’s  nutrition problems. On the other hand, the impact of these novel crops on environmental, animal and human health should be tested and their risk assessment is required. In this study, the aim of this study was to investigate the positive or possible negative effects of genetically modified maize on offspring rats which were between the start of dry food feeding and the time...

  4. The effects of nitrogen form on root morphological and physiological adaptations of maize, white lupin and faba bean under phosphorus deficiency.

    Science.gov (United States)

    Liu, Haitao; Tang, Caixian; Li, Chunjian

    2016-01-01

    Root morphological/physiological modifications are important for phosphorus (P) acquisition of plants under P deficiency, but strategies differ among plant species. Detailed studies on the response of maize roots to P deficiency are limited. Nitrogen (N) form influences root morphology/physiology, and thus may influence root responses to P deficiency. This work investigated adaptive mechanisms of maize roots to low P by comparison with white lupin and faba bean supplied with two N forms. Plants were grown for 7-16 days in hydroponics with sufficient (250 µmol L(-1)) and deficient P supply (1 µmol L(-1)) under supply of NH4NO3 or Ca(NO3)2 Plant growth and P uptake were measured, and release of protons and organic acid anions, and acid phosphatase activity in the root were monitored. The results showed that P deficiency significantly decreased shoot growth while increased root growth and total root length of maize and faba bean, but not white lupin. It enhanced the release of protons and organic acid anions, and acid phosphatase activity, from the roots of both legumes but not maize. Compared with Ca(NO3)2, NH4NO3 dramatically increased proton release by roots but did not alter root morphology or physiology of the three species in response to low P. It is concluded that the N form did not fundamentally change root morphological/physiological responses of the three species to P deficiency. Morphological variation in maize and morpho-physiological modifications in white lupin and faba bean were the main adaptive strategies to P deficiency. PMID:27519912

  5. The effects of nitrogen form on root morphological and physiological adaptations of maize, white lupin and faba bean under phosphorus deficiency

    Science.gov (United States)

    Liu, Haitao; Tang, Caixian; Li, Chunjian

    2016-01-01

    Root morphological/physiological modifications are important for phosphorus (P) acquisition of plants under P deficiency, but strategies differ among plant species. Detailed studies on the response of maize roots to P deficiency are limited. Nitrogen (N) form influences root morphology/physiology, and thus may influence root responses to P deficiency. This work investigated adaptive mechanisms of maize roots to low P by comparison with white lupin and faba bean supplied with two N forms. Plants were grown for 7–16 days in hydroponics with sufficient (250 µmol L−1) and deficient P supply (1 µmol L−1) under supply of NH4NO3 or Ca(NO3)2. Plant growth and P uptake were measured, and release of protons and organic acid anions, and acid phosphatase activity in the root were monitored. The results showed that P deficiency significantly decreased shoot growth while increased root growth and total root length of maize and faba bean, but not white lupin. It enhanced the release of protons and organic acid anions, and acid phosphatase activity, from the roots of both legumes but not maize. Compared with Ca(NO3)2, NH4NO3 dramatically increased proton release by roots but did not alter root morphology or physiology of the three species in response to low P. It is concluded that the N form did not fundamentally change root morphological/physiological responses of the three species to P deficiency. Morphological variation in maize and morpho-physiological modifications in white lupin and faba bean were the main adaptive strategies to P deficiency. PMID:27519912

  6. 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 ma

  7. A maize (Zea mays) line resistant to herbivory constitutively releases (E)-B-caryophyllene

    Science.gov (United States)

    Maize (Zea mays L.) is an important agricultural crop. Various insect pests such as those in the order of Lepidoptera frequently feed on young maize plants and pose a significant threat to plant development and survival. To deal with this problem, maize generates a wide variety of responses to att...

  8. The water footprint of sweeteners and bio-ethanol from sugar cane, sugar beet and maize

    NARCIS (Netherlands)

    Gerbens-Leenes, P.W.; Hoekstra, A.Y.

    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. Genome wide association mapping of Aspergillus flavus and aflatoxin accumulation resistance in maize

    Science.gov (United States)

    Contamination of maize with aflatoxin, produced by the fungus Aspergillus flavus, 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 sign...

  10. Evaluation of African-bred maize germplasm lines for resistance to aflatoxin accumulation

    Science.gov (United States)

    Aflatoxins, produced by the fungus Aspergillus flavus, contaminate maize grain and threatens human food and feed safety. Plant resistance is considered the best strategy for reducing aflatoxin accumulation. Six maize germplasm lines, TZAR101-TZAR106, were released by the IITA-SRRC maize breeding col...

  11. Fast-flowering mini-maize: seed to seed in 60 days

    Science.gov (United States)

    Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generatio...

  12. Multi-mycotoxin analysis of maize silage by LC-MS/MS

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Storm, Ida Marie Lindhardt Drejer; Rasmussen, Peter Have;

    2010-01-01

    This paper describes a method for determination of 27 mycotoxins and other secondary metabolites in maize silage. The method focuses on analytes which are known to be produced by common maize and maize-silage contaminants. A simple pH-buffered sample extraction was developed on the basis of a very...

  13. MODEM: multi-omics data envelopment and mining in maize

    Science.gov (United States)

    Liu, Haijun; Wang, Fan; Xiao, Yingjie; Tian, Zonglin; Wen, Weiwei; Zhang, Xuehai; Chen, Xi; Liu, Nannan; Li, Wenqiang; Liu, Lei; Liu, Jie; Yan, Jianbing; Liu, Jianxiao

    2016-01-01

    MODEM is a comprehensive database of maize multidimensional omics data, including genomic, transcriptomic, metabolic and phenotypic information from the cellular to individual plant level. This initial release contains approximately 1.06 M high quality SNPs for 508 diverse inbred lines obtained by combining variations from RNA sequencing on whole kernels (15 days after pollination) of 368 lines and a 50 K array for all 508 individuals. As all of these data were derived from the same diverse panel of lines, the database also allows various types of genetic mapping (including characterization of phenotypic QTLs, pQTLs; expression QTLs, eQTLs and metabolic QTLs, mQTLs). MODEM is thus designed to promote a better understanding of maize genetic architecture and deep functional annotation of the complex maize genome (and potentially those of other crop plants) and to explore the genotype–phenotype relationships and regulation of maize kernel development at multiple scales, which is also comprehensive for developing novel methods. MODEM is additionally designed to link with other databases to make full use of current resources, and it provides visualization tools for easy browsing. All of the original data and the related mapping results are freely available for easy query and download. This platform also provides helpful tools for general analyses and will be continually updated with additional materials, features and public data related to maize genetics or regulation as they become available. Database URL: (http://modem.hzau.edu.cn) PMID:27504011

  14. Maize transformation technology development for commercial event generation

    Directory of Open Access Journals (Sweden)

    Qiudeng eQue

    2014-08-01

    Full Text Available 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.

  15. Incidence of Fusarium Species and Mycotoxins in Silage Maize

    Science.gov (United States)

    Eckard, Sonja; Wettstein, Felix E.; Forrer, Hans-Rudolf; Vogelgsang, Susanne

    2011-01-01

    Maize is frequently infected by the Fusarium species producing mycotoxins. Numerous investigations have focused on grain maize, but little is known about the Fusarium species in the entire plant used for silage. Furthermore, mycotoxins persist during the ensiling process and thus endanger feed safety. In the current study, we analyzed 20 Swiss silage maize samples from growers’ fields for the incidence of Fusarium species and mycotoxins. The species spectrum was analyzed morphologically and mycotoxins were measured by LC-MS/MS. A pre-harvest visual disease rating showed few disease symptoms. In contrast, the infection rate of two-thirds of the harvest samples ranged from 25 to 75% and twelve different Fusarium species were isolated. The prevailing species were F. sporotrichioides, F. verticillioides and F. graminearum. No infection specificity for certain plant parts was observed. The trichothecene deoxynivalenol (DON) was found in each sample (ranging from 780 to 2990 µg kg−1). Other toxins detected in descending order were zearalenone, further trichothecenes (nivalenol, HT-2 and T-2 toxin, acetylated DON) and fumonisins. A generalized linear regression model containing the three cropping factors harvest date, pre-precrop and seed treatment was established, to explain DON contamination of silage maize. Based on these findings, we suggest a European-wide survey on silage maize. PMID:22069750

  16. MODEM: multi-omics data envelopment and mining in maize.

    Science.gov (United States)

    Liu, Haijun; Wang, Fan; Xiao, Yingjie; Tian, Zonglin; Wen, Weiwei; Zhang, Xuehai; Chen, Xi; Liu, Nannan; Li, Wenqiang; Liu, Lei; Liu, Jie; Yan, Jianbing; Liu, Jianxiao

    2016-01-01

    MODEM is a comprehensive database of maize multidimensional omics data, including genomic, transcriptomic, metabolic and phenotypic information from the cellular to individual plant level. This initial release contains approximately 1.06 M high quality SNPs for 508 diverse inbred lines obtained by combining variations from RNA sequencing on whole kernels (15 days after pollination) of 368 lines and a 50 K array for all 508 individuals. As all of these data were derived from the same diverse panel of lines, the database also allows various types of genetic mapping (including characterization of phenotypic QTLs, pQTLs; expression QTLs, eQTLs and metabolic QTLs, mQTLs). MODEM is thus designed to promote a better understanding of maize genetic architecture and deep functional annotation of the complex maize genome (and potentially those of other crop plants) and to explore the genotype-phenotype relationships and regulation of maize kernel development at multiple scales, which is also comprehensive for developing novel methods. MODEM is additionally designed to link with other databases to make full use of current resources, and it provides visualization tools for easy browsing. All of the original data and the related mapping results are freely available for easy query and download. This platform also provides helpful tools for general analyses and will be continually updated with additional materials, features and public data related to maize genetics or regulation as they become available.Database URL: (http://modem.hzau.edu.cn). PMID:27504011

  17. Atrazine accumulation and toxic responses in maize Zea mays

    Institute of Scientific and Technical Information of China (English)

    Xiuying Li; Tong Wu; Honglin Huang; Shuzhen Zhang

    2012-01-01

    Atrazine accumulation,oxidative stress,and defense response in maize seedlings exposed to extraneous atrazine were studied.Accumulation of atrazine in maize increased with increasing exposure concentration.The abscisic acid (ABA) content was positively correlated with the atrazine concentrations in maize roots and shoots (p < 0.05).Hydroxyl radical (·OH) in maize was determined in vivo with electron paramagnetic resonance spectroscopy.Its intensity was positively correlated with atrazine concentration in roots and shoots (p < 0.05),and higher level of ·OH generated in roots than in shoots corresponded to the major accumulation of atrazinein roots.Superoxide dismutase,peroxidase and catalase in roots were up-regulated by atrazine exposure at 1 mg/L compared to the control and malondialdehyde content in roots was enhanced when atrazine exposure concentration reached 10 mg/L.These results suggested the exposure and accumulation of atrazine caused oxidative toxicity and antioxidant response in maize.

  18. Evolution and expression of tandem duplicated maize flavonol synthase genes

    Directory of Open Access Journals (Sweden)

    María Lorena Falcone-Ferreyra

    2012-05-01

    Full Text Available Flavonoids are specialized compounds widely distributed and with diverse functions throughout the plant kingdom and with several benefits for human health. In particular, flavonols, synthesized by flavonol synthase (FLS, protect plants against UV-B radiation and are essential for male fertility in maize and other plants. We have recently characterized a UV-B inducible ZmFLS1, corresponding to the first to be described in monocot plants. Interestingly, the new assembly of the B73 maize genome revealed the presence of a second putative FLS gene (ZmFLS2, with very high identity with ZmFLS1. ZmFLSs expression was analyzed in different maize tissues, and by combining EMSA assays and transient expression experiments, we show that both genes are direct targets of anthocyanin (C1/PL1 + R/B and 3-deoxy flavonoid (P1 transcriptional regulators. ZmFLS expression analyses show higher levels of both transcripts in high altitude landraces than inbred lines, and both genes are regulated by UV-B radiation in all lines analyzed. Moreover, the high sequence conservation of the ZmFLS promoters between maize lines suggests that the differences observed in ZmFLS expression are due to allelic variations in the transcription factors that regulate their activities. Finally, we generated pFLS1::FLS1-RFP transgenic plants and analyzed ZmFLS1 expression in different maize tissues; we found that this enzyme is localized in the ER and the perinuclear region.

  19. Index selection of tropical maize genotypes for nitrogen use efficiency

    Directory of Open Access Journals (Sweden)

    Ítalo Stefanine Correia Granato

    2014-06-01

    Full Text Available Nitrogen (N limitation in maize crops is related to the fact that the efficiency of nitrogen fertilization in maize does not exceed 50%, primarily due to volatilization, denitrification and soil leaching. Therefore, the development of new nitrogen use efficient (NUE cultivars is necessary. The aim of the present study was to develop indices for the accurate selection of NUE maize genotypes for use in conditions of both high and low N availability. The experiment was conducted in a greenhouse (20º45'14"S; 42º52'53"W at the Federal University of Viçosa during October 2010. A total of 39 experimental hybrid combinations and 14 maize lines differing in NUE were evaluated under two N availability conditions. We determined the relative importance of the studied characters using principal component analysis, factor analysis and by developing efficient selection indices. We conclude that indirect and early selection of tropical maize genotypes can be performed using the indices I HN = 0.022 SDM + 0.35 RSDM + 0.35 RL A + 0.35 NUE for high N availability environments and I LN = -0.06 RSDM + 0.35 RSA A + 0.35 RL A + 0.39 SDM for low N availability environments.

  20. Analysis of gene functions in Maize chlorotic mottle virus.

    Science.gov (United States)

    Scheets, Kay

    2016-08-15

    Gene functions of strains of Maize chlorotic mottle virus, which comprises the monotypic genus Machlomovirus, have not been previously identified. In this study mutagenesis of the seven genes encoded in maize chlorotic mottle virus (MCMV) showed that the genes with positional and sequence similarity to their homologs in viruses of related tombusvirid genera had similar functions. p50 and its readthrough protein p111 are the only proteins required for replication in maize protoplasts, and they function at a low level in trans. Two movement proteins, p7a and p7b, and coat protein, encoded on subgenomic RNA1, are required for cell-to-cell movement in maize, and p7a and p7b function in trans. A unique protein, p31, expressed as a readthrough extension of p7a, is required for efficient systemic infection. The 5' proximal MCMV gene encodes a unique 32kDa protein that is not required for replication or movement. Transcripts lacking p32 expression accumulate to about 1/3 the level of wild type transcripts in protoplasts and produce delayed, mild infections in maize plants. Additional studies on p32, p31 and the unique amino-terminal region of p50 are needed to further characterize the life cycle of this unique tombusvirid. PMID:27242072

  1. 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

  2. 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.

  3. 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

    2012-01-01

    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. PMID:22307642

  4. Changes of copper speciation in maize rhizosphere soil

    International Nuclear Information System (INIS)

    Continuous changes in copper fractionization occurred within the maize rhizosphere. - Chemical forms of copper in the rhizosphere and bulk soil of maize were investigated using rhizobox cultivation and sequential extraction techniques. The copper accumulations were also determined. The results demonstrated that there were continuous changes in copper fractionation within the maize rhizosphere. Initially, the amount of exchangeable copper increased before dropping below the initial level after 40 days or so. Carbonate associated copper followed a similar trend of change, but with a slower pace than the exchangeable copper. The increase in carbonate associated copper only become evident after 30 days, with the net loss occurring after 60 days. There were also initial increases in oxide bound copper as well as decreases in the organic matter associated copper, both followed by a turnover after 40-50 days. The accumulation of copper in the maize plant was found to be biomass dependent. The amount of accumulated copper absorbed in the plant material exceeded the initial quantity of the exchangeable copper in the soil, revealing a transformation from less bioavailable to more bioavailable fractions. During cultivation, decreases in redox potential and increases in pH, dissolved organic carbon (DOC), and microbial activity in the maize rhizosphere were observed. The change in copper speciation may result from root-induced changes in DOC, redox potential, and microbial activity in the rhizosphere

  5. Mapping the diversity of maize races in Mexico.

    Directory of Open Access Journals (Sweden)

    Hugo Perales

    Full Text Available 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.

  6. Woody legume fallow productivity, biological N2-fixation and residual benefits to two successive maize crops in Zimbabwe

    NARCIS (Netherlands)

    Chikowo, R.; Mapfumo, P.; Nyamugafata, P.; Giller, K.E.

    2004-01-01

    Three woody legumes were planted as two-year 'improved fallows' to evaluate their residual nitrogen (N) effects on two subsequent maize crops under minimum and conventional tillage management. Maize monoculture and cowpea-maize-maize sequence treatments were included as controls. N-2-fixation was es

  7. Analysis of recombination QTLs, segregation distortion, and epistasis for fitness in maize multiple populations using ultra-high-density markers

    Science.gov (United States)

    Understanding the maize genomic features would be useful for the study of genetic diversity and evolution and for maize breeding. Here, we used two maize nested association mapping (NAM) populations separately derived in China (CN-NAM) and the US (US-NAM) to explore the maize genomic features. The t...

  8. Assessing changes to South African maize production areas in 2055 using empirical and process-based crop models

    Science.gov (United States)

    Estes, L.; Bradley, B.; Oppenheimer, M.; Beukes, H.; Schulze, R. E.; Tadross, M.

    2010-12-01

    Rising temperatures and altered precipitation patterns associated with climate change pose a significant threat to crop production, particularly in developing countries. In South Africa, a semi-arid country with a diverse agricultural sector, anthropogenic climate change is likely to affect staple crops and decrease food security. Here, we focus on maize production, South Africa’s most widely grown crop and one with high socio-economic value. We build on previous coarser-scaled studies by working at a finer spatial resolution and by employing two different modeling approaches: the process-based DSSAT Cropping System Model (CSM, version 4.5), and an empirical distribution model (Maxent). For climate projections, we use an ensemble of 10 general circulation models (GCMs) run under both high and low CO2 emissions scenarios (SRES A2 and B1). The models were down-scaled to historical climate records for 5838 quinary-scale catchments covering South Africa (mean area = 164.8 km2), using a technique based on self-organizing maps (SOMs) that generates precipitation patterns more consistent with observed gradients than those produced by the parent GCMs. Soil hydrological and mechanical properties were derived from textural and compositional data linked to a map of 26422 land forms (mean area = 46 km2), while organic carbon from 3377 soil profiles was mapped using regression kriging with 8 spatial predictors. CSM was run using typical management parameters for the several major dryland maize production regions, and with projected CO2 values. The Maxent distribution model was trained using maize locations identified using annual phenology derived from satellite images coupled with airborne crop sampling observations. Temperature and precipitation projections were based on GCM output, with an additional 10% increase in precipitation to simulate higher water-use efficiency under future CO2 concentrations. The two modeling approaches provide spatially explicit projections of

  9. BIOLOGICAL CONTROL OF SPODOPTERA FRUGIPERDA EGGS USING TELENOMUS REMUS NIXON IN MAIZE-BEAN-SQUASH POLYCULTURE

    Directory of Open Access Journals (Sweden)

    Antonio GutiA©rrez-MartAnez

    2012-01-01

    Full Text Available The maize earworm, Spodoptera frugiperda (J.E. Smith (Lepidoptera: Noctuidae, is an important pest in maize. Telenomus remus Nixon (Hymenoptera: Scelionidae is an important control agent of this pest due to its capacity to invade the whole egg mass. The percentage of parasitism by Telenomus remus Nixon (Hymenoptera: Scelionidae on Spodoptera frugiperda (J.E. Smith (Lepidoptera: Noctuidae eggs was evaluated in maize-bean, maize-squash and maize-bean-squash polyculture and maize monoculture systems. Data were analyzed statistically by using a Poisson regression (log-linear model. The analysis showed highly significant differences in the percentage of parasitism of S. frugiperda eggs by T. remus in plots with jarocho crema maize in polyculture systems (91.00±1.42% compared to the yellow maize genotype (68.90±3.10%. Parasitism percentages increased in the jarocho crema maize genotype in maize-bean, maize-squash, maize-bean-squash polycultures and maize monoculture by 87.88±3.27%, 89.75±1.99, 99.50±0.19 and 86.88±2.66%, respectively and in the yellow maize genotype they dropped by 70.00±7.05, 64.50±5.63, 77.88±6.51 and 63.25±5.20%, respectively. The percentage of T. remus parasitism on S. frugiperda eggs was found to be affected by the genotype of maize, bean and squash, polyculture system, weeds, densities of the host eggs and numbers and quality of egg masses.

  10. Kinetic mechanism and fidelity of nick sealing by Escherichia coli NAD+-dependent DNA ligase (LigA).

    Science.gov (United States)

    Chauleau, Mathieu; Shuman, Stewart

    2016-03-18

    Escherichia coli DNA ligase (EcoLigA) repairs 3'-OH/5'-PO4 nicks in duplex DNA via reaction of LigA with NAD(+) to form a covalent LigA-(lysyl-Nζ)-AMP intermediate (step 1); transfer of AMP to the nick 5'-PO4 to form an AppDNA intermediate (step 2); and attack of the nick 3'-OH on AppDNA to form a 3'-5' phosphodiester (step 3). A distinctive feature of EcoLigA is its stimulation by ammonium ion. Here we used rapid mix-quench methods to analyze the kinetic mechanism of single-turnover nick sealing by EcoLigA-AMP. For substrates with correctly base-paired 3'-OH/5'-PO4 nicks, kstep2 was fast (6.8-27 s(-1)) and similar to kstep3 (8.3-42 s(-1)). Absent ammonium, kstep2 and kstep3 were 48-fold and 16-fold slower, respectively. EcoLigA was exquisitely sensitive to 3'-OH base mispairs and 3' N:abasic lesions, which elicited 1000- to >20000-fold decrements in kstep2. The exception was the non-canonical 3' A:oxoG configuration, which EcoLigA accepted as correctly paired for rapid sealing. These results underscore: (i) how EcoLigA requires proper positioning of the nick 3' nucleoside for catalysis of 5' adenylylation; and (ii) EcoLigA's potential to embed mutations during the repair of oxidative damage. EcoLigA was relatively tolerant of 5'-phosphate base mispairs and 5' N:abasic lesions. PMID:26857547

  11. Crystal structures of complexes of NAD+-dependent formate dehydrogenase from methylotrophic bacterium Pseudomonas sp. 101 with formate

    International Nuclear Information System (INIS)

    Formate dehydrogenase (FDH) from the methylotrophic bacterium Pseudomonas sp. 101 catalyzes oxidation of formate to NI2 with the coupled reduction of nicotinamide adenine dinucleotide (NAD+). The three-dimensional structures of the apo form (the free enzyme) and the holo form (the ternary FDH-NAD+-azide complex) of FDH have been established earlier. In the present study, the structures of FDH complexes with formate are solved at 2.19 and 2.28 A resolution by the molecular replacement method and refined to the R factors of 22.3 and 20.5%, respectively. Both crystal structures contain four protein molecules per asymmetric unit. These molecules form two dimers identical to the dimer of the apo form of FDH. Two possible formatebinding sites are found in the active site of the FDH structure. In the complexes the sulfur atom of residue Cys354 exists in the oxidized state

  12. Crystal structures of type III{sub H} NAD-dependent D-3-phosphoglycerate dehydrogenase from two thermophiles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Pampa, K.J. [Department of Studies in Microbiology, University of Mysore, Mysore 570 006 (India); Manjula, M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Hemantha Kumar, G. [Department of Studies in Computer Science, University of Mysore, Mysore 570 006 (India); Kunishima, Naoki [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Hyogo 679-5148 (Japan); Lokanath, N.K., E-mail: lokanath@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India)

    2014-08-15

    Highlights: • Determined the crystal structures of PGDH from two thermophiles. • Monomer is composed of nucleotide binding domain and substrate binding domain. • Crystal structures of type III{sub H} PGDH. - Abstract: In the L-Serine biosynthesis, D-3-phosphoglycerate dehydrogenase (PGDH) catalyzes the inter-conversion of D-3-phosphoglycerate to phosphohydroxypyruvate. PGDH belongs to 2-hydroxyacid dehydrogenases family. We have determined the crystal structures of PGDH from Sulfolobus tokodaii (StPGDH) and Pyrococcus horikoshii (PhPGDH) using X-ray diffraction to resolution of 1.77 Å and 1.95 Å, respectively. The PGDH protomer from both species exhibits identical structures, consisting of substrate binding domain and nucleotide binding domain. The residues and water molecules interacting with the NAD are identified. The catalytic triad residues Glu-His-Arg are highly conserved. The residues involved in the dimer interface and the structural features responsible for thermostability are evaluated. Overall, structures of PGDHs with two domains and histidine at the active site are categorized as type III{sub H} and such PGDHs structures having this type are reported for the first time.

  13. Further studies on the bioaffinity chromatography of NAD(+)-dependent dehydrogenases using the locking-on effect.

    Science.gov (United States)

    O'Carra, P; Griffin, T; O'Flaherty, M; Kelly, N; Mulcahy, P

    1996-10-17

    Previous studies have capitalized on ordered kinetic mechanisms in the design of biospecific affinity chromatographic methods for highly efficient purifications and mechanistic studies of enzymes. The most direct tactic has been the use of immobilised analogues of the following, usually enzyme-specific substrates, e.g., lactate/pyruvate in the case of lactate dehydrogenase for which NAD+ is the leading substrate. Such immobilised specific substrates are, however, often difficult or impossible to synthesise. The locking-on strategy reverses the tactic by using the more accessible immobilised leading substrate, immobilised NAD+, as adsorbent with soluble analogues of the enzyme-specific ligands (e.g., lactate in the case of lactate dehydrogenase) providing a substantial reinforcement of biospecific adsorption sufficient to effect adsorptive selection of an enzyme from a group of enzymes such as the NAD(+)-specific enzymes. The value of this approach is demonstrated using model studies with lactate dehydrogenase (LDH, EC 1.1.1.27), alcohol dehydrogenase (ADH, EC 1.1.1.1), glutamate dehydrogenase (GDH, EC 1.4.1.3) and malate dehydrogenase (MDH, EC 1.1.1.37). Purification of bovine liver GDH in high yield from crude extracts is described using the tactic. PMID:8917627

  14. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough "Masa Agria" (Maiz Añejo).

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential.

  15. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough "Masa Agria" (Maiz Añejo).

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential. PMID:27524979

  16. Phenotyping for Abiotic Stress Tolerance in Maize

    Institute of Scientific and Technical Information of China (English)

    Benhilda Masuka; Jose Luis Araus; Biswanath Das; Kai Sonder; Jill E. Cairns

    2012-01-01

    The ability to quickly develop germplasm having tolerance to several complex polygenic inherited abiotic and biotic stresses combined is critical to the resilience of cropping systems in the face of climate change.Molecular breeding offers the tools to accelerate cereal breeding; however,suitable phenotyping protocols are essential to ensure that the much-anticipated benefits of molecular breeding can be realized.To facilitate the full potential of molecular tools,greater emphasis needs to be given to reducing the within-experimental site variability,application of stress and characterization of the environment and appropriate phenotyping tools.Yield is a function of many processes throughout the plant cycle,and thus integrative traits that encompass crop performance over time or organization level (i.e.canopy level) will provide a better alternative to instantaneous measurements which provide only a snapshot of a given plant process.Many new phenotyping tools based on remote sensing are now available including non-destructive measurements of growth-related parameters based on spectral reflectance and infrared thermometry to estimate plant water status.Here we describe key field phenotyping protocols for maize with emphasis on tolerance to drought and low nitrogen.

  17. Maize transpiration in response to meteorological conditions

    Science.gov (United States)

    Klimešová, Jana; Stŕedová, Hana; Stŕeda, Tomáš

    2013-09-01

    Differences in transpiration of maize (Zea mays L.) plants in four soil moisture regimes were quantified in a pot experiment. The transpiration was measured by the "Stem Heat Balance" method. The dependence of transpiration on air temperature, air humidity, global solar radiation, soil moisture, wind speed and leaf surface temperature were quantified. Significant relationships among transpiration, global radiation and air temperature (in the first vegetation period in the drought non-stressed variant, r = 0.881**, r = 0.934**) were found. Conclusive dependence of transpiration on leaf temperature (r = 0.820**) and wind speed (r = 0.710**) was found. Transpiration was significantly influenced by soil moisture (r = 0.395**, r = 0.528**) under moderate and severe drought stress. The dependence of transpiration on meteorological factors decreased with increasing deficiency of water. Correlation between transpiration and plant dry matter weight (r = 0.997**), plant height (r = 0.973**) and weight of corn cob (r = 0.987**) was found. The results of instrumental measuring of field crops transpiration under diverse moisture conditions at a concurrent monitoring of the meteorological elements spectra are rather unique. These results will be utilized in the effort to make calculations of the evapotranspiration in computing models more accurate.

  18. Studies in neutron mutagenesis in maize

    International Nuclear Information System (INIS)

    Pollen grains of Bz strain of maize were exposed to 14 MeV neutrons with single or fractionated treatments, and pollinated on the recessive stock. Mutation frequency from Bz to bz was observed after harvest of F1 seeds. No clear difference in the mutation frequencies between single and fractionation series was observed. To investigate the effects of water content upon mutation frequency of neutron and gamma-rays, seeds heterozygous for the Yq2-gene were used. Moisture-stabilized (13%) seeds and seeds steeped in water for 24 hrs were exposed to neutrons or to gamma-rays, and mutation from Yq2 to yq2 was detected as color change green to yellow-green in the seedlings. In the gamma-ray treatments, the mutation frequency of wet seeds was about 1.5 times higher than that of corresponding lot of dry seeds. In the neutron treatment, on the other hand, no clear difference in frequency between wet and dry seeds was observed. It may be concluded that no change or no recovery in neutron-induced mutation was observed not only in the fractionation treatment but also in the dry and wet seeds treatments. (author)

  19. Maize Leaves Turn Away from Neighbors1

    Science.gov (United States)

    Maddonni, Gustavo Angel; Otegui, María Elena; Andrieu, Bruno; Chelle, Michael; Casal, Jorge J.

    2002-01-01

    In commercial crops, maize (Zea mays) plants are typically grown at a larger distance between rows (70 cm) than within the same row (16–23 cm). This rectangular arrangement creates a heterogeneous environment in which the plants receive higher red light (R) to far-red light (FR) ratios from the interrow spaces. In field crops, the hybrid Dekalb 696 (DK696) showed an increased proportion of leaves toward interrow spaces, whereas the experimental hybrid 980 (Exp980) retained random leaf orientation. Mirrors reflecting FR were placed close to isolated plants to simulate the presence of neighbors in the field. In addition, localized FR was applied to target leaves in a growth chamber. During their expansion, the leaves of DK696 turned away from the low R to FR ratio signals, whereas Exp980 leaves remained unaffected. On the contrary, tillering was reduced and plant height was increased by low R to FR ratios in Exp980 but not in DK696. Isolated plants preconditioned with low R/FR-simulating neighbors in a North-South row showed reduced mutual shading among leaves when the plants were actually grouped in North-South rows. These observations contradict the current view that phytochrome-mediated responses to low R/FR are a relic from wild conditions, detrimental for crop yield. PMID:12427985

  20. Does Whole Grain Consumption Alter Gut Microbiota and Satiety?

    Directory of Open Access Journals (Sweden)

    Danielle N. Cooper

    2015-05-01

    Full Text Available This review summarizes recent studies examining whole grain consumption and its effect on gut microbiota and satiety in healthy humans. Studies comparing whole grains to their refined grain counterparts were considered, as were studies comparing different grain types. Possible mechanisms linking microbial metabolism and satiety are described. Clinical trials show that whole grain wheat, maize, and barley alter the human gut microbiota, but these findings are based on a few studies that do not include satiety components, so no functional claims between microbiota and satiety can be made. Ten satiety trials were evaluated and provide evidence that whole oats, barley, and rye can increase satiety, whereas the evidence for whole wheat and maize is not compelling. There are many gaps in the literature; no one clinical trial has examined the effects of whole grains on satiety and gut microbiota together. Once understanding the impact of whole grains on satiety and microbiota is more developed, then particular grains might be used for better appetite control. With this information at hand, healthcare professionals could make individual dietary recommendations that promote satiety and contribute to weight control.

  1. The molecular characterization of maize B chromosome specific AFLPs

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The origin and evolution of B chromosomes could be explained by the specific DNA sequence on them.But the specific sequences known were quite limited. To investigate maize B chromosome sqicific DNA sequeces, maize genomes with and without B chromosomes were analyzed by AFLP. Only 5 markers were found specific to genomes with B chromosomes among about 2000 AFLP markers. Southern hybridization and sequence analysis revealed that only the sequence of M8-2D was a B chromosome specific sequence.This sequence contained the telomeric repeat unit AGGGTTT conserved in plant chromosome telomeres.In addition, the sequence of M8-2D shared low homology to clones from maize chromosome 4 centromere as well. M8-2D were localized to B chromosome centromeric and telomeric regions.

  2. Aflatoxin Resistance in Maize: What Have We Learned Lately?

    Directory of Open Access Journals (Sweden)

    Marilyn L. Warburton

    2014-01-01

    Full Text Available Aflatoxin contamination of maize grain is a huge economic and health problem, causing death and increased disease burden in much of the developing world and income loss in the developed world. Despite the gravity of the problem, deployable solutions are still being sought. In the past 15 years, much progress has been made in creating resistant maize inbred lines; mapping of genetic factors associated with resistance; and identifying possible resistance mechanisms. This review highlights this progress, most of which has occurred since the last time a review was published on this topic. Many of the needs highlighted in the last reviews have been addressed, and several solutions, taken together, can now greatly reduce the aflatoxin problem in maize grain. Continued research will soon lead to further solutions, which promise to further reduce and even eliminate the problem completely.

  3. Structural properties of maize hybrids established by infrared spectra

    Directory of Open Access Journals (Sweden)

    Radenović Čedomir N.

    2015-01-01

    Full Text Available This paper discusses the application of the infrared (IR spectroscopy method for determination of structural properties of maize hybrid grains. The IR spectrum of maize grain has been registered in the following hybrids: ZP 341, ZP 434 and ZP 505. The existence of spectral bands varying in both number and intensity, as well as their shape, frequency and kinetics have been determined. They have been determined by valence oscillations and deformation oscillations of the following organic compounds: alkanes, alkenes, alkynes, amides, alcohols, ethers, carboxylic acids, esters and aldehydes and ketones, characteristic for biogenic compounds such as carbohydrates, proteins and lipids. In this way, possible changes in the grain structure of observed maize hybrids could be detected.

  4. Design, Construction and Testing of Simple Solar Maize Dryer

    Directory of Open Access Journals (Sweden)

    Joshua FOLARANMI

    2008-12-01

    Full Text Available This project reports the design, construction and testing of a simple solar maize dryer. It is design in such a way that solar radiation is not incident directly on the maize, but preheated air warmed during its flow through a low pressure thermosphonic solar energy air heater or collector made up of an insulating material (polystyrene of size 100mmx50mmx25.4mm, absorber plate (aluminium sheet painted black of size 100mmx50mm and a cover glass (5mm thickness measuring 100mmx50mm all arranged in this order contributed to the heating. The test results gave temperature above 45OC in the drying chamber, and the moisture content of 50kg of maize reduced to about 12.5% in three days of 9hours each day of drying.

  5. Agrobacterium-mediated transformation of maize (Zea mays) immature embryos.

    Science.gov (United States)

    Lee, Hyeyoung; Zhang, Zhanyuan J

    2014-01-01

    Agrobacterium tumefaciens-mediated transformation is one of the most efficient and simple gene delivery systems for genetic improvement and biology studies in maize. This system has become more widely used by both public and private laboratories. However, transformation efficiencies vary greatly from laboratory to laboratory for the same genotype. Here, we illustrate our advanced Agrobacterium-mediated transformation method in Hi-II maize using simple binary vectors. The protocol utilizes immature embryos as starting explants and the bar gene as a selectable marker coupled with bialaphos as a selective agent. The protocol offers efficient transformation results with high reproducibility, provided that some experimental conditions are well controlled. This transformation method, with minor modifications, can be also employed to transform certain maize inbreds.

  6. Global maize trade and food security: implications from a social network model.

    Science.gov (United States)

    Wu, Felicia; Guclu, Hasan

    2013-12-01

    In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability was decreased due to factors such as diversion to nonfood uses, climatic factors, or plant diseases. Using data on imports and exports from the U.N. Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, whereas Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents U.S. maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which U.S. maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide.

  7. Breeding for Parents of Hybrid Rice with Maize pepc Gene

    Institute of Scientific and Technical Information of China (English)

    WANG De-zheng; WANG Xiu-feng; JIAO De-mao; WU Shuang; LI Xia; LI Li; CHI Wei; WANG Shou-hai; LI Cheng-quan; LUO Yan-chang

    2002-01-01

    The results of the investigation on transgenic rice with maize C4-specific phosphoenolpyruvate carboxylase (pepc) gene showed that the transgenic rice plants with the maize pepc gene expressed at high level and the maize PEPC expression was inherited in the progenies in a Mendelian manner. The transgenic plants had PEPC activity of more than 10-fold higher than untransformed plants. As compared with untransformed plants, the panicle per plant, spikelet per panicle, 1000-grain weight and grain-weight per plant for transgenic plants increased by 14.9 %, 5.7%, 1.3 % and 13.9 %, respectively. By crossing the maize pepc gene was incorporated into the parents of hybrid rice, which were the photo-sensitive genic male sterile (PGMS)lines of two-line hybrid rice such as Peiai64s, 7001s, 2302s, 2304s and 2306s-1, and the BT type of cytoplasmic male sterile (CMS) line of three-line hybrid rice such as Shuangjiu A, and restorer lines 5129, Wanjing97 in the spring of 1998. The following progresses were made: (1) The inheritance of the high-level expression of the maize PEPC was stable in different genetic background of rice; (2) PEPC activity of F1 hybrid was the mean of the two parents. Its saturated photosynthetic rate (Pn) rose to 50 % higher than that of the receptor parent. These results demonstrated that it is possible to increase the vigor of the rice plant by transgenic approach with maize pepc gene; (3) The activity of PEPC in leaf could be considered as the major physiological index because the correlation coefficient between PEPC activity and Pn was 0.6470 * *; (4) We have developed three rice lines with maize pepc gene; (5) The selection method of high photosynthetic efficiency rice has been established, which includes soaking seeds into solution of hygromycin phosphotransferase to germinate, tracing the pepc gene by PCR analysis, evaluating the performance of the rice plants in the field and examining PEPC activities and Pn of rice plants with maize pepc gene.

  8. Water repellency in the rhizosphere of maize: measurements and modelling

    Science.gov (United States)

    Ahmed, Mutez; Kroener, Eva; Carminati, Andrea

    2016-04-01

    Although maize roots have been extensively studied, there is limited information on the effect of root exudates on the hydraulic properties of maize rhizosphere. Recent experiments suggested that the mucilaginous fraction of root exudates may cause water repellency of the rhizosphere. Our objectives were: 1) to investigate whether maize rhizosphere turns hydrophobic after drying and subsequent rewetting; 2) to develop a new method to collect root mucilage and test whether maize mucilage is hydrophobic; and 3) to find a quantitative relation between rhizosphere rewetting, particle size, soil matric potential and mucilage concentration. Maize plants were grown in aluminum containers filled with a sandy soil. When the plants were three-weeks-old, the soil was let dry and then it was irrigated. The soil water content during irrigation was imaged using neutron radiography. In a parallel experiment, ten maize plants were grown in sandy soil for five weeks. Mucilage was collected from young brace roots using a new developed method. Mucilage was placed on glass slides and let dry. The contact angle was measured with the sessile drop method for varying mucilage concentration. Additionally, we used neutron radiography to perform capillary rise experiments in soils of varying particle size mixed with maize mucilage. We then used a pore-network model in which mucilage was randomly distributed in a cubic lattice. The general idea was that rewetting of a pore is impeded when the concentration of mucilage on the pore surface (g cm-2) is higher than a given threshold value. The threshold value depended on soil matric potential, pore radius and contact angle. Then, we randomly distributed mucilage in the pore network and we calculated the percolation of water across a cubic lattice for varying soil particle size, mucilage concentration and matric potential. Our results showed that: 1) the rhizosphere of maize stayed temporarily dry after irrigation; 2) mucilage became water

  9. Study on Soil Denitrification in Wheat-Maize Rotation System

    Institute of Scientific and Technical Information of China (English)

    ZOU Guo-yuan; ZHANG Fu-suo; JU Xiao-tang; CHEN Xin-ping; LIU Xue-jun

    2006-01-01

    Soil denitrification was studied in wheat-maize rotation cropping system on an aquic cambisol. Results showed that the N loss amount by denitrification ranged from 4.7 to 9.7 kg per hectare with different levels of nitrogen application and the key stage for denitification was during summer maize-growth-period, especially within 1-2 weeks after fertilizer nitrogen was applied. Similar trend was found between soil N2O production/emission dynamic and denitrification dynamic in the rotation system, which may indicate that mainly N2O is produced in nitrification process.

  10. Fusarium temperatum and Fusarium subglutinans isolated from maize in Argentina.

    Science.gov (United States)

    Fumero, María Verónica; Reynoso, María Marta; Chulze, Sofía

    2015-04-16

    Fusarium temperatum and Fusarium subglutinans isolated from the Northwest region (NOA region) of Argentina were characterized using a polyphasic approach based on morphological, biological and molecular markers. Some interfertility between the species was observed. The phylogenetic analysis showed that the two species represented two clades strongly supported by bootstrap values. The toxigenic profile of the strains was also determined. F. temperatum strains were fusaproliferin and beauvericin producers, and only some strains were fumonisin B1 producers. All F. subglutinans strains produced fusaproliferin but none produced beauvericin, indicating a potential toxicological risk from maize harvested in the NOA region of Argentina. This study provides new information about F. temperatum isolated from maize in Argentina.

  11. Molecular basis for the CAT-2 null phenotype in maize

    International Nuclear Information System (INIS)

    Previous reports have described several maize lines whose developmental patterns of catalase gene expression vary from the typical maize line, W64A. Among these variants are the lines A16 and A338, both found to be null for the CAT-2 protein. Identification of a third CAT-2 null line, designated A340, is described. RNA blots and S1 nuclease protection analysis, using [32P]-labeled dCTP, indicate that all three CAT-2 null lines produce a similarly shortened Cat2 transcript. The molecular basis for this aberrant Cat2 transcript is discussed

  12. Organization of the R chromosome region in maize. Triennial report

    Energy Technology Data Exchange (ETDEWEB)

    Kermicle, J.L.

    1979-12-01

    Anthocyanin pigmentation in maize is strain and tissue specific. The primary source of variation is represented in maize races indigenous to widely separated geographic regions of North and South America. Secondary sources include variants which have appeared spontaneously in culture, arose following mutagenic treatment, or were incited through paramutation or by means of controlling elements. Much of the observed variation is attributable to a narrowly restricted segment of chromosome 10, designated the R region. The studies on R organization seek to analyze this variation in terms of the number, kind and arrangement of the components involved.

  13. Physiological response of wheat, maize and cotton to gamma irradiation

    International Nuclear Information System (INIS)

    Grains of wheat triticum aestivum vulgare cv. Giza 155, maize Zea mays cv. double hybrid strain 17 S and cotton seeds Gossypium barbadence cv. Giza 67 were irradiated with successive doses of gamma rays from 0 to 64 Krad. Irradiating wheat grains with 1 Krad, maize grains with 0.5 Krad and cotton seeds with 4 Krad stimulated their germination and enhanced the growth of seedlings and their chlorophyll content. Also, these doses activated Alpha- and Beta-Amylase in the seeds. Higher doses had suppression effects. Peroxidase value in the seedlings of the three species was accelerated progressively in concomitant with the increase in the dosage

  14. Environmental Impact of Genetically Modified Maize Expressing Cry1 Proteins

    DEFF Research Database (Denmark)

    Bartsch, Detlef; Devos, Yann; Hails, Rosie;

    2010-01-01

    For more than a decade, genes of Bacillus thuringiensis (‘Bt’) that encode lepidopteran-specific protein toxins (Cry1Ab and Cry1F) have been engineered into maize for protection against lepidopteran pests. An extensive body of research data and environmental risk assessments (ERA) has been...... assembled on the potential environmental impact of Cry1 expressing maize. The available literature so far suggests only minor environmental effects. The majority of laboratory studies and all the field studies reviewed did not reveal any unexpected adverse or long-term effectson the environment. Negative...

  15. Performance Evaluation Of A Grain Maize Solar Dryer

    Directory of Open Access Journals (Sweden)

    Osondu L. C.

    2015-08-01

    Full Text Available Abstract Drying under direct sunlight is one of the oldest techniques used by mankind to preserve Agriculture based food and non-food products. This paper focused on the use of solar dryer to reduce the moisture content of Agriculture produce such as maize. The experiment performed showed the moisture content of maize reduced from 20 to 13. It was also observed that the temperature increased with time. The assumed maximum temperature of the collector plate in the experiment was 100.

  16. Resistance to Bt maize by western corn rootworm: insights from the laboratory and the field.

    Science.gov (United States)

    Gassmann, Aaron J

    2016-06-01

    Western corn rootworm is a serious pest of maize. Beginning in 2003, management of western corn rootworm included transgenic maize that produces insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). The first Bt maize hybrids produced Cry3Bb1, but additional Bt toxins have since been introduced, including eCry3.1Ab, mCry3A and Cry34/35Ab1. Laboratory selection experiments found that western corn rootworm could develop resistance to all types of Bt maize following three to seven generations of selection. By 2009 cases of field-evolved resistance to Cry3Bb1 maize had been identified, with populations also showing cross-resistance to mCry3A maize. Factors likely contributing to resistance were the lack of a high dose of Bt toxin for maize targeting rootworm and minimal fitness costs of resistance. PMID:27436740

  17. Control of Aspergillus flavus in maize with plant essential oils and their components.

    Science.gov (United States)

    Montes-Belmont, R; Carvajal, M

    1998-05-01

    The effects of 11 plant essential oils for maize kernel protection against Aspergillus flavus were studied. Tests were conducted to determine optimal levels of dosages for maize protection, effects of combinations of essential oils, and residual effects and toxicity of essential oils to maize plants. Principal constituents of eight essential oils were tested for ability to protect maize kernels. Essential oils of Cinnamomum zeylanicum (cinnamon), Mentha piperita (peppermint), Ocimum basilicum (basil), Origanum vulgare (origanum), Teloxys ambrosioides (the flavoring herb epazote), Syzygium aromaticum (clove), and Thymus vulgaris (thyme) caused a total inhibition of fungal development on maize kernels. Thymol and o-methoxycinnamaldehyde significantly reduced maize grain contamination. The optimal dosage for protection of maize varied from 3 to 8%. Combinations of C. zeylanicum with the remaining oils gave efficient control. A residual effect of C. zeylanicum was detected after 4 weeks of kernel treatment. No phytotoxic effect on germination and corn growth was detected with any of these oils.

  18. A genome-wide survey of maize lipid-related genes: candidate genes mining,digital gene expression profiling and colocation with QTL for maize kernel oil

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Lipids play an important role in plants due to their abundance and their extensive participation in many metabolic processes.Genes involved in lipid metabolism have been extensively studied in Arabidopsis and other plant species.In this study,a total of 1003 maize lipid-related genes were cloned and annotated,including 42 genes with experimental validation,732 genes with full-length cDNA and protein sequences in public databases and 229 newly cloned genes.Ninety-seven maize lipid-related genes with tissue-preferential expression were discovered by in silico gene expression profiling based on 1984483 maize Expressed Sequence Tags collected from 182 cDNA libraries.Meanwhile,70 QTL clusters for maize kernel oil were identified,covering 34.5% of the maize genome.Fifty-nine (84%) QTL clusters co-located with at least one lipid-related gene,and the total number of these genes amounted to 147.Interestingly,thirteen genes with kernel-preferential expression profiles fell within QTL clusters for maize kernel oil content.All the maize lipid-related genes identified here may provide good targets for maize kernel oil QTL cloning and thus help us to better understand the molecular mechanism of maize kernel oil accumulation.

  19. Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid.

    Science.gov (United States)

    Louis, Joe; Basu, Saumik; Varsani, Suresh; Castano-Duque, Lina; Jiang, Victoria; Williams, W Paul; Felton, Gary W; Luthe, Dawn S

    2015-09-01

    Signaling networks among multiple phytohormones fine-tune plant defense responses to insect herbivore attack. Previously, it was reported that the synergistic combination of ethylene (ET) and jasmonic acid (JA) was required for accumulation of the maize insect resistance1 (mir1) gene product, a cysteine (Cys) proteinase that is a key defensive protein against chewing insect pests in maize (Zea mays). However, this study suggests that mir1-mediated resistance to corn leaf aphid (CLA; Rhopalosiphum maidis), a phloem sap-sucking insect pest, is independent of JA but regulated by the ET-signaling pathway. Feeding by CLA triggers the rapid accumulation of mir1 transcripts in the resistant maize genotype, Mp708. Furthermore, Mp708 provided elevated levels of antibiosis (limits aphid population)- and antixenosis (deters aphid settling)-mediated resistance to CLA compared with B73 and Tx601 maize susceptible inbred lines. Synthetic diet aphid feeding trial bioassays with recombinant Mir1-Cys Protease demonstrates that Mir1-Cys Protease provides direct toxicity to CLA. Furthermore, foliar feeding by CLA rapidly sends defensive signal(s) to the roots that trigger belowground accumulation of the mir1, signifying a potential role of long-distance signaling in maize defense against the phloem-feeding insects. Collectively, our data indicate that ET-regulated mir1 transcript accumulation, uncoupled from JA, contributed to heightened resistance to CLA in maize. In addition, our results underscore the significance of ET acting as a central node in regulating mir1 expression to different feeding guilds of insect herbivores. PMID:26253737

  20. Attention Alters Perceived Attractiveness.

    Science.gov (United States)

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  1. CYCLOXYDIM-TOLERANT MAIZE – BREEDERS STANDPOINT

    Directory of Open Access Journals (Sweden)

    G. Bekavac

    2008-09-01

    Full Text Available Cycloxydim-Tolerant Maize (CTM was developed by researches at the University of Minnesota. CTM plants were regenerated from tissue culture selected for callus growth in the presence of cycloxydim, and the resulting plants were shown to contain a nuclear mutation, expressed as a single, partially dominant gene (known as Acc1 that conferred tolerance to the herbicide. Cycloxydim is a systemic herbicide for post emergence application in dicot crops to selectively control grass weeds. Corn, like most grasses is susceptible to cycloxydim due to inhibited acetyl-coenzyimeA carboxylaze enzyme activity. There are two key benefits of this technology: first, cycloxydim applications in CTM hybrids can be delayed until the weed spectrum and population density exceed agro-economic threshold; second, cycloxydim can be applied at either stage of plant development with no effect on basic agronomic traits, compared to non treated plants. Nevertheless, this type of tolerance requires 2 genes to be fully effective, i.e. gene must be present in both inbred parents to provide complete tolerance in the resulting hybrid. Such type of tolerance doubles the chances for yield drag and doubles the number of inbred conversions needed. This also limits germplasm integration and increases time lag in developing hybrids. Despite these difficulties, many seed companies introduce tolerance to cycloxydim into their commercial inbreds, and many of them have already commercialized CTM hybrids. Finally, it came as a logical question what is more important – hybrid performance or new trait? Critical to the success of this technology has been yield performance of CTM hybrids. At the same time, performance and herbicide tolerance do not exclude each other and can surely co-exist. To be accepted, this coexistence must secure high profitability to corn producers. However, CTM hybrids will not replace conventional ones on a large scale, but could be used as a specific tool, or could

  2. Combining abilities of silage maize grain yield

    Directory of Open Access Journals (Sweden)

    Živanović Tomislav

    2005-01-01

    Full Text Available The aim of the present study was to evaluate the following parameters of maize grain yield: variability of inbred lines and their diallel hybrids superior-parent heterosis and general and special combining abilities. According to obtained results of the two-year study, it can be concluded that variability of this trait is significantly affected by a genotype, year and their interaction. As expected, hybrids had higher average grain yields than inbreds due to the depression of this trait that occurs in inbreds during inbreeding. The highest average value of heterosis for gain yield was detected in the hybrid ZPLB405 x ZPLB406 (123.0% and 178.1% in 1997 and 1998, respectively. The estimation of combining abilities was done on the basis of diallel hybrids after the method established by Griffing, 1956 (method II, mathematical model I. The analysis of variance of combining ability for grain yield indicated highly significant values of GCA and SCA for the observed trait in both study years. Grain yield inheritance was more affected by non-additive genes (dominance and epistasis as indicated by the GCA to SCA ratio that was smaller than unity. The inbreds ZPLB401 and ZPLB406 had high GCA effects, while the hybrid combinations ZPLB40Î x ZPLB402, ZPLB401 x ZPLB403, ZPLB401 x ZPLB405, ZPLB402 x ZPLB406, ZPLB403 x ZPLB406, ZPLB404 x ZPLB406, ZPLB405 x ZPLB406 had high SCA effects in both study years. These hybrid combinations include one parent with high GCA effects and other with low GCA effects. Furthermore, there are combinations ZPLB402 x ZPLB405, ZPLB403 x ZPLB405 and ZPLB404 x ZPLB405 with significant SCA effects that include parents with low GCA effects. This is probably the result of the additive type (additive x additive of interaction between parents.

  3. Glycaemic Response to Quality Protein Maize Grits

    Directory of Open Access Journals (Sweden)

    Leonora N. Panlasigui

    2010-01-01

    Full Text Available Background. Carbohydrates have varied rates of digestion and absorption that induces different hormonal and metabolic responses in the body. Given the abundance of carbohydrate sources in the Philippines, the determination of the glycaemic index (GI of local foods may prove beneficial in promoting health and decreasing the risk of diabetes in the country. Methods. The GI of Quality Protein Maize (QPM grits, milled rice, and the mixture of these two food items were determined in ten female subjects. Using a randomized crossover design, the control bread and three test foods were given on separate occasions after an overnight fast. Blood samples were collected through finger prick at time intervals of 0, 15, 30, 45, 60, 90, and 120 min and analyzed for glucose concentrations. Results. The computed incremental area under the glucose response curve (IAUC varies significantly across test foods (P<.0379 with the pure QPM grits yielding the lowest IAUC relative to the control by 46.38. Resulting GI values of the test foods (bootstrapped were 80.36 (SEM 14.24, 119.78 (SEM 18.81, and 93.17 (SEM 27.27 for pure QPM grits, milled rice, and rice-QPM grits mixture, respectively. Conclusion. Pure QPM corn grits has a lower glycaemic response compared to milled rice and the rice-corn grits mixture, which may be related in part to differences in their dietary fibre composition and physicochemical characteristics. Pure QPM corn grits may be a more health beneficial food for diabetic and hyperlipidemic individuals.

  4. Efficacy of diatomaceous earth and botanical powders against the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) on maize

    OpenAIRE

    Nukenine, E. K.; Goudoungou, J. W.; Adler, C.; Reichmuth, C

    2010-01-01

    The effectiveness of the diatomaceous earth SilicoSec, neem seed powder and Plectranthus glandulosus leaf powder, applied at four different rates with four exposure intervals (1, 3, 7 and 14 d) for the control of maize weevil, Sitophilus zeamais Motschulsky, on maize in the laboratory was determined. Treatment with SilicoSec was the most effective followed by neem seed powder and P. glandulosus powder. The highest tested content (2 g/kg) of SilicoSec caused 81.1% and 100% mortality of S. zeam...

  5. 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......-climatic factors on the maize area dynamics. Our results show that even the relatively small climate changes that have been realized in the last decades have been partly driving the spatiotemporal dynamics of an important agricultural crop towards its northern cultivation limit in Europe....

  6. Spatial distribution of transcript changes in the maize primary root elongation zone at low water potential

    Directory of Open Access Journals (Sweden)

    Bohnert Hans J

    2008-04-01

    Full Text Available Abstract Background Previous work showed that the maize primary root adapts to low Ψw (-1.6 MPa by maintaining longitudinal expansion in the apical 3 mm (region 1, whereas in the adjacent 4 mm (region 2 longitudinal expansion reaches a maximum in well-watered roots but is progressively inhibited at low Ψw. To identify mechanisms that determine these responses to low Ψw, transcript expression was profiled in these regions of water-stressed and well-watered roots. In addition, comparison between region 2 of water-stressed roots and the zone of growth deceleration in well-watered roots (region 3 distinguished stress-responsive genes in region 2 from those involved in cell maturation. Results Responses of gene expression to water stress in regions 1 and 2 were largely distinct. The largest functional categories of differentially expressed transcripts were reactive oxygen species and carbon metabolism in region 1, and membrane transport in region 2. Transcripts controlling sucrose hydrolysis distinguished well-watered and water-stressed states (invertase vs. sucrose synthase, and changes in expression of transcripts for starch synthesis indicated further alteration in carbon metabolism under water deficit. A role for inositols in the stress response was suggested, as was control of proline metabolism. Increased expression of transcripts for wall-loosening proteins in region 1, and for elements of ABA and ethylene signaling were also indicated in the response to water deficit. Conclusion The analysis indicates that fundamentally different signaling and metabolic response mechanisms are involved in the response to water stress in different regions of the maize primary root elongation zone.

  7. Architectural and biochemical changes in embryonic tissues of maize under cadmium toxicity.

    Science.gov (United States)

    Wahid, A; Khaliq, S

    2015-09-01

    Heavy metals greatly alter plant morphology and architecture, however detailed mechanisms of such changes are not fully explored. Two experiments were conducted to investigate the influence of cadmium (CdCl2 · 2.5H2 O) on some germination, morphological, biochemical and histological characteristics of developing embryonic tissue of maize. In the first experiment, maize seeds were germinated in increasing levels of CdCl2 (200-2000 μm) in sand and measurements were taken of changes in germination and seedling development attributes. Based on these parameters, 1000 μM CdCl2 was chosen for detailed biochemical and histological measurements. In the second experiment, seeds were germinated in Petri dishes and supplied with 0 (control) or 1000 μM CdCl2 (Cd-treated). Radicle, plumule, coleoptile and coleorhiza were measured for biochemical and histological changes. The highest amount of Cd was in the coleorhiza and radicle. Free proline, soluble sugars, anthocyanin, soluble phenolics, ascorbic acid, H2 O2 and MDA were significantly higher in coleorhizae, followed by the coleoptile, radicle and plumule. Although the radicle and coleorhiza were relatively poor targets of Cd than the other tissues, Cd stress reduced cortical cell size and vascular tissues, and deformed xylem and phloem parenchyma in all plant parts. In conclusion, the main reason for reduced germination was the influence of Cd on architecture of the coleorhiza and coleoptile, which was the result of oxidative stress and other physiological changes taking place in these tissues. PMID:25732002

  8. Mechanical Behavior of Areca Fiber and Maize Powder Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Kishan Naik

    2014-08-01

    Full Text Available Natural fibers are gaining the interest in packaging, domestic, low cost housing and other general applications. In this work the mechanical properties of randomly distributed areca fiber and maize powder reinforced phenol formaldehyde were studied. From the results Youngs modulus is maximum found in 300 ml of resin. The maximum tensile strength is for 300B composite plate. The maximum Young’s modulus for 300B is 135MPa, for bending strength of various composite plates, the composite plate with 400 ml PF resin shows the maximum bending load compared to other composite plates. The composite plate of 400C shows the maximum bending load compared to other composite plates. The maximum bending load for 400C composite plate is 0.854 kN. The adhesive tensile strength increases with decrease in Areca fiber and increase in maize powder up to 700 gms of Areca and 300 gms of maize powder. Later the adhesive tensile strength decreases with decrease in Areca fiber and increase in maize powder. Maximum adhesive tensile stress is 0.137 MPa for 400B composite plate compared to remaining composite plates.

  9. Interaction of genetic mechanisms regulating methionine concentration in maize grain

    Science.gov (United States)

    Methionine is a limiting amino acid in poultry diets so methionine supplementation is typically required to meet nutritional demands. Maize varieties with increased methionine levels have been developed utilizing three different approaches: i.) increased levels of the methionine-rich 10 kDa zein, ii...

  10. Persistence of lindane in rice and maize ecosystems in Nigeria

    International Nuclear Information System (INIS)

    A three year field study was undertaken to examine the fate of residues of lindane in soil and crops after repeated seasonal applications of lindane to soil in which maize and rice crops were grown. In the 1993 rice study, the lindane residues in the treated soil were 0.6 mgkg-1 (1day) and 0.04 mgkg-1 (2 months) after application respectively. In the soil from the maize plots, lindane residues were 0.19 mg kg-1 (1 day) and 0.16 mg kg-1 (1 month) after application and not detectable after 6 months. In the 1994 maize study, the lindane residues in the soil were 0.12 (1 day), 0.10 (1 month) and 0.033 mg kg-1 (2 months) after application respectively while in the crop they were 0.19 (1 day), 0.105 (2 weeks) and 0.05 (4 weeks) mg kg-1, respectively. In general, lindane residues were not detected in the soil one year after application indicating that there was no accumulation of lindane in the soil during the period 1992-1994 and therefore unlikely to be any long term effects on soil fauna. Lindane residues in rice and maize crops continued to decrease during the period up to harvest. (author). 6 refs, 2 tabs

  11. Genes related to high temperature tolerance during maize seed germination.

    Science.gov (United States)

    Dutra, S M F; Von Pinho, E V R; Santos, H O; Lima, A C; Von Pinho, R G; Carvalho, M L M

    2015-01-01

    The identification of genes related to heat tolerance is fundamental for the development of high-quality seeds that are tolerant to heat stress condition. The objective of this study was to evaluate maize lineages and the gene expression involved in high temperature tolerance during germination using physiological tests, proteomics, and transcriptome analysis. Seeds from six maize lineages (30, 44, 54, 63, 64, and 91) with different levels of tolerance to high temperatures were used. Lineages 54 and 91 were observed to be more tolerant to high temperature conditions. The highest expression of α-amylase was observed in maize seeds from lineages 30 and 91 that were subjected to controlled deterioration. The highest expression of α-amylase was observed in maize seeds from lineages 30 and 91 that were subjected to controlled deterioration; with the controlled deterioration, the highest level of gene expression did not occur in the most tolerant materials; the association of lower expression of genes involved in heat-resistant protein systems was observed in seeds from lineage 44, which were more susceptible to high temperatures, and the highest gene expression of LEA D-34, ZmAN13, and AOX-1 was observed in seeds from lineage 64 when submitted to controlled deterioration. PMID:26782452

  12. Extracellular Hemicellulolytic Enzymes from the Maize Endophyte Acremonium zeae

    Science.gov (United States)

    The maize endophyte Acremonium zeae was examined for production of extracellular enzymes that hydrolyze cellulose and hemicellulose. The most prominent enzyme activity in cell-free culture media from A. zeae NRRL 6415 was xylanase, with a specific activity of 60 U/mg from cultures grown on crude co...

  13. Biplot analysis of diallel crosses of NS maize inbred lines

    NARCIS (Netherlands)

    Bocanski, J.; Nastasic, A.; Stanisavljevic, D.; Sreckov, Z.; Mitrovic, B.; Treskic, S.; Vukosavljev, M.

    2011-01-01

    Bocanski J., A. Nastasic, D. Stanisavljevic, Z. Sreckov, B. Mitrovic, S. Treskic and M. Vukosavljev (2011): Biplot analysis of diallel crosses of NS maize inbred lines- Genetika, Vol 43, No. 2, 277 - 284. Genetic markers, from morphological to molecular, in function with early Heterosis is a prerequ

  14. Chemical characterization of Phoma pomorum isolated from Danish maize

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Aveskamp, M.M.; Thrane, Ulf;

    2010-01-01

    Strains of the genus Phoma are often isolated from various environmental samples including cereals and maize. In the present study we performed a chemical characterization of strains isolated from Danish samples derived from whole plant material collected at harvest. All strains were isolated using...

  15. The maize rachis affects Aspergillus flavus movement during ear development

    Science.gov (United States)

    Aspergillus flavus expressing green fluorescent protein (GFP) was used to follow infection in ears of maize hybrids resistant and susceptible to the fungus. Developing ears were needle-inoculated with GFP-transformed A. flavus 20 days after silk emergence, and GFP fluorescence in the pith was evalu...

  16. Changes in farmers' knowledge of maize diversity in highland Guatemala

    NARCIS (Netherlands)

    Etten, van J.

    2006-01-01

    Small-scale studies on long-term change in agricultural knowledge might uncover insights with broader, regional implications. This article evaluates change in farmer knowledge about crop genetic resources in highland Guatemala between 1927/37 and 2004. It concentrates on maize (Zea mays ssp. mays L.

  17. Technetium species induced in maize as measured by phosphorimager

    International Nuclear Information System (INIS)

    Leaves of plants have the ability to accumulate the long-lived fission product 99Tc. In the present work, an attempt was made to separate and characterize technetium species formed in maize grown on soil contaminated with TcVIIO4- solution. Data obtained from selective extraction, a Phosphorimager and liquid scintillation were employed

  18. Technetium species induced in maize as measured by phosphorimager

    Energy Technology Data Exchange (ETDEWEB)

    Simonoff, M. E-mail: simonoff@cenbg.in2p3.fr; Khijniak, T.V.; Sergeant, C.; Vesvres, M.H.; Pravikoff, M.S.; Leclerc-Cessac, E.; Echevarria, G.; Denys, S

    2003-07-01

    Leaves of plants have the ability to accumulate the long-lived fission product {sup 99}Tc. In the present work, an attempt was made to separate and characterize technetium species formed in maize grown on soil contaminated with Tc{sup VII}O{sub 4}{sup -} solution. Data obtained from selective extraction, a Phosphorimager and liquid scintillation were employed.

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

    NARCIS (Netherlands)

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

    2008-01-01

    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 funga

  20. Validation of Goudriaan's model: a case study for maize.

    NARCIS (Netherlands)

    Singh, R.S.; Jacobs, A.F.G.

    1995-01-01

    The crop microclimate model of Goudriaan was tested, using data collected in a maize field in the Netherlands during one day in summer 1986. Except for the soil heat flux, latent and sensible heat fluxes were simulated reasonably well. Goudriaan's model overestimated the latent and sensible heat flu

  1. Homogentisate solanesyl transferase (HST) cDNA’s in maize

    Science.gov (United States)

    Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This reaction ...

  2. Genetics and Biochemistry of Insect Resistance in Maize

    Science.gov (United States)

    Insects are a major concern for maize production worldwide. Host plant resistance to insects involves a number of chemical and biochemical factors that limit but rarely eliminate insect damage. Most chemical and many biochemical factors involved in resistance to insects are synthesized independent...

  3. Comparative genomics provides insight into maize adaptation in temperate regions.

    Science.gov (United States)

    Hufford, Matthew B

    2016-01-01

    A new study provides insights into the evolution of maize during its global spread into temperate regions from its origin in coastal Mexico.Please see related Research article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-1009-x. PMID:27411931

  4. Responses of young maize plants to root temperatures

    NARCIS (Netherlands)

    Grobbelaar, W.P.

    1963-01-01

    The effect of root temperatures on growth, water uptake and ion uptake of the maize single cross K 64r X E 184 has been studied during the early vegetative phase in culture solution in temperature-controlled rooms. A root temperature range of 5°-40°C with 5°C increments, a cons

  5. Gene regularity interactions at lateral organ buondaries in maize

    Science.gov (United States)

    Maize leaves have distinct tissues that serve specific purposes. The blade tilts back to photosynthesize and the sheath wraps around the stem to provide structural support and protect young leaves. At the junction between blade and sheath are the ligule and auricles, both of which are absent in the ...

  6. Screening Method for Transgenic Maize with Kanamycin Resistance

    Institute of Scientific and Technical Information of China (English)

    LU Meng-yu; DONG Fu-shuang; ZHANG Jun-min; WANG Hai-bo

    2011-01-01

    [Objective] The paper was to establish simple and effective method to screen marker gene in maize with kanamycin resistance.[Method] Using inbred line "Chang 7-2" and hybrid "Zhengdan 958" of maize as test materials,their seeds were soaked with different concentrations and volumes of kanamycin for 3 and 4 d,respectively,the rate of albino seedlings and average seedling height after sowing for 10 d were investigated.[Result] The rate of albino seedlings not only was related to kanamycin concentration,but also had relationship with solution volume during soaking process.The difference between inbred line and hybrid was no significant.When 100 ml of kanamycin solution with concentration of 200 mg/L was used to soak seeds for 3 d,the rate of albino seedlings basically could reach 100%.When 100 ml of kanamycin solution with concentration of 100 mg/L was used to soak 20 seeds for 3 d to carry out resistance screening,the accuracy was up to 84.8% after verifying the screening test of T1 transgenic maize plants.[Conclusion] The method was feasible,which could be used as a simple method for screening transgenic gene maize with kanamycin resistance.

  7. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize

    Directory of Open Access Journals (Sweden)

    Xiaolin eWu

    2015-01-01

    Full Text Available ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5, deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs, late embryogenesis abundant (LEA proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation.

  8. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize.

    Science.gov (United States)

    Wu, Xiaolin; Gong, Fangping; Yang, Le; Hu, Xiuli; Tai, Fuju; Wang, Wei

    2014-01-01

    ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5), deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs), late embryogenesis abundant (LEA) proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation. PMID:25653661

  9. Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.).

    Science.gov (United States)

    Savy, Davide; Cozzolino, Vincenza; Vinci, Giovanni; Nebbioso, Antonio; Piccolo, Alessandro

    2015-11-05

    The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM) was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by (31)P-NMR and (13)C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries.

  10. Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.).

    Science.gov (United States)

    Savy, Davide; Cozzolino, Vincenza; Vinci, Giovanni; Nebbioso, Antonio; Piccolo, Alessandro

    2015-01-01

    The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM) was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by (31)P-NMR and (13)C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries. PMID:26556330

  11. Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.

    Directory of Open Access Journals (Sweden)

    Davide Savy

    2015-11-01

    Full Text Available The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by 31P-NMR and 13C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries.

  12. Protective effects of selenium and vitamin E on rats consuming maize naturally contaminated with mycotoxins

    Institute of Scientific and Technical Information of China (English)

    Jie YU; Daiwen CHEN; Bing YU

    2009-01-01

    Protective effects of antioxidant additives of selenium and vitamin E on rats that consumed maize naturally contaminated with mycotoxins were explored in this paper. Thirty-two Wistar female rats were randomly divided into four groups. The control group was given the basic diet with normal maize. The contaminated maize group was given the diet in which normal maize was replaced by mycotoxin-contaminated maize. The selenium group and vitamin E group were respectively fed mycotoxin-contaminated diet supplemented with 0.4 mg.kg1 selenium weeks. Compared with the control group, antioxidative status was decreased significantly in the contaminated maize group. However, the status in the selenium group and vitamin E group was increased significantly compared with the contaminated maize group. The activities of enzymes related to liver function were significantly higher in the contaminated maize group than those in the control group, whereas they were significantly lower in the selenium group and/or the vitamin E group compared to the contaminated maize group. It is concluded that selenium and vitamin E were able to alleviate oxidative stress and liver function damage due to the consumption of maize naturally contaminated with mycotoxins.

  13. Choosing a genome browser for a Model Organism Database: surveying the maize community.

    Science.gov (United States)

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

    2010-01-01

    As the B73 maize genome sequencing project neared completion, MaizeGDB began to integrate a graphical genome browser with its existing web interface and database. To ensure that maize researchers would optimally benefit from the potential addition of a genome browser to the existing MaizeGDB resource, personnel at MaizeGDB surveyed researchers' needs. Collected data indicate that existing genome browsers for maize were inadequate and suggest implementation of a browser with quick interface and intuitive tools would meet most researchers' needs. Here, we document the survey's outcomes, review functionalities of available genome browser software platforms and offer our rationale for choosing the GBrowse software suite for MaizeGDB. Because the genome as represented within the MaizeGDB Genome Browser is tied to detailed phenotypic data, molecular marker information, available stocks, etc., the MaizeGDB Genome Browser represents a novel mechanism by which the researchers can leverage maize sequence information toward crop improvement directly. Database URL: http://gbrowse.maizegdb.org/

  14. Making better maize plants for sustainable grain production in a changing climate

    Directory of Open Access Journals (Sweden)

    Fangping eGong

    2015-10-01

    Full Text Available Achieving grain supply security with limited arable land is a major challenge in the 21st century, owing to the changing climate and increasing global population. Maize plays an increasingly vital role in global grain production. As a C4 plant, maize has a high yield potential. Maize is predicted to become the number one cereal in the world by 2020. However, maize production has plateaued in many countries, and hybrid and production technologies have been fully exploited. Thus, there is an urgent need to shape maize traits and architectures for increased stress tolerance and higher yield in a changing climate. Recent achievements in genomics, proteomics and metabolomics have provided an unprecedented opportunity to make better maize. In this paper, we discuss the current challenges and potential of maize production, particularly in China. We also highlight the need for enhancing maize tolerance to drought and heat waves, summarize the elite shoot and root traits and phenotypes, and propose an ideotype for sustainable maize production in a changing climate. This will facilitate targeted maize improvement through a conventional breeding program combined with molecular techniques.

  15. Association and linkage analysis of aluminum tolerance genes in maize.

    Directory of Open Access Journals (Sweden)

    Allison M Krill

    Full Text Available BACKGROUND: Aluminum (Al toxicity is a major worldwide constraint to crop productivity on acidic soils. Al becomes soluble at low pH, inhibiting root growth and severely reducing yields. Maize is an important staple food and commodity crop in acidic soil regions, especially in South America and Africa where these soils are very common. Al exclusion and intracellular tolerance have been suggested as two important mechanisms for Al tolerance in maize, but little is known about the underlying genetics. METHODOLOGY: An association panel of 282 diverse maize inbred lines and three F2 linkage populations with approximately 200 individuals each were used to study genetic variation in this complex trait. Al tolerance was measured as net root growth in nutrient solution under Al stress, which exhibited a wide range of variation between lines. Comparative and physiological genomics-based approaches were used to select 21 candidate genes for evaluation by association analysis. CONCLUSIONS: Six candidate genes had significant results from association analysis, but only four were confirmed by linkage analysis as putatively contributing to Al tolerance: Zea mays AltSB like (ZmASL, Zea mays aluminum-activated malate transporter2 (ALMT2, S-adenosyl-L-homocysteinase (SAHH, and Malic Enzyme (ME. These four candidate genes are high priority subjects for follow-up biochemical and physiological studies on the mechanisms of Al tolerance in maize. Immediately, elite haplotype-specific molecular markers can be developed for these four genes and used for efficient marker-assisted selection of superior alleles in Al tolerance maize breeding programs.

  16. THE QUALITY OF MAIZE SILAGES FROM WEST REGION OF SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Miroslav Juráček

    2012-12-01

    Full Text Available The aim of this work was to determine the quality of maize silages from Western Slovak Region analyzed in 2009 and 2010 on the Department of animal nutrition, Faculty of agrobiology and food resources, Slovak university of agriculture in Nitra, Slovakia. Maize silages were evaluated on the base of nutritional value, the result of fermentation process and silage quality according to Regulation of the Government of Slovak Republic no. 439/2006, appendix no.7, part C – Silage. We found in maize silages the average dry matter content 357.87 g.kg-1 (2009 and 340.00 g.kg-1 (2010 while only in 2010 samples had got 15.4 % of dry matter content below 300 g.kg-1. Content of crude fiber was lower than 260 g.kg-1 of dry matter in all samples. Higher content of acid detergent fiber and neutral detergent fiber had maize silages from 2010. The average value of net energy of lactation was 6.32 MJ.kg-1 of dry matter (2009 and 6.27 MJ.kg-1 of dry matter (2010. Only in one sample from 2010 we found a lower lactic acid content than 10 g.kg-1 of original matter. Content of acetic acid was lower in silages from 2009 (24.33 g.kg-1 of dry matter in comparison with silages from 2010 (28.92 g.kg-1 of dry matter. Undesirable butyric acid was not found in maize silages. The value of pH fluctuated from 3.52 to 3.80 (2009 and from 3.58 to 4.14 (2010. Only 17 % of evaluated samples satisfied the criteria for silage of I. class in 2009 and 23 % in 2010 mainly because of the higher acetic acid content.

  17. Status of Maize Technologies Adoption in Kisii Highlands of Kenya

    International Nuclear Information System (INIS)

    Maize is an important crop for the majority of the Kenyan population and is grown both in the low and high potential areas. It is grown by more than 90% of the smallholder farm families and is estimated to contribute more than 20% of the total agricultural production. Average maize yield in southwest Kenya is 2.5 t ha-1 which is far below the research achieved yields of 8 t ha-1. Farmers in the region have continued to grow maize under poor husbandry practices, minimal application of inputs and poor management. Formal and informal surveys were used for data gathering. The multi-stage sampling technique was used to sample survey units in Agroecological upper midland (UM1) and lower highland (LH1) both in the high potential areas of the region. Selected farmers were stratified according to resource base, sex of household head and the AEZ. Results indicated that components of maize technology package (varieties, inorganic fertilizers, pests/diseases, seedbed preparation and weed control) were at various stages of adoption. The most adopted components were use of improved hybrid seed, planting in rows and maintenance of recommended plant population. The most identified reason for non use of organic fertilizer was high cost. The limited use of inputs was aggravated by the liberalised state of inputs markets while the output market was imperfect and did not support the producer. Tough farmyard manure and compost are locally available alternatives, very few of the interviewed farmers used them. To further understand the adoption process, regression analysis of factors that influence the use of fertilizer on maize production was done. The results of the study will be used to improve and/or modify the existing technologies to conform to farmers' circumstances and needs as well as provide feedback to policy formulators

  18. Rhizosphere acidification of faba bean, soybean and maize

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, L.L. [College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant and Soil Interactions, Ministry of Education, Beijing, 100094 (China); Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100094 (China); Cao, J. [School of Life Science, Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000 (China); Zhang, F.S. [College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant and Soil Interactions, Ministry of Education, Beijing, 100094 (China); Li, L., E-mail: lilong@cau.edu.cn [College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant and Soil Interactions, Ministry of Education, Beijing, 100094 (China)

    2009-07-01

    Interspecific facilitation on phosphorus uptake was observed in faba bean/maize intercropping systems in previous studies. The mechanism behind this, however, remained unknown. Under nitrate supply, the difference in rhizosphere acidification potential was studied by directly measuring pH of the solution and by visualizing and quantifying proton efflux of roots between faba bean (Vicia faba L. cv. Lincan No.5), soybean (Glycine max L. cv. Zhonghuang No. 17) and maize (Zea mays L. cv. Zhongdan No.2) in monoculture and intercrop, supplied without or with 0.2 mmol L{sup -1} P as KH{sub 2}PO{sub 4}. The pH of the nutrient solution grown faba bean was lower than initial pH of 6.0 from day 1 to day 22 under P deficiency, whereas the pH of the solution with maize was declined from day 13 after treatment. Growing soybean increased solution pH irrespective of P supply. Under P deficiency, the proton efflux of faba bean both total (315.25 nmol h{sup -1} plant{sup -1}) and specific proton efflux (0.47 nmol h{sup -1} cm{sup -1}) was greater than that those of soybean (21.80 nmol h{sup -1} plant{sup -1} and 0.05 nmol h{sup -1} cm{sup -1}, respectively). Faba bean had much more ability of rhizosphere acidification than soybean and maize. The result can explain partly why faba bean utilizes sparingly soluble P more effectively than soybean and maize do, and has an important implication in understanding the mechanism behind interspecific facilitation on P uptake by intercropped species.

  19. Rhizosphere acidification of faba bean, soybean and maize

    International Nuclear Information System (INIS)

    Interspecific facilitation on phosphorus uptake was observed in faba bean/maize intercropping systems in previous studies. The mechanism behind this, however, remained unknown. Under nitrate supply, the difference in rhizosphere acidification potential was studied by directly measuring pH of the solution and by visualizing and quantifying proton efflux of roots between faba bean (Vicia faba L. cv. Lincan No.5), soybean (Glycine max L. cv. Zhonghuang No. 17) and maize (Zea mays L. cv. Zhongdan No.2) in monoculture and intercrop, supplied without or with 0.2 mmol L-1 P as KH2PO4. The pH of the nutrient solution grown faba bean was lower than initial pH of 6.0 from day 1 to day 22 under P deficiency, whereas the pH of the solution with maize was declined from day 13 after treatment. Growing soybean increased solution pH irrespective of P supply. Under P deficiency, the proton efflux of faba bean both total (315.25 nmol h-1 plant-1) and specific proton efflux (0.47 nmol h-1 cm-1) was greater than that those of soybean (21.80 nmol h-1 plant-1 and 0.05 nmol h-1 cm-1, respectively). Faba bean had much more ability of rhizosphere acidification than soybean and maize. The result can explain partly why faba bean utilizes sparingly soluble P more effectively than soybean and maize do, and has an important implication in understanding the mechanism behind interspecific facilitation on P uptake by intercropped species.

  20. INFLUENCE OF TREATMENT ON MAIZE SEED QUALITY

    Directory of Open Access Journals (Sweden)

    Ivica Beraković

    2012-12-01

    Full Text Available Due to the increasing occurrence of major pests ON corn, hybrid seed is necessary to be protected against pests and seed corn should be treated with appropriately insecticides. Choosing better technological solutions and choosing and appropriate insecticide seed treatment for corn can significantly reduce pest attack and thus enhance the production of corn. The aim of this research was to obtain based upon result information on the impact of treatment on quality of maize seed as well as the means to improve the conditions of storage and preservation of semen quality. Investigation and checking if insecticide treated seed adverse phytotoxic effect on plant growth and development in field conditions. The results indicate a significant effect of insecticide seed treatments on germination energy and non standard germination. A very significant influence of treated seed storage was also found on quality seeds. Looking at the impact of the treated hybrid on germination vigor and standard germination, a very significant hybrid impact was found out. The highest quality of the seed semen during the study was noticed with the seed of hybrid “H2”, followed by hybrid “H1”, while the hybrids “H3” and “H4” possessed less. The research shows that hybrids “H2” and “H1” are more suitable for seed treatment with insecticides than “H3” and “H4” hybrids. The field observations and research results obtained indicate a very significant impact of the treated seed on the above ground parts of plants, above ground mass, stem thickness and a very significant impact on plant spacing. The positive effect of treatment with “T1” and “T3” insecticides is visible in all conducted field researches. Plants treated with common fungicides and insecticides “T1” and “T3” had a greater height of the above ground plant parts, a larger mass of the above ground stems, greater stem thickness and better plant density treatments, compared to

  1. Photosynthesis, productivity, and yield of maize are not affected by open-air elevation of CO2 concentration in the absence of drought.

    Science.gov (United States)

    Leakey, Andrew D B; Uribelarrea, Martin; Ainsworth, Elizabeth A; Naidu, Shawna L; Rogers, Alistair; Ort, Donald R; Long, Stephen P

    2006-02-01

    While increasing temperatures and altered soil moisture arising from climate change in the next 50 years are projected to decrease yield of food crops, elevated CO2 concentration ([CO2]) is predicted to enhance yield and offset these detrimental factors. However, C4 photosynthesis is usually saturated at current [CO2] and theoretically should not be stimulated under elevated [CO2]. Nevertheless, some controlled environment studies have reported direct stimulation of C4 photosynthesis and productivity, as well as physiological acclimation, under elevated [CO2]. To test if these effects occur in the open air and within the Corn Belt, maize (Zea mays) was grown in ambient [CO2] (376 micromol mol(-1)) and elevated [CO2] (550 micromol mol(-1)) using Free-Air Concentration Enrichment technology. The 2004 season had ideal growing conditions in which the crop did not experience water stress. In the absence of water stress, growth at elevated [CO2] did not stimulate photosynthesis, biomass, or yield. Nor was there any CO2 effect on the activity of key photosynthetic enzymes, or metabolic markers of carbon and nitrogen status. Stomatal conductance was lower (-34%) and soil moisture was higher (up to 31%), consistent with reduced crop water use. The results provide unique field evidence that photosynthesis and production of maize may be unaffected by rising [CO2] in the absence of drought. This suggests that rising [CO2] may not provide the full dividend to North American maize production anticipated in projections of future global food supply. PMID:16407441

  2. Effect of Terminalia catappa Fruit Meal Fermented by Aspergillus niger as Replacement of Maize on Growth Performance, Nutrient Digestibility, and Serum Biochemical Profile of Broiler Chickens

    Directory of Open Access Journals (Sweden)

    David Friday Apata

    2011-01-01

    Full Text Available A feeding experiment was conducted to investigate the effect of fermented Terminalia catappa fruit meal (FTCM with Aspergillus niger as replacement for maize on broiler growth performance, nutrient digestibility, and serum biochemical constituents. Dietary maize was replaced by FTCM at 0, 20, 40, 60, or 80%. One hundred and eighty one-day-old Shaver broiler chicks were randomly allocated to the five dietary treatments, three replicate groups of twelve chicks each for a 42-day period. There was no significant difference (>.05 in the feed intake, weight gain, and feed; gain ratio between the broilers fed on 40% FTCM diet and the control group. The apparent digestibilities of nitrogen, crude fibre, and fat decreased significantly in broilers fed higher levels (>40% of FTCM replacement diets compared with the control or lower FTCM diets. Serum concentrations of total protein, albumin, and globulin were decreased (.05 altered among treatments. The activities of aspartate and alanine aminotransferases and alkaline phosphatase were significantly (<.05 increased with higher FTCM replacement. The results indicate that FTCM could replace up to 40% of dietary maize in the diets of broiler chickens without adverse effect on growth performance or serum constituents.

  3. On-Farm Study on Intercropping of Hybrid Maize with Different Short Duration Vegetables in the Charland of Tangail

    Directory of Open Access Journals (Sweden)

    MA Rahaman, MM Rahman, S Roy, M Ahmed, MS Bhuyan

    2015-12-01

    Full Text Available An experiment was conducted in charland at the Multi Location Testing (MLT site Bhuapur, Tangail during 2012-13 and 2013-14 under AEZ-8 to find out the suitable intercropping system of hybrid maize with different short duration vegetables with economic return. The experiment was laid out in RCB design with six dispersed (six farmers’ field replications. The hybrid maize (ver. BARI Hybrid maize-7, potato (Diamant, spinach (local, red amaranth (BARI Lalsak-1, Radish (BARI Mula-1 were used as the planting materials. Five treatment combinations viz. T1= Sole Maize, T2= 100% Maize (maize paired row + Potato (var. Diamant, T3= 100% Maize (maize paired row + Spinach (var. local, T4= 100% Maize (maize paired row + Red amaranth (var. BARI Lalshak-1 and T5= 100% Maize (Maize paired row + Radish (var. BARI Mula-1 were studied. Maize grain yield in intercropped combination varied from 5.59-7.62 t ha-1. But the highest grain yield (8.17 t ha-1 was obtained from sole maize. Maize equivalent yields in the intercrops situation ranged from 11.39-19.68 t ha-1 where highest maize equivalent yield 19.68 t ha-1 was recorded from the treatment T3 (100 % maize + spinach. The same combinations also gave highest gross return (Tk. 373930 ha-1 and gross margin (Tk. 258585 ha-1 as well as benefit cost ratio (3.24. Though highest grain yield was recorded from sole maize but equivalent yield and economic return was much lower than the treatment T3.

  4. Applying CSM-CERES-Maize to define a sowing window for irrigated maize crop - The Riacho´s Farm case study

    Directory of Open Access Journals (Sweden)

    Denise Freitas Silva

    2011-08-01

    Full Text Available Irrigation use constitutes an alternative to improve maize production in Central Minas Gerais State, Brazil. However, even under adequate water supply conditions, other environmental factors may influence maize crop growth and development and may, ultimately, affect grain yield. This study aimed to establish a sowing window for irrigated maize crop, based on simulation results obtained with the decision support model CSM-CERES-Maize. Simulations were made for crop management conditions of Riacho´s Farm, located in Matozinhos, Minas Gerais State, Brazil. It was employed the model´s seasonal tool, along with a data set containing 46 years of weather data records, to simulate maize yield for weekly sowing scenarios, starting on August 1st and ending on July 24th of each year. One defined an irrigated maize sowing window, taking into account the yield break risk that a farmer would be willing to take. The model proved to be an interesting tool to assist in decision making, regarding crop and irrigation management, for an irrigated maize production system. Assuming a 10% yield break in the expected average maximum maize yield, it was defined as sowing window, the period from January 23rd to March 6th, with February 20th as the best sowing date. Other sowing windows may be established according to the risk that the farmer would be willing to take.

  5. Effects of water-extratable humic substances on molecular physiology of nitrate uptake in two maize inbred lines with different nitrogen use efficiency

    OpenAIRE

    Tomasi, Nicola; Monte, Rossella; Rizzardo, Cecilia; Venuti, Silvia; Zamboni, Anita; Cesco, Stefano; Pinton, Roberto; Varanini, Zeno

    2009-01-01

    Soil humic substances are known to positively influence plant growth and nutrition. In particular, low-molecular fractions have been shown to increase NO3- uptake and PM H+-ATPase activity and alter expression of related genes. In this work, a water-extractable low-molecular humic fraction (WEHS) has been tested for its ability to affect molecular physiology of nitrate uptake in two maize inbred lines with different NUE. WEHS causes an acceleration of the increase in net nitrate uptake rate i...

  6. Functional diversity of staphylinid beetles (Coleoptera: Staphylinidae) in maize fields: testing the possible effect of genetically modified, insect resistant maize.

    Science.gov (United States)

    Svobodová, Z; Skoková Habuštová, O; Boháč, J; Sehnal, F

    2016-08-01

    Staphylinid beetles are recommended bioindicators for the pre-market environmental risk assessment of genetically modified (GM) insect protected maize expressing the Cry3Bb1 toxin. Our multiannual study is a unique European analysis of a staphylinid community within a 14 ha maize field. GM maize, its near-isogenic hybrid (with or without insecticide treatment), and two other reference hybrids were each grown in five 0.5 ha plots. The opportunity for exposure to Cry toxin from plant residues ploughed into the soil was shown by the presence of saprophagous dipteran larvae that are common prey of predatory staphylinid species and hosts of the parasitoid species. 2587 individuals belonging to 77 staphylinid species were sampled using pitfall traps. Lesteva longoelytrata (31%), Oxypoda acuminata (12%), Aloconota sulcifrons (8%) and Anotylus rugosus (7%) were the most abundant beetles in the field. Bionomics, food specialization, temperature requirements and size group were assigned for 25 most common species. These traits determine the occurrence of staphylinid beetles in the field, the food sources they could utilize and thus also their likely contact with the Cry3Bb1 toxin. Statistical analysis of activity abundance, Rao indices and multivariate analysis of distribution of particular categories of functional traits in the field showed negligible effects of the experimental treatments, including the GM maize, upon the staphylinid community. Staphylinid beetles represent a considerably diverse part of epigeic field fauna with wide food specialization; these features render them suitable for the assessment of environmental safety of GM insect protected maize. However, the availability of prey and the presence of particular staphylinid species and their abundance are highly variable; this complicates the interpretation of the results.

  7. Functional diversity of staphylinid beetles (Coleoptera: Staphylinidae) in maize fields: testing the possible effect of genetically modified, insect resistant maize.

    Science.gov (United States)

    Svobodová, Z; Skoková Habuštová, O; Boháč, J; Sehnal, F

    2016-08-01

    Staphylinid beetles are recommended bioindicators for the pre-market environmental risk assessment of genetically modified (GM) insect protected maize expressing the Cry3Bb1 toxin. Our multiannual study is a unique European analysis of a staphylinid community within a 14 ha maize field. GM maize, its near-isogenic hybrid (with or without insecticide treatment), and two other reference hybrids were each grown in five 0.5 ha plots. The opportunity for exposure to Cry toxin from plant residues ploughed into the soil was shown by the presence of saprophagous dipteran larvae that are common prey of predatory staphylinid species and hosts of the parasitoid species. 2587 individuals belonging to 77 staphylinid species were sampled using pitfall traps. Lesteva longoelytrata (31%), Oxypoda acuminata (12%), Aloconota sulcifrons (8%) and Anotylus rugosus (7%) were the most abundant beetles in the field. Bionomics, food specialization, temperature requirements and size group were assigned for 25 most common species. These traits determine the occurrence of staphylinid beetles in the field, the food sources they could utilize and thus also their likely contact with the Cry3Bb1 toxin. Statistical analysis of activity abundance, Rao indices and multivariate analysis of distribution of particular categories of functional traits in the field showed negligible effects of the experimental treatments, including the GM maize, upon the staphylinid community. Staphylinid beetles represent a considerably diverse part of epigeic field fauna with wide food specialization; these features render them suitable for the assessment of environmental safety of GM insect protected maize. However, the availability of prey and the presence of particular staphylinid species and their abundance are highly variable; this complicates the interpretation of the results. PMID:26781035

  8. Development of cold and drought tolerant short-season maize germplasm for fuel and feed utilization

    Directory of Open Access Journals (Sweden)

    Marcelo J Carena

    2013-04-01

    Full Text Available Maize has become a profitable alternative for North Dakota (ND farmers and ranchers. However, U.S. northern industry hybrids still lack cold and drought stress tolerance as well as adequate grain quality for ethanol and feedstock products. Moreover, there is a need to increase the value of feedstock operations before and after ethanol utilization. The ND maize breeding program initiated the development of hybrids with high quality protein content through the Early Quality Protein Maize for Feedstock (EarlyQPMF project. The North Dakota State University (NDSU maize breeding program acts as a genetic provider to foundation seed companies, retailer seed companies, processing industry, and breeders nationally and internationally. In the past 10 years, NDSU was awarded 9 PVP maize certificates and released 38 maize products. Within those, 13 inbred lines were exclusively released to a foundation seed company for commercial purposes. In addition, 2 hybrids were identified for commercial production in central and western ND.

  9. Which factors support the occurrence of Chenopodium album in maize fields in Northern Germany?

    Directory of Open Access Journals (Sweden)

    von Redwitz, Christoph

    2014-02-01

    Full Text Available The area cultivated with maize in Germany is continuously increasing throughout the last years. Nevertheless weeds in maize get small notice, probably since they are still easy to control. If maize cropping frequency and intensity continue to increase, problems with adapted weeds are likely to occur. To face these effects, it is worthwhile to know more about the appearance of typical maize weeds. In 2011 and 2012 a weed survey took place in four regions of Northern Germany. Weed species were identified and counted on 169 fields cropped with maize. Data about management of these fields was collected. One of the most wide spread weeds was Chenopodium album, which can also cause high yield losses. With a generalized linear mixed model five parameters were identified which influence the emergence of C. album: precipitation, cropping maize in the previous year, fertilizing with manure, soil organic matter and plant available phosphorous.

  10. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize.

    Science.gov (United States)

    Asters, Matthew C; Williams, W Paul; Perkins, Andy D; Mylroie, J Erik; Windham, Gary L; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimized a pipeline of analysis tools chosen from various programs to provide rigorous statistical analysis and state of the art data visualization. A network-based method was also explored to construct the empirical gene expression relational structures. Maize genes at the centers in the network were considered as important candidate genes for maize DNA marker studies. The methods in this research can be used to analyze large RT-qPCR datasets and establish complex empirical gene relational structures across multiple experimental conditions. PMID:24770700

  11. Density Equation of Bio-Coal Briquettes and Quantity of Maize Cob in Phitsanulok, Thailand

    Directory of Open Access Journals (Sweden)

    Patomsok Wilaipon

    2008-01-01

    Full Text Available One of the most important crops in Phitsanulok, a province in Northern Thailand, is maize. Base on the calculation, the quantity of maize cob produced in this region was approximately 220 kton year-1. The net heating value of maize cob was found to be 14.2 MJ kg-1. Therefore, the total energy over 874 TJ year-1 can be obtained from this agricultural waste. In the experiments, maize cob was utilized as the major ingredient for producing biomass-coal briquettes. The maize cob was treated with sodium hydroxide solution before mixing with coal fine. The ratios of coal:maize were 1:2 and 1:3, respectively. The range of briquetting pressures was from 4-8 MPa. The result showed that the density was strongly affected by both parameters. Finally, the relationship between biomass ratio, briquetting pressures and briquette density was developed and validated by using regression technique.

  12. Lack of detectable allergenicity in genetically modified maize containing "Cry" proteins as compared to native maize based on in silico & in vitro analysis.

    Directory of Open Access Journals (Sweden)

    Chandni Mathur

    Full Text Available Genetically modified, (GM crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release.To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize.An integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE and Immunoblot using food sensitized patients sera (n = 39 to non GM and GM maize antigens was performed.In silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05 variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF.Cry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize.

  13. Maize peroxidase Px5 has a highly conserved sequence in inbreds resistant to mycotoxin producing fungi which enhances fungal and insect resistance.

    Science.gov (United States)

    Dowd, Patrick F; Johnson, Eric T

    2016-01-01

    Mycotoxin presence in maize causes health and economic issues for humans and animals. Although many studies have investigated expression differences of genes putatively governing resistance to producing fungi, few have confirmed a resistance role, or examined putative resistance gene structure in more than a couple of inbreds. The pericarp expression of maize Px5 has previously been associated with resistance to Aspergillus flavus growth and insects in a set of inbreds. Genes from 14 different inbreds that included ones with resistance and susceptibility to A. flavus, Fusarium proliferatum, F. verticillioides and F. graminearum and/or mycotoxin production were cloned using high fidelity enzymes, and sequenced. The sequence of Px5 from all resistant inbreds was identical, except for a single base change in two inbreds, only one of which affected the amino acid sequence. Conversely, the Px5 sequence from several susceptible inbreds had several base variations, some of which affected amino acid sequence that would potentially alter secondary structure, and thus enzyme function. The sequence of the maize peroxidase Px5 common to inbreds resistant to mycotoxigenic fungi was overexpressed in maize callus. Callus transformants overexpressing the gene caused significant reductions in growth for fall armyworms, corn earworms, and F. graminearum compared to transformant callus with a β-glucuronidase gene. This study demonstrates rarer transcripts of potential resistance genes overlooked by expression screens can be identified by sequence comparisons. A role in pest resistance can be verified by callus expression of the candidate genes, which can thereby justify larger scale transformation and regeneration of transgenic plants expressing the resistance gene for further evaluation. PMID:26659597

  14. PROFITABILITY AND MARKETING EFFICIENCY OF MAIZE IN KWANDE LOCAL GOVERNMENT AREA OF BENUE STATE, NIGERIA

    OpenAIRE

    Zacharias Ternenge Nyiatagher; Ali Ocholi

    2015-01-01

    The paper presents profi tability and marketing effi - ciency of maize in Kwande Local Government Area of Benue State, Nigeria. Stratifi ed random sampling was used to select three hundred (300) maize marketers comprising producers (210), wholesalers (32) and retailers (58) in eight (8) major markets in the study area. Primary data were collected using structured questionnaires. Data were analyzed using descriptive statistics, marketing margin and marketing effi ciency. It was found that maiz...

  15. Analysis of aflatoxins B1 and G1 in maize by quechers

    OpenAIRE

    Bursić Vojislava P.; Vuković Gorica Lj.; Jajić Igor M.; Lazić Sanja D.; Kara Magdalena H.; Čolović Radmilo R.; Vukmirović Đuro M.

    2013-01-01

    A reliable and easy method has been developed for the determination of aflatoxins B1 and G2 in maize samples. High performance liquid chromatography coupled with FLD (HPLC-FLD) with photochemical derivatization was used. Mycotoxins were extracted from maize using a QuEChERS-based extraction procedure. The optimized analytical conditions were evaluated in terms of recoveries, reproducibility, LOD, LOQ and linearity for aflatoxin B1 and aflatoxin G1 in maize. Extraction, chromatographic a...

  16. Panzea: a database and resource for molecular and functional diversity in the maize genome

    OpenAIRE

    Zhao, Wei; Canaran, Payan; Jurkuta, Rebecca; Fulton, Theresa; Glaubitz, Jeffrey; Buckler, Edward; Doebley, John; Gaut, Brandon; Goodman, Major; Holland, Jim; Kresovich, Stephen; McMullen, Michael; Stein, Lincoln; Ware, Doreen

    2005-01-01

    Serving as a community resource, Panzea () is the bioinformatics arm of the Molecular and Functional Diversity in the Maize Genome project. Maize, a classical model for genetic studies, is an important crop species and also the most diverse crop species known. On average, two randomly chosen maize lines have one single-nucleotide polymorphism every ∼100 bp; this divergence is roughly equivalent to the differences between humans and chimpanzees. This exceptional genotypic diversity underlies t...

  17. Effect of particle size and microbial phytase on phytate degradation in incubated maize and soybean meal

    DEFF Research Database (Denmark)

    Ton Nu, Mai Anh; Blaabjerg, Karoline; Poulsen, Hanne Damgaard

    2014-01-01

    The objective of the study was to evaluate the effect of screen size (1, 2 and 3 mm) and microbial phytase (0 and 1000 FTU/kg as-fed) on phytate degradation in maize (100% maize), soybean meal (100% SBM) and maize–SBM (75% maize and 25% SBM) incubated in water for 0, 2, 4, 8 and 24 h at 38°C...

  18. Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize

    OpenAIRE

    Degani, Ofir; Drori, Ran; Goldblat, Yuval

    2014-01-01

    Late wilt, a severe vascular disease of maize caused by the fungus Harpophora maydis, is characterized by rapid wilting of maize plants before tasseling and until shortly before maturity. The pathogen is currently controlled by resistant maize cultivars, but the disease is constantly spreading to new areas. The plant’s late phenological stage at which the disease appears suggests that plant hormones may be involved in the pathogenesis. This work revealed that plant growth hormones, auxin (Ind...

  19. Risk analysis of new maize technology in Zaire: a portfolio approach

    OpenAIRE

    Ames, Glenn C.W.; Donald W. Reid; Hsiou, Li-Fang

    1993-01-01

    Risk associated with the adoption of new maize technology and the impact of mandatory cotton production on traditional farmers in the Kasai Oriental Region of Zaire are evaluated within a portfolio context using a quadratic programming model. Seasonal net returns for farm plans including four levels of maize technology in combination with staple food crops are evaluated, with and without mandatory cotton production. The results indicate that cropping systems that include new maize technology ...

  20. Adverse effects of lindane in a maize agro-ecosystem in Uganda

    International Nuclear Information System (INIS)

    The impact of lindane, at commercial rates of application, on invertebrate fauna, soil microbial activity, earthworm populations, crop damage and yields in a maize agro-ecosystem was studied and compared with unsprayed control plots of maize using a pitfall trap, D-Vac suction, litter bag, the earthworm formalin expulsion and crop assessment methods. The findings of the study generally portrayed lindane as having very few effects on the maize agro-ecosystem. (author). 5 refs, 9 tabs

  1. QTL Mapping of Low-Temperature Germination Ability in the Maize IBM Syn4 RIL Population

    OpenAIRE

    Hu, Shuaidong; Lübberstedt, Thomas; Zhao, Guangwu; Lee, Michael

    2016-01-01

    Low temperature is the primary factor to affect maize sowing in early spring. It is, therefore, vital for maize breeding programs to improve tolerance to low temperatures at seed germination stage. However, little is known about maize QTL involved in low-temperature germination ability. 243 lines of the intermated B73×Mo17 (IBM) Syn4 recombinant inbred line (RIL) population was used for QTL analysis of low-temperature germination ability. There were significant differences in germination-rela...

  2. MicroRNA Transcriptomic Analysis of Heterosis during Maize Seed Germination

    OpenAIRE

    Ding, Dong; Wang, Yinju; Han, Mingshui; Fu, Zhiyuan; Li, Weihua; Liu, Zonghua; Hu, Yanmin; Tang, Jihua

    2012-01-01

    Heterosis has been utilized widely in the breeding of maize and other crops, and plays an important role in increasing yield, improving quality and enhancing stresses resistance, but the molecular mechanism responsible for heterosis is far from clear. To illustrate whether miRNA-dependent gene regulation is responsible for heterosis during maize germination, a deep-sequencing technique was applied to germinating embryos of a maize hybrid, Yuyu22, which is cultivated widely in China and its pa...

  3. Termoresistant and germination of maize hybrids seed depending on the mode their drying

    OpenAIRE

    Кирпа, М. Я.; Стюрко, М. О.

    2014-01-01

    Heat (thermal) drying of maize seed is the most important operation in the process of post-harvest working. Typical drying mode is set on the basis of model calculations, namely static and dynamic characteristics of the thermal stability of maize seed and condition constant parameters of the drying process and it does not reflect the practical parameters in chamber dryer corn.Purpose. Determine the thermal resistance of different maize hybrids; establish the effect of drying regimes on the ge...

  4. Association mapping for cold tolerance in two large maize inbred panels

    OpenAIRE

    Revilla, Pedro; Rodríguez, Víctor Manuel; Ordás, Amando; Rincent, Renaud; Charcosset, Alain; Giauffret, Catherine; Melchinger, Albrecht E.; Schön, Chris-Carolin; Bauer, Eva; Altmann, Thomas; Brunel, Dominique; Moreno-González, Jesús; Campo, Laura; Ouzunova, Milena; Álvarez, Ángel

    2016-01-01

    Background Breeding for cold tolerance in maize promises to allow increasing growth area and production in temperate zones. The objective of this research was to conduct genome-wide association analyses (GWAS) in temperate maize inbred lines and to find strategies for pyramiding genes for cold tolerance. Two panels of 306 dent and 292 European flint maize inbred lines were evaluated per se and in testcrosses under cold and control conditions in a growth chamber. We recorded indirect measures ...

  5. RESEARCHES ON THE VEGETATION PERIOD OF SOME MAIZE HYBRIDS ASESSED BY THE NUMBER OF LEAVES

    Directory of Open Access Journals (Sweden)

    IVONA DAVID

    2013-12-01

    Full Text Available For to define more accurately the precocity group of some maize hybrids depending on vegetation conditions from maize growing area, different researches analyzed the number of leaves as invariable factor dependent on hybrid. In this writing we offer dates about number of leaves for ten maize hybrids cultivated in experimental field from Varieties Testing Centre, Targoviste. Differences between hybrids were clearly and for this reason we can classify these hybrids in two precocity groups (medium early or late.

  6. Ustilago maydis populations tracked maize through domestication and cultivation in the Americas

    OpenAIRE

    Munkacsi, Andrew B.; Stoxen, Sam; May, Georgiana

    2008-01-01

    The domestication of crops and the development of agricultural societies not only brought about major changes in human interactions with the environment but also in plants' interactions with the diseases that challenge them. We evaluated the impact of the domestication of maize from teosinte and the widespread cultivation of maize on the historical demography of Ustilago maydis, a fungal pathogen of maize. To determine the evolutionary response of the pathogen's populations, we obtained multi...

  7. Uptake, translocation, and toxicity of gold nanorods in maize

    Science.gov (United States)

    Moradi Shahmansouri, Nastaran

    Nanomaterials are widely used in many different products, such as electronics, cosmetics, industrial goods, biomedical uses, and other material applications. The heavy emission of nanomaterials into the environment has motived increasing concern regarding the effects on ecosystems, food chains, and, human health. Plants can tolerate a certain amount of natural nanomaterials, but large amounts of ENMs released from a variety of industries could be toxic to plants and possibly threaten the ecosystem. Employing phytoremediation as a contamination treatment method may show promise. However a pre-requisite to successful treatment is a better understanding of the behavior and effects of nanomaterials within plant systems. This study is designed to investigate the uptake, translocation, bioavailability, and toxicity of gold nanorods in maize plants. Maize is an important food and feed crop that can be used to understand the potential hazardous effects of nanoparticle uptake and distribution in the food chain. The findings could be an important contribution to the fields of phytoremediation, agri-nanotechnology, and nanoparticle toxicity on plants. In the first experiment, hydroponically grown maize seedlings were exposed to similar doses of commercial non-coated gold nanorods in three sizes, 10x34 nm, 20x75 nm, and 40x96 nm. The three nanorod species were suspended in solutions at concentrations of 350 mg/l, 5.8 mg/l, and 14 mg/l, respectively. Maize plants were exposed to all three solutions resulting in considerably lower transpiration and wet biomass than control plants. Likewise, dry biomass was reduced, but the effect is less pronounced than that of transpiration and wet biomass. The reduced transpiration and water content, which eventually proved fatal to exposed plants, were most likely a result of toxic effect of gold nanorod, which appeared to physically hinder the root system. TEM images proved that maize plants can uptake gold particles and accumulate them in

  8. Effects of Different Cropping Patterns of Soybean and Maize Seedlings on Soil Enzyme Activities and MBC and MBN

    Institute of Scientific and Technical Information of China (English)

    Yan Mu-chun; Xu Ting-ting; Song Peng-hui; Dai Jian-jun

    2012-01-01

    Through the pot experiment, the effects of different cropping patterns of soybean and maize seedlings on rhizosphere soil urease, catalase, polyphenol oxidase and invertase activities and microbial biomass carbon (MBC) and nitrogen (MBN) were studied. Six treatments of soybean-soybean, soybean-maize, soybean-mixed, maize-soybean, maize-maize and maize-mixed were conducted in pots. Results showed that catalase activity and invertase activity of maize-maize were the highest and significantly different from those of the other treatments except maize-soybean; soil polyphenol oxidase activity of soybean-maize was the highest, and reached significant level among the other treatments, but there was no significant difference of urease activity among treatment soils; MBC of maize-maize soil and MBN of maize-mixed soil reached the highest and significant levels compared with other treatments; MBC and C/N ratio had positive and very significant correlations with soil catalase activity and invertase activity, respectively. Therefore, different cropping patterns could affect rhizosphere soil enzyme activities and soil MBC and MBN, which influenced soil carbon and nitrogen mineralization.

  9. Research and Development of Statistical Analysis Software System of Maize Seedling Experiment

    Directory of Open Access Journals (Sweden)

    Hui Cao

    2014-03-01

    Full Text Available In this study, software engineer measures were used to develop a set of software system for maize seedling experiments statistics and analysis works. During development works, B/S structure software design method was used and a set of statistics indicators for maize seedling evaluation were established. The experiments results indicated that this set of software system could finish quality statistics and analysis for maize seedling very well. The development of this software system explored a new method for screening of maize seedlings.

  10. Influence of Water Stress on Endogenous Hormone Contents and Cell Damage of Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    Chunrong Wang; Aifang Yang; Haiying Yin; Juren Zhang

    2008-01-01

    Phytohormones play critical roles In regulating plant responses to stress. We Investigated the effects of water stress Induced by adding 12% (w/v) polyethylene glycol to the root medium on the levels of abscisic acid (ABA), indole-3-acid (IAA), zeatin (ZT), and gibberellin3 (GA3) in maize leaves. The results suggested that water stress had significant effects on the four hormone levels. There was a transient increase in the IAA content during the initial stage of adaptation to water stress in maize leaves, but it dropped sharply thereafter in response to water stress. ABA content increased dramatically in maize leaves after 24 h of exposure to water stress, and then the high levels of ABA were maintained to the end, The contents Of ZT and GA3 rapidly declined in maize leaves subjected to water stress. The effects of water stress on chlorophyll content, electrolyte leakage and malondialdehyde levels in maize leaves were also studied. The variation of cell damage was negatively correlated with ZT and GA3 levels in maize leaves under water stress. Thus, we explored the roles of ZT and GA3 on the growth of maize seedlings under water stress by exogenous application. It is possible that both ZT and GA3 were effective in protecting maize seedlings from water stress, which would be of great importance for the improvement of drought tolerance in maize by genetic manipulation.

  11. Maize Residue as a Viable Substrate for Farm Scale Cultivation of Oyster Mushroom (Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Abena O. Adjapong

    2015-01-01

    Full Text Available In the search for alternatives to sawdust as growing media in commercial mushroom cultivation, three organic substrates obtainable as crop residue, maize husk, maize cob, and maize stalk, with each being supplemented with rice bran, were evaluated as growth media for the oyster mushroom, Pleurotus ostreatus (Kummer. For the tested alternatives to sawdust, the harvested weight of fruiting bodies that sprouted on a kilogram maize husk media per crop (32.99 g was the highest. Sawdust media supported significantly (P<0.001 heavier fruiting bodies (42.18 than the maize residues. The peak mushroom harvests for the various substrates were obtained between the first and seventh fruiting body flushes. The biological efficiency of the substrates, which measured usable nutrients indicated that maize stalk supplemented with rice bran, was 39% compared to that of the sawdust media (60%. The maize husk media and the maize cob media had biological efficiencies of 32% and 9.5%, respectively. These results indicate that two of the tested growing media (maize stalk or husk produced mushrooms with yield characteristics that were comparable to the well-used sawdust in the cultivation of oyster mushrooms. The environmental and economic parameters involved in the use and carting of sawdust make these on-farm crop residues a viable alternative for mushroom cultivation in especially nonforest zones of Ghana.

  12. Dynamics in the microbiology of maize silage during whole-season storage

    DEFF Research Database (Denmark)

    Storm, Ida Marie Lindhardt Drejer; Kristensen, N.B.; Raun, B.M.L.;

    2010-01-01

    Aims: To monitor seasonal variations in the microbiology of maize silage and to determine whether the risk of fungal spoilage varies during whole-year storage. Methods and Results: A continuous survey of 20 maize silage stacks was conducted over a period from three to 11 months after ensiling...... variations in the microbiology of maize silage over a whole storage season. The risk of fungal spoilage was highest 5-7 months after ensiling and lowest after 11 months. Significance and Impact of the Study: This information is valuable in the assessment of health risks connected with spoiled maize silage...

  13. Competitiveness, Profitability, Input Demand and Output Supply of Maize Production in Bangladesh

    Directory of Open Access Journals (Sweden)

    Sanzidur Rahman

    2016-05-01

    Full Text Available The study assesses international competitiveness, profitability, output supply and input demand of maize production using a farm survey data of 165 farmers from two major maize growing areas (i.e., Dinajpur and Lalmonirhat districts of northwestern Bangladesh. Results revealed that maize production is globally competitive and, therefore, can successfully substitute its import. Maize production is also profitable at the farm level (Benefit Cost Ratio = 1.21 with no adverse influence of farm size on yield and profitability. Maize farmers are also responsive to changes in market prices of inputs and outputs. A 1% increase in maize price will increase output supply by 0.4%. The most dominant driver of maize supply and other input demands is land. A 1% increase in available land will increase maize supply by a substantial 3.9%. In addition, landless laborers will benefit through an increase in hired labor demand when land area increases. Policy implications include investments in R&D, tenurial reform to consolidate land holding and smooth functioning of the hired labor market in order to increase maize production and profitability in Bangladesh.

  14. 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....... Two major diseases have been identified: Eyespot (Kabatiella zeae) and Northern leaf blotch (Exserohilum turcicum). Other diseases, including Southern maize leaf blight or maydis leaf blight, caused by Bipolaris maydis, and Northern corn leaf spot, caused by Bipolaris zeicola, may potentially play...

  15. Determination of carotenoids in yellow maize, the effects of saponification and food preparations.

    Science.gov (United States)

    Muzhingi, Tawanda; Yeum, Kyung-Jin; Russell, Robert M; Johnson, Elizabeth J; Qin, Jian; Tang, Guangwen

    2008-05-01

    Maize is an important staple food consumed by millions of people in many countries. Yellow maize naturally contains carotenoids which not only provide provitamin A carotenoids but also xanthophylls, which are known to be important for eye health. This study was aimed at 1) evaluating the effect of saponification during extraction of yellow maize carotenoids, 2) determining the major carotenoids in 36 genotypes of yellow maize by high-performance liquid chromatography with a C30 column, and 3) determining the effect of cooking on the carotenoid content of yellow maize. The major carotenoids in yellow maize were identified as all-trans lutein, cis-isomers of lutein, all-trans zeaxanthin, alpha- and beta-cryptoxanthin, all-trans beta-carotene, 9-cis beta-carotene, and 13-cis beta-carotene. Our results indicated that carotenoid extraction without saponification showed a significantly higher yield than that obtained using saponification. Results of the current study indicate that yellow maize is a good source of provitamin A carotenoids and xanthophylls. Cooking by boiling yellow maize at 100 degrees C for 30 minutes increased the carotenoid concentration, while baking at 450 degrees F for 25 minutes decreased the carotenoid concentrations by almost 70% as compared to the uncooked yellow maize flour.

  16. Pollination between maize and teosinte: an important determinant of gene flow in Mexico.

    Science.gov (United States)

    Baltazar, Baltazar M; de Jesús Sánchez-Gonzalez, José; de la Cruz-Larios, Lino; Schoper, John B

    2005-02-01

    Gene flow between maize [Zea mays (L.)] and its wild relatives does occur, but at very low frequencies. Experiments were undertaken in Tapachula, Nayarit, Mexico to investigate gene flow between a hybrid maize, landraces of maize and teosinte (Z. mays ssp. mexicana, races Chalco and Central Plateau). Hybridization, flowering synchrony, pollen size and longevity, silk elongation rates, silk and trichome lengths and tassel diameter and morphology were measured. Hybrid and open-pollinated maize ears produced a mean of 8 and 11 seeds per ear, respectively, when hand-pollinated with teosinte pollen, which is approximately 1-2% of the ovules normally produced on a hybrid maize ear. Teosinte ears produced a mean of 0.2-0.3 seeds per ear when pollinated with maize pollen, which is more than one-fold fewer seeds than produced on a maize ear pollinated with teosinte pollen. The pollination rate on a per plant basis was similar in the context of a maize plant with 400-500 seeds and a teosinte plant with 30-40 inflorescences and 9-12 fruitcases per inflorescence. A number of other factors also influenced gene-flow direction: (1) between 90% and 95% of the fruitcases produced on teosinte that was fertilized by maize pollen were sterile; (2) teosinte collections were made in an area where incompatibility systems that limit fertilization are present; (3) silk longevity was much shorter for teosinte than for maize (approx. 4 days vs. approx. 11 days); (4) teosinte produced more pollen on a per plant basis than the landraces and commercial hybrid maize; (5) teosinte frequently produced lateral branches with silks close to a terminal tassel producing pollen. Collectively these factors tend to favor crossing in the direction of teosinte to maize. Our results support the hypothesis that gene flow and the subsequent introgression of maize genes into teosinte populations most probably results from crosses where teosinte first pollinates maize. The resultant hybrids then backcross with

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

    OpenAIRE

    Subash Subedi

    2015-01-01

    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 bottle...

  18. Energy and economic potential of maize straw used for biofuels production

    Directory of Open Access Journals (Sweden)

    Zbytek Zbyszek

    2016-01-01

    Full Text Available The paper presents the energy and economic comparison of two technologies of maize straw utilization: solid biofuel production (briquettes and methane fermentation. The research experiments have shown that maize straw is the material which can be efficiently implemented in both technologies. Maize straw usage as briquettes can generate more energy (10.956 GJ Mg−1 than methane fermentation (9.74. In Europe, biogas is used in co-generation units for production of electric and heat energy. Due to higher price of electricity, economic profitability of maize straw usage for biogas production is over twice higher (182 USD than in case of briquettes production (96 USD.

  19. Study on the Photosynthetic Characteristics in Spring Maize (Zea mays L.)of Different Quality Type

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Photosynthetic characteristics were probed by sweet maize, waxy maize, high starch maize and common maize. The results revealed that leaf area index (LAI), chlorophyll a content, chlorophyll b content, photosynthetic rate(PR) showed single peak curve at the whole growth stage. The stages of peak were different according to different varieties. NEAUS4 had the lowest peak and while SIDAN 19 had the highest among all stages. Ratio of chlorophyll a to b was low at seedling stage, reached the peak at jointing stage and then declined. SIDAN 19 had the lower level at the last stages.

  20. Forecasting the market outlook for the South African maize and sorghum sector using econometric modeling

    OpenAIRE

    Poonyth, Daneswar; van Zyl, Johan; Meyer, Ferdinand H.

    2000-01-01

    In this study, an econometric model of the South African maize and sorghum sector is estimated. Using the developed model, a market outlook for the two major grain sectors – maize and sorghum - for 1999/00 to 2006/07, is generated under the specified assumptions. Results indicate that for both maize and sorghum, consumption will gradually increase over time. In spite of varying areas of maize and sorghum being harvested, total production will also gradually increase over time due to increas...

  1. Distribution of aflatoxins and fumonisins in dry-milled maize fractions

    OpenAIRE

    Pietri, Amedeo; Zanetti, Marco; Bertuzzi, Terenzio

    2009-01-01

    Abstract The aim of this study was to evaluate the distribution of aflatoxins and fumonisins in fractions derived from dry-milling processing of contaminated maize. Two maize lots with different contamination levels were processed and sampled: the first (maize 1) showed aflatoxin B1 (AFB1) and fumonisin B1 (FB1) levels of 3.6 and 5379 ?g kg-1, respectively; the second (maize 2) showed corresponding levels of 91.1 and 8841 ?g kg-1, respectively. The cleaning step reduced AFB1 and FB...

  2. Detection of genetically modified maize events in Brazilian maize-derived food products

    Directory of Open Access Journals (Sweden)

    Maria Regina Branquinho

    2013-09-01

    Full Text Available The Brazilian government has approved many transgenic maize lines for commercialization and has established a threshold of 1% for food labeling, which underscores need for monitoring programs. Thirty four samples including flours and different types of nacho chips were analyzed by conventional and real-time PCR in 2011 and 2012. The events MON810, Bt11, and TC1507 were detected in most of the samples, and NK603 was present only in the samples analyzed in 2012. The authorized lines GA21, T25, and the unauthorized Bt176 were not detected. All positive samples in the qualitative tests collected in 2011 showed a transgenic content higher than 1%, and none of them was correctly labeled. Regarding the samples collected in 2012, all positive samples were quantified higher than the threshold, and 47.0% were not correctly labeled. The overall results indicated that the major genetically modified organisms detected were MON810, TC1507, Bt11, and NK603 events. Some industries that had failed to label their products in 2011 started labeling them in 2012, demonstrating compliance with the current legislation observing the consumer rights. Although these results are encouraging, it has been clearly demonstrated the need for continuous monitoring programs to ensure consumers that food products are labeled properly.

  3. Molecular biology of maize Ac/Ds elements: an overview.

    Science.gov (United States)

    Lazarow, Katina; Doll, My-Linh; Kunze, Reinhard

    2013-01-01

    Maize Activator (Ac) is one of the prototype transposable elements of the hAT transposon superfamily, members of which were identified in plants, fungi, and animals. The autonomous Ac and nonautonomous Dissociation (Ds) elements are mobilized by the single transposase protein encoded by Ac. To date Ac/Ds transposons were shown to be functional in approximately 20 plant species and have become the most widely used transposable elements for gene tagging and functional genomics approaches in plants. In this chapter we review the biology, regulation, and transposition mechanism of Ac/Ds elements in maize and heterologous plants. We discuss the parameters that are known to influence the functionality and transposition efficiency of Ac/Ds transposons and need to be considered when designing Ac transposase expression constructs and Ds elements for application in heterologous plant species.

  4. 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...... production and in vitro cytotoxicity have been determined for fungal agar and silage extracts. All 8 fungal species significantly affected Caco-2 cell viability in the resazurin assay, with large variations for each species and growth medium. The 50% inhibition concentrations (IC50) of the major P....... 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...

  5. Screening of tropical maize for salt stress tolerance

    Directory of Open Access Journals (Sweden)

    Carlos Daniel Giaveno

    2007-01-01

    Full Text Available Since salinity is a common stress factor in agricultural areas, the objective of this study was to evaluate thefeasibility of morphological and physiological traits as selection criteria of maize genotypes under salt stress. The experimentswere carried out in the stages of germination and early seedling growth. Root and shoot weight, leaf area, root and leaf waterpotential, photochemical efficiency and growth rate were measured during salt stress and stress recovery. Our resultsindicated the presence of genetic variability for germination, but no association between germination and early seedlinggrowth under salt stress. Traits associated with seedling vigor, such as seedling weight and growth rate, and photochemicalefficiency under stress conditions can be used as selection criteria for salt-tolerant maize in breeding programs.

  6. Aflatoxins and ochratoxin A in maize of Punjab, Pakistan.

    Science.gov (United States)

    Iram, Wajiha; Anjum, Tehmina; Abbas, Mateen; Khan, Abdul Muqeet

    2014-01-01

    Aflatoxin and ochratoxin levels were determined in maize samples collected from store houses of 15 districts belonging to three agro-ecological zones of Punjab, Pakistan. Toxins were extracted by Aflaochra immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC). Mean moisture content of maize kernels was recorded above the safe storage level of 15%. Results indicated that aflatoxin B1 and B2 contamination was found in 97.3% and 78.9% of the collected samples, respectively. Aflatoxin G1, aflatoxin G2 and ochratoxin A were not detected in any sample. Among positive samples, 77.3% contained aflatoxin B1 and 28% aflatoxin B2, exceeding the legal limits as set by the European Union (EU) and the United States Food and Drug Administration (USFDA). It was concluded that a significant number of samples contained aflatoxin B1 and B2 above the legal limits.

  7. Using observed warming to identify hazards to Mozambique maize production

    Science.gov (United States)

    Funk, Christopher C.; Harrison, Laura; Eilerts, Gary

    2011-01-01

    New Perspectives on Crop Yield Constraints because of Climate Change. Climate change impact assessments usually focus on changes to precipitation because most global food production is from rainfed cropping systems; however, other aspects of climate change may affect crop growth and potential yields.A recent (2011) study by the University of California, Santa Barbara (UCSB) Climate Hazards Group, determined that climate change may be affecting Mozambique's primary food crop in a usually overlooked, but potentially significant way (Harrison and others, 2011). The study focused on the direct relation between maize crop development and growing season temperature. It determined that warming during the past three decades in Mozambique may be causing more frequent crop stress and yield reductions in that country's maize crop, independent of any changes occurring in rainfall. This report summarizes the findings and conclusions of that study.

  8. The maize cystatin CC9 interacts with apoplastic cysteine proteases.

    Science.gov (United States)

    van der Linde, Karina; Mueller, André N; Hemetsberger, Christoph; Kashani, Farnusch; van der Hoorn, Renier A L; Doehlemann, Gunther

    2012-11-01

    In a recent study we identified corn cystain9 (CC9) as a novel compatibility factor for the interaction of the biotrophic smut fungus Ustilago maydis with its host plant maize. CC9 is transcriptionally induced during the compatible interaction with U. maydis and localizes in the maize apoplast where it inhibits apoplastic papain-like cysteine proteases. The proteases are activated during incompatible interaction and salicylic acid (SA) treatment and, in turn, are sufficient to induce SA signaling including PR-gene expression. Therefore the inhibition of apoplastic papain-like cysteine proteases by CC9 is essential to suppress host immunity during U. maydis infection. Here were present new experimental data on the cysteine protease-cystatin interaction and provide an in silco analysis of plant cystatins and the identified apoplastic cysteine proteases.

  9. 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...... in the presence of H1 differed from that observed in the absence of H1. HMGA and the HMGB proteins bound H1-containing nucleosome particles with similar affinity. The plant HMG proteins could also bind nucleosomes that were briefly treated with trypsin (removing the N-terminal domains of the core histones......), suggesting that the histone N-termini are dispensable for HMG protein binding. In the presence of untreated nucleosomes and trypsinised nucleosomes, HMGB1 could be chemically crosslinked with a core histone, which indicates that the trypsin-resistant part of the histones within the nucleosome is the main...

  10. Temperatures and the growth and development of maize and rice

    DEFF Research Database (Denmark)

    Sánchez, Berta; Rasmussen, Anton; Porter, John Roy

    2014-01-01

    Because of global land surface warming, extreme temperature events are expected to occur more often and more intensely, affecting the growth and development of the major cereal crops in several ways, thus affecting the production component of food security. In this study, we have identified rice...... crops for the key physiological processes such as leaf initiation, shoot growth and root growth and for the most susceptible phenological phases such as sowing to emergence, anthesis and grain filling. Our summary shows that cardinal temperatures are conservative between studies and are seemingly well...... 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...

  11. Cytoplasm T-maize tissue culture to obtain methomyl resistance

    International Nuclear Information System (INIS)

    The calli of two cytoplasm T-maize hybrids were cultured in vitro with methomyl in the medium in order to obtain resistance. A mutagenic pretreatment was performed in one of the hybrids by injecting ethylmethane sulphonate (EMS) into the ear cob before fetilization. The atrophic tissue method was utilized to obtain totipotent callus. After treatment, coloured pericarp grains were observed in the regenerated plants. Different esterase electrophoretic patterns also appeared in one of them. In the methomyl resistance test, some nearly resistant (R-) and some less susceptible (S-) plants were detected within the same descendance (possibly due to mitochondrial variability). The interaction between mutagenic treatment with EMS and in vitro culture may be a suitable method for inducing changes of methomyl susceptibility in cms-T maize plants. (author)

  12. THE RADIO SENSITIZING EFFECT OF METRONIDAZOLE IN MAIZE

    Directory of Open Access Journals (Sweden)

    VICCINI LYDERSON FACIO

    1997-01-01

    Full Text Available The identification of chemical substances which increase the efficiency of radiation is important to make easier the obtention of plants with structural chromosome aberrations which may be used in an alternative program for hybrid maize production. The present work was carried out to investigate the effect of the chemical substance metronidazole in maize seedlings submitted to gamma radiation. Several treatments were done, soaking the seeds in solutions with varied concentrations of the active substance combined with solution filtration and gamma radiation. On the third day of the experiment, germination percentage, root and stem lengths were evaluated. At a high concentration (1,250 mg/50 mL metronidazole behaved as a radiosensibilizer in the presence of radiation. Even at a low concentration (250 mg/50 mL; 750 mg/50 mL and in the absence of radiation, metronidazole behaved as toxic substance.

  13. The developmental dynamics of the maize leaf transcriptome.

    Science.gov (United States)

    Li, Pinghua; Ponnala, Lalit; Gandotra, Neeru; Wang, Lin; Si, Yaqing; Tausta, S Lori; Kebrom, Tesfamichael H; Provart, Nicholas; Patel, Rohan; Myers, Christopher R; Reidel, Edwin J; Turgeon, Robert; Liu, Peng; Sun, Qi; Nelson, Timothy; Brutnell, Thomas P

    2010-12-01

    We have analyzed the maize leaf transcriptome using Illumina sequencing. We mapped more than 120 million reads to define gene structure and alternative splicing events and to quantify transcript abundance along a leaf developmental gradient and in mature bundle sheath and mesophyll cells. We detected differential mRNA processing events for most maize genes. We found that 64% and 21% of genes were differentially expressed along the developmental gradient and between bundle sheath and mesophyll cells, respectively. We implemented Gbrowse, an electronic fluorescent pictograph browser, and created a two-cell biochemical pathway viewer to visualize datasets. Cluster analysis of the data revealed a dynamic transcriptome, with transcripts for primary cell wall and basic cellular metabolism at the leaf base transitioning to transcripts for secondary cell wall biosynthesis and C(4) photosynthetic development toward the tip. This dataset will serve as the foundation for a systems biology approach to the understanding of photosynthetic development.

  14. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    Science.gov (United States)

    Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

    2016-08-01

    The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II.

  15. The comparative analysis based on maize integrated QTL map and meta-analysis of plant height QTLs

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; YAO Ji; ZHANG Zhengfeng; ZHENG Yonglian

    2006-01-01

    1201 published maize QTLs conferring for 68 traits were collected and imported into local CMap software to construct an integrated QTL map, which can be used for marker-mining, QTL localization, gene cloning and marker-assisted selection. The maize integrated QTL map showed that maize QTLs for various traits usually clustered in all chromosomes. 22 plant height QTLs of maize were co-linear with 64 plant height QTLs of rice, 43 grain yield QTLs of maize were co-liner with 7 grain yield QTLs of rice. 127 plant height QTLs of maize were refined by means of "overview" analysis. At last, 40 "real" QTLs were identifed. A substantial number of candidate quantitative trait genes for plant height of maize were found. These results established an important bioinformatics platform for extracting most of maize QTL information.

  16. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    Science.gov (United States)

    Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

    2016-08-01

    The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II. PMID:26919987

  17. Mechanical Behavior of Areca Fiber and Maize Powder Hybrid Composites

    OpenAIRE

    Kishan Naik; Swamy, R.P.

    2014-01-01

    Natural fibers are gaining the interest in packaging, domestic, low cost housing and other general applications. In this work the mechanical properties of randomly distributed areca fiber and maize powder reinforced phenol formaldehyde were studied. From the results Youngs modulus is maximum found in 300 ml of resin. The maximum tensile strength is for 300B composite plate. The maximum Young’s modulus for 300B is 135MPa, for bending strength of various composite plates, the co...

  18. FERMENTATION PROCESS CHARACTERISTICS OF DIFFERENT MAIZE SILAGE HYBRIDS

    Directory of Open Access Journals (Sweden)

    Daniel Bíro

    2009-03-01

    Full Text Available The aim of this study was to detect the fermentation process differences in different hybrid maize silage. We conserved in laboratory conditions hybrids of whole maize plants with different length of the vegetative period (FAO number. Maize hybrids for silage were harvested in the vegetation stage of the milk-wax maturity of corn and the content of dry matter was from 377.7 to 422.8 g.kg-1. The highest content of dry matter was typical for silages made from the hybrids with FAO number 310 (400.0 g.kg-1 and FAO 300a (400.4 g.kg-1. The content of desirable lactic acid ranged from 23.7 g.kg-1 of dry matter (FAO 350 to 58.9 g.kg-1 of dry matter (FAO 420. We detected the occurrence of undesirable butyric acid in silages from hybrids FAO 250, 300b, 310 and 380. The highest content of total alcohols we found in silages made from hybrid with FAO number 240 (25.2 g.kg-1 of dry matter. Ammonia contents were in tested silages from 0.153 (FAO 270 to 0.223 g.kg-1 of dry matter (FAO 240. The lowest value of silage titration acidity we analyzed in silage made from hybrid FAO 420 (3.66. We observed in maize silages with different length of plant maturity tested in the experiment differences in content of lactic acid, total alcohols, titration acidity, pH and content of fermentation products.

  19. Mapping RFLP Loci in Maize Using B-a Translocations

    OpenAIRE

    Weber, D.; Helentjaris, T

    1989-01-01

    Plants hypoploid for specific segments of each of the maize (Zea mays L.) chromosomes were generated using 24 different B-A translocations. Plants carrying each of the B-A translocations were crossed as male parents to inbreds, and sibling progeny hypoploid or not hypoploid for specific chromosomal segments were recovered. Genomic DNAs from the parents, hypoploid progeny, and nonhypoploid (euploid or hyperploid) progeny for each of these B-A translocations were digested with restriction enzym...

  20. 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 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...

  1. Characterization of a Novel Polerovirus Infecting Maize in China

    Directory of Open Access Journals (Sweden)

    Sha Chen

    2016-04-01

    Full Text Available A novel virus, tentatively named Maize Yellow Mosaic Virus (MaYMV, was identified from the field-grown maize plants showing yellow mosaic symptoms on the leaves collected from the Yunnan Province of China by the deep sequencing of small RNAs. The complete 5642 nucleotide (nt-long genome of the MaYMV shared the highest nucleotide sequence identity (73% to Maize Yellow Dwarf Virus-RMV. Sequence comparisons and phylogenetic analyses suggested that MaYMV represents a new member of the genus Polerovirus in the family Luteoviridae. Furthermore, the P0 protein encoded by MaYMV was demonstrated to inhibit both local and systemic RNA silencing by co-infiltration assays using transgenic Nicotiana benthamiana line 16c carrying the GFP reporter gene, which further supported the identification of a new polerovirus. The biologically-active cDNA clone of MaYMV was generated by inserting the full-length cDNA of MaYMV into the binary vector pCB301. RT-PCR and Northern blot analyses showed that this clone was systemically infectious upon agro-inoculation into N. benthamiana. Subsequently, 13 different isolates of MaYMV from field-grown maize plants in different geographical locations of Yunnan and Guizhou provinces of China were sequenced. Analyses of their molecular variation indicate that the 3′ half of P3–P5 read-through protein coding region was the most variable, whereas the coat protein- (CP- and movement protein- (MP-coding regions were the most conserved.

  2. Transcriptional analyses of natural leaf senescence in maize.

    Directory of Open Access Journals (Sweden)

    Wei Yang Zhang

    Full Text Available Leaf senescence is an important biological process that contributes to grain yield in crops. To study the molecular mechanisms underlying natural leaf senescence, we harvested three different developmental ear leaves of maize, mature leaves (ML, early senescent leaves (ESL, and later senescent leaves (LSL, and analyzed transcriptional changes using RNA-sequencing. Three sets of data, ESL vs. ML, LSL vs. ML, and LSL vs. ESL, were compared, respectively. In total, 4,552 genes were identified as differentially expressed. Functional classification placed these genes into 18 categories including protein metabolism, transporters, and signal transduction. At the early stage of leaf senescence, genes involved in aromatic amino acids (AAAs biosynthetic process and transport, cellular polysaccharide biosynthetic process, and the cell wall macromolecule catabolic process, were up-regulated. Whereas, genes involved in amino acid metabolism, transport, apoptosis, and response to stimulus were up-regulated at the late stage of leaf senescence. Further analyses reveals that the transport-related genes at the early stage of leaf senescence potentially take part in enzyme and amino acid transport and the genes upregulated at the late stage are involved in sugar transport, indicating nutrient recycling mainly takes place at the late stage of leaf senescence. Comparison between the data of natural leaf senescence in this study and previously reported data for Arabidopsis implies that the mechanisms of leaf senescence in maize are basically similar to those in Arabidopsis. A comparison of natural and induced leaf senescence in maize was performed. Athough many basic biological processes involved in senescence occur in both types of leaf senescence, 78.07% of differentially expressed genes in natural leaf senescence were not identifiable in induced leaf senescence, suggesting that differences in gene regulatory network may exist between these two leaf senescence

  3. Differential Role for Trehalose Metabolism in Salt-Stressed Maize

    OpenAIRE

    Henry, Clemence; Bledsoe, Samuel W.; Cara A Griffiths; Kollman, Alec; Paul, Matthew J.; Sakr, Soulaiman; Lagrimini, L. Mark

    2015-01-01

    Little is known about how salt impacts primary metabolic pathways of C-4 plants, particularly related to kernel development and seed set. Osmotic stress was applied to maize (Zea mays) B73 by irrigation with increasing concentrations of NaCl from the initiation of floral organs until 3 d after pollination. At silking, photosynthesis was reduced to only 2% of control plants. Salt treatment was found to reduce spikelet growth, silk growth, and kernel set. Osmotic stress resulted in higher conce...

  4. Characterization of a Maize Wip1 Promoter in Transgenic Plants

    Directory of Open Access Journals (Sweden)

    Shengxue Zhang

    2013-12-01

    Full Text Available The Maize Wip1 gene encodes a wound-induced Bowman-Birk inhibitor (BBI protein which is a type of serine protease inhibitor, and its expression is induced by wounding or infection, conferring resistance against pathogens and pests. In this study, the maize Wip1 promoter was isolated and its function was analyzed. Different truncated Wip1 promoters were fused upstream of the GUS reporter gene and transformed into Arabidopsis, tobacco and rice plants. We found that (1 several truncated maize Wip1 promoters led to strong GUS activities in both transgenic Arabidopsis and tobacco leaves, whereas low GUS activity was detected in transgenic rice leaves; (2 the Wip1 promoter was not wound-induced in transgenic tobacco leaves, but was induced by wounding in transgenic rice leaves; (3 the truncated Wip1 promoter had different activity in different organs of transgenic tobacco plants; (4 the transgenic plant leaves containing different truncated Wip1 promoters had low GUS transcripts, even though high GUS protein level and GUS activities were observed; (5 there was one transcription start site of Wip1 gene in maize and two transcription start sites of GUS in Wip1::GUS transgenic lines; (6 the adjacent 35S promoter which is present in the transformation vectors enhanced the activity of the truncated Wip1 promoters in transgenic tobacco leaves, but did not influence the disability of truncated Wip1231 promoter to respond to wounding signals. We speculate that an ACAAAA hexamer, several CAA trimers and several elements similar to ACAATTAC octamer in the 5'-untranslated region might contribute to the strong GUS activity in Wip1231 transgenic lines, meanwhile, compared to the 5'-untranslated region from Wip1231 transgenic lines, the additional upstream open reading frames (uORFs in the 5'-untranslated region from Wip1737 transgenic lines might contribute to the lower level of GUS transcript and GUS activity.

  5. Some mutants in maize obtained by irradiation with thermal neutrons

    International Nuclear Information System (INIS)

    Irradiation was carried out at the Bucharest Institute of Atomic Physics and the National Laboratory Brookhaven, USA. A description is given of 22 genic mutants affecting leaf color, plant size, and branching capacity. Characteristics related to pollen fertility and the vegetative period were affected in all the mutants. Improvement of pollen fertility was attempted over four generations without success. The maize mutants obtained by irradiation may be considered as being without practical significance. (author). 7 figs., 1 tab. 11 ref

  6. Maize cytokinin dehydrogenase isozymes are localized predominantly to the vacuoles.

    Science.gov (United States)

    Zalabák, David; Johnová, Patricie; Plíhal, Ondřej; Šenková, Karolina; Šamajová, Olga; Jiskrová, Eva; Novák, Ondřej; Jackson, David; Mohanty, Amitabh; Galuszka, Petr

    2016-07-01

    The maize genome encompasses 13 genes encoding for cytokinin dehydrogenase isozymes (CKXs). These enzymes are responsible for irreversible degradation of cytokinin plant hormones and thus, contribute regulating their levels. Here, we focus on the unique aspect of CKXs: their diverse subcellular distribution, important in regulating cytokinin homeostasis. Maize CKXs were tagged with green fluorescent protein (GFP) and transiently expressed in maize protoplasts. Most of the isoforms, namely ZmCKX1, ZmCKX2, ZmCKX4a, ZmCKX5, ZmCKX6, ZmCKX8, ZmCKX9, and ZmCKX12, were associated with endoplasmic reticulum (ER) several hours after transformation. GFP-fused CKXs were observed to accumulate in putative prevacuolar compartments. To gain more information about the spatiotemporal localization of the above isoforms, we prepared stable expression lines of all ZmCKX-GFP fusions in Arabidopsis thaliana Ler suspension culture. All the ER-associated isoforms except ZmCKX1 and ZmCKX9 were found to be targeted primarily to vacuoles, suggesting that ER-localization is a transition point in the intracellular secretory pathway and vacuoles serve as these isoforms' final destination. ZmCKX9 showed an ER-like localization pattern similar to those observed in the transient maize assay. Apoplastic localization of ZmCKX1 was further confirmed and ZmCKX10 showed cytosolic/nuclear localization due to the absence of the signal peptide sequence as previously reported. Additionally, we prepared GFP-fused N-terminal signal deletion mutants of ZmCKX2 and ZmCKX9 and clearly demonstrated that the localization pattern of these mutant forms was cytosolic/nuclear. This study provides the first complex model for spatiotemporal localization of the key enzymes of the cytokinin degradation/catabolism in monocotyledonous plants. PMID:27031423

  7. Maize nutrient uptake affected by genotype and fertilization

    Directory of Open Access Journals (Sweden)

    Đalović Ivica

    2015-01-01

    Full Text Available The content of nutrients in maize are commonly related with fertilization and soil quality and rarely explained with the individual hybrid properties. Therefore, the aim of this study is to access a long term fertilization system on ear leaf of Mg, Fe, Mn and Cu content in six maize hybrids(NS 3014, NS 4015, NS 5043, NS 6010, NS 6030 and NS 7020. Samples were collected from a long-term experiment at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad. The study included maize monoculture and 2-year rotations with the application of NPK and manure. Results showed that ear Mg content was influenced with the treatments, hybrid and their interaction and ranged from 1.77-2.69 g kg-1. Iron variability was significantly affected with the treatments and interaction (hybrid x treatments in range from 103.2 to151.9g kg-1. The ear manganese content (41.1-63.6g kg-1 derived from treatments and hybrid effect and Cu (12.3-23.6 g kg-1 was significantly influenced with treatments. Across all treatments, in average, NS6030 had higher values of nutrient and NS3014 was lower in ear nutrient content. This indicates that vegetation length could favor nutrient accumulation. Obtained results suggested that even on fairly productive soil such as Chernozem hybrid selection and the balanced fertilization is crucial for managing the maize nutrient content. [Projekat Ministarsva nauke Republike Srbije, br. TR031073

  8. Production of bio-gas from maize cobs

    Directory of Open Access Journals (Sweden)

    Luter Leke, Anne Ada Ogbanje, Dekaa Henry Terfa, Tyoalumun Ikyaagba

    2013-01-01

    Full Text Available Anaerobic digestion of energy crop residues and wastes is of increasing interest in order to reduce greenhouse gas emissions and to facilitate a sustainable development of energy supply. Production of biogas provides a versatile carrier of renewable energy, as methane can be used for replacement of fossil fuels in both heat and power generation as vehicle fuel. Biogas fuel production from blends of biological wastes such as Cow rumen liquor (CL, Poultry droppings (PD, and Goat Faeces (GF with Maize cobs (M were studied. 20 g of each inoculum was mixed with 100g of degraded maize cobs in the first three digesters while the fourth contained CL 10g, PD 10 g, and M 100 g. 100 g of M alone in the fifth digester served as the control. The blends were subjected to anaerobic digestion for 10 days on the prevailing atmospheric ambient temperature and pressure conditions. Physiochemical properties of the blends such as moisture content, crude protein, ash, fat, crude fibre, carbohydrate content, C/N ratio, and pH were also determined. Results of the daily performances of each system showed that maize cobs (M alone had cumulative biogas yield of 1.50 cm3 while those of the blends (MCL, MPD, MGF and MCLPD were 6.11 cm3, 3.05 cm3, 2.50 cm3, and 63.00 cm3 respectively, pH and C/N ratio affected the biogas yield of the systems significantly. These results indicate that the low biogas production from maize cobs can be enhanced significantly by blending with cow rumen liquor and poultry droppings.

  9. Production of bio-gas from maize cobs

    Energy Technology Data Exchange (ETDEWEB)

    Leke, Luter [College of Physical Sciences, University of Aberdeen, AB24 3UE, Aberdeen (United Kingdom); Department of Chemistry, Benue State University, P M B 102119, Makurdi (Nigeria); Ogbanje, Anne Ada [Department of Chemistry, Benue State University, P M B 102119, Makurdi (Nigeria); Department of Renewable Energy, Energy Commission of Nigeria, Garki-Abuja (Nigeria); Terfa, Dekaa Henry [Department of Chemistry, Benue State University, P M B 102119, Makurdi (Nigeria); Ikyaagba, Tyoalumun [College of Physical Sciences, University of Aberdeen, AB24 3UE, Aberdeen (United Kingdom)

    2013-07-01

    Anaerobic digestion of energy crop residues and wastes is of increasing interest in order to reduce greenhouse gas emissions and to facilitate a sustainable development of energy supply. Production of biogas provides a versatile carrier of renewable energy, as methane can be used for replacement of fossil fuels in both heat and power generation as vehicle fuel. Biogas fuel production from blends of biological wastes such as Cow rumen liquor (CL), Poultry droppings (PD), and Goat Faeces (GF) with Maize cobs (M) were studied. 20 g of each inoculum was mixed with 100g of degraded maize cobs in the first three digesters while the fourth contained CL 10g, PD 10 g, and M 100 g. 100 g of M alone in the fifth digester served as the control. The blends were subjected to anaerobic digestion for 10 days on the prevailing atmospheric ambient temperature and pressure conditions. Physiochemical properties of the blends such as moisture content, crude protein, ash, fat, crude fibre, carbohydrate content, C/N ratio, and pH were also determined. Results of the daily performances of each system showed that maize cobs (M) alone had cumulative biogas yield of 1.50 cm3 while those of the blends (MCL, MPD, MGF and MCLPD) were 6.11 cm3, 3.05 cm3, 2.50 cm3, and 63.00 cm3 respectively, pH and C/N ratio affected the biogas yield of the systems significantly. These results indicate that the low biogas production from maize cobs can be enhanced significantly by blending with cow rumen liquor and poultry droppings.

  10. Anaerobic digestion of maize hybrids for methane production

    OpenAIRE

    P. Vindis; B. Mursec; M. Janzekovic; D. Stajnko; F. Cus

    2010-01-01

    Purpose: This research project was aimed at optimising anaerobic digestion of maize and find out which maturity class of corn and which hybrid of a particular maturity class produces the highest rate of biogas and biomethane. Also the chemical composition of gases was studied.Design/methodology/approach: Biogas and biomethane production and composition in mesophilic (35 degrees C) conditions were measured and compared. The corn hybrids of FAO 300 - FAO 600 maturity class were tested. Experime...

  11. Dihydrodipicolinate synthase in opaque and floury maize mutants

    NARCIS (Netherlands)

    Varisi, V.A.; Medici, L.O.; Meer, van der I.M.; Lea, P.J.; Azevedo, J.L.

    2007-01-01

    Dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) was isolated and studied in four high-lysine maize mutants (Oh43o1, Oh43o2, Oh43fl1 and Oh43fl2). The activity of DHDPS was analyzed at 16, 20, and 24 DAP and characterized in the presence of the amino acids, lysine, S-(2-aminoethyl)-l-cysteine (AEC)

  12. Proteome balancing of the maize seed for higher nutritional value

    OpenAIRE

    Wu, Yongrui; Messing, Joachim

    2014-01-01

    Most flowering plant seeds are composed of the embryo and endosperm, which are surrounded by maternal tissue, in particular the seed coat. Whereas the embryo is the dormant progeny, the endosperm is a terminal organ for storage of sugars and amino acids in proteins and carbohydrates, respectively. Produced in maternal leaves during photosynthesis, sugars, and amino acids are transported to developing seeds after flowering, and during germination they nourish early seedlings growth. Maize endo...

  13. Effect of endosperm mutants on maize seed germination

    OpenAIRE

    Pajić Zorica; Đukanović Lana; Erić Uroš

    2004-01-01

    The expression of genetic potential of yielding and quality of a certain genotype depends among other factors on seed quality. Seed is very important not only for the reproduction of the particular plant species, but also, for the contemporary plant production. Each part of maize seed (pericarp endosperm and germ) has a specific function in the complex process of germination and emergence. The following three genotypes of different endosperm types were observed: ZPSC 42A (standard grain quali...

  14. Ideal seeds harvest moment of different maize hybrids

    OpenAIRE

    Elias Abrahão Jacob Junior; Liliane Marcia Mertz; Fernando Augusto Henning; Silmar Teichert Peske; Francisco Amaral Villela; Leopoldo Mario Baudet Labbé

    2014-01-01

    The aim of this study was to identify the ideal maize seed harvest moment by different characteristics, as black layer formation, milk line development, seed moisture content and seed dry matter accumulation. Three simple hybrids from Syngenta Company were used in this work; ears from plants in the same development stage were collected, the first harvesting began 40 days after flowering, at four days interval until all seeds in an ear had the black layer formation. The characteristics evaluat...

  15. Early carbon mobilization and radicle protrusion in maize germination

    OpenAIRE

    Sánchez-Linares, Luis; Gavilanes-Ruíz, Marina; Díaz-Pontones, David; Guzmán-Chávez, Fernando; Calzada-Alejo, Viridiana; Zurita-Villegas, Viridiana; Luna-Loaiza, Viridiana; Moreno-Sánchez, Rafael; Bernal-Lugo, Irma; Sánchez-Nieto, Sobeida

    2012-01-01

    Considerable amounts of information is available on the complex carbohydrates that are mobilized and utilized by the seed to support early seedling development. These events occur after radicle has protruded from the seed. However, scarce information is available on the role of the endogenous soluble carbohydrates from the embryo in the first hours of germination. The present work analysed how the soluble carbohydrate reserves in isolated maize embryos are mobilized during 6–24 h of water imb...

  16. Fusarium spp. on maize in Belgium, from biodiversity to biocontrol

    OpenAIRE

    Scauflaire, Jonathan; Lienard, Charlotte; Gourgue, Mélanie; Foucart, Guy; Mary, Michael; Renard, Fabien; Callebaut, Alfons; Legrève, Anne; Munaut, Françoise; EFS12

    2013-01-01

    Numerous Fusarium species are important mycotoxin-producing pathogens affecting maize in Belgium. Crop quality is often reduced by Fusarium rot diseases, and mycotoxin contaminations can pose a serious problem for animal health. As several of these mycotoxins are integrated into European legislation, field monitoring and accurate identification of the Fusarium species remain important tasks, allowing relevant preventive or curative measures. Impacts of environmental factors, cultural practice...

  17. The variations in maize grain composition induced by different environments

    OpenAIRE

    Dragičević Vesna D.; Mladenović-Drinić Snežana D.; Babić Vojka B.; Filipović Milomir R.; Čamdžija Zoran F.; Kovačević Dragan R.

    2014-01-01

    Nine maize hybrids were grown with the aim to determine variations in chemical composition of the grain. Analyzed hybrids were grown in split-plot experimental design with tree replications in Sremska Mitrovica and Zemun Polje, during the summer of 2010 and 2011. Grain yield, protein, starch, oil, as well as, antioxidants like phytate, soluble phenolics and free sulfhydryl groups (PSH) were analyzed. Unfavorable meteorological conditions affected not only g...

  18. Characterisation of the tryptophan synthase alpha subunit in maize

    Directory of Open Access Journals (Sweden)

    Gierl Alfons

    2008-04-01

    Full Text Available Abstract Background In bacteria, such as Salmonella typhimurium, tryptophan is synthesized from indole-3-glycerole phosphate (IGP by a tryptophan synthase αββα heterotetramer. Plants have evolved multiple α (TSA and β (TSB homologs, which have probably diverged in biological function and their ability of subunit interaction. There is some evidence for a tryptophan synthase (TS complex in Arabidopsis. On the other hand maize (Zea mays expresses the TSA-homologs BX1 and IGL that efficiently cleave IGP, independent of interaction with TSB. Results In order to clarify, how tryptophan is synthesized in maize, two TSA homologs, hitherto uncharacterized ZmTSA and ZmTSAlike, were functionally analyzed. ZmTSA is localized in plastids, the major site of tryptophan biosynthesis in plants. It catalyzes the tryptophan synthase α-reaction (cleavage of IGP, and forms a tryptophan synthase complex with ZmTSB1 in vitro. The catalytic efficiency of the α-reaction is strongly enhanced upon complex formation. A 160 kD tryptophan synthase complex was partially purified from maize leaves and ZmTSA was identified as native α-subunit of this complex by mass spectrometry. ZmTSAlike, for which no in vitro activity was detected, is localized in the cytosol. ZmTSAlike, BX1, and IGL were not detectable in the native tryptophan synthase complex in leaves. Conclusion It was demonstrated in vivo and in vitro that maize forms a tryptophan synthase complex and ZmTSA functions as α-subunit in this complex.

  19. Effects of land preparation and maize cultivar on efficiency of N-fertilizer in maize-mungbean intercrop using 15N

    International Nuclear Information System (INIS)

    A field experiment was conducted using 15N-labelled urea on a reddish brown lateritic (peleustult) soil. Growing two crops on flat land and on soil ridges of 15 cm height produced similar comparative effects from fertilizer on maize. However, fertilizer applied by broadcasting on maize with a 50 cm effective band followed by incorporating was more useful to mungbean than that applied by bandling below the cereal seed rows when crops were grown on flat land. The reverse was observed when crops were grown on ridges. It was deduced that the maize cultivar was not likely to affect comparative efficiencies of fertilizer. For fertilizer application at sowing, broadcasting in 50 cm maize effective band followed by incorporating was slightly superior to bandling below maize seed rows. Side-dressing of fertilizer to maize at 4 weeks after sowing was superior to application at sowing. Evenly split application, at sowing and at 4 weeks after sowing, was either only slightly superior or comparable to non-split application bandling below maize seed rows at sowing, depending on placement method of the first application. Soil moisture status as a possible factor rendering discrepancy in the comparative efficiencies obtained by different authors is discussed

  20. Analysis of DNA methylation in different maize tissues

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    DNA methylation plays an important role in gene expression regulation during biological development and tissue differentiation in plants. This study adopted methylation-sensitive Amplified fragment length polymorphism (AFLP) to compare the levels of DNA cytosine methylation at CCGG sites in tassel, bracteal leaf, and ear leaf from maize inbred lines, 18 White and 18 Red, respectively, and also examined specific methylation patterns of the three tissues. Significant differences in cytosine methylation level among the three tissues and the same changing tendency in two inbred lines were detected. Both MSAP (methylation sensitive amplification polymorphism) ratio and full methylation level were the highest in bracteal leaf, and the lowest in tassel. Meanwhile, different methylation levels were observed in the same tissue from the inbred lines, 18 White and 18 Red. Full methylation of internal cytosine was the dominant type in the maize genome. The differential methylation patterns in the three tissues were observed. In addition, sequencing of nine differentially methylated fragments and the subsequent blast search revealed that the cytosine methylated 5′-CCGG-3′ sequences were distributed in repeating sequences, in the coding and noncoding regions. Southern hybridization was used to verify the methylation polymorphism. These results clearly demonstrated the power of the MSAP technique for large-scale DNA methylation detection in the maize genome, and the complexity of DNA methylation change during plant growth and development. The different methylation levels may be related to specific gene expression in various tissues.

  1. Polyphenolic Profile of Maize Seedlings Treated with 24-Epibrassinolide

    Directory of Open Access Journals (Sweden)

    Hadi Waisi

    2015-01-01

    Full Text Available High-performance thin-layer chromatography (HPTLC combined with image analysis and pattern recognition methods were used for fingerprinting of phenolic compounds present in seedlings of two maize genotypes ZP 434 (new generation hybrid, drought tolerant and ZP 704 (older generation hybrid, drought sensitive treated with different concentrations of 24-epibrassinolide. This is the first report of TLC chromatographic profile of phenolics’ mixtures in maize seed extracts influenced by brassinosteroid phytohormones. Nine samples of shoot of seedlings for the whole concentration range of phytohormones (5.2 × 10−7–5.2 × 10−15 M, one sample of root of seedlings treated with 5.2 × 10−15 M 24-epibrassinolide, and the control samples of nontreated seedlings, for both genotypes, were analyzed. Phenolic profiles of root extracts indicate the absence of more polar compounds such as phenolic acids and glycosides present in shoot of seedlings. Also, hormones applied in higher concentrations have an inhibiting effect on the content of phenolics in ZP 434. Application of chemometric methods enables characterization of particular genotype of maize according to its phenolic profile.

  2. Intraplant communication in maize contributes to defense against insects.

    Science.gov (United States)

    Varsani, Suresh; Basu, Saumik; Williams, W Paul; Felton, Gary W; Luthe, Dawn S; Louis, Joe

    2016-08-01

    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. Furthermore, accumulation of Mir1-CP in the vasculature suggests that Mir1-CP can potentially function as a phloem-mobile protein. In a recent study, we provided evidence that Mir1-CP can curtail the growth of phloem-sap sucking insect, corn leaf aphid (CLA; Rhopalosiphum maidis). Our current study further examined whether aboveground feeding by CLA can induce resistance to subsequent herbivory by belowground feeding western corn rootworm (WCR; Diabrotica virgifera virgifera). Aboveground feeding by CLA systemically induced the accumulation of Mir1-CP in the roots. Furthermore, foliage feeding by CLA provided enhanced resistance to subsequent herbivory by belowground feeding of WCR. Taken together, our previous findings and results presented here indicate that long-distance transport of Mir1-CP is critical for providing enhanced resistance to insect attack in maize. PMID:27467304

  3. Dry Priming of Maize Seeds Reduces Aluminum Stress.

    Directory of Open Access Journals (Sweden)

    Berenice Kussumoto Alcântara

    Full Text Available Aluminum (Al toxicity is directly related to acidic soils and substantially limits maize yield. Earlier studies using hormones and other substances to treat the seeds of various crops have been carried out with the aim of inducing tolerance to abiotic stress, especially chilling, drought and salinity. However, more studies regarding the effects of seed treatments on the induction of Al tolerance are necessary. In this study, two independent experiments were performed to determine the effect of ascorbic acid (AsA seed treatment on the tolerance response of maize to acidic soil and Al stress. In the first experiment (greenhouse, the AsA seed treatment was tested in B73 (Al-sensitive genotype. This study demonstrates the potential of AsA for use as a pre-sowing seed treatment (seed priming because this metabolite increased root and shoot growth under acidic and Al stress conditions. In the second test, the evidence from field experiments using an Al-sensitive genotype (Mo17 and an Al-tolerant genotype (DA suggested that prior AsA seed treatment increased the growth of both genotypes. Enhanced productivity was observed for DA under Al stress after priming the seeds. Furthermore, the AsA treatment decreased the activity of oxidative stress-related enzymes in the DA genotype. In this study, remarkable effects using AsA seed treatment in maize were observed, demonstrating the potential future use of AsA in seed priming.

  4. Role of Dehydrodiferulates in Maize Resistance to Pests and Diseases

    Directory of Open Access Journals (Sweden)

    Rosa A. Malvar

    2010-02-01

    Full Text Available Phenolic esters have attracted considerable interest due to the potential they offer for peroxidase catalysed cross-linking of cell wall polysaccharides. Particularly, feruloyl residues undergo radical coupling reactions that result in cross-linking (intra-/intermolecular between polysaccharides, between polysaccharides and lignin and, between polysaccharides and proteins. This review addresses for the first time different studies in which it is established that cross-linking by dehydrodiferulates contributes to maize’s defences to pests and diseases. Dehydrodiferulate cross-links are involved in maize defence mechanisms against insects such as the European, Mediterranean, and tropical corn borers and, storage pest as the maize weevil. In addition, cross-links are also discussed to be involved in genetic resistance of maize to fungus diseases as Gibberella ear and stalk rot. Resistance against insects and fungus attending dehydrodiferulates could go hand in hand. Quantitative trait loci mapping for these cell wall components could be a useful tool for enhancing resistance to pest and diseases in future breeding programs.

  5. A novel in vitro system for gamete fusion in maize

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Various systems by using electric pulse, calcium, or polyethylene glycol have been developed in the past decade for the in vitro fusion of plant gametes. These in vitro systems provide a new way to study the fertilization mechanisms of plants. In this study, we developed a bovine serum albumin (BSA)-mediated fusion system for the in vitro fusion of maize gametes. The in vitro fusion of the isolated single egg cell and sperm cell of maize was observed microscopically in the BSA solution and the fertilized egg cell showed normal cell wall regeneration and nuclear division. The effects of the BSA concentration, pH value and calcium level on the efficiency of the maize gamete fusion were also assessed. BSA concentration and pH value did significantly affect the efficiency of the gamete fusion. Calcium was not necessary for the gamete fusion when BSA was present. The optimal solution for the gamete fusion contained 0.1% BSA, pH 6.0. The fusion frequency was as high as 96.7% in that optimal solution. This new in vitro fertilization system offers an alternative tool for the in vitro study of fertilization mechanisms with much simpler manipulating procedure than PEG system,and it will be especially useful for the in vitro study of the calcium dynamics during plant fertilization.

  6. Measuring Maize Seedling Drought Response in Search of Tolerant Germplasm

    Directory of Open Access Journals (Sweden)

    Dirk Hays

    2013-02-01

    Full Text Available To identify and develop drought tolerant maize (Zea mays L., high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and their hybrid testcross progeny were evaluated for germination, survival and recovery after a series of drought cycles. Genotypic differences among inbred lines and hybrid testcrosses were best explained approximately 13 and 18 days after planting, respectively. Genotypic effects were significant and explained over 6% of experimental variance. Specifically three inbred lines had significant survival, and 14 hybrids had significant recovery. However, no significant correlation was observed between hybrids and inbreds (R2 = 0.03, indicating seedling stress response is more useful as a secondary screening parameter in hybrids than in inbred lines per se. Field yield data under full and limited irrigation indicated that seedling drought mechanisms were independent of drought responses at flowering in this study.

  7. Adoption of Improved Maize Seed Varieties in Southern Zambia

    Directory of Open Access Journals (Sweden)

    Thomson Kalinda

    2014-01-01

    Full Text Available Maize is the principal agricultural crop produced by Zambian smallholder farmers for household consumption and sale. Their production strategy is therefore important in meeting food security and income needs. This study uses data collected from a survey of a random sample of farm households in southern Zambia to develop a Tobit regression model. The model identifies farm and farmer characteristics important for adoption of improved maize seed varieties as well as to determine the role of farmer perceptions of technology attributes in maize varietal adoption. The results indicate that expectations about output price and yield are important determinants of adoption. Other factors directly correlated with the probability of adoption include the status of being male-headed, farm size and membership to farmer organizations. Households with more wealth and educated heads were also significantly more likely to adopt improved varieties. Some of the policy implications of these findings are that intervention strategies should be designed and implemented to encourage poor households and those with low levels of formal education to participate in local farmer organizations. The positive interaction between membership to organizations and the adoption of technologies also suggests that group based extension approaches should be encouraged not only for their role in collective action but also for their positive impact on information diffusion and technology adoption.

  8. Knowledge model-based decision support system for maize management

    Institute of Scientific and Technical Information of China (English)

    GUO Yinqiao; ZHAO Chuande; WANG Wenxin; LI Cundong

    2007-01-01

    Based on the relationship between crops and circumstances,a dynamic knowledge model for maize management with wide applicability was developed using the system method and mathematical modeling technique.With soft component characteristics incorporated,a component and digital knowledge model-based decision support system for maize management was established on the Visual C++platform.This system realized six major functions:target yield calculation,design of pre-sowing plan,prediction of regular indices,real-time management control,expert knowledge reference and system administration.Cases were studied on the target yield knowledge model with data sets that include different eco-sites,yield levels of the last three years,and fertilizer and water management levels.The results indicated that this system overcomes the shortcomings of traditional expert systems and planting patterns,such as sitespecific conditions and narrow applicability,and can be used more under different conditions and environments.This system provides a scientific knowledge system and a broad decision-making tool for maize management.

  9. The water budget of rainfed maize and bean intercrop

    Science.gov (United States)

    Walker, S.; Ogindo, H. O.

    Food production in the South African Development Community (SADC) region is predominantly under rainfed conditions and therefore experiences annual fluctuations due to the rainfall variability. Although the staple food of maize ( Zea mays) is commonly grown in the same field as dry beans ( Phaseolus vulgaris) little work has been done to characterize the soil water budget of this intercropping system. The evapotranspiration can theoretically be divided into transpiration from the leaves and evaporation from the soil surface. However, it is difficult to separate the components in field studies. In this paper the Ritchie model is used to estimate the soil surface evaporation using the fractional radiation interception which depends on the crop leaf area. The intercropping system has higher leaf area than the sole crops of both maize and beans in all seasons. Therefore, the soil surface is shaded and the canopy is more dense resulting in a lower soil surface evaporation. The water budget thus gives a higher value of transpiration for the intercrop during each of the four growing seasons. This appears to be due to the complimentary use of the water resources by the maize and bean plants in the intercropping system. This illustrates the ability of the intercrop to use the available soil water in a semi-arid environment more productively. Thus the experience of the small-holder farmers in the SADC region is based on sound physical principles of water use by the two crops.

  10. Study on Haploid Inducing and Its Meiotic Abnormality in Maize

    Institute of Scientific and Technical Information of China (English)

    TANG Qi-lin; FENG Yun-chao; HAN Xue-li; ZHENG Ming-min; RONG Ting-zhao

    2009-01-01

    The haploid-inducing line Stock 6 was used to produce haploid maize and expected to obtain maize haploid plants successfully. The detailed meiotic studies on selected haploid maize (n=x=10) were conducted. Cytogenetie analysis revealed a high frequency of meiotic abnormality occurred in both meiosis Ⅰ and meiosis Ⅱ. During the prophase I, univalents were common configurations, and there were bivalents or trivalents in some pollen mother cells, however, a few cells containing five bivalents were also observed. After prophase I, chromosomes did not congregate in a single metaphase plate but they were scattered in the cytoplasm. At anaphase I, the chromosome distribution was highly irregular with almost all possible combinations. In some cells, chromosomes were grouped into the three or four masses and several spindles appeared. At the tetrad stage of meiosis Ⅱ, cytokinesis splitting abnormality occurred, and a variety of diad, triad, tetrad, pentad, hexad, as well as decury microspores were easily observed. As a consequence of abnormalities of the two meiotic stages, various microspores and the pollen grains with different size were formed, and its pollen grains were almost completely sterile.

  11. Intraplant communication in maize contributes to defense against insects.

    Science.gov (United States)

    Varsani, Suresh; Basu, Saumik; Williams, W Paul; Felton, Gary W; Luthe, Dawn S; Louis, Joe

    2016-08-01

    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. Furthermore, accumulation of Mir1-CP in the vasculature suggests that Mir1-CP can potentially function as a phloem-mobile protein. In a recent study, we provided evidence that Mir1-CP can curtail the growth of phloem-sap sucking insect, corn leaf aphid (CLA; Rhopalosiphum maidis). Our current study further examined whether aboveground feeding by CLA can induce resistance to subsequent herbivory by belowground feeding western corn rootworm (WCR; Diabrotica virgifera virgifera). Aboveground feeding by CLA systemically induced the accumulation of Mir1-CP in the roots. Furthermore, foliage feeding by CLA provided enhanced resistance to subsequent herbivory by belowground feeding of WCR. Taken together, our previous findings and results presented here indicate that long-distance transport of Mir1-CP is critical for providing enhanced resistance to insect attack in maize.

  12. Comparison of morphological and molecular genetic distances of maize inbreds

    Directory of Open Access Journals (Sweden)

    Babić Milosav

    2012-01-01

    Full Text Available Due to an unknown mechanism of genetic control and great environmental effects in the process of trait expression, morphological markers are often considered unreliable indicators of genetic relationships. Morphological characterization of 19 maize inbreds was done according to the UPOV descriptor, while molecular characterization was performed with RAPD markers. Based on the estimation of phenotypes according to the UPOV descriptor, the squared Euclidean distance was calculated and then, on the basis of this distance, a morphological similarity matrix was formed. Jaccard similarity coefficients were calculated on the basis of presence absence of bands on gels in the RAPD analysis. When data were standardized, the comparison between morphological and genetic similarity of observed maize inbreds was done. The correlations varied from 0.47 (inbred L 217 to 0.76 (inbred L 86. The average value of correlations for all studied inbreds amounted to 0.64. Furthermore, the results of the cluster analysis for both markers, molecular and morphological, had high concordance with pedigree data. Environmental effects were decreased in morphological markers (according to the UPOV descriptor by rescaling a measurement scale from a scale to an ordinal level of measurement and in such a way results of morphological markers approached results of molecular markers in the estimation of the genetic distance (GD of maize inbred lines.

  13. Stability of the MON 810 transgene in maize.

    Science.gov (United States)

    La Paz, Jose Luis; Pla, Maria; Papazova, Nina; Puigdomènech, Pere; Vicient, Carlos M

    2010-12-01

    We analysed the DNA variability of the transgene insert and its flanking regions in maize MON 810 commercial varieties. Southern analysis demonstrates that breeding, since the initial transformation event more than 10 years ago, has not resulted in any rearrangements. A detailed analysis on the DNA variability at the nucleotide level, using DNA mismatch endonuclease assays, showed the lack of polymorphisms in the transgene insert. We conclude that the mutation rate of the transgene is not significantly different from that observed in the maize endogenous genes. Six SNPs were observed in the 5'flanking region, corresponding to a Zeon1 retrotransposon long terminal repeat. All six SNPs are more than 500 bp upstream of the point of insertion of the transgene and do not affect the reliability of the established PCR-based transgene detection and quantification methods. The mutation rate of the flanking region is similar to that expected for a maize repetitive sequence. We detected low levels of cytosine methylation in leaves of different transgenic varieties, with no significant differences on comparing different transgenic varieties, and minor differences in cytosine methylation when comparing leaves at different developmental stages. There was also a reduction in cryIAb mRNA accumulation during leaf development. PMID:20936423

  14. Inheritance of Ear Tip-Barrenness Trait in Maize

    Institute of Scientific and Technical Information of China (English)

    MENG Zhao-dong; ZHANG Fa-jun; DING Zhao-hua; SUN Qi; WANG Li-ming; GUO Qing-fa; WANG Hong-gang

    2007-01-01

    The aim of this paper is to study the inheritance pattern of ear tip-barrenness trait in maize (Zea mays L.). Ear tipbarrenness trait in maize can be classified into two types, tip-barren and tip-barrenless. Two inbred lines, Ix01-3 (tipbarrenless type), wx04-1 (tip-barren type), and their F1, F2, BC1, BC2 generations were analyzed on their ear tip-barrenness types. Results showed that F1 was tip-barren type; the ratio of tip-barren type versus tip-barrenless type followed a 12.78∶1 ratio in F2 segregation population and a 2.75∶1 ratio in BC1. χ2 test indicated that the trait of ear tip-barrenness type followed an inheritance pattern of 2 duplicate dominant genes. SPSS analysis indicated that the trait of ear tip-barrenness length is of abnormal distribution. Above results mean that: (1) The trait of maize ear tip-barrenness type is controlled by2 duplicate dominant genes; tip-barren type is dominant over tip-barrenless type; (2) the trait of tip-barrenness length is a quantitative character controlled by polygene with major genes expected.

  15. Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers.

    Science.gov (United States)

    Abeni, F; Migliorati, L; Terzano, G M; Capelletti, M; Gallo, A; Masoero, F; Pirlo, G

    2014-10-01

    The aim of this trial was to assess the effects of the administration of different combinations of mycotoxins in naturally contaminated maize grains on dairy heifer growth, blood measurements and puberty onset. A total of 35 Friesian female heifers were randomly allotted to three experimental groups from 18-21 to 42-45 weeks of age. During the 24-week experimental period (EP), heifers were fed the same diet, but with maize meal derived from three differently contaminated lots: very low contamination, as control (C); medium-low aflatoxin-contaminated (A); and mixed aflatoxin-fumonisin contaminated (A-F). At the end of the EP, they returned to a common diet without contaminated maize, and they were monitored for an additional period of 12 weeks (post-experimental period, PEP). BW, wither height, hip height, body length and heart girth were measured every 4 weeks from the beginning of EP to the end of PEP. At the same time, body condition score was evaluated and blood samples were taken from the jugular vein to be analysed for haematological, serum protein and metabolic profiles. Age at puberty was assessed by measuring weekly plasma progesterone levels from 40 to 52 weeks of age. Body growth measurements were processed both by ANOVA of average daily gain of EP and PEP separately, and by the analysis of growth curve parameters. Haematological, serum protein and metabolic profile were evaluated using a mixed model, taking into account the repeated measurements in time on each animal. Heifers' growth was delayed both in A and A-F groups during EP, as evidenced by the different linear coefficients of the BW growth curve in the three groups. Differently contaminated diets did not affect the haematological profile, so that it can be concluded that these levels of mycotoxin contamination do not determine any specific effect on haematopoiesis and immunity in growing heifers. The main blood marker of mycotoxin chronic toxicity was the γ-glutamyl transferase activity level in

  16. The Maize Price Spike of 2012/13: Understanding the Paradox of High Prices despite Abundant Supplies

    OpenAIRE

    Sitko, Nicholas J.; Kuteya, Auckland N.

    2013-01-01

    The 2012 harvest was, according to the Ministry of Agriculture and Livestock national food balance sheet estimates, a major surplus production season. However, by November the same year, Zambia started experiencing widespread maize meal shortages and skyrocketing maize meal prices. Responding to these shortages and price spikes, the government increased the price subsidies it provided on maize sold by the parastatal Food Reserve Agency (FRA) to large-scale maize mills and imposed de facto pri...

  17. Bacterial diversity and mycotoxin reduction during maize fermentation (steeping for ogi production

    Directory of Open Access Journals (Sweden)

    Chiamaka A Okeke

    2015-12-01

    Full Text Available Bacterial diversity and community structure of two maize varieties (white and yellow during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%. Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24–72h. Mycotoxin concentrations (µg/kg in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3 = 68.4–483; zearalenone = 3.3 and yellow maize (aflatoxins (B1/B2/M1 = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3 = 252–1,586; zearalenone = 205. Mycotoxins in both maize varieties were significantly (p<0.05 reduced across steeping periods. This study reports for the first time: (a the association of L. paraplantarum, P. acidilactici and P. claussenii with ogi production from maize, (b citrinin occurrence in Nigerian maize and ogi, and (c aflatoxin M1, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food.

  18. The R2R3-MYB transcription factor gene family in maize.

    Directory of Open Access Journals (Sweden)

    Hai Du

    Full Text Available MYB proteins comprise a large family of plant transcription factors, members of which perform a variety of functions in plant biological processes. To date, no genome-wide characterization of this gene family has been conducted in maize (Zea mays. In the present study, we performed a comprehensive computational analysis, to yield a complete overview of the R2R3-MYB gene family in maize, including the phylogeny, expression patterns, and also its structural and functional characteristics. The MYB gene structure in maize and Arabidopsis were highly conserved, indicating that they were originally compact in size. Subgroup-specific conserved motifs outside the MYB domain may reflect functional conservation. The genome distribution strongly supports the hypothesis that segmental and tandem duplication contribute to the expansion of maize MYB genes. We also performed an updated and comprehensive classification of the R2R3-MYB gene families in maize and other plant species. The result revealed that the functions were conserved between maize MYB genes and their putative orthologs, demonstrating the origin and evolutionary diversification of plant MYB genes. Species-specific groups/subgroups may evolve or be lost during evolution, resulting in functional divergence. Expression profile study indicated that maize R2R3-MYB genes exhibit a variety of expression patterns, suggesting diverse functions. Furthermore, computational prediction potential targets of maize microRNAs (miRNAs revealed that miR159, miR319, and miR160 may be implicated in regulating maize R2R3-MYB genes, suggesting roles of these miRNAs in post-transcriptional regulation and transcription networks. Our comparative analysis of R2R3-MYB genes in maize confirm and extend the sequence and functional characteristics of this gene family, and will facilitate future functional analysis of the MYB gene family in maize.

  19. Field-evolved resistance by western corn rootworm to multiple Bacillus thuringiensis toxins in transgenic maize.

    Science.gov (United States)

    Gassmann, Aaron J; Petzold-Maxwell, Jennifer L; Clifton, Eric H; Dunbar, Mike W; Hoffmann, Amanda M; Ingber, David A; Keweshan, Ryan S

    2014-04-01

    The widespread planting of crops genetically engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) places intense selective pressure on pest populations to evolve resistance. Western corn rootworm is a key pest of maize, and in continuous maize fields it is often managed through planting of Bt maize. During 2009 and 2010, fields were identified in Iowa in which western corn rootworm imposed severe injury to maize producing Bt toxin Cry3Bb1. Subsequent bioassays revealed Cry3Bb1 resistance in these populations. Here, we report that, during 2011, injury to Bt maize in the field expanded to include mCry3A maize in addition to Cry3Bb1 maize and that laboratory analysis of western corn rootworm from these fields found resistance to Cry3Bb1 and mCry3A and cross-resistance between these toxins. Resistance to Bt maize has persisted in Iowa, with both the number of Bt fields identified with severe root injury and the ability western corn rootworm populations to survive on Cry3Bb1 maize increasing between 2009 and 2011. Additionally, Bt maize targeting western corn rootworm does not produce a high dose of Bt toxin, and the magnitude of resistance associated with feeding injury was less than that seen in a high-dose Bt crop. These first cases of resistance by western corn rootworm highlight the vulnerability of Bt maize to further evolution of resistance from this pest and, more broadly, point to the potential of insects to develop resistance rapidly when Bt crops do not achieve a high dose of Bt toxin.

  20. A rapid and efficient method for assessing pathogenicity of ustilago maydis on maize and teosinte lines.

    Science.gov (United States)

    Chavan, Suchitra; Smith, Shavannor M

    2014-01-03

    Maize is a major cereal crop worldwide. However, susceptibility to biotrophic pathogens is the primary constraint to increasing productivity. U. maydis is a biotrophic fungal pathogen and the causal agent of corn smut on maize. This disease is responsible for significant yield losses of approximately $1.0 billion annually in the U.S.(1) Several methods including crop rotation, fungicide application and seed treatments are currently used to control corn smut(2). However, host resistance is the only practical method for managing corn smut. Identification of crop plants including maize, wheat, and rice that are resistant to various biotrophic pathogens has significantly decreased yield losses annually(3-5). Therefore, the use of a pathogen inoculation method that efficiently and reproducibly delivers the pathogen in between the plant leaves, would facilitate the rapid identification of maize lines that are resistant to U. maydis. As, a first step toward indentifying maize lines that are resistant to U. maydis, a needle injection inoculation method and a resistance reaction screening method was utilized to inoculate maize, teosinte, and maize x teosinte introgression lines with a U. maydis strain and to select resistant plants. Maize, teosinte and maize x teosinte introgression lines, consisting of about 700 plants, were planted, inoculated with a strain of U. maydis, and screened for resistance. The inoculation and screening methods successfully identified three teosinte lines resistant to U. maydis. Here a detailed needle injection inoculation and resistance reaction screening protocol for maize, teosinte, and maize x teosinte introgression lines is presented. This study demonstrates that needle injection inoculation is an invaluable tool in agriculture that can efficiently deliver U. maydis in between the plant leaves and has provided plant lines that are resistant to U. maydis that can now be combined and tested in breeding programs for improved disease resistance.

  1. Effects of INH, DNP, 2,4-D and CMU on the photosynthetic activity of barley and maize plants; Efecto de cuatro inhibidores metabolicos (INH, DNP, 2, 4-D y CMU) sobre la actividad fotosintetica de plantular de cebada (Hordeum vulgare L.) y Maiz (Zea mais L.)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.; Prieto, M. P.

    1979-07-01

    Determinations of the rate of photosynthesis were made in barley and maize leaves treated with INH, DNP, 2,4-D or CMU. 1 ppm of the chemicals in nutritive solutions was absorbed by roots during 24 or 48 hours in both dark and light conditions. After this period, photosynthetic activity, compensation point and 14{sup C}O{sub 2} assimilation were determined. Results show that INH increases the rate of photosynthesis, DNP and 2,4-D do not alter it sensibly and CMU acts as a strong inhibitor of photosynthesis. Some possible applications for ths obtention of labelled compounds by biosynthesis are discussed. (Author) 87 refs.

  2. Functional diversity of staphylinid beetles (Coleoptera: Staphylinidae) in maize fields: testing the possible effect of genetically modified, insect resistant maize

    OpenAIRE

    Svobodová, Zdeňka

    2016-01-01

    Staphylinid beetles are recommended bioindicators for the pre-market environmental risk assessment of genetically modified (GM) insect protected maize expressing the Cry3Bb1 toxin. Bionomics, food specialization, temperature requirements and size group were assigned for 25 most common staphylinid species. These traits determine the occurrence of staphylinid beetles in the field, the food sources they could utilize and thus also their likely contact with the Cry3Bb1 toxin. The opportunity for ...

  3. Field trials to evaluate the effects of transgenic cry1Ie maize on the community characteristics of arthropod natural enemies.

    Science.gov (United States)

    Guo, Jingfei; He, Kanglai; Hellmich, Richard L; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Ahmed, Tofael; Wang, Zhenying

    2016-02-26

    Possible non-target effect of transgenic cry1Ie maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr comparison of transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community biodiversity were compared with whole plant inspections, pitfall traps and suction sampler. Natural enemy diversity indices (Shannon-Wiener', Simpson's and Pielou's index) and abundance suggested there were no significant differences between the two types of maize. The only exceptions were the Pielou's index for whole plant inspections in 2013 and abundance for pitfall traps in 2012, which were significantly higher in Bt maize than those of non-Bt maize. The main species of natural enemies were identical in Bt and non-Bt maize plots for each method and the three methods combined. For whole plant inspections, Bt maize had no time-dependent effect on the entire arthropod natural enemy community, and also no effect on community dissimilarities between Bt and non-Bt maize plots. These results suggested that despite the presence of a relatively minor difference in natural enemy communities between Bt and non-Bt maize, transgenic cry1Ie maize had little, if any, effect on natural enemy community biodiversity.

  4. The Maize PIN Gene Family of Auxin Transporters.

    Science.gov (United States)

    Forestan, Cristian; Farinati, Silvia; Varotto, Serena

    2012-01-01

    Auxin is a key regulator of plant development and its differential distribution in plant tissues, established by a polar cell to cell transport, can trigger a wide range of developmental processes. A few members of the two families of auxin efflux transport proteins, PIN-formed (PIN) and P-glycoprotein (ABCB/PGP), have so far been characterized in maize. Nine new Zea mays auxin efflux carriers PIN family members and two maize PIN-like genes have now been identified. Four members of PIN1 (named ZmPIN1a-d) cluster, one gene homologous to AtPIN2 (ZmPIN2), three orthologs of PIN5 (ZmPIN5a-c), one gene paired with AtPIN8 (ZmPIN8), and three monocot-specific PINs (ZmPIN9, ZmPIN10a, and ZmPIN10b) were cloned and the phylogenetic relationships between early-land plants, monocots, and eudicots PIN proteins investigated, including the new maize PIN proteins. Tissue-specific expression patterns of the 12 maize PIN genes, 2 PIN-like genes and ZmABCB1, an ABCB auxin efflux carrier, were analyzed together with protein localization and auxin accumulation patterns in normal conditions and in response to drug applications. ZmPIN gene transcripts have overlapping expression domains in the root apex, during male and female inflorescence differentiation and kernel development. However, some PIN family members have specific tissue localization: ZmPIN1d transcript marks the L1 layer of the shoot apical meristem and inflorescence meristem during the flowering transition and the monocot-specific ZmPIN9 is expressed in the root endodermis and pericycle. The phylogenetic and gene structure analyses together with the expression pattern of the ZmPIN gene family indicate that subfunctionalization of some maize PINs can be associated to the differentiation and development of monocot-specific organs and tissues and might have occurred after the divergence between dicots and monocots. PMID:22639639

  5. Comparison of true metabolisable energy and true amino acid availability between normal maize and quality protein maize (Shandan 17

    Directory of Open Access Journals (Sweden)

    Mei Li Zhang

    2010-01-01

    Full Text Available A precision-fed assay was conducted to determine true metabolisable energy and true amino acid digestibility in Chinese quality protein maize (QPM compared with normal maize (NM. Thirty adult roosters, kept in individual cages, were made to fast for 48h and then tub-fed 50g QPM or NM per bird and their excreta was colleted for the subsequent 48h. Additional fifteen roosters were made to fast in order to estimate endogenous losses of energy and amino acids (AA in excreta. Gross energy of the two types of maize were similar; the lysine content in NM and QPM were 0.27% and 0.41% (DM basis, respectively. True metabolisable energy (TME and true metabolisable energy nitrogen corrected (TMEn values of QPM and NM were not significantly different (P>0.05. Digestibility of some AA, including lysine and methionine, in QPM were higher than those in NM (P<0.05. The results of this study indicated that the nutritive value of QPM might be higher than that of NM.

  6. Mycorrhiza and PGPB modulate maize biomass, nutrient uptake and metabolic pathways in maize grown in mining-impacted soil.

    Science.gov (United States)

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2015-12-01

    Abiotic stress factors including poor nutrient content and heavy metal contamination in soil, can limit plant growth and productivity. The main goal of our study was to evaluate element uptake, biomass and metabolic responses in maize roots growing in mining-impacted soil with the combination of arbuscular mycorrhiza (My) and plant growth promoting bacteria (PGPB/B). Maize plants subjected to PGPB, My and combined treatments showed a significant increase in biomass and uptake of some elements in shoot and root. Metabolite analysis identified 110 compounds that were affected ≥2-fold compared to control, with 69 metabolites upregulated in the My group, 53 metabolites in the My+B group and 47 metabolites in B group. Pathway analysis showed that impact on glyoxylate and dicarboxylate metabolism was common between My and My+B groups, whereas PGPB group showed a unique effect on fatty acid biosynthesis with significant increase in palmitic acid and stearic acid. Differential regulation of some metabolites by mycorrhizal treatment correlated with root biomass while PGPB regulated metabolites correlated with biomass increase in shoot. Overall, the combination of rhizospheric microorganisms used in our study significantly increased maize nutrient uptake and growth relative to control. The changes in metabolic pathways identified during the symbiotic interaction will improve our understanding of mechanisms involved in rhizospheric interactions that are responsible for increased growth and nutrient uptake in crop plants.

  7. Root growth regulation and gravitropism in maize roots does not require the epidermis

    Science.gov (United States)

    Bjorkman, T.; Cleland, R. E.

    1991-01-01

    We have earlier published observations showing that endogenous alterations in growth rate during gravitropism in maize roots (Zea mays L.) are unaffected by the orientation of cuts which remove epidermal and cortical tissue in the growing zone (Bjorkman and Cleland, 1988, Planta 176, 513-518). We concluded that the epidermis and cortex are not essential for transporting a growth-regulating signal in gravitropism or straight growth, nor for regulating the rate of tissue expansion. This conclusion has been challenged by Yang et al. (1990, Planta 180, 530-536), who contend that a shallow girdle around the entire perimeter of the root blocks gravitropic curvature and that this inhibition is the result of a requirement for epidermal cells to transport the growth-regulating signal. In this paper we demonstrate that the entire epidermis can be removed without blocking gravitropic curvature and show that the position of narrow girdles does not affect the location of curvature. We therefore conclude that the epidermis is not required for transport of a growth-regulating substance from the root cap to the growing zone, nor does it regulate the growth rate of the elongating zone of roots.

  8. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize.

    Science.gov (United States)

    Séralini, Gilles-Eric; Clair, Emilie; Mesnage, Robin; Gress, Steeve; Defarge, Nicolas; Malatesta, Manuela; Hennequin, Didier; de Vendômois, Joël Spiroux

    2012-11-01

    The health effects of a Roundup-tolerant genetically modified maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone (from 0.1 ppb in water), were studied 2 years in rats. In females, all treated groups died 2-3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs. All results were hormone and sex dependent, and the pathological profiles were comparable. Females developed large mammary tumors almost always more often than and before controls, the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5-5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3-2.3 greater. Males presented 4 times more large palpable tumors than controls which occurred up to 600 days earlier. Biochemistry data confirmed very significant kidney chronic deficiencies; for all treatments and both sexes, 76% of the altered parameters were kidney related. These results can be explained by the non linear endocrine-disrupting effects of Roundup, but also by the overexpression of the transgene in the GMO and its metabolic consequences. PMID:22999595

  9. Sensory characteristics of high-amylose maize-resistant starch in three food products.

    Science.gov (United States)

    Maziarz, Mindy; Sherrard, Melanie; Juma, Shanil; Prasad, Chandan; Imrhan, Victorine; Vijayagopal, Parakat

    2013-03-01

    Type 2 resistant starch from high-amylose maize (HAM-RS2) is considered a functional ingredient due to its positive organoleptic and physiochemical modifications associated with food and physiological benefits related to human health. The sensory characteristics of three types of food products (muffins, focaccia bread, and chicken curry) with and without HAM-RS2 were evaluated using a 9-point hedonic scale. The HAM-RS2-enriched muffins, focaccia bread, and chicken curry contained 5.50 g/100 g, 13.10 g/100 g, and 8.94 g/100 g RS, respectively, based on lyophilized dry weight. The HAM-RS2-enriched muffin had higher moisture content and was perceived as being significantly moister than the control according to the sensory evaluation. The addition of HAM-RS2 to muffins significantly enhanced all sensory characteristics and resulted in a higher mean overall likeability score. The HAM-RS2-enriched focaccia bread appeared significantly darker in color, was more dense, and had the perception of a well-done crust versus the control. A grainer texture was observed with the chicken curry containing HAM-RS2 which did not significantly affect overall likeability. We concluded that the addition of HAM-RS2 may not significantly alter consumer's acceptability in most food products.

  10. Influence of maize and pigweed on tarnished plant bug (Hemiptera: Miridae) populations infesting cotton

    Science.gov (United States)

    The influence of maize, lea mays L., and pigweed, Amaranthus spp., on populations of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), adults infesting cotton, Gossypium hirsucum L., in the Mississippi Delta was studied using stable isotope analyses. Cotton fields adjacent to maize and th...

  11. Co-occurence of aflatoxins and fumonisins in maize: guatemala as a case study

    Science.gov (United States)

    Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are found in maize. AFB1 is a genotoxic carcinogen (IARC Group 1) and FB1 a liver cancer promoter in rodents and trout (IARC Group 2B). Therefore, the possibility of co-exposure is a health concern, most notably in areas where maize serves as a dietary st...

  12. Comparison of nine PCR primer sets designed to detect Pantoea stewartii subsp. stewartii in maize

    Science.gov (United States)

    Pantoea stewartii subsp. stewartii, the causal agent of Stewart's bacterial wilt of maize, is a major quarantine pest in maize seed. Verifying freedom from P. stewartii remains a significant hurdle in exporting corn seed from the U.S. Several PCR primer sets have been developed and suggested as bein...

  13. Panzea: A Database and Resource for Molecular and Functional Diversity in the Maize Genome

    Science.gov (United States)

    Maize, a classical model for genetic studies, is an important agronomic crop, and the genome is known to contain many natural differences in the DNA between different strains. On average, two randomly chosen maize lines have an average of one single nucleotide polymorphism (SNP) every ~100 bp; this...

  14. The flux of ozone to a maize crop and the underlying soil during a growing season.

    NARCIS (Netherlands)

    Pul, van A.

    1992-01-01

    To observe the flux or deposition of ozone above a maize crop, experiments were carried out during the growing season of maize in 1988. The flux of ozone was determined using meteorological techniques. The measurements used in the present study were carried out under atmospheric conditions in which

  15. Ear leaf photosynthesis and related parameters of transgenic and non-GMO maize hybrids

    Science.gov (United States)

    Hybrid maize (Zea mays L.) has undergone transformation by using transgenic technology to include d-endotoxins for insect control and tolerance for the herbicides glyphosate and glufosinate . Maize hybrids are being grown with multiple transgenic traits into their genotype (stacked-gene). Limited...

  16. Genetic, Genomic, and Breeding Approaches to Further Explore Kernel Composition Traits and Grain Yield in Maize

    Science.gov (United States)

    Da Silva, Helena Sofia Pereira

    2009-01-01

    Maize ("Zea mays L.") is a model species well suited for the dissection of complex traits which are often of commercial value. The purpose of this research was to gain a deeper understanding of the genetic control of maize kernel composition traits starch, protein, and oil concentration, and also kernel weight and grain yield. Germplasm with…

  17. Using Live-Cell Markers in Maize to Analyze Cell Division Orientation and Timing.

    Science.gov (United States)

    Rasmussen, Carolyn G

    2016-01-01

    Recently developed live-cell markers provide an opportunity to explore the dynamics and localization of proteins in maize, an important crop and model for monocot development. A step-by-step method is outlined for observing and analyzing the process of division in maize cells. The steps include plant growth conditions, sample preparation, time-lapse setup, and calculation of division rates.

  18. Genomewide identification, classification and analysis of NAC type gene family in maize

    Indian Academy of Sciences (India)

    Xiaojian Peng; Yang Zhao; Xiaoming Li; Min Wu; Wenbo Chai; Lei Sheng; Yu Wang; Qing Dong; Haiyang Jiang; Beijiu Cheng

    2015-09-01

    NAC transcription factors comprise a large plant-specific gene family. Increasing evidence suggests that members of this family have diverse functions in plant growth and development. In this study, we performed a genomewide survey of NAC type genes in maize (Zea mays L.). A complete set of 148 nonredundant NAC genes (ZmNAC1–ZmNAC148) were identified in the maize genome using Blast search tools, and divided into 12 groups (a–l) based on phylogeny. Chromosomal location of these genes revealed that they are distributed unevenly across all 10 chromosomes. Segmental and tandem duplication contributed largely to the expansion of the maize NAC gene family. The a/s ratio suggested that the duplicated genes of maize NAC family mainly experienced purifying selection, with limited functional divergence after duplication events. Microarray analysis indicated most of the maize NAC genes were expressed across different developmental stages. Moreover, 19 maize NAC genes grouped with published stress-responsive genes from other plants were found to contain putative stress-responsive cis-elements in their promoter regions. All these stress-responsive genes belonged to the group d (stress-related). Further, these genes showed differential expression patterns over time in response to drought treatments by quantitative real-time PCR analysis. Our results reveal a comprehensive overview of the maize NAC, and form the foundation for future functional research to uncover their roles in maize growth and development.

  19. Morphological analysis of leaf growth of maize : responses to temperature and light intensity

    NARCIS (Netherlands)

    Bos, H.J.; Tijani-Eniola, H.; Struik, P.C.

    2000-01-01

    To increase understanding of the mechanisms involved in leaf-area expansion in the Poaceae, effects of environmental factors on leaf growth of the non-tillering species maize (Zea mays L.) were analysed quantitatively. A growth chamber experiment was carried out with maize cv. Luna including differe

  20. Morphological analysis of plant density effects on early leaf area growth in maize

    NARCIS (Netherlands)

    Bos, H.J.; Vos, J.; Struik, P.C.

    2000-01-01

    The mechanisms of density-related reduced leaf area per plant in non-tillering maize (Zea mays) were investigated. Maize cv. Luna crops with a wide range of plant densities were grown in the field at Wageningen for two years. Half of the plots were shaded (50% transmittance). Detailed measurements o