Science.gov

Sample records for maize rayado fino

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Infectious Maize rayado fino virus from cloned cDNA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV) is the type member of the marafiviruses within the family Tymoviridae. A cDNA clone from which infectious RNA can be transcribed was produced from a US isolate of MRFV (MRFV-US). Infectivity of transcripts derived from cDNA clones was demonstrated by infection of mai...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Infectious Maize rayado fino virus from Cloned cDNA.

    PubMed

    Edwards, Michael C; Weiland, John J; Todd, Jane; Stewart, Lucy R

    2015-06-01

    A full-length cDNA clone was produced from a U.S. isolate of Maize rayado fino virus (MRFV), the type member of the genus Marafivirus within the family Tymoviridae. Infectivity of transcripts derived from cDNA clones was demonstrated by infection of maize plants and protoplasts, as well as by transmission via the known leafhopper vectors Dalbulus maidis and Graminella nigrifrons that transmit the virus in a persistent-propagative manner. Infection of maize plants through vascular puncture inoculation of seed with transcript RNA resulted in the induction of fine stipple stripe symptoms typical of those produced by wild-type MRFV and a frequency of infection comparable with that of the wild type. Northern and Western blotting confirmed the production of MRFV-specific RNAs and proteins in infected plants and protoplasts. An unanticipated increase in subgenomic RNA synthesis over levels in infected plants was observed in protoplasts infected with either wild-type or cloned virus. A conserved cleavage site motif previously demonstrated to function in both Oat blue dwarf virus capsid protein and tymoviral nonstructural protein processing was identified near the amino terminus of the MRFV replicase polyprotein, suggesting that cleavage at this site also may occur.

  5. Evaluating the silencing suppressor activity of proteins encoded by maize rayado fino virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV), the type member of the genus Marafivirus, family Tymoviridae, is transmitted in a persistent, circulative manner by leafhoppers of the genus Dalbulus. Symptoms of MRFV infection on leaves of its maize host are small chlorotic spots that coalesce into short stripes. T...

  6. ORF43 of Maize rayado fino virus is dispensable for systemic infection of maize and transmission by leafhoppers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV) possesses an open reading frame (ORF) encoding a protein with predicted mass of 43 kDa (ORF43) that has been postulated to be a viral movement protein. Using a clone of MRFV (pMRFV-US) from which infectious RNA can be produced, point mutations were introduced to eithe...

  7. Maize rayado fino virus capsid proteins assemble into virus-like particles in Escherichia coli.

    PubMed

    Hammond, Rosemarie W; Hammond, John

    2010-02-01

    Maize rayado fino virus (MRFV; genus Marafivirus; family Tymoviridae) is an isometric plant virus of 30 nm containing two components: empty shells and complete virus particles (encapsidating the 6.3 kb genomic RNA). Both particles are composed of two serologically related, carboxy co-terminal, coat proteins (CP) of apparent molecular mass 21-22 kDa (CP2) and 24-28 kDa (CP1) in a molar ratio of 3:1, respectively; CP1 contains a 37 amino acid amino terminal extension of CP2. In our study, expression of CP1 or CP2 in Escherichia coli resulted in assembly of each capsid protein into virus-like particles (VLPs), appearing in electron microscopy as stain-permeable (CP2) or stain-impermeable particles (CP1). CP1 VLPs encapsidated bacterial 16S ribosomal RNA, but not CP mRNA, while CP2 VLPs encapsidated neither CP mRNA nor 16S ribosomal RNA. Expression of CP1 and CP2 in E. coli using a co-expression vector resulted in the assembly of VLPs which were stain-impermeable and encapsidated CP mRNA. These results suggest that the N-terminal 37 amino acid residues of CP1, although not required for particle formation, may be involved in the assembly of complete virions and that the presence of both CP1 and CP2 in the particle is required for specific encapsidation of MRFV CP mRNA.

  8. Partial characterization of Maize rayado fino virus isolates from Ecuador: phylogenetic analysis supports a Central American origin of the virus.

    PubMed

    Chicas, Mauricio; Caviedes, Mario; Hammond, Rosemarie; Madriz, Kenneth; Albertazzi, Federico; Villalobos, Heydi; Ramírez, Pilar

    2007-06-01

    Maize rayado fino virus (MRFV) infects maize and appears to be restricted to, yet widespread in, the Americas. MRFV was previously unreported from Ecuador. Maize plants exhibiting symptoms of MRFV infection were collected at the Santa Catalina experiment station in Quito, Ecuador. RT-PCR reactions were performed on total RNA extracted from the symptomatic leaves using primers specific for the capsid protein (CP) gene and 3' non-translated region of MRFV and first strand cDNA as a template. Nucleotide sequence comparisons to previously sequenced MRFV isolates from other geographic regions revealed 88-91% sequence identity. Phylogenetic trees constructed using Maximum Likelihood, UPGMA, Minimal Evolution, Neighbor Joining, and Maximum Parsimony methods separated the MRFV isolates into four groups. These groups may represent geographic isolation generated by the mountainous chains of the American continent. Analysis of the sequences and the genetic distances among the different isolates suggests that MRFV may have originated in Mexico and/or Guatemala and from there it dispersed to the rest of the Americas.

  9. Analysis of the solvent accessibility of cysteine residues on maize rayado fino virus virus-like particles produced in Nicotiana benthamiana plants and cross-linking of peptides to VLPs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method to analyze the solvent accessibility of the thiol group of cysteine residues of Maize rayado fino virus-virus-like particles (VLPs) followed by a peptide cross-linking reaction is described. The method takes advantage of the availability of several chemical groups on the surface of the VLPs...

  10. Maize rayado fino virus-like particles expressed in tobacco plants: a new platform for cysteine selective bioconjugation peptide display

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of plant virus coat proteins to self-assemble into virus-like particles (VLPs), coupled with unique properties including three-dimensional structures, orthogonal reactivities, suitability for genetic manipulation and chemical bio-conjugation, provide potential utility in nanotechnology a...

  11. Standardization of Meteorological Data from FINO Offshore Platforms

    NASA Astrophysics Data System (ADS)

    Leiding, Tina; Bastigkeit, Ilona; Bégué, Friederike; Gates, Lydia; Herklotz, Kai; Müller, Stefan; Neumann, Thomas; Schwenk, Patrick; Senet, Christian; Tinz, Birger; Wilts, Friedrich

    2015-04-01

    In order to investigate conditions for offshore wind power generation in the German coastal waters, three research platforms were constructed in the North Sea (FINO1 and 3) and the Baltic Sea (FINO2). Measurement masts at each offshore platform are equipped with a range of meteorological sensors at heights of 30 to 100 m above sea level. Standardized analysis and interpretation of the data is necessary to compare the results of the different platforms and will improve the knowledge of the marine ambient conditions at the three locations. International Electrotechnical Commission Standards (IEC) cannot always be applied as some requirements are not applicable to offshore masts e.g. due to the wake of the structure. In the FINO-Wind project, therefore, a standardization method is developed. Recorded measurement data are checked automatically on the basis of a comprehensive quality control. The routine starts with a formal check, followed by climatological, temporal, repetition, and consistency checks. After successful completion of each sequence, the data are assigned standardized quality flags. By default, 10-minute data are processed. A special focus is on mast effects on the wind data of the three masts due to the different shapes of the construction (square or triangular shapes and different boom structures). These effects are investigated in comparison with wind tunnel measurements, LiDAR, Computational Fluid Dynamics calculations, and a 'uniform ambient flow mast correction' method. An adjustment for such effects will be applied to all wind data. The comparison of sensor equipment, its installation and orientation as well as of the mast constructions will lead to suggestions on how wind measurements at offshore platforms mast can be improved. The research project FINO-Wind is funded under the 'Wind Energy' initiative of the German Federal Ministry for the Economic Affairs and Energy for the period 2013 to 2015. For further information see www.dwd.de/fino-wind.

  12. Congenital stationary night blindness in a Thoroughbred and a Paso Fino.

    PubMed

    Nunnery, Catherine; Pickett, J Phillip; Zimmerman, Kurt L

    2005-01-01

    This report documents congenital stationary night blindness (CSNB) in two non-Appaloosa horse breeds (Thoroughbred and Paso Fino). History of vision impairment since birth, normal ocular structures on ophthalmic examination, and electroretinographic findings were consistent with CSNB. In one horse (Thoroughbred), a 9-year follow-up was carried out. In the Paso Fino, severe vision impairment from birth to approximately 1 year of age in both dim and bright light situations led to humane euthanasia and histopathologic confirmation of the disorder.

  13. N. meningitidis 1681 is a member of the FinO family of RNA chaperones

    PubMed Central

    Chaulk, Steven; Lu, Jun; Tan, Kemin; Arthur, David C; Edwards, Ross A; Frost, Laura S; Joachimiak, Andrzej

    2010-01-01

    The conjugative transfer of F-like plasmids between bacteria is regulated by the plasmid-encoded RNA chaperone, FinO, which facilitates sense—antisense RNA interactions to regulate plasmid gene expression. FinO was thought to adopt a unique structure, however many putative homologs have been identified in microbial genomes and are considered members of the FinO_conjugation_repressor superfamily. We were interested in determining whether other members were also able to bind RNA and promote duplex formation, suggesting that this motif does indeed identify a putative RNA chaperone. We determined the crystal structure of the N. meningitidis MC58 protein NMB1681. It revealed striking similarity to FinO, with a conserved fold and a large, positively charged surface that could function in RNA interactions. Using assays developed to study FinO-FinP sRNA interactions, NMB1681, like FinO, bound tightly to FinP RNA stem-loops with short 5′ and 3′ single-stranded tails but not to ssRNA. It also was able to catalyze strand exchange between an RNA duplex and a complementary single-strand, and facilitated duplexing between complementary RNA hairpins. Finally, NMB1681 was able to rescue a finO deficiency and repress F plasmid conjugation. This study strongly suggests that NMB1681 is a FinO-like RNA chaperone that likely regulates gene expression through RNA-based mechanisms in N. meningitidis. PMID:21045552

  14. Maize databases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

  15. Genotype and harvest time influence the phytochemical quality of Fino lemon juice (Citrus limon (L.) Burm. F.) for industrial use.

    PubMed

    González-Molina, Elena; Moreno, Diego A; García-Viguera, Cristina

    2008-03-12

    Two clonal selections of lemon tree (Citrus limon Burm. f. cv. Fino), named Fino-49-5 and Fino-95, were studied to ascertain the influence of genetic (clone) and environmental (season) factors on the human-health bioactive compounds of lemon juice (vitamin C and flavonoids) and the possible relationship between composition and in vitro antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power) of the juice. The cultivar Fino-49-5 performed better in terms of flavonoid and vitamin C contents. Variability in the weather conditions determined, at least in part, differences in the content of lemon juice bioactives more importantly than the genetic background did. Therefore, the food industry would have phytochemically rich and nutritive lemons with practically complete independence of the harvest time and the selected cultivar.

  16. Population analysis of biofilm yeasts during fino sherry wine aging in the Montilla-Moriles D.O. region.

    PubMed

    Marin-Menguiano, Miriam; Romero-Sanchez, Sandra; Barrales, Ramón R; Ibeas, Jose I

    2017-03-06

    Fino is the most popular sherry wine produced in southern Spain. Fino is matured by biological aging under a yeast biofilm constituted of Saccharomyces cerevisiae yeasts. Although different S. cerevisiae strains can be identified in such biofilms, their diversity and contribution to wine character have been poorly studied. In this work, we analyse the flor yeast population in five different wineries from the Montilla-Moriles D.O. (Denominación de Origen) in southern Spain. Yeasts present in wines of different ages were identified using two different culture-dependent molecular techniques. From 2000 individual yeast isolates, five different strains were identified with one of them dominating in four out of the five wineries analysed, and representing 76% of all the yeast isolates collected. Surprisingly, this strain is similar to the predominant strain isolated twenty years ago in Jerez D.O. wines, suggesting that this yeast is particularly able to adapt to such a stressful environment. Fino wine produced with pure cultures of three of the isolated strains resulted in different levels of acetaldehyde. Because acetaldehyde levels are a distinctive characteristic of fino wines and an indicator of fino aging, the use of molecular techniques for yeast identification and management of yeast populations may be of interest for fino wine producers looking to control one of the main features of this wine.

  17. Reinventing MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

  18. Vertical Structure of the Wind Speed Profile at the North Sea Offshore Measurement Platform FINO1

    NASA Astrophysics Data System (ADS)

    Kettle, A. J.

    2013-12-01

    The vertical wind speed profile in the lowest 100m of the marine atmospheric boundary layer has been characterized from data collected at the FINO1 offshore research platform in the German North Sea sector for 2005. Located in 30m of water, the platform has a dense vertical array of meteorological instrumentation to measure wind speed, air temperature, relative humidity, and atmospheric turbulence characteristics. Along measurements of the ocean temperature and surface waves, the platform is well-equipped to characterize wind properties in the near-surface boundary layer. Preliminary analysis reveals a high incidence of vertical wind speed profiles that deviate significantly from Monin-Obukhov similarity theory with wind speed inflections that suggest decoupled layers near the surface. The presentation shows how the properties of the vertical wind speed profile change mainly depending on the wind speed, wind direction, and time of year. The results are significant because there are few reports of inflections in the vertical wind speed profile over the ocean and there is an a priori assumption that the vertical wind speed profile varies smoothly according to similarity theory. There are possible consequences for the wind energy development in terms of understanding the forces acting on offshore wind turbines whose rotors sweep across heights 150-200m above the sea surface.

  19. Chromatography-Olfactometry Study of the Aroma of Fino Sherry Wines

    PubMed Central

    Zea, L.; Moyano, L.; Ruiz, M. J.; Medina, M.

    2010-01-01

    The aroma of Fino sherry wines produced by industrial biological aging for 0, 1.5, 2.5, 4.5, and 6 years in the Montilla-Moriles region (southern Spain) was studied by gas chromatography-olfactometry. The aroma sensations detected by 3 trained sniffers were classified according to their odor descriptors into 8 odorant series (fruity, empyreumatic, chemical, fatty, balsamic, vegetable, floral, and spicy), describing the aroma profile of the studied wines. The results showed 47 detected odors in the unaged wines, 50 in the 1.5-years-old wines and 59, 61 and 69 in the wines aged 2.5, 4.5, and 6 years, respectively. According to the frequency of the perceived aromas, the fruity and empyreumatic series were the most characteristic odorant series. By exception of chemical, floral and balsamic series without changes during aging of the wines, the remainder series increased their participation during the aging, mainly the fruity, empyreumatic, and fatty series. PMID:20689702

  20. MaizeCyc: Metabolic networks in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

  1. The TIGR Maize Database.

    PubMed

    Chan, Agnes P; Pertea, Geo; Cheung, Foo; Lee, Dan; Zheng, Li; Whitelaw, Cathy; Pontaroli, Ana C; SanMiguel, Phillip; Yuan, Yinan; Bennetzen, Jeffrey; Barbazuk, William Brad; Quackenbush, John; Rabinowicz, Pablo D

    2006-01-01

    Maize is a staple crop of the grass family and also an excellent model for plant genetics. Owing to the large size and repetitiveness of its genome, we previously investigated two approaches to accelerate gene discovery and genome analysis in maize: methylation filtration and high C(0)t selection. These techniques allow the construction of gene-enriched genomic libraries by minimizing repeat sequences due to either their methylation status or their copy number, yielding a 7-fold enrichment in genic sequences relative to a random genomic library. Approximately 900,000 gene-enriched reads from maize were generated and clustered into Assembled Zea mays (AZM) sequences. Here we report the current AZM release, which consists of approximately 298 Mb representing 243,807 sequence assemblies and singletons. In order to provide a repository of publicly available maize genomic sequences, we have created the TIGR Maize Database (http://maize.tigr.org). In this resource, we have assembled and annotated the AZMs and used available sequenced markers to anchor AZMs to maize chromosomes. We have constructed a maize repeat database and generated draft sequence assemblies of 287 maize bacterial artificial chromosome (BAC) clone sequences, which we annotated along with 172 additional publicly available BAC clones. All sequences, assemblies and annotations are available at the project website via web interfaces and FTP downloads.

  2. Application of an elastic 2D tube-waveform tomography to estimate the shear modulus in the vicinity of the FINO3 offshore platform

    NASA Astrophysics Data System (ADS)

    Köhn, D.; Wilken, D.; Rabbel, W.

    2012-04-01

    The FINO3 project is aimed at the construction of an offshore research platform in the north-sea, hosting research projects dealing with offshore wind energy topics. As part of FINO3 our sub-project deals with the development of new seismic acquisition and inversion concepts for offshore-building foundation soil analysis. We are focussed on the determination of seismic parameters and structural information of the building plot of the platform. Possible changes of the shear modulus of the sediments in the vicinity of the FINO3 monopile due to mechanic loads on the platform are estimated by a tube-waveform tomography. The tube-waves are excited by a hammer blow at the internal wall of the FINO3 monopile above the water line. The tube-waves are propagating through the water column and the sediments and are measured in situ by hydrophones at the external wall of the monopile. Homogenous long wavelength starting models for the waveform tomography are estimated using simple 2D finite difference models. Possible shear-wave velocity starting models range from 150-300 m/s. The resolution of the tube-waveform tomography is estimated by simple chequerboard and random media models. Additionally first results of the data application in the vicinity of the monopile are presented.

  3. MaizeGDB, the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

  4. Sorghum and Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum and maize are closely related cereal grains grown throughout the world. Sorghum, a drought tolerant crop grown in semi-arid regions, is a basic food staple in many parts of the developing world, while primarily an animal feed in western countries. Maize, a major worldwide crop, is used for...

  5. Maize Genetic Resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the resources held at the Maize Genetics Cooperation • Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

  6. MAIZE ALLELIC DIVERSITY PROJECT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the estimated 250-300 races of maize, only 24 races are represented in materials utilized by the Germplasm Enhancement of Maize (GEM) project, a collaborative effort between USDA-ARS and public and private sector research scientists. This is largely a result of poor performance of many races in ...

  7. Maize (Zea mays L.).

    PubMed

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

    2015-01-01

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

  8. Modified Rice Straw as Adsorbent Material to Remove Aflatoxin B1 from Aqueous Media and as a Fiber Source in Fino Bread

    PubMed Central

    Mohamed, Sherif R.; El-Desouky, Tarek A.; Hussein, Ahmed M. S.; Mohamed, Sherif S.; Naguib, Khayria M.

    2016-01-01

    The aims of the current work are in large part the benefit of rice straw to be used as adsorbent material and natural source of fiber in Fino bread. The rice straw was subjected to high temperature for modification process and the chemical composition was carried out and the native rice straw contained about 41.15% cellulose, 20.46% hemicellulose, and 3.91% lignin while modified rice straw has 42.10, 8.65, and 5.81%, respectively. The alkali number was tested and showed an increase in the alkali consumption due to the modification process. The different concentrations of modified rice straw, aflatoxin B1, and pH were tested for removal of aflatoxin B1 from aqueous media and the maximum best removal was at 5% modified rice straw, 5 ng/mL aflatoxin B1, and pH 7. The modified rice straw was added to Fino bread at a level of 5, 10, and 15% and the chemical, rheological, baking quality, staling, and sensory properties were studied. Modified rice straw induced an increase of the shelf life and the produced Fino bread has a better consistency. PMID:26989411

  9. Modified Rice Straw as Adsorbent Material to Remove Aflatoxin B1 from Aqueous Media and as a Fiber Source in Fino Bread.

    PubMed

    Mohamed, Sherif R; El-Desouky, Tarek A; Hussein, Ahmed M S; Mohamed, Sherif S; Naguib, Khayria M

    2016-01-01

    The aims of the current work are in large part the benefit of rice straw to be used as adsorbent material and natural source of fiber in Fino bread. The rice straw was subjected to high temperature for modification process and the chemical composition was carried out and the native rice straw contained about 41.15% cellulose, 20.46% hemicellulose, and 3.91% lignin while modified rice straw has 42.10, 8.65, and 5.81%, respectively. The alkali number was tested and showed an increase in the alkali consumption due to the modification process. The different concentrations of modified rice straw, aflatoxin B1, and pH were tested for removal of aflatoxin B1 from aqueous media and the maximum best removal was at 5% modified rice straw, 5 ng/mL aflatoxin B1, and pH 7. The modified rice straw was added to Fino bread at a level of 5, 10, and 15% and the chemical, rheological, baking quality, staling, and sensory properties were studied. Modified rice straw induced an increase of the shelf life and the produced Fino bread has a better consistency.

  10. Genomic variation in maize

    SciTech Connect

    Rivin, C.J.

    1990-01-01

    We have endeavored to learn to learn how different DNA sequences and sequence arrangements contribute to genome plasticity in maize. We describe quantitative variation among maize inbred lines for tandemly arrayed and dispersed repeated DNA sequences and gene families, and qualitative variation for sequences homologous to the Mutator family of transposons. The potential of these sequences to undergo unequal crossing over, non-allelic (ectopic) recombination and transposition makes them a source of genome instability. We have found examples of rapid genomic change involving these sequences in F1 hybrids, tissue culture cells and regenerated plants.

  11. MaizeGDB - Past, present, and future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year. This editorial outlines MaizeGDB's history and connection to the Maize Genetics Cooperation, describes key components of how the MaizeGDB interface will be completely redesigned over the course of the next two years to meet cur...

  12. (Genomic variation in maize)

    SciTech Connect

    Rivin, C.J.

    1991-01-01

    These studies have sought to learn how different DNA sequences and sequence arrangements contribute to genome plasticity in maize. We describe quantitative variation among maize inbred lines for tandemly arrayed and dispersed repeated DNA sequences and gene families, and qualitative variation for sequences homologous to the Mutator family of transposons. The potential of these sequences to undergo unequal crossing over, non-allelic (ectopic) recombination and transposition makes them a source of genome instability. We have found examples of rapid genomic change involving these sequences in Fl hybrids, tissue culture cells and regenerated plants. We describe the repetitive portion of the maize genome as composed primarily of sequences that vary markedly in copy number among different genetic stocks. The most highly variable is the 185 bp repeat associated with the heterochromatic chromosome knobs. Even in lines without visible knobs, there is a considerable quantity of tandemly arrayed repeats. We also found a high degree of variability for the tandemly arrayed 5S and ribosomal DNA repeats. While such variation might be expected as the result of unequal cross-over, we were surprised to find considerable variation among lower copy number, dispersed repeats as well. One highly repeated sequence that showed a complex tandem and dispersed arrangement stood out as showing no detectable variability among the maize lines. In striking contrast to the variability seen between the inbred stocks, individuals within a stock were indistinguishable with regard to their repeated sequence multiplicities.

  13. Betaine deficiency in maize

    SciTech Connect

    Lerma, C. ); Rich, P.J.; Ju, G.C.; Yang, Wenju; Rhodes, D. ); Hanson, A.D. )

    1991-04-01

    Maize (Zea mays L.) is a betaine-accumulating species, but certain maize genotypes lack betaine almost completely; a single recessive gene has been implicated as the cause of this deficiency. This study was undertaken to determine whether betaine deficiency in diverse maize germplasm is conditioned by the same genetic locus, and to define the biochemical lesion(s) involved. Complementation tests indicated that all 13 deficient genotypes tested shared a common locus. One maize population (P77) was found to be segregating for betaine deficiency, and true breeding individuals were used to produce related lines with and without betaine. Leaf tissue of both betaine-positive and betaine-deficient lines readily converted supplied betaine aldehyde to betaine, but only the betaine-containing line was able to oxidize supplied choline to betaine. This locates the lesion in betaine-deficient plants at the choline {r arrow} betaine aldehyde step of betaine synthesis. Consistent with this location, betaine-deficient plants were shown to have no detectable endogenous pool of betaine aldehyde.

  14. MaizeGDB: The Maize Genetics and Genomics Database.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project’s website...

  15. Genetic mechanisms of Maize dwarf mosaic virus resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize resistance to viruses has been well-characterized at the genetic level, and loci responsible for resistance to potyviruses including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), have been mapped in several ge...

  16. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is provided each year to our stakeholders in the maize genetic community. In this report, we describe the five-year plan for MaizeGDB reviewed in early 2008 by the USDA-ARS peer review process and which was developed with inputs from our Working Group and the Allerton 2007 Report (MNL 82...

  17. Maize variety and method of production

    DOEpatents

    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.

  18. The MaizeGDB Genome Browser

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of an effort to develop MaizeGDB as a more sequence-centric resource, we implemented a genome browser based on information we gathered by surveying the community of maize geneticists. Based on commu...

  19. Metabolic pathway resources at MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two maize metabolic networks are available at MaizeGDB: MaizeCyc (http://maizecyc.maizegdb.org, also at Gramene) and CornCyc (http://corncyc.maizegdb.org, also at the Plant Metabolic Network). MaizeCyc was developed by Gramene, and CornCyc by the Plant Metabolic Network, both in collaboration with M...

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

    PubMed Central

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

    2017-01-01

    Maize is the principal grain crop of the world. It is also the crop where genetic engineering has been employed to a great extent to improve its various traits. The ability to transform maize is a crucial step for application of gene technology in maize improvement. There have been constant improvements in the maize transformation technologies over past several years. The choice of genotype and the explant material to initiate transformation and the different types of media to be used in various stages of tissue culture can have significant impact on the outcomes of the transformation efforts. Various methods of gene transfer, like the particle bombardment, protoplast transformation, Agrobacterium-mediated, in planta transformation, etc., have been tried and improved over years. Similarly, various selection systems for retrieval of the transformants have been attempted. The commercial success of maize transformation and transgenic development is unmatched by any other crop so far. Maize transformation with newer gene editing technologies is opening up a fresh dimension in transformation protocols and work-flows. This review captures the various past and recent facets in improvement in maize transformation technologies and attempts to present a comprehensive updated picture of the current state of the art in this area. PMID:28111576

  1. MaizeGDB: The Maize Genetics and Genomics Database.

    PubMed

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

    2016-01-01

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

  2. Sequencing the maize genome.

    PubMed

    Martienssen, Robert A; Rabinowicz, Pablo D; O'Shaughnessy, Andrew; McCombie, W Richard

    2004-04-01

    Sequencing of complex genomes can be accomplished by enriching shotgun libraries for genes. In maize, gene-enrichment by copy-number normalization (high C(0)t) and methylation filtration (MF) have been used to generate up to two-fold coverage of the gene-space with less than 1 million sequencing reads. Simulations using sequenced bacterial artificial chromosome (BAC) clones predict that 5x coverage of gene-rich regions, accompanied by less than 1x coverage of subclones from BAC contigs, will generate high-quality mapped sequence that meets the needs of geneticists while accommodating unusually high levels of structural polymorphism. By sequencing several inbred strains, we propose a strategy for capturing this polymorphism to investigate hybrid vigor or heterosis.

  3. Influence of maize/lablab intercropping on lepidopterous stem borer infestation in maize.

    PubMed

    Maluleke, Mary H; Addo-Bediako, Abraham; Ayisi, Kingsley K

    2005-04-01

    Lepidopterous stem borers seriously affect production of maize, Zea mays L., in sub-Saharan Africa. Intercropping maize with legumes such as lablab, Lablab purpurens (L.), is one of the effective systems to control stem borers. Sole culture maize and maize/lablab intercrop system of different lablab densities were planted at two locations to investigate the effects of intercrop system on incidence and severity of stem borers with particular reference to Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae). Stem borer infestation was found to be more severe in sole culture maize than maize in maize/lablab intercrop. There was a significantly negative relationship between lablab densities and maize grain yields, suggesting a possible competition for resources between the two crops. It was concluded that density of lablab and date of planting of lablab in maize/lablab intercropping have significant affects on stem borer populations and maize grain yields.

  4. Inbreeding drives maize centromere evolution.

    PubMed

    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.

  5. The chemical characterization of the aroma of dessert and sparkling white wines (Pedro Ximénez, Fino, Sauternes, and Cava) by gas chromatography-olfactometry and chemical quantitative analysis.

    PubMed

    Campo, Eva; Cacho, Juan; Ferreira, Vicente

    2008-04-09

    Wines from Pedro Ximénez (PX), Fino, botrytized Sauternes, and Cava were screened by gas chromatography-olfactometry (GC-O), and the most relevant aroma compounds were further quantified in six different wines of each group. The comparison of GC-O and quantitative data with similar data from white young wines has made it possible to identify the aroma compounds potentially responsible for the specific sensory characteristics of these wines. Results have shown that all these wines are relatively rich in 3-methylbutanal, phenylacetaldehyde, methional, sotolon, and the ethyl esters of 2-, 3-, and 4-methylpentanoic acids. While Cava has a less specific aroma profile halfway between these special wines and young white wines, PX is richest in 3-methylbutanal, furfural, beta-damascenone, ethyl cyclohexanoate, and sotolon; Fino in acetaldehyde, diacetyl, ethyl esters of branched aliphatic acids with four, five, or six carbon atoms, and 4-ethylguaiacol; and Sauternes in phenylacetaldehyde, 3-mercaptohexanol, and 4-methyl-4-mercaptopentanone.

  6. MaizeGDB: New tools and resource

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB, the USDA-ARS genetics and genomics database, is a highly curated, community-oriented informatics service to researchers focused on the crop plant and model organism Zea mays. MaizeGDB facilitates maize research by curating, integrating, and maintaining a database that serves as the central...

  7. The Genetic Architecture of Maize Flowering Time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering time is the key trait controlling adaptation of plants to their local environment, and, in an outcrossing species like maize, it is a complex trait. Variation for this complex trait was dissected in maize using a novel set of 5000 recombinant inbred lines (maize Nested Association Mapping...

  8. MaizeGDB's New Genome Browser Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. Based upon the 2006 MaizeGDB Working Group Report (available at http://www.maizegdb.org/working_group.php) and the Allerton Report (http://www.maizegdb.org/AllertonReport.doc), it has become evident that th...

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

    PubMed

    Assem, Shireen K

    2015-01-01

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

  10. Global maize production, utilization, and consumption.

    PubMed

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

    2014-04-01

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

  11. Maize-targeted mutagenesis: A knockout resource for maize.

    PubMed

    May, Bruce P; Liu, Hong; Vollbrecht, Erik; Senior, Lynn; Rabinowicz, Pablo D; Roh, Donna; Pan, Xiaokang; Stein, Lincoln; Freeling, Mike; Alexander, Danny; Martienssen, Rob

    2003-09-30

    We describe an efficient system for site-selected transposon mutagenesis in maize. A total of 43,776 F1 plants were generated by using Robertson's Mutator (Mu) pollen parents and self-pollinated to establish a library of transposon-mutagenized seed. The frequency of new seed mutants was between 10-4 and 10-5 per F1 plant. As a service to the maize community, maize-targeted mutagenesis selects insertions in genes of interest from this library by using the PCR. Pedigree, knockout, sequence, phenotype, and other information is stored in a powerful interactive database (maize-targeted mutagenesis database) that enables analysis of the entire population and the handling of knockout requests. By inhibiting Mu activity in most F1 plants, we sought to reduce somatic insertions that may cause false positives selected from pooled tissue. By monitoring the remaining Mu activity in the F2, however, we demonstrate that seed phenotypes depend on it, and false positives occur in lines that appear to lack it. We conclude that more than half of all mutations arising in this population are suppressed on losing Mu activity. These results have implications for epigenetic models of inbreeding and for functional genomics.

  12. Betaine Deficiency in Maize 1

    PubMed Central

    Lerma, Claudia; Rich, Patrick J.; Ju, Grace C.; Yang, Wen-Ju; Hanson, Andrew D.; Rhodes, David

    1991-01-01

    Maize (Zea mays L.) is a betaine-accumulating species, but certain maize genotypes lack betaine almost completely; a single recessive gene has been implicated as the cause of this deficiency (D Rhodes, PJ Rich [1988] Plant Physiol 88: 102-108). This study was undertaken to determine whether betaine deficiency in diverse maize germplasm is conditioned by the same genetic locus, and to define the biochemical lesion(s) involved. Complementation tests indicated that all 13 deficient genotypes tested shared a common locus. One maize population (P77) was found to be segregating for betaine deficiency, and true breeding individuals were used to produce related lines with and without betaine. Leaf tissue of both betaine-positive and betaine-deficient lines readily converted supplied betaine aldehyde to betaine, but only the betaine-containing line was able to oxidize supplied choline to betaine. This locates the lesion in betaine-deficient plants at the choline → betaine aldehyde step of betaine synthesis. Consistent with this location, betaine-deficient plants were shown to have no detectable endogenous pool of betaine aldehyde. PMID:16668098

  13. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2007 report for MaizeGDB lists the new hires who will focus on curation/outreach and the genome sequence, respectively. Currently all sequence in the database comes from a PlantGDB pipeline and is presented with deep links to external resources such as PlantGDB, Dana Farber, GenBank, the Arizona...

  14. Ontogeny of the maize shoot apical meristem.

    PubMed

    Takacs, Elizabeth M; Li, Jie; Du, Chuanlong; Ponnala, Lalit; Janick-Buckner, Diane; Yu, Jianming; Muehlbauer, Gary J; Schnable, Patrick S; Timmermans, Marja C P; Sun, Qi; Nettleton, Dan; Scanlon, Michael J

    2012-08-01

    The maize (Zea mays) shoot apical meristem (SAM) arises early in embryogenesis and functions during stem cell maintenance and organogenesis to generate all the aboveground organs of the plant. Despite its integral role in maize shoot development, little is known about the molecular mechanisms of SAM initiation. Laser microdissection of apical domains from developing maize embryos and seedlings was combined with RNA sequencing for transcriptomic analyses of SAM ontogeny. Molecular markers of key events during maize embryogenesis are described, and comprehensive transcriptional data from six stages in maize shoot development are generated. Transcriptomic profiling before and after SAM initiation indicates that organogenesis precedes stem cell maintenance in maize; analyses of the first three lateral organs elaborated from maize embryos provides insight into their homology and to the identity of the single maize cotyledon. Compared with the newly initiated SAM, the mature SAM is enriched for transcripts that function in transcriptional regulation, hormonal signaling, and transport. Comparisons of shoot meristems initiating juvenile leaves, adult leaves, and husk leaves illustrate differences in phase-specific (juvenile versus adult) and meristem-specific (SAM versus lateral meristem) transcript accumulation during maize shoot development. This study provides insight into the molecular genetics of SAM initiation and function in maize.

  15. MaizeGDB: Global support for maize research through open access information [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the open-access global repository for maize genetic and genomic information – from single genes that determine nutritional quality to whole genome-scale data for complex traits including yield and drought tolerance. The data and tools at MaizeGDB enable researchers from Ethiopia to Ghan...

  16. Application of sequence-independent amplification (SIA) for the identification of RNA viruses in bioenergy crops.

    PubMed

    Agindotan, Bright O; Ahonsi, Monday O; Domier, Leslie L; Gray, Michael E; Bradley, Carl A

    2010-10-01

    Miscanthus x giganteus, energycane, and Panicum virgatum (switchgrass) are three potential biomass crops being evaluated for commercial cellulosic ethanol production. Viral diseases are potentially significant threats to these crops. Therefore, identification of viruses infecting these bioenergy crops is important for quarantine purposes, virus resistance breeding, and production of virus-free planting materials. The application is described of sequence-independent amplification, for the identification of RNA viruses in bioenergy crops. The method involves virus partial purification from a small amount of infected leaf tissue (miniprep), extraction of viral RNA, amplification of randomly primed cDNAs, cloning, sequencing, and BLAST searches for sequence homology in the GenBank. This method has distinct advantage over other virus characterization techniques in that it does not require reagent specific to target viruses. Using this method, a possible new species was identified in the genus Marafivirus in switchgrass related to Maize rayado fino virus, its closest relative currently in GenBank. Sugarcane mosaic virus (SCMV), genus Potyvirus, was identified in M.xgiganteus, energycane, corn (Zea mays), and switchgrass. Other viruses identified were: Maize dwarf mosaic virus (MDMV), genus Potyvirus, in johnsongrass (Sorghum halepense); Soil borne wheat mosaic virus (SBWMV), genus Furovirus, in wheat (Triticum aestivum); and Bean pod mottle virus (BPMV), genus Comovirus, in soybean (Glycine max). The method was as sensitive as conventional RT-PCR. This is the first report of a Marafivirus infecting switchgrass, and SCMV infecting both energycane and M. x giganteus.

  17. Maize genome sequencing by methylation filtration.

    PubMed

    Palmer, Lance E; Rabinowicz, Pablo D; O'Shaughnessy, Andrew L; Balija, Vivekanand S; Nascimento, Lidia U; Dike, Sujit; de la Bastide, Melissa; Martienssen, Robert A; McCombie, W Richard

    2003-12-19

    Gene enrichment strategies offer an alternative to sequencing large and repetitive genomes such as that of maize. We report the generation and analysis of nearly 100,000 undermethylated (or methylation filtration) maize sequences. Comparison with the rice genome reveals that methylation filtration results in a more comprehensive representation of maize genes than those that result from expressed sequence tags or transposon insertion sites sequences. About 7% of the repetitive DNA is unmethylated and thus selected in our libraries, but potentially active transposons and unmethylated organelle genomes can be identified. Reverse transcription polymerase chain reaction can be used to finish the maize transcriptome.

  18. The iojap gene in maize

    SciTech Connect

    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.

  19. [New technology in maize breeding].

    PubMed

    Konstantinov, K; Mladenović, S; Stojkov, S; Delić, N; Gosić, S; Petrović, R; Lević, J; Denić, M

    1992-01-01

    Results obtained by several approaches in the application of Biotechnology in maize breeding are reviewed. RFLP technology in the determination of genetic variation; gene transfer by the use of different methods of gene delivery and the determination of gene integration. Three technologies for foreign gene introduction have been applied; injection of plasmid pRT100 neo into archesporial tissue before micro and macro sporogenesis, slightly modified pollen-tube pathway technology and dry seed incubation in plasmid DNA solution. NPTII gene integration was followed by dot-blot and Southern blot analysis of plant DNA of both T1 and T2 plants. Gene expression was analysed by neomycin phosphotransferase activity. Transformed plants contained the selective NPTII gene sequence in an active form. Bacterial gene integration induced several heritable changes of plant phenotype. As an important change, alteration of the flowering time has been used as a criterion for selection and plant propagation to keep transformed progeny. Besides plant genome transformation, endogenous bacteria living in different maize tissue were found. As a perspective approach for biotechnology application in maize breeding biological vaccine construction has been selected. Therefore, antagonistic effect of gram positive bacterial strains to several pathogenic fungi was investigated. Results obtained after in vivo experiments are discussed.

  20. Resistance of maize landraces to the maize weevil Sitophilus zeamais Motsch. (Coleoptera: Curculionidae).

    PubMed

    Mikami, A Y; Carpentieri-Pípolo, V; Ventura, Maurício Ursi

    2012-10-01

    The maize weevil Sitophilus zeamais Motsch. is an important pest of maize that attacks the grain both in the field and during storage. The damage caused by the maize weevil S. zeamais on maize landraces, Amarelo Antigo, Asteca, Caiano, Carioca, and Ferrinho, was evaluated by no-choice tests under laboratory conditions. The commercial varieties Sol da Manhã, BR 106, BR 451, and the synthetics PC 0203 and PC 9903 were evaluated for comparisons with the maize landraces. The parameters evaluated were susceptibility index, number of weevil progeny, development time, weevil progeny dry weight, and grain dry weight loss. The landraces were more susceptible to the maize weevil as compared to the commercial varieties. Based on the cluster analysis, two groups of susceptibility to the maize weevil were observed: one of more susceptible populations formed by local landraces and BR 451, and another less susceptible, with commercial varieties, synthetics, and the landrace Amarelo.

  1. Registration of maize inbred line 'GT888'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) inbred line GT888 (PI 670116) was developed and released by the USDA-ARS in cooperation with the University of Georgia, and in participation with the USDA Germplasm Enhancement of Maize (GEM) project. GT888 was derived from GEM population DK888:N11 (GEMN-0177), which has 50% tro...

  2. Use of tropical maize for bioethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. A meteorologically driven maize stress indicator model

    NASA Technical Reports Server (NTRS)

    Taylor, T. W.; Ravet, F. W. (Principal Investigator)

    1981-01-01

    A maize soil moisture and temperature stress model is described which was developed to serve as a meteorological data filter to alert commodity analysts to potential stress conditions in the major maize-producing areas of the world. The model also identifies optimum climatic conditions and planting/harvest problems associated with poor tractability.

  4. Maize metabolic network construction and transcriptome analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A framework for understanding the synthesis and catalysis of metabolites and other biochemicals by proteins is crucial for unraveling the physiology of cells. To create such a framework for Zea mays ssp. mays (maize), we developed MaizeCyc a metabolic network of enzyme catalysts, proteins, carbohydr...

  5. The genetic architecture of maize height

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Viruses in maize and Johnsongrass in southern Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two major maize viruses in the United States, Maize dwarf mosaic virus and Maize chlorotic dwarf virus, were first described in Southern Ohio and surrounding regions in the 1960s when they were major problems in maize (Zea mays L.) production. Planting resistant varieties and changing cultural prac...

  7. Transgenic maize plants by tissue electroporation.

    PubMed Central

    D'Halluin, K; Bonne, E; Bossut, M; De Beuckeleer, M; Leemans, J

    1992-01-01

    In this paper, we describe the transformation of regenerable maize tissues by electroporation. In many maize lines, immature zygotic embryos can give rise to embryogenic callus cultures from which plants can be regenerated. Immature zygotic embryos or embryogenic type I calli were wounded either enzymatically or mechanically and subsequently electroporated with a chimeric gene encoding neomycin phosphotransferase (neo). Transformed embryogenic calli were selected from electroporated tissues on kanamycin-containing media and fertile transgenic maize plants were regenerated. The neo gene was transmitted to the progeny of kanamycin-resistant transformants in a Mendelian fashion. This showed that all transformants were nonchimeric, suggesting that transformation and regeneration are a single-cell event. The maize transformation procedure presented here does not require the establishment of genotype-dependent embryogenic type II callus or cell suspension cultures and facilitates the engineering of new traits into agronomically relevant maize inbred lines. PMID:1334743

  8. Co-infection and disease severity of Ohio Maize dwarf mosaic virus and Maize chlorotic dwarf virus strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two major maize viruses have been reported in the United States: Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV). These viruses co-occur in regions where maize is grown such that co-infections are likely. Co-infection of different strains of MCDV is also observed frequently...

  9. INTEGRATED WEED CONTROL IN MAIZE.

    PubMed

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

    2015-01-01

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

  10. Effects of salts on the gelatinization and retrogradation properties of maize starch and waxy maize starch.

    PubMed

    Wang, Wei; Zhou, Hongxian; Yang, Hong; Zhao, Siming; Liu, Youming; Liu, Ru

    2017-01-01

    The objective of this study was to evaluate the effects of salts on the gelatinization and retrogradation of maize and waxy maize starch. Experimental results showed that the salting-out or structure-making ions, such as F(-) and SO4(2-), decreased the swelling power, solubility and transparency of both starches, but increased the gelatinization temperature, enthalpy, and syneresis, due to the tendency of these ions to protect the hydrogen bond links among starch molecules. On the other hand, the salting-in or structure-breaking ions, such as I(-) and SCN(-), exhibited the opposite effects. Microscopic observations confirmed such effects of salts on both starches. Furthermore, the effects of salts were more significant on waxy maize and on normal maize starch. Generally, salts could significantly influence on the gelatinization and retrogradation of maize and waxy maize starch, following the order of the Hofmeister series.

  11. Reshaping of the maize transcriptome by domestication

    PubMed Central

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

    2012-01-01

    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. PMID:22753482

  12. Cytological modifications in maize plants infected by barley yellow dwarf virus and maize dwarf mosaic virus.

    PubMed

    Musetti, R; Bruni, L; Favali, M A

    2002-01-01

    Three inbred lines of maize (33-16, MO17 and B73) differing in their susceptibility to Barley yellow dwarf virus and Maize dwarf mosaic virus were studied to compare the ultrastructural modifications induced by the two viruses in leaf tissues of different age. The results demonstrate that the alterations induced by the two viruses in the different maize lines could depend on the particular line tested.

  13. Hardness methods for testing maize kernels.

    PubMed

    Fox, Glen; Manley, Marena

    2009-07-08

    Maize is a highly important crop to many countries around the world, through the sale of the maize crop to domestic processors and subsequent production of maize products and also provides a staple food to subsistance farms in undeveloped countries. In many countries, there have been long-term research efforts to develop a suitable hardness method that could assist the maize industry in improving efficiency in processing as well as possibly providing a quality specification for maize growers, which could attract a premium. This paper focuses specifically on hardness and reviews a number of methodologies as well as important biochemical aspects of maize that contribute to maize hardness used internationally. Numerous foods are produced from maize, and hardness has been described as having an impact on food quality. However, the basis of hardness and measurement of hardness are very general and would apply to any use of maize from any country. From the published literature, it would appear that one of the simpler methods used to measure hardness is a grinding step followed by a sieving step, using multiple sieve sizes. This would allow the range in hardness within a sample as well as average particle size and/or coarse/fine ratio to be calculated. Any of these parameters could easily be used as reference values for the development of near-infrared (NIR) spectroscopy calibrations. The development of precise NIR calibrations will provide an excellent tool for breeders, handlers, and processors to deliver specific cultivars in the case of growers and bulk loads in the case of handlers, thereby ensuring the most efficient use of maize by domestic and international processors. This paper also considers previous research describing the biochemical aspects of maize that have been related to maize hardness. Both starch and protein affect hardness, with most research focusing on the storage proteins (zeins). Both the content and composition of the zein fractions affect

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

    PubMed Central

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

    2008-01-01

    In 2001 maize became the number one production crop in the world with the Food and Agriculture Organization of the United Nations reporting over 614 million tonnes produced. Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses. Not only is maize an excellent source of food, feed, and fuel, but also its by-products are used in the production of various commercial products. Maize's unparalleled success in agriculture stems from basic research, the outcomes of which drive breeding and product development. In order for basic, translational, and applied researchers to benefit from others' investigations, newly generated data must be made freely and easily accessible. MaizeGDB is the maize research community's central repository for genetics and genomics information. The overall goals of MaizeGDB are to facilitate access to the outcomes of maize research by integrating new maize data into the database and to support the maize research community by coordinating group activities. PMID:18769488

  15. Choosing a Genome Browser for a Model Organism Database (MOD): Surveying the Maize Community

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the maize genome sequencing is nearing its completion, the Maize Genetics and Genomics Database (MaizeGDB), the Model Organism Database for maize, integrated a genome browser to its already existing Web interface and database. The addition of the MaizeGDB Genome Browser to MaizeGDB will allow it ...

  16. Evaluation of maize yield in an on-farm maize-soybean and maize-Lablab crop rotation systems in the Northern Guinea Savanna of Nigeria.

    PubMed

    Okogun, J A; Sanginga, N; Abaidoo, R C

    2007-11-01

    An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS) of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-cycle of soybean/maize and Lablab/maize crop rotation in NGS Nigeria was assessed in researcher-managed and farmer-managed plots. Though maize that followed the soybean received between 5 kg N ha(-1) from improved soybean variety (TGx 1448-2E) and 17 kg N ha(-1) from farmer soybean variety (Samsoy-2) as N balance, this did not significantly (p = 0.05) affect the maize yields. The soybean shed 90-100% of its leaves at physiological maturity which resulted in about 110 kg N ha(-1) N uptake. This source of N might be one of the factors responsible for the increase in maize yield that followed soybean (20 to 24%) compared with continuous maize yield plot. Maize yield in previous Lablab plot was significantly (p = 0.05) higher than in all other treatments. Maize yield in farmer-managed plot ranged between 0.13 and 4.53 t ha(-1), maize yield in researcher-managed plot was over 200% higher than maize yield in farmer-managed plot because of poor crop management on the part of the farmer.

  17. Open chromatin reveals the functional maize genome

    PubMed Central

    Rodgers-Melnick, Eli; Vera, Daniel L.; Bass, Hank W.

    2016-01-01

    Cellular processes mediated through nuclear DNA must contend with chromatin. Chromatin structural assays can efficiently integrate information across diverse regulatory elements, revealing the functional noncoding genome. In this study, we use a differential nuclease sensitivity assay based on micrococcal nuclease (MNase) digestion to discover open chromatin regions in the maize genome. We find that maize MNase-hypersensitive (MNase HS) regions localize around active genes and within recombination hotspots, focusing biased gene conversion at their flanks. Although MNase HS regions map to less than 1% of the genome, they consistently explain a remarkably large amount (∼40%) of heritable phenotypic variance in diverse complex traits. MNase HS regions are therefore on par with coding sequences as annotations that demarcate the functional parts of the maize genome. These results imply that less than 3% of the maize genome (coding and MNase HS regions) may give rise to the overwhelming majority of phenotypic variation, greatly narrowing the scope of the functional genome. PMID:27185945

  18. High-value products from transgenic maize.

    PubMed

    Naqvi, Shaista; Ramessar, Koreen; Farré, Gemma; Sabalza, Maite; Miralpeix, Bruna; Twyman, Richard M; Capell, Teresa; Zhu, Changfu; Christou, Paul

    2011-01-01

    Maize (also known as corn) is a domesticated cereal grain that has been grown as food and animal feed for tens of thousands of years. It is currently the most widely grown crop in the world, and is used not only for food/feed but also to produce ethanol, industrial starches and oils. Maize is now at the beginning of a new agricultural revolution, where the grains are used as factories to synthesize high-value molecules. In this article we look at the diversity of high-value products from maize, recent technological advances in the field and the emerging regulatory framework that governs how transgenic maize plants and their products are grown, used and traded.

  19. [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].

    PubMed

    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

  20. Climate Change and Maize Yield in Iowa

    PubMed Central

    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. PMID:27219116

  1. Climate Change and Maize Yield in Iowa.

    PubMed

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2001, maize became the number one production crop in the world (with over 614 million tons produced; http://faostat.fao.org). Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses: not only is maize an excellent source of food, feed, and fuel, its...

  3. MaizeGDB update: New tools, data, and interface for the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

  4. Impact of 9 years of Bt-maize cultivation on the distribution of maize viruses.

    PubMed

    Achon, Maria Angeles; Alonso-Dueñas, Natalia

    2009-06-01

    This study assesses the effect of Bt-maize on the distribution of maize viruses. Random surveys were conducted in Spain between 2001 and 2006 to evaluate the occurrence of maize viruses in Bt-maize cultivation areas and in areas where this crop had not been introduced. Maize dwarf mosaic virus (MDMV) was the predominant virus in Bt-areas, and Maize rough dwarf virus (MRDV) was the most predominant one in non-Bt-areas, with MRDV an emergent virus in both types of areas. A decline in the occurrence of MDMV and an increase in that of Sugarcane mosaic virus was observed in Bt-areas. Additionally, data obtained over 6 years in experimental fields showed non-significant differences between the infection rates exhibited by two generations of Bt varieties and the non-transformed isogenics varieties for any of the viruses. Our data suggest that differences in virus distribution are linked to the genetic background of the maize varieties and the distribution of virus reservoirs rather than to Bt-maize cultivation.

  5. Expression of an anthranilate synthase from maize mutant bf-1 in maize line HiII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize mutant bf-1 was one of a series of maize mutants generated by radiation from the Bikini Atoll atomic bomb test in 1946. It is characterized by blue fluorescence in seedlings and anthers under ultraviolet illumination and by mutant plants giving off a characteristic grape-like odor due to the ...

  6. Expanding maize genetic resources with predomestication alleles: maize-teosinte introgression populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teosinte (Zea mays ssp. parviglumis) has greater genetic diversity than maize inbreds and landraces (Z. mays ssp. mays). There are, however, limited genetic resources to efficiently evaluate and tap this diversity. To broaden resources for genetic diversity studies in maize, we developed and evaluat...

  7. Network analysis of maize RNA transport pathway genes associated with maize resistance to aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is a pathogenic fungus producing alfatoxins that cause significant economic losses in maize production. This study analyzes the differences in expression levels of maize genes in response to A. flavus infection and aflatoxin accumulation. Identification of defense related genes an...

  8. Complete sequence of Fig fleck-associated virus, a novel member of the family Tymoviridae.

    PubMed

    Elbeaino, Toufic; Digiaro, Michele; Martelli, Giovanni P

    2011-11-01

    The complete nucleotide sequence and the genome organization were determined of a novel virus, tentatively named Fig fleck-associated virus (FFkaV). The viral genome is a positive-sense, single-stranded RNA 7046 nucleotides in size excluding the 3'-terminal poly(A) tract, and comprising two open reading frames. ORF1 encodes a polypeptide of 2161 amino acids (p240), which contains the signatures of replication-associated proteins and the coat protein cistron (p24) at its 3' end. ORF2 codes for a 461 amino acid protein (p50) identified as a putative movement proteins (MP). In phylogenetic trees constructed with sequences of the putative polymerase and CP proteins FFkaV consistently groups with members of the genus Maculavirus, family Tymoviridae. However, the genome organization diverges from that of the two completely sequenced maculaviruses, Grapevine fleck virus (GFkV) and Bombix mori Macula-like virus (BmMLV), as it exhibits a structure resembling that of Maize rayado fino virus (MRFV), the type species of the genus Marafivirus and of Olive latent virus 3 (OLV-3), an unclassified virus in the family Tymoviridae. FFkaV was found in field-grown figs from six Mediterranean countries with an incidence ranging from 15% to 25%.

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

    PubMed

    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 <0.01, <0.01, and 0.01-0.03 mg kg(-1), respectively. The final pesticide residues on maize were lower than the maximum residue limit (MRL) of 0.02 mg kg(-1) after a 14-day pre-harvest interval. Therefore, a dosage of 72 g a.i. ha(-1) was recommended, as it can be considered safe to human beings and animals.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Genetic architecture of domestication-related traits in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 genet...

  12. Study Progress on Tissue Culture of Maize Mature Embryo

    NASA Astrophysics Data System (ADS)

    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.

  13. The genetic architecture of maize height.

    PubMed

    Peiffer, Jason A; Romay, Maria C; Gore, Michael A; Flint-Garcia, Sherry A; Zhang, Zhiwu; Millard, Mark J; Gardner, Candice A C; McMullen, Michael D; Holland, James B; Bradbury, Peter J; Buckler, Edward S

    2014-04-01

    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 among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in >64,500 plots across 13 environments. These plots contained >7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be >90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of height variation. The effects of two tropical alleles at this QTL were independently validated by fine mapping in NIL families. Several significant associations found by GWAS colocalized with established height loci, including brassinosteroid-deficient dwarf1, dwarf plant1, and semi-dwarf2. GBLUP explained >80% of height variation in the panels and outperformed bootstrap aggregation of family-nested QTL models in evaluations of prediction accuracy. These results revealed maize height was under strong genetic control and had a highly polygenic genetic architecture. They also showed that multiple models of genetic architecture differing in polygenicity and effect sizes can plausibly explain a population's variation in maize height, but they may vary in predictive efficacy.

  14. Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

    PubMed

    Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

    2002-01-01

    Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system.

  15. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are often 1 to 2 Mg/ha lower than those achieved when maize is grown in rotation with soybean in the U.S. Midwest. One factor contributing to this difference is the release of phytotoxic compounds as the previous year’s maize residue decomposes. Based on laboratory results sh...

  16. Comprehensive genotyping of the USA national maize inbred seed bank

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The germplasm bank at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa, preserves maize inbred lines from breeding programs from all over the world, including some of the key lines from the breeding history of maize. We genotyped 2,815 maize inbred accessions, mo...

  17. MaizeGDB: everything old is new again! [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The focus of genetic, genomic, and breeding research evolves over time, making it necessary to continually redefine the paradigm for data access and data analysis tools. Here we report the reinvention of MaizeGDB, the maize genetics and genomics database, to meet maize researchers’ ever changing nee...

  18. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are limited by the release of phytotoxic compounds as the previous year’s maize residue decomposes. We tested the hypothesis that soil biochar applications could help mitigate maize autotoxicity and the associated yield depression. Eighteen small field plots (23.7 m2) were es...

  19. Mapping QTL Contributing to SCMV Resistance in Tropical Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane mosaic virus (SCMV) has been increasing in importance as a maize disease in Brazil. In this study, were mapped and characterized quantitative trait loci (QTL) associated to resistance to SCMV in a maize population consisting of 150 F2:3 families from the cross between two tropical maize i...

  20. Fate of maize intrinsic and recombinant genes in calves fed genetically modified maize Bt11.

    PubMed

    Chowdhury, Emdadull H; Mikami, Osamu; Murata, Hideo; Sultana, Parvin; Shimada, Nobuaki; Yoshioka, Miyako; Guruge, Keerthi S; Yamamoto, Sachiko; Miyazaki, Shigeru; Yamanaka, Noriko; Nakajima, Yasuyuki

    2004-02-01

    The presence of maize intrinsic and recombinant cry1Ab genes in the gastrointestinal (GI) contents, peripheral blood mononuclear cells (PBMC), and visceral organs of calves fed genetically modified Bt11 maize was examined by PCR in a subchronic 90-day performance study. Samples were collected from six Japanese Black/Holstein calves fed Bt11 maize and from six calves fed non-Bt maize. Fragments of maize zein (Ze1), invertase, chloroplast, and cry1Ab were detected inconsistently in the rumen fluid and rectal contents 5 and 18 h after feeding. The chloroplast DNA fragments of ribulose-1,5-bisphosphate carboxylase/oxygenase and tRNA were detected inconsistently in the PBMC, the visceral organs, and the longissimus muscle, while the cry1Ab gene was never detected in PBMC or in the visceral organs. These results suggest that feed-derived maize DNA was mostly degraded in the GI tract but that fragmented DNA was detectable in the GI contents as a possible source of transfer to calf tissues. These results also suggest that the recombinant cry1Ab genes were not transferred to the PBMC and tissues of calves fed Bt11 maize.

  1. Fungal growth and fusarium mycotoxin content in isogenic traditional maize and genetically modified maize grown in France and Spain.

    PubMed

    Bakan, B; Melcion, D; Richard-Molard, D; Cahagnier, B

    2002-02-13

    Fungi of the genus Fusarium are common fungal contaminants of maize and are also known to produce mycotoxins. Maize that has been genetically modified to express a Bt endotoxin has been used to study the effect of insect resistance on fungal infection of maize grains by Fusarium species and their related mycotoxins. Maize grain from Bt hybrids and near-isogenic traditional hybrids was collected in France and Spain from the 1999 crop, which was grown under natural conditions. According to the ergosterol level, the fungal biomass formed on Bt maize grain was 4-18 times lower than that on isogenic maize. Fumonisin B(1) grain concentrations ranged from 0.05 to 0.3 ppm for Bt maize and from 0.4 to 9 ppm for isogenic maize. Moderate to low concentrations of trichothecenes and zearalenone were measured on transgenic as well as on non-transgenic maize. Nevertheless, significant differences were obtained in certain regions. The protection of maize plants against insect damage (European corn borer and pink stem borer) through the use of Bt technology seems to be a way to reduce the contamination of maize by Fusarium species and the resultant fumonisins in maize grain grown in France and Spain.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

    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.

  4. Digital gene expression signatures for maize development.

    PubMed

    Eveland, Andrea L; Satoh-Nagasawa, Namiko; Goldshmidt, Alexander; Meyer, Sandra; Beatty, Mary; Sakai, Hajime; Ware, Doreen; Jackson, David

    2010-11-01

    Genome-wide expression signatures detect specific perturbations in developmental programs and contribute to functional resolution of key regulatory networks. In maize (Zea mays) inflorescences, mutations in the RAMOSA (RA) genes affect the determinacy of axillary meristems and thus alter branching patterns, an important agronomic trait. In this work, we developed and tested a framework for analysis of tag-based, digital gene expression profiles using Illumina's high-throughput sequencing technology and the newly assembled B73 maize reference genome. We also used a mutation in the RA3 gene to identify putative expression signatures specific to stem cell fate in axillary meristem determinacy. The RA3 gene encodes a trehalose-6-phosphate phosphatase and may act at the interface between developmental and metabolic processes. Deep sequencing of digital gene expression libraries, representing three biological replicate ear samples from wild-type and ra3 plants, generated 27 million 20- to 21-nucleotide reads with frequencies spanning 4 orders of magnitude. Unique sequence tags were anchored to 3'-ends of individual transcripts by DpnII and NlaIII digests, which were multiplexed during sequencing. We mapped 86% of nonredundant signature tags to the maize genome, which associated with 37,117 gene models and unannotated regions of expression. In total, 66% of genes were detected by at least nine reads in immature maize ears. We used comparative genomics to leverage existing information from Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) in functional analyses of differentially expressed maize genes. Results from this study provide a basis for the analysis of short-read expression data in maize and resolved specific expression signatures that will help define mechanisms of action for the RA3 gene.

  5. Blue maize: morphology and starch synthase characterization of starch granule.

    PubMed

    Utrilla-Coello, Rubi G; Agama-Acevedo, Edith; de la Rosa, Ana Paulina Barba; Martinez-Salgado, Jose L; Rodriguez-Ambriz, Sandra L; Bello-Perez, Luis A

    2009-03-01

    The use of pigmented maize varieties has increased due to their high anthocyanins content, but very few studies are reported about the starch properties of these grains. The aim of this work was to isolate the starch granules from pigmented blue maize and carry out the morphological, physicochemical, and biochemical characterization studies. The proximate composition of starch granules showed high protein contents, after purification, the blue maize starch presented lower protein amount than starch from white maize (control). Although the purity of starch granules was increased, the damaged starch (determined for the Maltase cross absence) was also increased. Scanning electron microscopy showed the presence of some pores and channels in the blue maize starch. The electrophoretic protein profiles showed differences in the bands that correspond to the enzymes involved in the starch biosynthesis; these differences could explain the variation in morphological characteristics of blue maize starches against starch from white maize.

  6. Early Events in Maize Seed Development 1

    PubMed Central

    Fong, Franklin; Smith, James D.; Koehler, Don E.

    1983-01-01

    Preharvest sprouting or vivipary is induced in developing maize (Zea mays, inbred Tx 5855 and Va 35) seeds by fluridone, a pyridinone inhibitor of carotenoid biosynthesis. Fluridone has a maximal effect on vivipary at 11 days after pollination (DAP) and little effect at 13 DAP in the inbred maize line Tx 5855. Abscisic acid partially reversed the chemically induced vivipary. Though the precise mechanism of fluridone-induced vivipary is unknown, these results indicate that there are important developmental changes occurring at 11 DAP which reversibly commit the immature embryo to vivipary or dormancy. Images Fig. 1 PMID:16663339

  7. Genomic variation in maize. Progress report, 1990

    SciTech Connect

    Rivin, C.J.

    1990-12-31

    We have endeavored to learn to learn how different DNA sequences and sequence arrangements contribute to genome plasticity in maize. We describe quantitative variation among maize inbred lines for tandemly arrayed and dispersed repeated DNA sequences and gene families, and qualitative variation for sequences homologous to the Mutator family of transposons. The potential of these sequences to undergo unequal crossing over, non-allelic (ectopic) recombination and transposition makes them a source of genome instability. We have found examples of rapid genomic change involving these sequences in F1 hybrids, tissue culture cells and regenerated plants.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. [Detection of genetic modification in maize and maize products by ELISA-test].

    PubMed

    Urbanek-Karłowska, Bogumiła; Sawilska-Rautenstrauch, Dorota; Jedra, Małgorzata; Badowski, Paweł

    2003-01-01

    Enzyme immunoassay methods--TRAIT Test--was applied for detection of genetic modification in maize seeds and foodstuffs, which have been produced from this crop. TRAIT Test is based on the identification GMO protein Cry 1Ab produced by a gene derived from Bacillus thuringiensis (Bt) incorporated into insect resistant corn grain. The experiment was carried out on maize standards and foodstuffs from Warsaw market. The positive result was obtained for one maize product, which was not labelled as GMO. The presence of GMO material was approximately equal to 1%. In conclusion, this test is proper for fast routine qualitative (yes/no) determination GMO material in maize seeds and unprocessed food products.

  10. Individual detection of genetically modified maize varieties in non-identity-preserved maize samples.

    PubMed

    Akiyama, Hiroshi; Sakata, Kozue; Kondo, Kazunari; Tanaka, Asako; Liu, Ming S; Oguchi, Taichi; Furui, Satoshi; Kitta, Kazumi; Hino, Akihiro; Teshima, Reiko

    2008-03-26

    In many countries, the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved GM varieties. The GMO content in a maize sample containing the combined-trait (stacked) GM maize as determined by the currently available methodology is likely to be overestimated. However, there has been little information in the literature on the mixing level and varieties of stacked GM maize in real sample grains. For the first time, the GMO content of non-identity-preserved (non-IP) maize samples imported from the United States has been successfully determined by using a previously developed individual kernel detection system coupled to a multiplex qualitative PCR method followed by multichannel capillary gel electrophoresis system analysis. To clarify the GMO content in the maize samples imported from the United States, determine how many stacked GM traits are contained therein, and which GM trait varieties frequently appeared in 2005, the GMO content (percent) on a kernel basis and the varieties of the GM kernels in the non-IP maize samples imported from the United States were investigated using the individual kernel analysis system. The average (+/-standard deviation) of the GMO contents on a kernel basis in five non-IP sample lots was determined to be 51.0+/-21.6%, the percentage of a single GM trait grains was 39%, and the percentage of the stacked GM trait grains was 12%. The MON810 grains and NK603 grains were the most frequent varieties in the single GM traits. The most frequent stacked GM traits were the MON810xNK603 grains. In addition, the present study would provide the answer and impact for the quantification of GM maize content in the GM maize kernels on labeling regulation.

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

    PubMed Central

    Mousa, Walaa K.; Shearer, Charles R.; Limay-Rios, Victor; Zhou, Ting; Raizada, Manish N.

    2015-01-01

    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. PMID:26500660

  12. Use and impact of Bt maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is an invited article for a free science library and personal training tool sponsored by Nature Publishing Group, which will be included under the topics Agriculture and Biotechnology (http://www.nature.com/scitable). The focus of this article is on Bacillus thuringiensis (Bt) maize. Growers of...

  13. The genetic architecture of maize stalk strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stalk strength is an important trait in maize (Zea mays L.). Strong stalks reduce lodging and maximize harvestable yield. Studies show rind penetrometer resistance (RPR), or the force required to pierce a stalk rind with a spike, is a valid approximation of strength. We measured RPR across 4,892 rec...

  14. Registration of maize inbred line GT603

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GT603 (Reg. No. xxxx, PI xxxxxx) is a yellow dent maize (Zea mays L.) inbred line developed and released by the USDA-ARS Crop Protection and Management Research Unit in cooperation with the University of Georgia Coastal Plain Experiment Station in 2010. GT603 was developed through seven generations ...

  15. Maize and tripsacum: experiments in intergeneric hybridization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research in maize-Tripsacum hybridization is extensive and encompasses a period of more than 60 years of collective research. The publication “The origin of Indian corn and its relatives” describes some of the initial research in this area (Mangelsdorf and Reeves, 1939) and is recommended reading f...

  16. Synthesis and Functions of Jasmonates in Maize

    PubMed Central

    Borrego, Eli J.; Kolomiets, Michael V.

    2016-01-01

    Of the over 600 oxylipins present in all plants, the phytohormone jasmonic acid (JA) remains the best understood in terms of its biosynthesis, function and signaling. Much like their eicosanoid analogues in mammalian system, evidence is growing for the role of the other oxylipins in diverse physiological processes. JA serves as the model plant oxylipin species and regulates defense and development. For several decades, the biology of JA has been characterized in a few dicot species, yet the function of JA in monocots has only recently begun to be elucidated. In this work, the synthesis and function of JA in maize is presented from the perspective of oxylipin biology. The maize genes responsible for catalyzing the reactions in the JA biosynthesis are clarified and described. Recent studies into the function of JA in maize defense against insect herbivory, pathogens and its role in growth and development are highlighted. Additionally, a list of JA-responsive genes is presented for use as biological markers for improving future investigations into JA signaling in maize. PMID:27916835

  17. The transcriptome landscape of early maize meiosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. [Genomic variation in maize]. Final project report

    SciTech Connect

    Rivin, C.J.

    1991-12-31

    These studies have sought to learn how different DNA sequences and sequence arrangements contribute to genome plasticity in maize. We describe quantitative variation among maize inbred lines for tandemly arrayed and dispersed repeated DNA sequences and gene families, and qualitative variation for sequences homologous to the Mutator family of transposons. The potential of these sequences to undergo unequal crossing over, non-allelic (ectopic) recombination and transposition makes them a source of genome instability. We have found examples of rapid genomic change involving these sequences in Fl hybrids, tissue culture cells and regenerated plants. We describe the repetitive portion of the maize genome as composed primarily of sequences that vary markedly in copy number among different genetic stocks. The most highly variable is the 185 bp repeat associated with the heterochromatic chromosome knobs. Even in lines without visible knobs, there is a considerable quantity of tandemly arrayed repeats. We also found a high degree of variability for the tandemly arrayed 5S and ribosomal DNA repeats. While such variation might be expected as the result of unequal cross-over, we were surprised to find considerable variation among lower copy number, dispersed repeats as well. One highly repeated sequence that showed a complex tandem and dispersed arrangement stood out as showing no detectable variability among the maize lines. In striking contrast to the variability seen between the inbred stocks, individuals within a stock were indistinguishable with regard to their repeated sequence multiplicities.

  19. Regulatory modules controlling maize inflorescence architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic control of branching is a primary determinant of yield, regulating seed number and harvesting ability, yet little is known about the molecular networks that shape grain-bearing inflorescences of cereal crops. Here, we used the maize (Zea mays) inflorescence to investigate gene networks that...

  20. Digital gene expression signatures for maize development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genome-wide expression signatures detect specific perturbations in developmental programs and contribute to functional resolution of key regulatory networks. In maize (Zea mays) inflorescences, mutations in the RAMOSA (RA) genes affect determinacy of axillary meristems and thus alter branching patt...

  1. New trait data at MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB has several ways to archive trait data used for QTL and GWAS analyses. The simplest is simple posting of files provided by researchers along with links to the publication. More recently we have begun to integrate these data for diversity recombinant germplasm, and association panels. The go...

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Ontogeny of the Maize Shoot Apical Meristem[W][OA

    PubMed Central

    Takacs, Elizabeth M.; Li, Jie; Du, Chuanlong; Ponnala, Lalit; Janick-Buckner, Diane; Yu, Jianming; Muehlbauer, Gary J.; Schnable, Patrick S.; Timmermans, Marja C.P.; Sun, Qi; Nettleton, Dan; Scanlon, Michael J.

    2012-01-01

    The maize (Zea mays) shoot apical meristem (SAM) arises early in embryogenesis and functions during stem cell maintenance and organogenesis to generate all the aboveground organs of the plant. Despite its integral role in maize shoot development, little is known about the molecular mechanisms of SAM initiation. Laser microdissection of apical domains from developing maize embryos and seedlings was combined with RNA sequencing for transcriptomic analyses of SAM ontogeny. Molecular markers of key events during maize embryogenesis are described, and comprehensive transcriptional data from six stages in maize shoot development are generated. Transcriptomic profiling before and after SAM initiation indicates that organogenesis precedes stem cell maintenance in maize; analyses of the first three lateral organs elaborated from maize embryos provides insight into their homology and to the identity of the single maize cotyledon. Compared with the newly initiated SAM, the mature SAM is enriched for transcripts that function in transcriptional regulation, hormonal signaling, and transport. Comparisons of shoot meristems initiating juvenile leaves, adult leaves, and husk leaves illustrate differences in phase-specific (juvenile versus adult) and meristem-specific (SAM versus lateral meristem) transcript accumulation during maize shoot development. This study provides insight into the molecular genetics of SAM initiation and function in maize. PMID:22911570

  4. The 50th Annual Maize Genetics Conference

    SciTech Connect

    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

  5. Processing maize flour and corn meal food products

    PubMed Central

    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

  6. Genome-Wide Association Implicates Candidate Genes Conferring Resistance to Maize Rough Dwarf Disease in Maize.

    PubMed

    Chen, Gengshen; Wang, Xiaoming; Hao, Junjie; Yan, Jianbing; Ding, Junqiang

    2015-01-01

    Maize rough dwarf disease (MRDD) is a destructive viral disease in China, which results in 20-30% of the maize yield losses in affected areas and even as high as 100% in severely infected fields. Understanding the genetic basis of resistance will provide important insights for maize breeding program. In this study, a diverse maize population comprising of 527 inbred lines was evaluated in four environments and a genome-wide association study (GWAS) was undertaken with over 556000 SNP markers. Fifteen candidate genes associated with MRDD resistance were identified, including ten genes with annotated protein encoding functions. The homologous of nine candidate genes were predicted to relate to plant defense in different species based on published results. Significant correlation (R2 = 0.79) between the MRDD severity and the number of resistance alleles was observed. Consequently, we have broadened the resistant germplasm to MRDD and identified a number of resistance alleles by GWAS. The results in present study also imply the candidate genes in defense pathway play an important role in resistance to MRDD in maize.

  7. Close Split of Sorghum and Maize Genome Progenitors

    PubMed Central

    Swigoňová, Zuzana; Lai, Jinsheng; Ma, Jianxin; Ramakrishna, Wusirika; Llaca, Victor; Bennetzen, Jeffrey L.; Messing, Joachim

    2004-01-01

    It is generally believed that maize (Zea mays L. ssp. mays) arose as a tetraploid; however, the two progenitor genomes cannot be unequivocally traced within the genome of modern maize. We have taken a new approach to investigate the origin of the maize genome. We isolated and sequenced large genomic fragments from the regions surrounding five duplicated loci from the maize genome and their orthologous loci in sorghum, and then we compared these sequences with the orthologous regions in the rice genome. Within the studied segments, we identified 11 genes that were conserved in location, order, and orientation. We performed phylogenetic and distance analyses and examined the patterns of estimated times of divergence for sorghum and maize gene orthologs and also the time of divergence for maize orthologs. Our results support a tetraploid origin of maize. This analysis also indicates contemporaneous divergence of the ancestral sorghum genome and the two maize progenitor genomes about 11.9 million years ago (Mya). On the basis of a putative conversion event detected for one of the genes, tetraploidization must have occurred before 4.8 Mya, and therefore, preceded the major maize genome expansion by gene amplification and retrotransposition. PMID:15466289

  8. Endophytic Chaetomium globosum enhances maize seedling copper stress tolerance.

    PubMed

    Abou Alhamed, M F; Shebany, Y M

    2012-09-01

    This study aims at characterisation of the impact of Chaetomium globosum on copper stress resistance of maize seedlings. Higher levels of copper treatment decreased maize dry weight and induced a marked increase in osmotic solutes, antioxidant enzyme activity and the level of lipid peroxidation. On the other hand, addition of the endophytic C. globosum alleviated the toxic effect of copper on maize growth. The combination of copper sulphate and Chaetomium increased seedling dry weight, osmotic solute content and antioxidant enzyme activity compared to copper sulphate alone, while lipid peroxidation levels were also decreased. The fungal scavenger system might be important for supporting the ability of maize seedlings to resist copper toxicity.

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

    PubMed

    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.

  10. Ultraweak photon emission from herbivory-injured maize plants

    NASA Astrophysics Data System (ADS)

    Yoshinaga, Naoko; Kato, Kimihiko; Kageyama, Chizuko; Fujisaki, Kenji; Nishida, Ritsuo; Mori, Naoki

    2006-01-01

    Following perception of herbivory or infection, plants exhibit a wide range of inducible responses. In this study, we found ultraweak photon emissions from maize leaves damaged by Helicoverpa armigera (Noctuidae). Interestingly, mechanically damaged maize leaves treated with caterpillar regurgitants emitted the same intensity and pattern of photon emissions as those from maize leaves damaged by caterpillars. Furthermore, two-dimensional imaging of the leaf section treated with the oral secretions clearly shows that photon emissions were observed specifically at the lip of the wound exposed to the secretions. These results suggest that the direct interaction between maize leaf cells and chemicals contained in caterpillar regurgitants triggers these photon emissions.

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

    PubMed

    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.

  12. Iron bioavailability of maize hemoglobin in a Caco-2 cell culture model.

    PubMed

    Bodnar, Anastasia L; Proulx, Amy K; Scott, M Paul; Beavers, Alyssa; Reddy, Manju B

    2013-07-31

    Maize ( Zea mays ) is an important staple crop in many parts of the world but has low iron bioavailability, in part due to its high phytate content. Hemoglobin is a form of iron that is highly bioavailable, and its bioavailability is not inhibited by phytate. It was hypothesized that maize hemoglobin is a highly bioavailable iron source and that biofortification of maize with iron can be accomplished by overexpression of maize globin in the endosperm. Maize was transformed with a gene construct encoding a translational fusion of maize globin and green fluorescent protein under transcriptional control of the maize 27 kDa γ-zein promoter. Iron bioavailability of maize hemoglobin produced in Escherichia coli and of stably transformed seeds expressing the maize globin-GFP fusion was determined using an in vitro Caco-2 cell culture model. Maize flour fortified with maize hemoglobin was found to have iron bioavailability that is not significantly different from that of flour fortified with ferrous sulfate or bovine hemoglobin but is significantly higher than unfortified flour. Transformed maize grain expressing maize globin was found to have iron bioavailability similar to that of untransformed seeds. These results suggest that maize globin produced in E. coli may be an effective iron fortificant, but overexpressing maize globin in maize endosperm may require a different strategy to increase bioavailable iron content in maize.

  13. Root gravitropism in maize and Arabidopsis

    NASA Technical Reports Server (NTRS)

    Evans, Michael L.

    1993-01-01

    Research during the period 1 March 1992 to 30 November 1993 focused on improvements in a video digitizer system designed to automate the recording of surface extension in plants responding to gravistimulation. The improvements included modification of software to allow detailed analysis of localized extension patterns in roots of Arabidopsis. We used the system to analyze the role of the postmitotic isodiametric growth zone (a region between the meristem and the elongation zone) in the response of maize roots to auxin, calcium, touch and gravity. We also used the system to analyze short-term auxin and gravitropic responses in mutants of Arabidopsis with reduced auxin sensitivity. In a related project, we studied the relationship between growth rate and surface electrical currents in roots by examining the effects of gravity and thigmostimulation on surface potentials in maize roots.

  14. Maize arabinoxylan gels as protein delivery matrices.

    PubMed

    Berlanga-Reyes, Claudia M; Carvajal-Millán, Elizabeth; Lizardi-Mendoza, Jaime; Rascón-Chu, Agustin; Marquez-Escalante, Jorge A; Martínez-López, Ana Luisa

    2009-04-08

    The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v) in the presence of insulin or beta-lactoglobulin at 0.1% (w/v) was investigated. Insulin and beta-lacto-globulin did not modify either the gel elasticity (9 Pa) or the cross-links content (0.03 and 0.015 microg 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 x 10(-7) and 0.79 x 10(-7) cm(2)/s for insulin (5 kDa) and beta-lactoglobulin (18 kDa), respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.

  15. Peptide regulation of Maize defense reponses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ZmPEP1 is a peptide signal encoded by a previously uncharacterized maize gene that we have named ZmPROPEP1. The ZmPROPEP1 gene was identified by homology to the Arabidopsis AtPROPEP1 gene that encodes the precursor protein to the peptide signal AtPEP1. Together with its receptors, AtPEPR1 and AtPEP...

  16. Genetic erosion in maize's center of origin.

    PubMed

    Dyer, George A; López-Feldman, Alejandro; Yúnez-Naude, Antonio; Taylor, J Edward

    2014-09-30

    Crop genetic diversity is an indispensable resource for farmers and professional breeders responding to changing climate, pests, and diseases. Anecdotal appraisals in centers of crop origin have suggested serious threats to this diversity for over half a century. However, a nationwide inventory recently found all maize races previously described for Mexico, including some formerly considered nearly extinct. A flurry of social studies seems to confirm that farmers maintain considerable diversity. Here, we compare estimates of maize diversity from case studies over the past 15 y with nationally and regionally representative matched longitudinal data from farmers across rural Mexico. Our findings reveal an increasing bias in inferences based on case study results and widespread loss of diversity. Cross-sectional, case study data suggest that farm-level richness has increased by 0.04 y(-1) nationwide; however, direct estimates using matched longitudinal data reveal that richness dropped -0.04 y(-1) between 2002 and 2007, from 1.43 to 1.22 varieties per farm. Varietal losses occurred across regions and altitudinal zones, and regardless of farm turnover within the sector. Extinction of local maize populations may not have resulted in an immediate loss of alleles, but low varietal richness and changes in maize's metapopulation dynamics may prevent farmers from accessing germplasm suitable to a rapidly changing climate. Declining yields could then lead farmers to leave the sector and result in a further loss of diversity. Similarities in research approaches across crops suggest that methodological biases could conceal a loss of diversity at other centers of crop origin.

  17. Intraspecific variation of recombination rate in maize

    PubMed Central

    2013-01-01

    Background In sexually reproducing organisms, meiotic crossovers ensure the proper segregation of chromosomes and contribute to genetic diversity by shuffling allelic combinations. Such genetic reassortment is exploited in breeding to combine favorable alleles, and in genetic research to identify genetic factors underlying traits of interest via linkage or association-based approaches. Crossover numbers and distributions along chromosomes vary between species, but little is known about their intraspecies variation. Results Here, we report on the variation of recombination rates between 22 European maize inbred lines that belong to the Dent and Flint gene pools. We genotype 23 doubled-haploid populations derived from crosses between these lines with a 50 k-SNP array and construct high-density genetic maps, showing good correspondence with the maize B73 genome sequence assembly. By aligning each genetic map to the B73 sequence, we obtain the recombination rates along chromosomes specific to each population. We identify significant differences in recombination rates at the genome-wide, chromosome, and intrachromosomal levels between populations, as well as significant variation for genome-wide recombination rates among maize lines. Crossover interference analysis using a two-pathway modeling framework reveals a negative association between recombination rate and interference strength. Conclusions To our knowledge, the present work provides the most comprehensive study on intraspecific variation of recombination rates and crossover interference strength in eukaryotes. Differences found in recombination rates will allow for selection of high or low recombining lines in crossing programs. Our methodology should pave the way for precise identification of genes controlling recombination rates in maize and other organisms. PMID:24050704

  18. Gibberellins and Heterosis in Maize 1

    PubMed Central

    Rood, Stewart B.; Blake, Terence J.; Pharis, Richard P.

    1983-01-01

    Two maize inbreds, CM7 and CM49, and CM7 × CM49, their F1 hybrid (which displayed significant heterosis), were examined with regard to response to exogenous gibberellin A3 (GA3), and in their ability to metabolize GA20, a native GA of maize. The leaf sheath elongation response to GA3 was far greater for the imbreds than for their hybrid. The inbreds also displayed significant elongation of the leaf blades in response to GA3, whereas the hybrid was unaffected. Promotion of cell division in the leaf sheath of CM7 and the hybrid was effected by GA3, but no promotion of cell elongation was observed in CM49, even though significant leaf sheath elongation occurred. Shoot dry weight of both inbreds was significantly increased by GA3, but response by the hybrid in this parameter was slight and variable. Root dry weight of CM7 was significantly increased by GA3, but was unchanged in CM49 and the hybrid. Thus, inbred shoot dry weight increases effected by GA3 were not at the expense of the root system. Rapid metabolism of [2,3-3H]GA20 occurred in all genotypes, although genotypic differences were observed. The hybrid had the highest rates of metabolism to GA glucosyl conjugate-like substances. Oxidative metabolism was also fastest in the hybrid, followed by CM7, and slowest in CM49, the slowest-growing inbred. Thus, rate of GA20 metabolism is under genetic control in normal (i.e. not dwarfed) maize genotypes. These results, taken together with previous reports that the hybrid has significantly enhanced levels of endogenous GA-like substances, suggest that GA play a role in the expression of heterosis in maize. Images Fig. 2 PMID:16662881

  19. Effects of Selected Diazotrophs on Maize Growth

    PubMed Central

    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

  20. Temperature sensing by primary roots of maize

    NASA Technical Reports Server (NTRS)

    Poff, K. L.

    1990-01-01

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

  1. Phenotyping maize for adaptation to drought

    PubMed Central

    Araus, Jose L.; Serret, María D.; Edmeades, Gregory O.

    2012-01-01

    The need of a better adaptation of crops to drought is an issue of increasing urgency. However, enhancing the tolerance of maize has, therefore, proved to be somewhat elusive in terms of plant breeding. In that context, proper phenotyping remains as one of the main factors limiting breeding advance. Topics covered by this review include the conceptual framework for identifying secondary traits associated with yield response to drought and how to measure these secondary traits in practice. PMID:22934056

  2. Natural maize phenolic acids for control of aflatoxigenic fungi on maize.

    PubMed

    Nesci, A; Gsponer, N; Etcheverry, M

    2007-06-01

    Natural phytochemicals may be an alternative to synthetic chemicals for controlling fungal growth and mycotoxin production in stored maize. A key to progress in this field is to select the best natural maize phytochemicals to be applied in a storage maize ecosystem. This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) and ferulic acid (FA) alone at concentrations of 20 to 30 mM and in 5 combinations on Aspergillus flavus Link and A. parasiticus Speare populations and aflatoxin B(1) production. Studies on Aspergillus population and aflatoxin B(1) production were carried out in maize grain in relation to a water activity a(w) of 0.99, 0.97, 0.95, and 0.93. CA and FA at concentrations of 25 to 30 mM, respectively, and CA-FA mixture T9 (25 + 30 mM) were the treatments most effective at inhibiting A. flavus and A. parasiticus population at all a(w) assayed after 11 d of incubation. At all a(w) values, the mixture CA-FA T9 (25 + 30 mM) completely inhibited (100%) aflatoxin B(1) production by both strains at a(w)= 0.99, 0.97, 0.95, and 0.93. Decreased aflatoxin B(1) levels in comparison with the control were observed with mixtures CA-FA T6 (10 + 25 mM), T7 (20 + 20 mM), and T8 (20 + 30 mM) of both strains in the majority of a(w) assayed. The data show that CA and FA could be considered as effective fungitoxicants for A. flavus and A. parasiticus in maize in the a(w) range 0.99 to 0.93. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.

  3. Brassinosteroid control of sex determination in maize.

    PubMed

    Hartwig, Thomas; Chuck, George S; Fujioka, Shozo; Klempien, Antje; Weizbauer, Renate; Potluri, Devi Prasad V; Choe, Sunghwa; Johal, Gurmukh S; Schulz, Burkhard

    2011-12-06

    Brassinosteroids (BRs) are plant hormones that regulate growth and development. They share structural similarities with animal steroids, which are decisive factors of sex determination. BRs are known to regulate morphogenesis and environmental stress responses, but their involvement in sex determination in plants has been only speculative. We show that BRs control sex determination in maize revealed through characterization of the classical dwarf mutant nana plant1 (na1), which also feminizes male flowers. na1 plants carry a loss-of-function mutation in a DET2 homolog--a gene in the BR biosynthetic pathway. The mutant accumulates the DET2-specific substrate (24R)-24-methylcholest-4-en-3-one with a concomitant decrease of downstream BR metabolites. Treatment of wild-type maize plants with BR biosynthesis inhibitors completely mimicked both dwarf and tasselseed phenotypes of na1 mutants. Tissue-specific na1 expression in anthers throughout their development supports the hypothesis that BRs promote masculinity of the male inflorescence. These findings suggest that, in the monoecious plant maize, BRs have been coopted to perform a sex determination function not found in plants with bisexual flowers.

  4. Historical genomics of North American maize.

    PubMed

    van Heerwaarden, Joost; Hufford, Matthew B; Ross-Ibarra, Jeffrey

    2012-07-31

    Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density SNP genotyping to characterize a set of North American maize lines spanning the history of modern breeding. We provide a unique analysis of genome-wide developments in genetic diversity, ancestry, and selection. The genomic history of maize is marked by a steady increase in genetic differentiation and linkage disequilibrium, whereas allele frequencies in the total population have remained relatively constant. These changes are associated with increasing genetic separation of breeding pools and decreased diversity in the ancestry of individual lines. We confirm that modern heterotic groups are the product of ongoing divergence from a relatively homogeneous landrace population, but show that differential landrace ancestry remains evident. Using a recent association approach, we characterize signals of directional selection throughout the genome, identifying a number of candidate genes of potential agronomic relevance. However, overall we find that selection has had limited impact on genome-wide patterns of diversity and ancestry, with little evidence for individual lines contributing disproportionately to the accumulation of favorable alleles in today's elite germplasm. Our data suggest breeding progress has mainly involved selection and recombination of relatively common alleles, contributed by a representative but limited set of ancestral lines.

  5. Sequence composition and genome organization of maize

    PubMed Central

    Messing, Joachim; Bharti, Arvind K.; Karlowski, Wojciech M.; Gundlach, Heidrun; Kim, Hye Ran; Yu, Yeisoo; Wei, Fusheng; Fuks, Galina; Soderlund, Carol A.; Mayer, Klaus F. X.; Wing, Rod A.

    2004-01-01

    Zea mays L. ssp. mays, or corn, one of the most important crops and a model for plant genetics, has a genome ≈80% the size of the human genome. To gain global insight into the organization of its genome, we have sequenced the ends of large insert clones, yielding a cumulative length of one-eighth of the genome with a DNA sequence read every 6.2 kb, thereby describing a large percentage of the genes and transposable elements of maize in an unbiased approach. Based on the accumulative 307 Mb of sequence, repeat sequences occupy 58% and genic regions occupy 7.5%. A conservative estimate predicts ≈59,000 genes, which is higher than in any other organism sequenced so far. Because the sequences are derived from bacterial artificial chromosome clones, which are ordered in overlapping bins, tagged genes are also ordered along continuous chromosomal segments. Based on this positional information, roughly one-third of the genes appear to consist of tandemly arrayed gene families. Although the ancestor of maize arose by tetraploidization, fewer than half of the genes appear to be present in two orthologous copies, indicating that the maize genome has undergone significant gene loss since the duplication event. PMID:15388850

  6. Aflatoxin Control in Maize by Trametes versicolor

    PubMed Central

    Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A.; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

    2014-01-01

    Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1. PMID:25525683

  7. Distribution of expansins in graviresponding maize roots

    NASA Technical Reports Server (NTRS)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    To test if expansins, wall loosening proteins that disrupt binding between microfibrils and cell wall matrix, participate in the differential elongation of graviresponding roots, Zea mays L. cv. Merit roots were gravistimulated and used for immunolocalization with anti-expansin. Western blots showed cross-reaction with two proteins of maize, one of the same mass as cucumber expansin (29 kDa), the second slightly larger (32 kDa). Maize roots contained mainly the larger protein, but both were found in coleoptiles. The expansin distribution in cucumber roots and hypocotyls was similar to the distribution in maize. Roots showed stronger expansin signals on the expanding convex side than the concave flank as early as 30 min after gravistimulation. Treatment with brefeldin A, a vesicle transport inhibitor, or the auxin transport inhibitor, naphthylphthalamic acid, showed delayed graviresponse and the appearance of differential staining. Our results indicate that expansins may be transported and secreted to cell walls via vesicles and function in wall expansion.

  8. Transcriptome Dynamics during Maize Endosperm Development

    PubMed Central

    Feng, Jiaojiao; Xu, Shutu; Wang, Lei; Li, Feifei; Li, Yibo; Zhang, Renhe; Zhang, Xinghua; Xue, Jiquan; Guo, Dongwei

    2016-01-01

    The endosperm is a major organ of the seed that plays vital roles in determining seed weight and quality. However, genome-wide transcriptome patterns throughout maize endosperm development have not been comprehensively investigated to date. Accordingly, we performed a high-throughput RNA sequencing (RNA-seq) analysis of the maize endosperm transcriptome at 5, 10, 15 and 20 days after pollination (DAP). We found that more than 11,000 protein-coding genes underwent alternative splicing (AS) events during the four developmental stages studied. These genes were mainly involved in intracellular protein transport, signal transmission, cellular carbohydrate metabolism, cellular lipid metabolism, lipid biosynthesis, protein modification, histone modification, cellular amino acid metabolism, and DNA repair. Additionally, 7,633 genes, including 473 transcription factors (TFs), were differentially expressed among the four developmental stages. The differentially expressed TFs were from 50 families, including the bZIP, WRKY, GeBP and ARF families. Further analysis of the stage-specific TFs showed that binding, nucleus and ligand-dependent nuclear receptor activities might be important at 5 DAP, that immune responses, signalling, binding and lumen development are involved at 10 DAP, that protein metabolic processes and the cytoplasm might be important at 15 DAP, and that the responses to various stimuli are different at 20 DAP compared with the other developmental stages. This RNA-seq analysis provides novel, comprehensive insights into the transcriptome dynamics during early endosperm development in maize. PMID:27695101

  9. The mycotoxin distribution in maize milling fractions under experimental conditions.

    PubMed

    Burger, H-M; Shephard, G S; Louw, W; Rheeder, J P; Gelderblom, W C A

    2013-07-01

    Mycotoxin contamination of maize and maize-based food and feed products poses a health risk to humans and animals if not adequately controlled and managed. The current study investigates the effect of dry milling on the reduction of fumonisins (FB), deoxynivalenol (DON) and zearalenone (ZEA) in maize. Five composite samples, constructed to represent different mycotoxin contamination levels were degermed yielding degermed maize and the germ. The degermed maize was milled under laboratory conditions and four major milling fractions (SPECIAL, SUPER, semolina (SEM) and milling hominy feed) collected. The whole maize, degermed maize and total hominy feed (germ+milling hominy feed) were reconstructed to ensure homogenous samples for mycotoxin analyses. For comparison, commercial dry milling fractions (whole maize, SPECIAL, SUPER and total hominy feed), collected from three South African industrial mills, were analysed for the same mycotoxins and hence a more accurate assessment of the distribution between the different milling fractions. The distribution of the mycotoxins during the experimental dry milling of the degermed maize differs, with FB mainly concentrated in the SPECIAL, DON in the SEM whereas ZEA was equally distributed between the two milling fractions. Distribution of mycotoxins between the fractions obtained during commercial dry milling generally provided similar results with the total hominy feed containing the highest and the SUPER milling fractions the lowest mycotoxin levels although variations existed. Although milling is an effective way to reduce mycotoxins in maize, kernel characteristics and resultant fungal colonisation may impact on the distribution of specific mycotoxins among the different milling fractions. Differences in industrial dry milling practices and problems encountered in sampling bulk maize remain a large problem in assessing mycotoxin contamination in milling fractions intended for human consumption.

  10. Aflatoxin Regulations in a Network of Global Maize Trade

    PubMed Central

    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 B1, B2, G1, and G2) 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. PMID:23049773

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

    PubMed

    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.

  12. Intraplant communication in maize contributes to defense against insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Fumonisin biomarkers in maize eaters and implications for human disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is the predominant food source contaminated by fumonisins and this has particular health risks for communities consuming maize as a staple diet. The main biochemical effect of fumonisins is the inhibition of ceramide biosynthesis causing an increase in sphingoid bases and sphingoid base 1-pho...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Maize development: cell wall changes in leaves and sheaths

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developmental changes occur in maize (Zea mays L.) as it transitions from juvenile stages to the mature plant. Changes also occur as newly formed cells mature into adult cells. Maize leaf blades, including the midribs and sheaths, undergo cell wall changes as cells transition to fully mature cell ty...

  16. Genetic Properties of the Maize Nested Association Mapping Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the world’s most diverse species, and this variation can be used to understand the molecular basis of phenotypic variation and to improve agricultural efficiency and sustainability. To access this genetic variation, 25 diverse inbred maize lines were crossed to the B73 reference lin...

  17. Genetic analysis of teosinte for kernel composition traits in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teosinte (Zea mays ssp. parviglumis) is the wild ancestor of modern maize (Zea mays ssp. mays). Teosinte contains greater genetic diversity compared to maize inbreds and landraces, but its use is limited by insufficient genetic resources to evaluate its value. A population of teosinte near isogenic ...

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

    PubMed

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

    2014-04-01

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

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

    PubMed Central

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

    2010-01-01

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

  20. Climate change compromises the immune response of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Interaction of F. verticillioides and Talaromyces sp. in maize seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted studies in maize fields (Illinois, USA, 2013) to observe the interactions of Talaromyces species with fumonisin producing Fusarium verticillioides in corn seeds. Maize ears were inoculated during the milk phase using sterile wooden toothpicks dipped in conidium suspensions, or sterile d...

  2. Entering the second century of maize quantitative genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is the most widely grown cereal in the world. In addition to its role in global agriculture, it has also long served as a model organism for genetic research. Maize stands at a genetic crossroads, as it has access to all the tools available for plant genetics but exhibits a genetic architectur...

  3. Stewardship of the Maize B73 feference genome assembly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The release of version 4 of the B73 reference genome assembly is imminent. However, continued improvement of the assembly is likely to fall to the maize research community. Toward this end, and recognizing the importance of an accurate and well-curated reference genome, MaizeGDB, Gramene, and the Ge...

  4. The art and design of genetic screens: maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Entering the second century of maize quantitative genetics

    PubMed Central

    Wallace, J G; Larsson, S J; Buckler, E S

    2014-01-01

    Maize is the most widely grown cereal in the world. In addition to its role in global agriculture, it has also long served as a model organism for genetic research. Maize stands at a genetic crossroads, as it has access to all the tools available for plant genetics but exhibits a genetic architecture more similar to other outcrossing organisms than to self-pollinating crops and model plants. In this review, we summarize recent advances in maize genetics, including the development of powerful populations for genetic mapping and genome-wide association studies (GWAS), and the insights these studies yield on the mechanisms underlying complex maize traits. Most maize traits are controlled by a large number of genes, and linkage analysis of several traits implicates a ‘common gene, rare allele' model of genetic variation where some genes have many individually rare alleles contributing. Most natural alleles exhibit small effect sizes with little-to-no detectable pleiotropy or epistasis. Additionally, many of these genes are locked away in low-recombination regions that encourage the formation of multi-gene blocks that may underlie maize's strong heterotic effect. Domestication left strong marks on the maize genome, and some of the differences in trait architectures may be due to different selective pressures over time. Overall, maize's advantages as a model system make it highly desirable for studying the genetics of outcrossing species, and results from it can provide insight into other such species, including humans. PMID:23462502

  6. A Single Molecule Scaffold for the Maize Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Maize water use in living mulch systems with stover removal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Constraints to maize stover biomass harvest may be mitigated by using a living mulch (LM) to offset C exports and control soil erosion. Living mulches can compete with the main crop for resources, particularly water. The objectives of this research were to quantify soil water dynamics and maize wate...

  8. Comparative population genomics of maize domestication and improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestication and modern breeding represent exemplary case studies of evolution in action. Maize is an outcrossing species with a complex genome, and an understanding of maize evolution is thus relevant for both plant and animal systems. This study is the largest plant resequencing effort to date, ...

  9. Mutant maize variety containing the glt1-1 allele

    DOEpatents

    Nelson, O.E.; Pan, D.

    1994-07-19

    A maize plant has in its genome a non-mutable form of a mutant allele designated vitX-8132. The allele is located at a locus designated as glt which conditions kernels having an altered starch characteristic. Maize plants including such a mutant allele produce a starch that does not increase in viscosity on cooling, after heating. 2 figs.

  10. Mutant maize variety containing the glt1-1 allele

    DOEpatents

    Nelson, Oliver E.; Pan, David

    1994-01-01

    A maize plant has in its genome a non-mutable form of a mutant allele designated vitX-8132. The allele is located at a locus designated as glt which conditions kernels having an altered starch characteristic. Maize plants including such a mutant allele produce a starch that does not increase in viscosity on cooling, after heating.

  11. Constructing a Cytogenetic Map of the Maize Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We are developing a pachytene cytogenetic FISH (Fluorescence in situ Hybridization) map of the maize (Zea mays L.) genome using maize marker-selected sorghum BACs (Bacterial Artificial Chromosome) as described by Koumbaris and Bass (2003, Plant J. 35:647). The two main projects are the production of...

  12. Susceptibility to aflatoxin contamination among maize landraces from Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize, the critical staple food for billions of people, was domesticated in Mexico about 9,000 YBP. Today, a great array of maize land races (MLRs) across rural Mexico is harbored in a living library that has been passed among generations since before establishment of the modern state. MLRs have bee...

  13. Molecular and Ultrastructural Properties of Maize White Line Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  14. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Code of Federal Regulations, 2010 CFR

    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...

  15. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 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...

  16. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 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...

  17. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 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...

  18. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Breeder survey, tools, and resources to visualize diversity and pedigree relationships at MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In collaboration with maize researchers, the MaizeGDB Team prepared a survey to identify breeder needs for visualizing pedigrees, diversity data, and haplotypes, and distributed it to the maize community on behalf of the Maize Genetics Executive Committee (Summer 2015). We received 48 responses from...

  1. Impact of deficit irrigation on maize physical and chemical properties and ethanol yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the effect of irrigation levels (five levels from 102 to 457 mm of water) on the physical and chemical properties and ethanol fermentation performance of maize. Twenty maize samples with two crop rotation systems, grain sorghum–maize and maize–maize, were ...

  2. Mining natural variation for maize improvement: Selection on phenotypes and genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is highly genetically and phenotypically diverse. Tropical maize and teosinte are important genetic resources that harbor unique alleles not found in temperate maize hybrids. To access these resources, breeders must be able to extract favorable unique alleles from tropical maize and teosinte f...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Ancient maize from Chacoan great houses: Where was it grown?

    PubMed Central

    Benson, Larry; Cordell, Linda; Vincent, Kirk; Taylor, Howard; Stein, John; Farmer, G. Lang; Futa, Kiyoto

    2003-01-01

    In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in pre-Columbian times, a finding fundamental to understanding the organization of pre-Columbian southwestern societies. In addition, this article provides support for the hypothesis that major construction events in Chaco Canyon were made possible because maize was brought in to support extra-local labor forces. PMID:14563925

  5. A Biochemical Phenotype for a Disease Resistance Gene of Maize.

    PubMed Central

    Meeley, RB; Johal, GS; Briggs, SP; Walton, JD

    1992-01-01

    In maize, major resistance to the pathogenic fungus Cochliobolus (Helminthosporium) carbonum race 1 is determined by the dominant allele of the nuclear locus hm. The interaction between C. carbonum race 1 and maize is mediated by a pathogen-produced, low molecular weight compound called HC-toxin. We recently described an enzyme from maize, called HC-toxin reductase, that inactivates HC-toxin by pyridine nucleotide-dependent reduction of an essential carbonyl group. We now report that this enzyme activity is detectable only in extracts of maize that are resistant to C. carbonum race 1 (genotype Hm/Hm or Hm/hm). In several genetic analyses, in vitro HC-toxin reductase activity was without exception associated with resistance to C. carbonum race 1. The results indicate that detoxification of HC-toxin is the biochemical basis of Hm-specific resistance of maize to infection by C. carbonum race 1. PMID:12297630

  6. Maize authentication: quality control methods and multivariate analysis (chemometrics).

    PubMed

    Arvanitoyannis, Ioannis S; Vlachos, Antonios

    2009-06-01

    Maize is one of the most important cereals because of its numerous applications in processed foods where it is the major or minor component. Apart from maize authenticity issues related to cultivar and geographical origin (national and/or international level), there is another important issue related to genetically modified maize. Various objective parameters such as fatty acids, phenolic compounds, pigments, heavy metals were determined in conjunction with subjective (sensory analysis) in order to identify the maize authenticity. However, the implementation of multivariate analysis (principal component analysis, cluster analysis, discriminant analysis, canonical analysis) is of great importance toward reaching valid conclusions on authenticity issues. This review summarized the most important finding of both objective and subjective evaluations of maize in five comprehensive tables in conjunction with the discussion.

  7. Ancient maize from Chacoan great houses: Where was it grown?

    USGS Publications Warehouse

    Benson, L.; Cordell, L.; Vincent, K.; Taylor, H.; Stein, J.; Farmer, G.L.; Futa, K.

    2003-01-01

    In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river flood-plains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in pre-Columbian times, a finding fundamental to understanding the organization of pre-Columbian southwestern societies. In addition, this article provides support for the hypothesis that major construction events in Chaco Canyon were made possible because maize was brought in to support extra-local labor forces.

  8. Ancient maize from Chacoan great houses: where was it grown?

    PubMed

    Benson, Larry; Cordell, Linda; Vincent, Kirk; Taylor, Howard; Stein, John; Farmer, G Lang; Futa, Kiyoto

    2003-10-28

    In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in pre-Columbian times, a finding fundamental to understanding the organization of pre-Columbian southwestern societies. In addition, this article provides support for the hypothesis that major construction events in Chaco Canyon were made possible because maize was brought in to support extra-local labor forces.

  9. European corn borer (Ostrinia nubilalis) induced defenses in maize enhance susceptibility in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbivore-induced plant defenses have been widely described following attack on leaves; however, less attention has been paid to analogous local processes that occur in stems. Early studies of maize responses to stem boring by European corn borer (ECB, Ostrinia nubilalis) larvae revealed the prese...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a follow-up to our previous study, second year information will be presented addressing questions on haploid induction and doubling, utilizing exotic and elite maize. These projects result from collaborations between Iowa State Doubled Haploid Facility (http://www.plantbreeding.iastate.edu/DHF/D...

  12. Tripsacum-Maize Interaction: A Novel Cytogenetic System

    PubMed Central

    de Wet, J. M. J.; Harlan, J. R.

    1974-01-01

    The genera Zea and Tripsacum cross readily when they are not isolated by gametophytic barriers, and it has been postulated that intergeneric introgression played a role in the evolution of maize. The basic x = 9 Tripsacum and x = 10 Zea genomes have little cytological affinity for each other in hybrids that combine 10 Zea with 18 Tripsacum chromosomes. However, one to four Tripsacum chromosomes sometimes associate with Zea chromosomes in hybrids between Z. mays (2n = 20) and T. dactyloides (2n = 72). These hybrids with 10 Zea and 36 Tripsacum chromosomes frequently produce functional female gametes with 36 Tripsacum chromosomes only. When they are pollinated with maize, their offspring again have 36 Tripsacum and 10 maize chromosomes, but the Tripsacum genome is contaminated with maize genetic material. In these individuals, intergenome pairing is the rule, and when they are pollinated with maize, their offspring have 36 Tripsacum and 10, 12, 14, 16, 18, or 20 Zea chromosomes. Plants with 36 Tripsacum and 20 Zea chromosomes behave cytologically as alloploids, although the Tripsacum genome is contimated with maize, and one basic maize genome is contaminated with with Tripsacum genetic material. When they are pollinated with maize, offspring with 18 Tripsacum and 20 Zea chromosome are obtained. Further successive backcrosses with maize selectively eliminate Tripsacum chromosomes, and eventually plants with 2n = 20 Zea chromosomes are recovered. Many of these maize plants are highly "tripsacoid." Strong gametophytic selection for essentially pure Zea gametes, however, eliminates all obvious traces of Tripsacum morphology within a relatively few generations. PMID:17248666

  13. A few sequence polymorphisms among isolates of Maize bushy stunt phytoplasma associate with organ proliferation symptoms of infected maize plants

    PubMed Central

    Orlovskis, Zigmunds; Canale, Maria Cristina; Haryono, Mindia; Lopes, João Roberto Spotti

    2017-01-01

    Background and Aims Maize bushy stunt phytoplasma (MBSP) is a bacterial pathogen of maize (Zea mays L.) across Latin America. MBSP belongs to the 16SrI-B sub-group within the genus ‘Candidatus Phytoplasma’. MBSP and its insect vector Dalbulus maidis (Hemiptera: Cicadellidae) are restricted to maize; both are thought to have coevolved with maize during its domestication from a teosinte-like ancestor. MBSP-infected maize plants show a diversity of symptoms. and it is likely that MBSP is under strong selection for increased virulence and insect transmission on maize hybrids that are widely grown in Brazil. In this study it was investigated whether the differences in genome sequences of MBSP isolates from two maize-growing regions in South-east Brazil explain variations in symptom severity of the MBSP isolates on various maize genotypes. Methods MBSP isolates were collected from maize production fields in Guaíra and Piracicaba in South-east Brazil for infection assays. One representative isolate was chosen for de novo whole-genome assembly and for the alignment of sequence reads from the genomes of other phytoplasma isolates to detect polymorphisms. Statistical methods were applied to investigate the correlation between variations in disease symptoms of infected maize plants and MBSP sequence polymorphisms. Key Results MBSP isolates contributed consistently to organ proliferation symptoms and maize genotype to leaf necrosis, reddening and yellowing of infected maize plants. The symptom differences are associated with polymorphisms in a phase-variable lipoprotein, which is a candidate effector, and an ATP-dependent lipoprotein ABC export protein, whereas no polymorphisms were observed in other candidate effector genes. Lipoproteins and ABC export proteins activate host defence responses, regulate pathogen attachment to host cells and activate effector secretion systems in other pathogens. Conclusions Polymorphisms in two putative virulence genes among MBSP isolates

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

    PubMed Central

    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

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

    PubMed

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-08-20

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

  16. The maize Dof protein PBF activates transcription of gamma-zein during maize seed development.

    PubMed

    Marzábal, Pau; Gas, Elisabet; Fontanet, Pilar; Vicente-Carbajosa, Jesús; Torrent, Margarita; Ludevid, M Dolores

    2008-07-01

    Maize PBF (prolamin-box binding factor) belongs to the Dof class of plant specific transcription factors containing one highly conserved zinc finger DNA-binding domain, called Dof (DNA binding with one finger) domain. Maize PBF trans-activates the gamma-zein gene (gammaZ) promoter in developing maize seeds as shown by transient expression in maize endosperms. Co-transfection of a gammaZ:GUS construct with 35S:PBF resulted in a sevenfold increase in GUS expression, however, PBF mutation in Cys residues within the Dof domain abolishes both, binding to DNA and the capacity to activate gammaZ promoter. We present two pieces of evidence that PBF transactivates gammaZ promoter by binding to the Pb3 motif (TGTAAAG). First, recombinant Dof domain of PBF (bdPBF) specifically recognized Pb3 site as shown by gel mobility shift assays and second, co-expression of PBF with gammaZ promoter mutated in Pb3 motif suppressed PBF trans-activation capacity. Immunocytochemical analysis on developing endosperm sections shows that PBF is localized in the nuclei of the peripheral layer cells of starchy endosperm, the tissue in which the initial accumulation of gamma-zein protein occurs. By contrast, PBF is detected in the cytosol of the starchy endosperm cells newly differentiated from aleurone daughter cells, where gamma-zein was absent. Taken together these data indicate that maize PBF plays an essential role in the regulation of the temporal and spatial expression of gammaZ gene.

  17. l-Phenylalanine Ammonia-lyase (Maize)

    PubMed Central

    Reid, Philip D.; Havir, Evelyn A.; Marsh, Herbert V.

    1972-01-01

    Extracts of maize leaf sheath tissue deaminate both l-phenylalanine and l-tyrosine. The activities with both substrates are enhanced by treating the plant with gibberellic acid. Both activities decrease rapidly at the same rate when tissue is incubated in a moist atmosphere, and this decrease can be slowed by treatment with cycloheximide. The ratio of the activities was constant throughout a series of purification steps which included acetone and ammonium sulfate precipitation, and passage through an agarose column. The two activities could not be separated by isoelectric focusing. These results support our earlier conclusion that both activities occur at the same catalytic site. PMID:16658200

  18. Viruses in maize and Johnsongrass in southern Ohio.

    PubMed

    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.

  19. Effects of temperature changes on maize production in Mozambique

    USGS Publications Warehouse

    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.

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

    PubMed

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

    2016-01-25

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.

  1. Silicon improves maize photosynthesis in saline-alkaline soils.

    PubMed

    Xie, Zhiming; Song, Ri; Shao, Hongbo; Song, Fengbin; Xu, Hongwen; Lu, Yan

    2015-01-01

    The research aimed to determine the effects of Si application on photosynthetic characteristics of maize on saline-alkaline soil, including photosynthetic rate (P n ), stomatal conductance (g s ), transpiration rate (E), and intercellular CO2 concentration (C i ) 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 P n, g s, and C i 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.

  2. Nutritional evaluation of genetically modified maize corn performed on rats.

    PubMed

    Chrenková, Mária; Sommer, A; Ceresnáková, Zuzana; Nitrayová, Sona; Prostredná, Miroslava

    2002-06-01

    The aim of this study was to determine the composition and nutritional value of conventional and transgenic, so-called Roundup Ready (RR) maize with an introduced gene of glyphosate resistance. Crude protein, crude fibre, ash, fat, starch, sugar, amino acids, fatty acid and macroelement levels were determined by chemical analysis. In both maize lines a low level of Ca (0.15 g.kg-1 DM) and of the essential amino acids lysine and tryptophan (2.6 and 1.7 g.kg-1 DM, respectively) were observed. In the biological experiment carried out on rats the tested maize lines were the only dietary sources of nitrogen, thus, the experimental diets contained 9% CP in dietary dry matter. In the feeding experiment no significant differences in the protein efficiency ratio (PER) were observed between groups receiving conventional or transgenic maize (1.51 and 1.41, respectively). Also almost equal results were obtained in the balance experiments. Both maize lines revealed a high nitrogen digestibility (84.9 and 84.5%, respectively) and the net protein utilization amounted to 63.5 and 63.2%, respectively. From these results can be concluded that regarding nutrient composition and utilisation, genetically modified (RR) maize is equivalent to isogenic maize.

  3. Silicon Improves Maize Photosynthesis in Saline-Alkaline Soils

    PubMed Central

    Xie, Zhiming; Song, Ri; Shao, Hongbo; Song, Fengbin; Xu, Hongwen; Lu, Yan

    2015-01-01

    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. PMID:25629083

  4. Genetic diversity and selection in the maize starch pathway

    PubMed Central

    Whitt, Sherry R.; Wilson, Larissa M.; Tenaillon, Maud I.; Gaut, Brandon S.; Buckler, Edward S.

    2002-01-01

    Maize is both phenotypically and genetically diverse. Sequence studies generally confirm the extensive genetic variability in modern maize is consistent with a lack of selection. For more than 6,000 years, Native Americans and modern breeders have exploited the tremendous genetic diversity of maize (Zea mays ssp. mays) to create the highest yielding grain crop in the world. Nonetheless, some loci have relatively low levels of genetic variation, particularly loci that have been the target of artificial selection, like c1 and tb1. However, there is limited information on how selection may affect an agronomically important pathway for any crop. These pathways may retain the signature of artificial selection and may lack genetic variation in contrast to the rest of the genome. To evaluate the impact of selection across an agronomically important pathway, we surveyed nucleotide diversity at six major genes involved in starch metabolism and found unusually low genetic diversity and strong evidence of selection. Low diversity in these critical genes suggests that a paradigm shift may be required for future maize breeding. Rather than relying solely on the diversity within maize or on transgenics, future maize breeding would perhaps benefit from the incorporation of alleles from maize's wild relatives. PMID:12244216

  5. Structure and expression of maize phytochrome family homeologs.

    PubMed Central

    Sheehan, Moira J; Farmer, Phyllis R; Brutnell, Thomas P

    2004-01-01

    To begin the study of phytochrome signaling in maize, we have cloned and characterized the phytochrome gene family from the inbred B73. Through DNA gel blot analysis of maize genomic DNA and BAC library screens, we show that the PhyA, PhyB, and PhyC genes are each duplicated once in the genome of maize. Each gene pair was positioned to homeologous regions of the genome using recombinant inbred mapping populations. These results strongly suggest that the duplication of the phytochrome gene family in maize arose as a consequence of an ancient tetraploidization in the maize ancestral lineage. Furthermore, sequencing of Phy genes directly from BAC clones indicates that there are six functional phytochrome genes in maize. Through Northern gel blot analysis and a semiquantitative reverse transcriptase polymerase chain reaction assay, we determined that all six phytochrome genes are transcribed in several seedling tissues. However, expression from PhyA1, PhyB1, and PhyC1 predominate in all seedling tissues examined. Dark-grown seedlings express higher levels of PhyA and PhyB than do light-grown plants but PhyC genes are expressed at similar levels under light and dark growth conditions. These results are discussed in relation to phytochrome gene regulation in model eudicots and monocots and in light of current genome sequencing efforts in maize. PMID:15280251

  6. Definition and feasibility of isolation distances for transgenic maize cultivation.

    PubMed

    Sanvido, Olivier; Widmer, Franco; Winzeler, Michael; Streit, Bernhard; Szerencsits, Erich; Bigler, Franz

    2008-06-01

    A major concern related to the adoption of genetically modified (GM) crops in agricultural systems is the possibility of unwanted GM inputs into non-GM crop production systems. Given the increasing commercial cultivation of GM crops in the European Union (EU), there is an urgent need to define measures to prevent mixing of GM with non-GM products during crop production. Cross-fertilization is one of the various mechanisms that could lead to GM-inputs into non-GM crop systems. Isolation distances between GM and non-GM fields are widely accepted to be an effective measure to reduce these inputs. However, the question of adequate isolation distances between GM and non-GM maize is still subject of controversy both amongst scientists and regulators. As several European countries have proposed largely differing isolation distances for maize ranging from 25 to 800 m, there is a need for scientific criteria when using cross-fertilization data of maize to define isolation distances between GM and non-GM maize. We have reviewed existing cross-fertilization studies in maize, established relevant criteria for the evaluation of these studies and applied these criteria to define science-based isolation distances. To keep GM-inputs in the final product well below the 0.9% threshold defined by the EU, isolation distances of 20 m for silage and 50 m for grain maize, respectively, are proposed. An evaluation using statistical data on maize acreage and an aerial photographs assessment of a typical agricultural landscape by means of Geographic Information Systems (GIS) showed that spatial resources would allow applying the defined isolation distances for the cultivation of GM maize in the majority of the cases under actual Swiss agricultural conditions. The here developed approach, using defined criteria to consider the agricultural context of maize cultivation, may be of assistance for the analysis of cross-fertilization data in other countries.

  7. A single molecule scaffold for the maize genome.

    PubMed

    Zhou, Shiguo; Wei, Fusheng; Nguyen, John; Bechner, Mike; Potamousis, Konstantinos; Goldstein, Steve; Pape, Louise; Mehan, Michael R; Churas, Chris; Pasternak, Shiran; Forrest, Dan K; Wise, Roger; Ware, Doreen; Wing, Rod A; Waterman, Michael S; Livny, Miron; Schwartz, David C

    2009-11-01

    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 for ensuring the quality of the current sequence build. For this purpose, we constructed a genome-wide, high-resolution optical map of the maize inbred line B73 genome containing >91,000 restriction sites (averaging 1 site/ approximately 23 kb) accrued from mapping genomic DNA molecules. Our optical map comprises 66 contigs, averaging 31.88 Mb in size and spanning 91.5% (2,103.93 Mb/ approximately 2,300 Mb) of the maize genome. A new algorithm was created that considered both optical map and unfinished BAC sequence data for placing 60/66 (2,032.42 Mb) optical map contigs onto the maize iMap. The alignment of optical maps against numerous data sources yielded comprehensive results that proved revealing and productive. For example, gaps were uncovered and characterized within the iMap, the FPC (fingerprinted contigs) map, and the chromosome-wide pseudomolecules. Such alignments also suggested amended placements of FPC contigs on the maize genetic map and proactively guided the assembly of chromosome-wide pseudomolecules, especially within complex genomic regions. Lastly, we think that the full integration of B73 optical maps with the maize iMap would greatly facilitate maize sequence finishing efforts that would make it a valuable reference for comparative studies among cereals, or other maize inbred lines and cultivars.

  8. Studies on the transfer techniques of three maize genes.

    PubMed

    Wang, G; Zhang, H; Ding, Q; Xie, Y; Dai, J

    1996-01-01

    Maize transformation has been carried out through microprojectile bombardment, ultrasonication in a DNA buffer, and ovary-injection with a self-made microinjector. The plasmid pB48.415, which carries a 3'-truncated Bt-toxin protein gene and a hygromycin phosphotransferase (hpt) gene, was used in the transformation. Transgenic maize plants were obtained from immature embryos and embryogenic calli bombarded with a particle gun, embryogenic calli ultrasonicated under different conditions of ovaries injected 10-20 hours after pollination. The results of Dot blotting and Southern blotting analyses proved the integration of the Bt gene into maize genome.

  9. Controlling-Element Events at the Shrunken Locus in Maize

    PubMed Central

    Burr, B.; Burr, F. A.

    1981-01-01

    We have examined insertions of the controlling element Ds at the Shrunken locus of maize. A cDNA probe complementary to a portion of the Shrunken locus mRNA was prepared. This probe recognizes a unique sequence in maize DNA. Using lines carrying derivatives of the same short arm of chromosome 9, we have detected modifications at the nucleic acid level caused by Ds. The changes appear to be large insertions, one of which may be more than 20 kilobase pairs in length. These observations provide a basis for the isolation and molecular characterization of one of the maize controlling elements. PMID:17249083

  10. Polypeptides of the Maize Amyloplast Stroma1

    PubMed Central

    Yu, Ying; He Mu, Helen; Mu-Forster, Chen; Wasserman, Bruce P.

    1998-01-01

    In the developing endosperm of monocotyledonous plants, starch granules are synthesized and deposited within the amyloplast. A soluble stromal fraction was isolated from amyloplasts of immature maize (Zea mays L.) endosperm and analyzed for enzyme activities and polypeptide content. Specific activities of starch synthase and starch-branching enzyme (SBE), but not the cytosolic marker alcohol dehydrogenase, were strongly enhanced in soluble amyloplast stromal fractions relative to soluble extracts obtained from homogenized kernels or endosperms. Immunoblot analysis demonstrated that starch synthase I, SBEIIb, and sugary1, the putative starch-debranching enzyme, were each highly enriched in the amyloplast stroma, providing direct evidence for the localization of starch-biosynthetic enzymes within this compartment. Analysis of maize mutants shows the deficiency of the 85-kD SBEIIb polypeptide in the stroma of amylose extender cultivars and that the dull mutant lacks a >220-kD stromal polypeptide. The stromal fraction is distinguished by differential enrichment of a characteristic group of previously undocumented polypeptides. N-terminal sequence analysis revealed that an abundant 81-kD stromal polypeptide is a member of the Hsp70 family of stress-related proteins. Moreover, the 81-kD stromal polypeptide is strongly recognized by antibodies specific for an Hsp70 of the chloroplast stroma. These findings are discussed in light of implications for the correct folding and assembly of soluble, partially soluble, and granule-bound starch-biosynthetic enzymes during import into the amyloplast. PMID:9536063

  11. Phytotoxic lesions of chromium in maize.

    PubMed

    Sharma, D C; Sharma, C P; Tripathi, R D

    2003-04-01

    Chromium (Cr) is fairly abundant in the earth's crust and ranks fourth among the 29 elements of biological importance. Besides natural sources, Cr enters biotic components of the ecosystem in various ways. Of other major industrial sources, tanning and chrome-plating industries are prominent sources. Cr(VI) form of chromium is highly reactive and influences both plants and animals. Due to Mn present in soil, Cr(III) is oxidized to Cr(VI) which remains in soil for a long time and can affect plant growth and development. Since maize is an important food and fodder plant for human beings and cattle, a study was conducted to investigate the effects of Cr on some metabolic activities of maize (Zea mays L. cv. Ganga 5). Chromium caused visible lesions of interveinal chlorosis. Young leaves showed vein clearing. Also, a papery appearance was observed in leaves. Margins of leaves were curled and the leaves appeared pale at greater Cr exposure. Concentrations of both chlorophyll a and b were reduced by exposure to Cr, the activities of ribonuclease and phenyl phosphatase were greater while the activity of iron-porphyrin enzyme catalase was less and the activity of amylase was also much less in plants exposed to Cr. Chromium also caused retardation of soluble protein. Accumulation of Cr in roots was much at all the levels of chromium supply. Exposure to Cr resulted in reduction in grain production and quality.

  12. Neocentromere-mediated Chromosome Movement in Maize

    PubMed Central

    Yu, Hong-Guo; Hiatt, Evelyn N.; Chan, Annette; Sweeney, Mary; Dawe, R. Kelly

    1997-01-01

    Neocentromere activity is a classic example of nonkinetochore chromosome movement. In maize, neocentromeres are induced by a gene or genes on Abnormal chromosome 10 (Ab10) which causes heterochromatic knobs to move poleward at meiotic anaphase. Here we describe experiments that test how neocentromere activity affects the function of linked centromere/kinetochores (kinetochores) and whether neocentromeres and kinetochores are mobilized on the spindle by the same mechanism. Using a newly developed system for observing meiotic chromosome congression and segregation in living maize cells, we show that neocentromeres are active from prometaphase through anaphase. During mid-anaphase, normal chromosomes move on the spindle at an average rate of 0.79 μm/min. The presence of Ab10 does not affect the rate of normal chromosome movement but propels neocentromeres poleward at rates as high as 1.4 μm/min. Kinetochore-mediated chromosome movement is only marginally affected by the activity of a linked neocentromere. Combined in situ hybridization/immunocytochemistry is used to demonstrate that unlike kinetochores, neocentromeres associate laterally with microtubules and that neocentromere movement is correlated with knob size. These data suggest that microtubule depolymerization is not required for neocentromere motility. We argue that neocentromeres are mobilized on microtubules by the activity of minus end–directed motor proteins that interact either directly or indirectly with knob DNA sequences. PMID:9362502

  13. Maize endophytic bacteria as mineral phosphate solubilizers.

    PubMed

    de Abreu, C S; Figueiredo, J E F; Oliveira, C A; Dos Santos, V L; Gomes, E A; Ribeiro, V P; Barros, B A; Lana, U G P; Marriel, I E

    2017-02-16

    In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.

  14. Real-time TaqMan RT-PCR for detection of maize chlorotic mottle virus in maize seeds.

    PubMed

    Zhang, Yongjiang; Zhao, Wenjun; Li, Mingfu; Chen, Hongjun; Zhu, Shuifang; Fan, Zaifeng

    2011-01-01

    Maize chlorotic mottle virus (MCMV) causes corn lethal necrosis disease, and can be transmitted through infected maize seeds. It remains a challenge to detect this virus in the seeds to prevent its introduction and infection. For this purpose, a real-time TaqMan RT-PCR procedure for efficient detection of MCMV was developed. The sensitivity of the method was 4 fg of total RNA or 25 copies of RNA transcripts, which was approximately ten-fold higher than conventional RT-PCR gel electrophoresis method. The successful detection of MCMV in maize seeds suggested the feasibility of this procedure for routine testing.

  15. Quantitative detection system for maize sample containing combined-trait genetically modified maize.

    PubMed

    Akiyama, Hiroshi; Watanabe, Takahiro; Wakabayashi, Kaoru; Nakade, Shinsuke; Yasui, Shuji; Sakata, Kozue; Chiba, Ryoko; Spiegelhalter, Frank; Hino, Akihiro; Maitani, Tamio

    2005-11-15

    Various countries have established regulations that stipulate the labeling of agricultural commodities, feed, and food products that contain or are made from genetically modified (GM) material or that contain adventitious GM material in amounts that exceed certain threshold levels. While regulations in some countries refer to GM material on a weight per weight (w/w) percentage, the currently applied detection methods do not directly measure the w/w percentage of the GM material. Depending on the particular method and the sample matrix it is applied to, the conversion of analytical results to a w/w percentage is challenging or not possible. The first rapid PCR system for GM maize detection on a single kernel basis has been developed. The equipment for the grinding of individual kernels and a silica membrane-based 96-well DNA extraction kit were both significantly revised and optimized for this particular purpose, respectively. We developed a multiplex real-time PCR method for the rapid quantification of GM DNA sequences in the obtained DNA solutions. In addition, a multiplex qualitative PCR detection method allows for the simultaneous detection of different GM maize traits in each kernel and thereby for identification of individual kernels that contain a combination of two or more GM traits. Especially for grain samples that potentially contain combined-trait GM maize kernels, the proposed methods can deliver informative results in a rapid, precise, and reliable manner.

  16. Infrared Imaging of Sunflower and Maize Root Anatomy

    SciTech Connect

    Dokken,K.; Davis, L.

    2007-01-01

    Synchrotron radiation infrared microspectroscopy (SR-IMS) permits the direct analysis of plant cell-wall architecture at the cellular level in situ, combining spatially localized information and chemical information from IR absorbances to produce a chemical map that can be linked to a particular morphology or functional group. This study demonstrated the use of SR-IMS to probe biopolymers, such as cellulose, lignin, and proteins, in the root tissue of hydroponically grown sunflower and maize plants. Principal components analysis (PCA) was employed to reveal the major spectral variance between maize and sunflower plant tissues. The use of PCA showed distinct separation of maize and sunflower samples using the IR spectra of the epidermis and xylem. The infrared band at 1635 cm-1, representing hydrocinnamic acid in (H type) lignin, provided a conclusive means of distinguishing between maize and sunflower plant tissues.

  17. Assessment of factors influencing the biomethane yield of maize silages.

    PubMed

    Mayer, Frédéric; Gerin, Patrick A; Noo, Anaïs; Foucart, Guy; Flammang, Jos; Lemaigre, Sébastien; Sinnaeve, Georges; Dardenne, Pierre; Delfosse, Philippe

    2014-02-01

    A large set of maize silage samples was produced to assess the major traits influencing the biomethane production of this crop. The biomass yield, the volatile solids contents and the biochemical methane potential (BMP) were measured to calculate the biomethane yield per hectare (average=7266m(3)ha(-1)). The most influential factor controlling the biomethane yield was the cropping environment. The biomass yield had more impact than the anaerobic digestibility. Nevertheless, the anaerobic digestibility of maize silages was negatively affected by high VS content in mature maize. Late maturing maize varieties produced high biomass yield with high digestibility resulting in high biomethane yield per hectare. The BMP was predicted with good accuracy using solely the VS content.

  18. Positional cloning in maize (Zea mays subsp. mays, Poaceae)1

    PubMed Central

    Gallavotti, Andrea; Whipple, Clinton J.

    2015-01-01

    • Premise of the study: Positional (or map-based) cloning is a common approach to identify the molecular lesions causing mutant phenotypes. Despite its large and complex genome, positional cloning has been recently shown to be feasible in maize, opening up a diverse collection of mutants to molecular characterization. • Methods and Results: Here we outline a general protocol for positional cloning in maize. While the general strategy is similar to that used in other plant species, we focus on the unique resources and approaches that should be considered when applied to maize mutants. • Conclusions: Positional cloning approaches are appropriate for maize mutants and quantitative traits, opening up to molecular characterization the large array of genetic diversity in this agronomically important species. The cloning approach described should be broadly applicable to other species as more plant genomes become available. PMID:25606355

  19. Is there a strategy I iron uptake mechanism in maize?

    PubMed

    Li, Suzhen; Zhou, Xiaojin; Chen, Jingtang; Chen, Rumei

    2016-03-28

    Iron is a metal micronutrient that is essential for plant growth and development. Graminaceous and nongraminaceous plants have evolved different mechanisms to mediate Fe uptake. Generally, strategy I is used by nongraminaceous plants like Arabidopsis, while graminaceous plants, such as rice, barley, and maize, are considered to use strategy II Fe uptake. Upon the functional characterization of OsIRT1 and OsIRT2 in rice, it was suggested that rice, as an exceptional graminaceous plant, utilizes both strategy I and strategy II Fe uptake systems. Similarly, ZmIRT1 and ZmZIP3 were identified as functional zinc and iron transporters in the maize genome, along with the determination of several genes encoding Zn and Fe transporters, raising the possibility that strategy I Fe uptake also occurs in maize. This mini-review integrates previous reports and recent evidence to obtain a better understanding of the mechanisms of Fe uptake in maize.

  20. Micronutrient and functional compounds biofortification of maize grains.

    PubMed

    Messias, Rafael da Silva; Galli, Vanessa; Silva, Sérgio Delmar Dos Anjos E; Schirmer, Manoel Artigas; Rombaldi, César Valmor

    2015-01-01

    Maize, in addition to being the main staple food in many countries, is used in the production of hundreds of products. It is rich in compounds with potential benefits to health, such as carotenoids, phenolic compounds, vitamin E, and minerals that act as cofactors for antioxidant enzymes. Many of these compounds have been neglected thus far in the scientific literature. Nevertheless, deficiencies in the precursors of vitamin A and some minerals, such as iron and zinc, in maize, in association with the great genetic variability in its cultivars and our genomic, transcriptomic, and metabolomic knowledge of this species make targeted biofortification strategies for maize promising. This review discusses the potential of the main microconstituents found in maize with a focus on studies aimed at biofortification.

  1. Early allelic selection in maize as revealed by ancient DNA.

    PubMed

    Jaenicke-Després, Viviane; Buckler, Ed S; Smith, Bruce D; Gilbert, M Thomas P; Cooper, Alan; Doebley, John; Pääbo, Svante

    2003-11-14

    Maize was domesticated from teosinte, a wild grass, by approximately 6300 years ago in Mexico. After initial domestication, early farmers continued to select for advantageous morphological and biochemical traits in this important crop. However, the timing and sequence of character selection are, thus far, known only for morphological features discernible in corn cobs. We have analyzed three genes involved in the control of plant architecture, storage protein synthesis, and starch production from archaeological maize samples from Mexico and the southwestern United States. The results reveal that the alleles typical of contemporary maize were present in Mexican maize by 4400 years ago. However, as recently as 2000 years ago, allelic selection at one of the genes may not yet have been complete.

  2. Determining density of maize canopy. 1: Digitized photography

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Swain, P. H.

    1972-01-01

    The relationship between different densities of maize (Zea mays L.) canopies and the energy reflected by these canopies was studied. Field plots were laid out, representing four growth stages of maize, on a dark soil and on a very light colored surface soil. Spectral and spatial data were obtained from color and color infrared photography taken from a vertical distance of 10 m above the maize canopies. Estimates of ground cover were related to field measurements of leaf area index. Ground cover was predicted from leaf area index measurements by a second order equation. Color infrared photography proved helpful in determining the density of maize canopy on dark soils. Color photography was useful for determining canopy density on light colored soils. The near infrared dye layer is the most valuable in canopy density determinations.

  3. Ustilago maydis induced accumulation of putrescine in maize leaves

    PubMed Central

    Rodríguez-Kessler, Margarita

    2009-01-01

    Polyamines are implicated in the regulation of many processes in the plant cell, including functioning of ion channels, DNA replication, gene transcription, mRNA translation, cell proliferation and programmed cell death. Plant polyamines occur either in free form, covalently bound to proteins, or conjugated to hydroxycinnamic acids forming phenol amides. Ustilago maydis is a dimorphic and biotrophic pathogenic fungus responsible for common smut or “huitlacoche” in maize; and it is considered an excellent model for the study of plant-pathogen interactions. Recently, we reported alterations in polyamine metabolism of maize tumors induced on leaf blades by Ustilago maydis infection. Our data revealed a striking increase in maize polyamine biosynthesis, mainly free and conjugated putrescine in the tumors and in the green plant tissue surrounding the tumor. In this addendum, we describe that changes in polyamine metabolism take place even in earlier stages of maize plant infection with Ustilago maydis. PMID:19794848

  4. Modelling of maize production in Croatia: present and future climate

    PubMed Central

    VUČETIĆ, V.

    2011-01-01

    SUMMARY Maize is one of the most important agricultural crops in Croatia, and was selected for research of the effect of climate warming on yields. The Decision Support System for the Agrotechnology Transfer model (DSSAT) is one of the most utilized crop–weather models in the world, and was used in this paper for the investigation of maize growth and production in the present and future climate. The impact of present climate on maize yield was studied using DSSAT 4.0 with meteorological data from the Zagreb–Maksimir station covering the period 1949–2004. Pedological, physiological and genetic data from a 1999 field maize experiment at the same location were added. The location is representative of the continental climate in central Croatia. The linear trends of model outputs and the non-parametric Mann–Kendall test indicate that the beginning of silking has advanced significantly by 1·4 days/decade since the mid-1990s, and maturity by 4·5 days/decade. It also shows a decrease in biomass by 122 kg/ha and in maize yield by 216 kg/ha in 10 years. Estimates of the sensitivity of maize growth and yield in future climates were made by changing the initial weather and CO2 conditions of the DSSAT 4.0 model according to the different climatic scenarios for Croatia at the end of the 21st century. Changed climate suggests increases in global solar radiation, minimal temperature and maximal temperature (×1·07, 2 and 4°C, respectively), but a decrease in the amount of precipitation (×0·92), compared with weather data from the period 1949–2004. The reduction of maize yield was caused by the increase in minimal and maximal temperature and the decrease in precipitation amount, related to the present climate, is 6, 12 and 3%, respectively. A doubling of CO2 concentration stimulates leaf assimilation, but maize yield is only 1% higher, while global solar radiation growth by 7% increases evapotranspiration by 3%. Simultaneous application of all these climate changes

  5. The Role of cis Regulatory Evolution in Maize Domestication

    PubMed Central

    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

  6. Meiotic drive of chromosomal knobs reshaped the maize genome.

    PubMed Central

    Buckler, E S; Phelps-Durr, T L; Buckler, C S; Dawe, R K; Doebley, J F; Holtsford, T P

    1999-01-01

    Meiotic drive is the subversion of meiosis so that particular genes are preferentially transmitted to the progeny. Meiotic drive generally causes the preferential segregation of small regions of the genome; however, in maize we propose that meiotic drive is responsible for the evolution of large repetitive DNA arrays on all chromosomes. A maize meiotic drive locus found on an uncommon form of chromosome 10 [abnormal 10 (Ab10)] may be largely responsible for the evolution of heterochromatic chromosomal knobs, which can confer meiotic drive potential to every maize chromosome. Simulations were used to illustrate the dynamics of this meiotic drive model and suggest knobs might be deleterious in the absence of Ab10. Chromosomal knob data from maize's wild relatives (Zea mays ssp. parviglumis and mexicana) and phylogenetic comparisons demonstrated that the evolution of knob size, frequency, and chromosomal position agreed with the meiotic drive hypothesis. Knob chromosomal position was incompatible with the hypothesis that knob repetitive DNA is neutral or slightly deleterious to the genome. We also show that environmental factors and transposition may play a role in the evolution of knobs. Because knobs occur at multiple locations on all maize chromosomes, the combined effects of meiotic drive and genetic linkage may have reshaped genetic diversity throughout the maize genome in response to the presence of Ab10. Meiotic drive may be a major force of genome evolution, allowing revolutionary changes in genome structure and diversity over short evolutionary periods. PMID:10471723

  7. Gene Loss and Movement in the Maize Genome

    PubMed Central

    Lai, Jinsheng; Ma, Jianxin; Swigoňová, Zuzana; Ramakrishna, Wusirika; Linton, Eric; Llaca, Victor; Tanyolac, Bahattin; Park, Yong-Jin; Jeong, O-Young; Bennetzen, Jeffrey L.; Messing, Joachim

    2004-01-01

    Maize (Zea mays L. ssp. mays), one of the most important agricultural crops in the world, originated by hybridization of two closely related progenitors. To investigate the fate of its genes after tetraploidization, we analyzed the sequence of five duplicated regions from different chromosomal locations. We also compared corresponding regions from sorghum and rice, two important crops that have largely collinear maps with maize. The split of sorghum and maize progenitors was recently estimated to be 11.9 Mya, whereas rice diverged from the common ancestor of maize and sorghum ∼50 Mya. A data set of roughly 4 Mb yielded 206 predicted genes from the three species, excluding any transposon-related genes, but including eight gene remnants. On average, 14% of the genes within the aligned regions are noncollinear between any two species. However, scoring each maize region separately, the set of noncollinear genes between all four regions jumps to 68%. This is largely because at least 50% of the duplicated genes from the two progenitors of maize have been lost over a very short period of time, possibly as short as 5 million years. Using the nearly completed rice sequence, we found noncollinear genes in other chromosomal positions, frequently in more than one. This demonstrates that many genes in these species have moved to new chromosomal locations in the last 50 million years or less, most as single gene events that did not dramatically alter gene structure. PMID:15466290

  8. Recruitment of entomopathogenic nematodes by insect-damaged maize roots.

    PubMed

    Rasmann, Sergio; Köllner, Tobias G; Degenhardt, Jörg; Hiltpold, Ivan; Toepfer, Stefan; Kuhlmann, Ulrich; Gershenzon, Jonathan; Turlings, Ted C J

    2005-04-07

    Plants under attack by arthropod herbivores often emit volatile compounds from their leaves that attract natural enemies of the herbivores. Here we report the first identification of an insect-induced belowground plant signal, (E)-beta-caryophyllene, which strongly attracts an entomopathogenic nematode. Maize roots release this sesquiterpene in response to feeding by larvae of the beetle Diabrotica virgifera virgifera, a maize pest that is currently invading Europe. Most North American maize lines do not release (E)-beta-caryophyllene, whereas European lines and the wild maize ancestor, teosinte, readily do so in response to D. v. virgifera attack. This difference was consistent with striking differences in the attractiveness of representative lines in the laboratory. Field experiments showed a fivefold higher nematode infection rate of D. v. virgifera larvae on a maize variety that produces the signal than on a variety that does not, whereas spiking the soil near the latter variety with authentic (E)-beta-caryophyllene decreased the emergence of adult D. v. virgifera to less than half. North American maize lines must have lost the signal during the breeding process. Development of new varieties that release the attractant in adequate amounts should help enhance the efficacy of nematodes as biological control agents against root pests like D. v. virgifera.

  9. Photomorphogenic Responses in Maize Seedling Development1[w

    PubMed Central

    Markelz, Nicole H.; Costich, Denise E.; Brutnell, Thomas P.

    2003-01-01

    As an emerging maize (Zea mays) seedling senses light, there is a decrease in the rate of mesocotyl elongation, an induction of root growth, and an expansion of leaves. In leaf tissues, mesophyll and bundle sheath cell fate is determined, and the proplastids of each differentiate into the dimorphic chloroplasts typical of each cell type. Although it has been inferred from recent studies in several model plant species that multiple photoreceptor systems mediate this process, surprisingly little is known of light signal transduction in maize. Here, we examine two photomorphogenic responses in maize: inhibition of mesocotyl elongation and C4 photosynthetic differentiation. Through an extensive survey of white, red, far-red, and blue light responses among a diverse collection of germplasm, including a phytochrome-deficient mutant elm1, we show that light response is a highly variable trait in maize. Although all inbreds examined appear to have a functional phytochrome signal transduction pathway, several lines showed reduced sensitivity to blue light. A significant correlation was observed between light response and subpopulation, suggesting that light responsiveness may be a target of artificial selection. An examination of C4 gene expression patterns under various light regimes in the standard W22 inbred and elm1 indicate that cell-specific patterns of C4 gene expression are maintained in fully differentiated tissues independent of light quality. To our knowledge, these findings represent the first comprehensive survey of light response in maize and are discussed in relation to maize breeding strategies. PMID:14645729

  10. Post-Domestication Selection in the Maize Starch Pathway

    PubMed Central

    Fan, Longjiang; Bao, Jiandong; Wang, Yu; Yao, Jianqiang; Gui, Yijie; Hu, Weiming; Zhu, Jinqing; Zeng, Mengqian; Li, Yu; Xu, Yunbi

    2009-01-01

    Modern crops have usually experienced domestication selection and subsequent genetic improvement (post-domestication selection). Chinese waxy maize, which originated from non-glutinous domesticated maize (Zea mays ssp. mays), provides a unique model for investigating the post-domestication selection of maize. In this study, the genetic diversity of six key genes in the starch pathway was investigated in a glutinous population that included 55 Chinese waxy accessions, and a selective bottleneck that resulted in apparent reductions in diversity in Chinese waxy maize was observed. Significant positive selection in waxy (wx) but not amylose extender1 (ae1) was detected in the glutinous population, in complete contrast to the findings in non-glutinous maize, which indicated a shift in the selection target from ae1 to wx during the improvement of Chinese waxy maize. Our results suggest that an agronomic trait can be quickly improved into a target trait with changes in the selection target among genes in a crop pathway. PMID:19859548

  11. Genomic variation in recently collected maize landraces from Mexico.

    PubMed

    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.

  12. Genomic variation in recently collected maize landraces from Mexico

    PubMed Central

    Arteaga, María Clara; Moreno-Letelier, Alejandra; Mastretta-Yanes, Alicia; Vázquez-Lobo, Alejandra; Breña-Ochoa, Alejandra; Moreno-Estrada, Andrés; Eguiarte, Luis E.; Piñero, Daniel

    2015-01-01

    The present dataset comprises 36,931 SNPs genotyped in 46 maize landraces native to Mexico as well as the teosinte subspecies Zea maiz ssp. parviglumis and ssp. mexicana. These landraces were collected directly from farmers mostly between 2006 and 2010. We accompany these data with a short description of the variation within each landrace, as well as maps, principal component analyses and neighbor joining trees showing the distribution of the genetic diversity relative to landrace, geographical features and maize biogeography. High levels of genetic variation were detected for the maize landraces (HE = 0.234 to 0.318 (mean 0.311), while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (HE = 0.262 and 0.234, respectively). The distribution of genetic variation was better explained by environmental variables given by the interaction of altitude and latitude than by landrace identity. This dataset is a follow up product of the Global Native Maize Project, an initiative to update the data on Mexican maize landraces and their wild relatives, and to generate information that is necessary for implementing the Mexican Biosafety Law. PMID:26981357

  13. A crop population perspective on maize seed systems in Mexico

    PubMed Central

    Dyer, George A.; Taylor, J. Edward

    2008-01-01

    Improvement of local germplasm through artificial selection is regarded as the main force behind maize evolution and diversity in Mexico, the crop's center of origin. This perspective neglects the larger social context of maize evolution. Using a theoretical approach and Mexico-wide data, we show that farmer-led evolution of maize is largely driven by a technological diffusion and appropriation process that selectively integrates nonlocal germplasm into local seed stocks. Our approach construes farmer practices as events in the life history of seed to build a demographic model. The model shows how random and systematic differences in management combine to structure maize seed populations into subpopulations that can spread or become extinct, in some cases independently of visible agronomic advantages. The process involves continuous population bottlenecks that can lead to diversity loss. Nonlocal germplasm thus might play a critical role in maintaining diversity in individual localities. Empirical estimates show that introduction of nonlocal seed in Central and Southeastern Mexico is rarer than previously thought; prompt replacement further prevents new seed from spreading. Yet introduced seed perceived as valuable diffuses rapidly, contributing variation in the form of type diversity or through introgression into local seed. Maize seed dynamics and evolution are thus part of a complex social process driven by farmers' desire to appropriate the value in maize farming, not always achieved by preserving or improving local seed stocks. PMID:18184814

  14. MaizeGDB: curation and outreach go hand-in-hand.

    PubMed

    Schaeffer, Mary L; Harper, Lisa C; Gardiner, Jack M; Andorf, Carson M; Campbell, Darwin A; Cannon, Ethalinda K S; Sen, Taner Z; Lawrence, Carolyn J

    2011-01-01

    First released in 1991 with the name MaizeDB, the Maize Genetics and Genomics Database, now MaizeGDB, celebrates its 20th anniversary this year. MaizeGDB has transitioned from a focus on comprehensive curation of the literature, genetic maps and stocks to a paradigm that accommodates the recent release of a reference maize genome sequence, multiple diverse maize genomes and sequence-based gene expression data sets. The MaizeGDB Team is relatively small, and relies heavily on the research community to provide data, nomenclature standards and most importantly, to recommend future directions, priorities and strategies. Key aspects of MaizeGDB's intimate interaction with the community are the co-location of curators with maize research groups in multiple locations across the USA as well as coordination with MaizeGDB's close partner, the Maize Genetics Cooperation--Stock Center. In this report, we describe how the MaizeGDB Team currently interacts with the maize research community and our plan for future interactions that will support updates to the functional and structural annotation of the B73 reference genome.

  15. Genetic control of leaf curl in maize.

    PubMed

    Entringer, G C; Guedes, F L; Oliveira, A A; Nascimento, J P; Souza, J C

    2014-03-17

    Among the many implications of climatic change on agriculture, drought is expected to continue to have a major impact on agribusinesses. Leaf curling is an anatomical characteristic that might be potentially used to enhance plant tolerance to water deficit. Hence, we aimed to study the genetic control of leaf curl in maize. From 2 contrasting inbred lines for the trait, generations F1, F2, and the backcrosses were obtained. All of these generations were evaluated in a randomized block design with 2 replicates. Leaf curl samples were collected from 3 leaves above the first ear at the tasseling stage, and quantified by dividing the width of the leaf blade with natural curling against its extended width. The mean and variance components were estimated by the weighted least square method. It was found that the trait studied has predominance of the additive effects, with genetic control being attributed to few genes that favor selection and exhibit minimal influence from the environment.

  16. Maize mitochondria synthesize organ-specific polypeptides

    SciTech Connect

    Newton, K.J.; Walbot, V.

    1985-10-01

    The authors detected both quantitative and qualitative organ-specific differences in the total protein composition of mitochondria of maize. Labeling of isolated mitochondria from each organ demonstrated that a few protein differences are due to changes in the polypeptides synthesized by the organelle. The synthesis of developmental stage-specific mitochondrial polypeptides was found in the scutella of developing and germinating kernels. The approximately 13-kDa polypeptide synthesized by mitochondria from seedlings of the Texas (T) male-sterile cytoplasm was shown to be constitutively expressed in all organs of line B37T tested. Methomyl, an insecticide known to inhibit the growth of T sterile plants, was shown to be an effective inhibitor of protein synthesis in mitochondria from T plants.

  17. Regulatory modules controlling maize inflorescence architecture.

    PubMed

    Eveland, Andrea L; Goldshmidt, Alexander; Pautler, Michael; Morohashi, Kengo; Liseron-Monfils, Christophe; Lewis, Michael W; Kumari, Sunita; Hiraga, Susumu; Yang, Fang; Unger-Wallace, Erica; Olson, Andrew; Hake, Sarah; Vollbrecht, Erik; Grotewold, Erich; Ware, Doreen; Jackson, David

    2014-03-01

    Genetic control of branching is a primary determinant of yield, regulating seed number and harvesting ability, yet little is known about the molecular networks that shape grain-bearing inflorescences of cereal crops. Here, we used the maize (Zea mays) inflorescence to investigate gene networks that modulate determinacy, specifically the decision to allow branch growth. We characterized developmental transitions by associating spatiotemporal expression profiles with morphological changes resulting from genetic perturbations that disrupt steps in a pathway controlling branching. Developmental dynamics of genes targeted in vivo by the transcription factor RAMOSA1, a key regulator of determinacy, revealed potential mechanisms for repressing branches in distinct stem cell populations, including interactions with KNOTTED1, a master regulator of stem cell maintenance. Our results uncover discrete developmental modules that function in determining grass-specific morphology and provide a basis for targeted crop improvement and translation to other cereal crops with comparable inflorescence architectures.

  18. Hydrothermal carbonization of anaerobically digested maize silage.

    PubMed

    Mumme, Jan; Eckervogt, Lion; Pielert, Judith; Diakité, Mamadou; Rupp, Fabian; Kern, Jürgen

    2011-10-01

    Hydrochars were prepared by hydrothermal carbonization (HTC) of maize silage previously treated at 55 °C in a two-stage solid-state reactor system. The HTC was carried out in a 1-L stirred pressure reactor with pH regulation by citric acid. The treated silage carbonized at relatively mild conditions (190 °C, 2 h), and the hydrochars showed mainly amorphous macro-size features with a carbon content of 59-79% (ash-free, dry) and a higher heating value of 25-36 MJ kg⁻¹. Temperature was the main influencing factor. The surface area according to Brunauer-Emmett-Teller (BET) analysis was highest at 190 °C (12.3 m²) g⁻¹). Based on these results, the hydrochars are potentially interesting for applications such as an alternative fuel or a soil conditioner.

  19. Hexokinase from Maize Endosperm and Scutellum 1

    PubMed Central

    Cox, Edward L.; Dickinson, David B.

    1973-01-01

    Hexokinase (EC 2.7.1.1) was isolated from endosperm and scutellum of developing and germinating maize (Zea mays) seeds. With fructose as the variable substate, Michaelis constant values for the scutellum enzyme were about onethird those of the endosperm enzyme (0.05 versus 0.15 mm), and no developmental differences were observed. With glucose as the variable substrate, Michaelis constant values were all in the range 0.1 to 0.2 mm. The enzyme preparation from germinating scutellum was studied further; when glucose was varied over a wide range, a Michaelis constant of 3.4 mm was observed in addition to the much lower Michaelis constant noted above. This low affinity binding of glucose may have regulatory significance and may indicate the presence of a glucokinase in addition to hexokinase. PMID:16658446

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

    PubMed Central

    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. PMID:27366645

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

    PubMed

    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.

  2. Zealactones. Novel natural strigolactones from maize.

    PubMed

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

    2017-05-01

    In the root exudate and root extracts of maize hybrid cv NK Falkone seven putative strigolactones were detected using UPLC-TQ-MS-MS. All seven compounds displayed MS-MS-fragmentation common for strigolactones and particularly the presence of a fragment of m/z 97 Da, which may indicate the presence of the so-called D-ring, suggests they are strigolactones. The levels of all these putative strigolactones increased upon phosphate starvation and decreased upon fluridone (carotenoid biosynthesis inhibitor) treatment, both of which are a common response for strigolactones. All seven compounds were subsequently isolated with prep-HPLC-MS. They all exhibited Striga hermonthica seed germination inducing activity just as the synthetic strigolactone analog GR24. The structure of two of the seven compounds was elucidated by NMR spectroscopy as: methyl (2E,3E)-4-(3,3-dimethyl-5-oxo-2-(prop-1-en-2-yl)tetrahydrofuran-2-yl)-2-(((4-methyl-5-oxo-2,5-dihydrofuran-2-yl)oxy)methylene)but-3-enoate (two diastereomers 1a and 1b). Strigolactones (1a/b) are closely related to the methyl ester of carlactonoic acid (MeCLA) and heliolactone. However, they contain a unique 4,4-dimethyltetrahydrofuran-2-one motif as the "A-ring" instead of the classical (di)methylcyclohexene. Because these compounds were isolated from maize (Zea mays) we called them "zealactone 1a and 1b". The implications of this discovery for our view on strigolactones and their biosynthesis are discussed.

  3. Data assimilation of MODIS and TM observations into CERES-Maize model to estimate regional maize yield

    NASA Astrophysics Data System (ADS)

    Jin, Huaan; Wang, Jindi; Bo, Yanchen; Chen, Guifen; Xue, Huazhu

    2010-08-01

    Accurate and real-time estimation of crop yield over large areas is critical for many applications such as crop management, and agricultural management decision-making. This study presents a scheme to assimilate multi-temporal MODIS and Landsat TM reflectance data into the CERES-Maize crop growth model which is coupled with the radiative transfer model SAIL for maize yield estimation. We extract the directional reflectance data of MODIS subpixels corresponding to pure maize conditions with the objective to increase time series observations at the TM scale. The variables to be assimilated were chosen by conducting the sensitivity analysis on the coupled model. The SCE-UA algorithm was applied to determine the optimal set of these sensitive variables. Finally the maize yields maps were produced at TM scale with the coupled assimilation model. The proposed scheme was applied over Yushu County located in Jilin province of Northeast China and validated by using field yield measurement dataset during the maize growing season in 2007. The measurement data include the species of planting maize, soil type and fertility, field observed leaf, canopy and soil reflectance data etc. Furthermore, yield data were gained in specially designed experimental campaigns. The validation results indicate that the yield estimation scheme using multiple remote sensing data assimilation is very promising. The accuracy of TM yield map produced by adding time series MODIS subpixel information was improved comparing with that only using TM data.

  4. Addition of individual chromosomes of maize inbreds B73 and Mo17 to oat cultivars Starter and Sun II: maize chromosome retention, transmission, and plant phenotype.

    PubMed

    Rines, Howard W; Phillips, Ronald L; Kynast, Ralf G; Okagaki, Ron J; Galatowitsch, Mark W; Huettl, Paul A; Stec, Adrian O; Jacobs, Morrison S; Suresh, Jayanti; Porter, Hedera L; Walch, Matthew D; Cabral, Candida B

    2009-11-01

    Oat-maize addition (OMA) lines with one, or occasionally more, chromosomes of maize (Zea mays L., 2n = 2x = 20) added to an oat (Avena sativa L., 2n = 6x = 42) genomic background can be produced via embryo rescue from sexual crosses of oat x maize. Self-fertile disomic addition lines of different oat genotypes, mainly cultivar Starter, as recipient for maize chromosomes 1, 2, 3, 4, 5, 6, 7, 9, and the short arm of 10 and a monosomic addition line for chromosome 8, have been reported previously in which the sweet corn hybrid Seneca 60 served as the maize chromosome donor. Here we report the production and characterization of a series of new OMA lines with inbreds B73 and Mo17 as maize chromosome donors and with oat cultivars Starter and Sun II as maize chromosome recipients. Fertile disomic OMA lines were recovered for B73 chromosomes 1, 2, 4, 5, 6, 8, 9, and 10 and Mo17 chromosomes 2, 4, 5, 6, 8, and 10. These lines together with non-fertile (oat x maize) F(1) plants with chromosome 3 and chromosome 7 of Mo17 individually added to Starter oat provide DNA of additions to oat of all ten individual maize chromosomes between the two maize inbreds. The Mo17 chromosome 10 OMA line was the first fertile disomic OMA line obtained carrying a complete chromosome 10. The B73 OMA line for chromosome 1 and the B73 and Mo17 OMA lines for chromosome 8 represent disomic OMA lines with improved fertility and transmission of the addition chromosome compared to earlier Seneca 60 versions. Comparisons among the four oat-maize parental genotype combinations revealed varying parental effects and interactions on frequencies of embryo recovery, embryo germination, F(1) plantlets with maize chromosomes, the specific maize chromosomes retained and transmitted to F(2) progeny, and phenotypes of self-fertile disomic addition plants. As opposed to the previous use of a hybrid Seneca 60 maize stock as donor of the added maize chromosomes, the recovered B73 and Mo17 OMA lines provide predictable

  5. Prospects for reducing fumonisin contamination of maize through genetic modification.

    PubMed Central

    Duvick, J

    2001-01-01

    Fumonisins (FB) are mycotoxins found in (italic)Fusarium verticillioides-infected maize grain worldwide. Attention has focused on FBs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. FBs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. Among the strategies for reducing risk of FB contamination in maize supplied to the market, development and deployment of Fusarium ear mold-resistant maize germplasm is a high priority. Breeding for increased ear mold tolerance and reduced mycotoxin levels is being practiced today in both commercial and public programs, but the amount of resistance achievable may be limited due to complicated genetics and/or linkage to undesirable agronomic traits. Molecular markers can be employed to speed up the incorporation of chromosomal regions that have a quantitative effect on resistance (quantitative trait loci). Transgenic approaches to ear mold/mycotoxin resistance are now feasible as well. These potentially include genetically enhanced resistance to insect feeding, increased fungal resistance, and detoxification/prevention of mycotoxins in the grain. An example of the first of these approaches is already on the market, namely transgenic maize expressing Bacillus thuringiensis (Bt) toxin, targeted to the European corn borer. Some Bt maize hybrids have the potential to reduce FB levels in field-harvested grain, presumably through reduced feeding of Bt-susceptible insects in ear tissues. However, improved ear mold resistance per se is still an important goal, as the plant will still be vulnerable to noninsect routes of entry to (italic)Fusarium. A second approach, transgene-mediated control of the ability of Fusarium to infect and colonize the ear, could potentially be achieved through overexpression of specific antifungal proteins and metabolites, or enhancement of the plant's own

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

    PubMed

    Pechanova, Olga; Pechan, Tibor

    2015-11-30

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

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

    PubMed Central

    Pechanova, Olga; Pechan, Tibor

    2015-01-01

    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. PMID:26633370

  8. Uneven chromosome contraction and expansion in the maize genome.

    PubMed

    Bruggmann, Rémy; Bharti, Arvind K; Gundlach, Heidrun; Lai, Jinsheng; Young, Sarah; Pontaroli, Ana C; Wei, Fusheng; Haberer, Georg; Fuks, Galina; Du, Chunguang; Raymond, Christina; Estep, Matt C; Liu, Renyi; Bennetzen, Jeffrey L; Chan, Agnes P; Rabinowicz, Pablo D; Quackenbush, John; Barbazuk, W Brad; Wing, Rod A; Birren, Bruce; Nusbaum, Chad; Rounsley, Steve; Mayer, Klaus F X; Messing, Joachim

    2006-10-01

    Maize (Zea mays or corn), both a major food source and an important cytogenetic model, evolved from a tetraploid that arose about 4.8 million years ago (Mya). As a result, maize has extensive duplicated regions within its genome. We have sequenced the two copies of one such region, generating 7.8 Mb of sequence spanning 17.4 cM of the short arm of chromosome 1 and 6.6 Mb (25.6 cM) from the long arm of chromosome 9. Rice, which did not undergo a similar whole genome duplication event, has only one orthologous region (4.9 Mb) on the short arm of chromosome 3, and can be used as reference for the maize homoeologous regions. Alignment of the three regions allowed identification of syntenic blocks, and indicated that the maize regions have undergone differential contraction in genic and intergenic regions and expansion by the insertion of retrotransposable elements. Approximately 9% of the predicted genes in each duplicated region are completely missing in the rice genome, and almost 20% have moved to other genomic locations. Predicted genes within these regions tend to be larger in maize than in rice, primarily because of the presence of predicted genes in maize with larger introns. Interestingly, the general gene methylation patterns in the maize homoeologous regions do not appear to have changed with contraction or expansion of their chromosomes. In addition, no differences in methylation of single genes and tandemly repeated gene copies have been detected. These results, therefore, provide new insights into the diploidization of polyploid species.

  9. Functional properties of selected starter cultures for sour maize bread.

    PubMed

    Edema, Mojisola O; Sanni, Abiodun I

    2008-06-01

    This paper focuses on the functional properties of maize sour-dough microflora selected and tested for their use as starter cultures for sour maize bread. Lactic acid bacteria and yeasts isolated from spontaneously fermented maize dough were selected based on dominance during fermentation and presence at the end of fermentation. Functional properties examined included acidification, leavening and production of some antimicrobial compounds in the fermenting matrix. The organisms previously identified as Lactobacillus plantarum, Lb. brevis, Lb. fermentum, Lb. acidophilus, Pediococcus acidilactici, Leuconostoc mesenteroides and Leuconostoc dextranicum and Saccharomyces cerevisiae were used singly and as mixed cultures in the fermentation (fermentation time: 12h at 28+/-2 degrees C) of maize meal (particle size >0.2mm). The pH fell from an initial value of 5.62-3.05 in maize meals fermented with Lb. plantarum; 4.37 in L. dextranicum+S. cerevisiae compared with the value for the control (no starter) of 4.54. Significant differences (P maize dough were confirmed by their abilities to inhibit the growth of Salmonella typhi, Escherichia coli, Staphylococcus aureus and Aspergillus flavus from an initial inoculum concentration of 7 log cfu ml(-1)) for test bacteria and zone of inhibition of up to 1.33 cm for aflatoxigenic A. flavus. The findings of this study form a database for further studies on the

  10. Genome-wide association study of maize identifies genes affecting leaf architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    U.S. maize yield has increased eightfold in the past 80 years with half of the improvement attributed to genetics. Changes in maize leaf angle and size provided a basis for more efficient light capture as plant densities increased. Through a genome wide association study (GWAS) of the maize nested a...

  11. Use of Maize (Zea mays L.) for phytomanagement of Cd-contaminated soils: a critical review.

    PubMed

    Rizwan, Muhammad; Ali, Shafaqat; Qayyum, Muhammad Farooq; Ok, Yong Sik; Zia-Ur-Rehman, Muhammad; Abbas, Zaheer; Hannan, Fakhir

    2017-04-01

    Maize (Zea mays L.) has been widely adopted for phytomanagement of cadmium (Cd)-contaminated soils due to its high biomass production and Cd accumulation capacity. This paper reviewed the toxic effects of Cd and its management by maize plants. Maize could tolerate a certain level of Cd in soil while higher Cd stress can decrease seed germination, mineral nutrition, photosynthesis and growth/yields. Toxicity response of maize to Cd varies with cultivar/varieties, growth medium and stress duration/extent. Exogenous application of organic and inorganic amendments has been used for enhancing Cd tolerance of maize. The selection of Cd-tolerant maize cultivar, crop rotation, soil type, and exogenous application of microbes is a representative agronomic practice to enhance Cd tolerance in maize. Proper selection of cultivar and agronomic practices combined with amendments might be successful for the remediation of Cd-contaminated soils with maize. However, there might be the risk of food chain contamination by maize grains obtained from the Cd-contaminated soils. Thus, maize cultivation could be an option for the management of low- and medium-grade Cd-contaminated soils if grain yield is required. On the other hand, maize can be grown on Cd-polluted soils only if biomass is required for energy production purposes. Long-term field trials are required, including risks and benefit analysis for various management strategies aiming Cd phytomanagement with maize.

  12. Susceptibility to Bt proteins not required for Agrotis ipsilon aversion to Bt maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although Bacillus thuringiensis (Bt) maize has been widely adopted in diverse regions around the world, relatively little is known about the susceptibility and behavioral response of certain insect pests to Bt maize in countries where this maize is not currently cultivated. These are important facto...

  13. The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments

    PubMed Central

    Campos, Renata Calixto; Hernández, Malva Isabel Medina

    2015-01-01

    Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h), a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional) associated with maize management techniques. In Southern Brazil’s scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost. PMID:26694874

  14. [Contamination with genetically modified maize MON863 of processed foods on the market].

    PubMed

    Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

    2009-06-01

    Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Effect of feeding cows genetically modified maize on the bacterial community in the bovine rumen.

    PubMed

    Wiedemann, S; Gürtler, P; Albrecht, C

    2007-12-01

    Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics of six ruminal bacterial strains (investigated by real-time PCR) compared to the conventional maize silage.

  17. Identification of a bioactive Bowman-Birk inhibitor from an insect-resistant early maize inbred

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding of maize, Zea mays, has improved insect resistance, but the genetic and biochemical basis of many of these improvements is unknown. Maize oligonucleotide microarrays were utilized to identify differentially expressed genes in leaves of three maize inbreds, parents Oh40B and W8 and progeny O...

  18. Occurrence of Pyrrocidine and Dihydroresorcyclide Production among Acremonium zeae Populations from Maize Grown in Different Regions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acremonium zeae is recognized as a protective endophyte of maize. It is thus a potential confounding variable in maize variety trials for resistance to pathogenic microbes and their mycotoxins. This fungus grows systemically in maize and produces pyrrocidines A and B, polyketide amino acid derived...

  19. Maize redness in Serbia caused by stolbur phytoplasma is transmitted by Reptalus panzeri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize redness (MR) causes midrib, leaf and stalk reddening and abnormal ear development in maize in Serbia, Romania and Bulgaria. High populations of the ciixid Reptalus panzeri were found in MR affected maize fields in the southern Banat region of Serbia in 2005 and 2006, and stolbur phytoplasma w...

  20. Evaluation of maize cultivars for drought tolerance based on physiological traits associated with cell wall plasticity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is negatively affected by many environmental factors during growth, with drought stress being one of the most common causes for reduction in maize yield world-wide. There is wide variation in stand establishment for various maize cultivars to water deficit condition, such as occur in in arid a...

  1. MADS-box genes in maize: Frequent targets of selection during domestication

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MADS-box genes encode transcription factors that are key regulators of plant inflorescence and flower development. We examined DNA sequence variation in 32 maize MADS-box genes and 32 random loci from the maize genome and investigated their involvement in maize domestication and improvement. Using n...

  2. Physiological and molecular analysis of selected Kenyan maize lines for aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) toxicity is an important limitation to maize production in many tropical and sub-tropical acid soil areas. The aim of this study was to survey the variation in Al tolerance in a panel of maize lines adapted for Kenya and look for novel sources of Al tolerance. 112 Kenyan maize accessio...

  3. Effects of corn fiber gum (CFG) on the pasting and thermal behaviors of maize starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn fiber gum (CFG) is a novel arabinoxylan hydrocolloid. Recent research showed its considerable potential in food processing. In this study, the interactions of maize starch and CFG were studied. Maize starch/CFG blend gels were prepared from maize starch suspension mixed with 0.1%, 0.25%, 0.5%, ...

  4. Mortality impact of MON863 transgenic maize roots on western corn rootworm larvae in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mortality of western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae due to feeding on MON863 transgenic maize (Zea mays L.) expressing the Cry3Bb1 protein relative to survivorship on maize with the same genetic background without the gene (isoline maize) was evaluated at three Missour...

  5. The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments.

    PubMed

    Campos, Renata Calixto; Hernández, Malva Isabel Medina

    2015-01-01

    Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h), a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional) associated with maize management techniques. In Southern Brazil's scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost.

  6. Gene Flow Among Different Teosinte Taxa and Into the Domesticated Maize Gene Pool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays ssp. mays) was domesticated from one wild species ancestor, the Balsas teosinte (Zea mays ssp. parviglumis) about 9000 years ago. Higher levels of gene diversity are found in teosinte taxa compared to maize following domestication and selection bottlenecks. Diversity in maize can b...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Complete genome sequences of Maize dwarf mosaic and Sugarcane mosaic virus isolates coinfecting maize in Spain.

    PubMed

    Achon, M A; Serrano, L; Alonso-Dueñas, N; Porta, C

    2007-01-01

    The genomes of Spanish isolates of Maize dwarf mosaic virus (MDMV-Sp) and Sugarcane mosaic virus (SCMV-Sp) were completely sequenced. Nucleotide sequence identities of SCMV-Sp to those of other SCMV isolates ranged from 79 to 90%. MDMV-Sp shared 85% nucleotide identity with the only other fully sequenced isolate of MDMV. MDMV-Sp and SCMV-Sp differed from each other by 31% in their nucleotide sequences. Phylogenetic analyses showed that SCMV isolates group by host rather than by geographical location. Two significant recombination signals were identified in the NIa and NIb regions of the SCMV-Sp genome.

  9. Maize Domestication and Anti-Herbivore Defences: Leaf-Specific Dynamics during Early Ontogeny of Maize and Its Wild Ancestors

    PubMed Central

    Maag, Daniel; Erb, Matthias; Bernal, Julio S.; Wolfender, Jean-Luc; Turlings, Ted C. J.; Glauser, Gaétan

    2015-01-01

    As a consequence of artificial selection for specific traits, crop plants underwent considerable genotypic and phenotypic changes during the process of domestication. These changes may have led to reduced resistance in the cultivated plant due to shifts in resource allocation from defensive traits to increased growth rates and yield. Modern maize (Zea mays ssp. mays) was domesticated from its ancestor Balsas teosinte (Z. mays ssp. parviglumis) approximately 9000 years ago. Although maize displays a high genetic overlap with its direct ancestor and other annual teosintes, several studies show that maize and its ancestors differ in their resistance phenotypes with teosintes being less susceptible to herbivore damage. However, the underlying mechanisms are poorly understood. Here we addressed the question to what extent maize domestication has affected two crucial chemical and one physical defence traits and whether differences in their expression may explain the differences in herbivore resistance levels. The ontogenetic trajectories of 1,4-benzoxazin-3-ones, maysin and leaf toughness were monitored for different leaf types across several maize cultivars and teosinte accessions during early vegetative growth stages. We found significant quantitative and qualitative differences in 1,4-benzoxazin-3-one accumulation in an initial pairwise comparison, but we did not find consistent differences between wild and cultivated genotypes during a more thorough examination employing several cultivars/accessions. Yet, 1,4-benzoxazin-3-one levels tended to decline more rapidly with plant age in the modern maize cultivars. Foliar maysin levels and leaf toughness increased with plant age in a leaf-specific manner, but were also unaffected by domestication. Based on our findings we suggest that defence traits other than the ones that were investigated are responsible for the observed differences in herbivore resistance between teosinte and maize. Furthermore, our results indicate

  10. Effect of soybean fortification on Ghanaian fermented maize dough aroma.

    PubMed

    Annan, N T; Plahar, W A; Poll, L; Jakobsen, M

    2005-08-01

    The effect of soy fortification on the development of aroma compounds, dough acidity and growth of the predominant microorganisms were investigated in Ghanaian maize dough fermented spontaneously over a period of 72 h. The fortified maize dough was prepared from a milled mixture of soaked maize grains and pre-soaked, blanched and dehulled soybeans added at 20% replacement level. Extracts of volatiles from the soy-fortified and unfortified dough samples were obtained by Likens-Nickerson simultaneous distillation and extraction method analysed by gas chromatography-mass spectrometry and gas chromatography-olfactometry (gas chromatography-sniffing). Major aroma compound groups identified in the fermented dough samples were carbonyls, alcohols, esters and volatile organic acids. Twenty-nine carbonyls were found in soy-fortified maize dough compared with 21 in the unfortified dough. Although the same alcohols were found in both dough samples, the total concentration of alcohols was slightly different, being less for the soy-fortified sample. Total concentration of esters in soy-fortified dough decreased after 72 h while levels in the unfortified dough increased. Increases in the production of lactic and acetic acids occurred in soy-fortified samples, but the maximum concentrations of acetic acid achieved did not differ significantly between the two types of dough. Twenty-three compounds were perceived to be contributing to the typical aroma of soy-fortified maize dough by the method of gas chromatography-sniffing. These included 12 carbonyls, six alcohols, two esters, two acids and one furan.

  11. Mapping the Diversity of Maize Races in Mexico

    PubMed Central

    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

  12. Mapping the diversity of maize races in Mexico.

    PubMed

    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.

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

    PubMed Central

    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

    PubMed Central

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M.

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed. PMID:25140170

  15. Detection of moniliformin in maize using capillary zone electrophoresis.

    PubMed

    Maragos, C M

    2004-08-01

    Moniliformin is a mycotoxin produced by certain fungi pathogenic to maize. It is capable of causing disease in domestic animals, possibly through inhibition of pyruvate dehydrogenase. Testing for MON commonly involves extraction of maize, isolation of moniliformin using solid-phase extraction columns and detection with high-performance liquid chromatography (HPLC) or gas chromatography. A capillary zone electrophoresis-diode array detection (CZE-DAD) method for determination of moniliformin in maize is reported. The extraction and isolation procedures are similar to those of a commonly used HPLC method, while the detection step requires only 10 min. Sixty-three samples of maize were tested by an established HPLC method using absorbance at 229 nm (HPLC-ultraviolet light) and by the CZE-DAD method. The limit of detection of the CZE-DAD method was 0.1 microg MON g(-1) maize compared with 0.05 microg g(-1) for the HPLC-ultraviolet light method. The CZE-DAD method gave good agreement with the HPLC-ultraviolet light method for samples tested at levels up to 1500 microg g(-1), with a linear regression of r(2) = 0.996.

  16. Incidence of Fusarium species and mycotoxins in silage maize.

    PubMed

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

    2011-08-01

    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.

  17. Field trials to evaluate the effects of transgenic cry1le maize on the community characteristics of arthropod natural enemies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Possible non-target effects of transgenic cry1Ie gene maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr study of transgenic cry1Ie gene maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Surveying the maize community for their diversity and pedigree visualization needs to prioritize tool development and curation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Genetics and Genomics Database (MaizeGDB) team prepared a survey to identify breeders’ needs for visualizing pedigrees, diversity data, and haplotypes in order to prioritize tool development and curation efforts at MaizeGDB. The survey was distributed to the maize research community on beh...

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

    PubMed

    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.

  1. A novel maize-infecting mastrevirus from La Réunion Island.

    PubMed

    Pande, Daniel; Kraberger, Simona; Lefeuvre, Pierre; Lett, Jean-Michel; Shepherd, Dionne N; Varsani, Arvind; Martin, Darren P

    2012-08-01

    Despite extensive sampling, only one virus belonging to the genus Mastrevirus of the family Geminiviridae, maize streak virus (MSV), has until now been detected in maize with maize streak disease (MSD) symptoms. Here, we report for the first time a second, highly divergent, mastrevirus isolated from two maize plants displaying characteristic MSD-like symptoms, sampled on the South-west Indian Ocean Island, La Réunion. The two isolates shared <57 % genome-wide identity with all other known mastreviruses. We propose calling the new species Maize streak Réunion virus.

  2. Maize Leaves Turn Away from Neighbors1

    PubMed Central

    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

  3. Auxin signaling modules regulate maize inflorescence architecture

    PubMed Central

    Galli, Mary; Liu, Qiujie; Moss, Britney L.; Malcomber, Simon; Li, Wei; Gaines, Craig; Federici, Silvia; Roshkovan, Jessica; Meeley, Robert; Nemhauser, Jennifer L.; Gallavotti, Andrea

    2015-01-01

    In plants, small groups of pluripotent stem cells called axillary meristems are required for the formation of the branches and flowers that eventually establish shoot architecture and drive reproductive success. To ensure the proper formation of new axillary meristems, the specification of boundary regions is required for coordinating their development. We have identified two maize genes, BARREN INFLORESCENCE1 and BARREN INFLORESCENCE4 (BIF1 and BIF4), that regulate the early steps required for inflorescence formation. BIF1 and BIF4 encode AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins, which are key components of the auxin hormone signaling pathway that is essential for organogenesis. Here we show that BIF1 and BIF4 are integral to auxin signaling modules that dynamically regulate the expression of BARREN STALK1 (BA1), a basic helix-loop-helix (bHLH) transcriptional regulator necessary for axillary meristem formation that shows a striking boundary expression pattern. These findings suggest that auxin signaling directly controls boundary domains during axillary meristem formation and define a fundamental mechanism that regulates inflorescence architecture in one of the most widely grown crop species. PMID:26464512

  4. Auxin signaling modules regulate maize inflorescence architecture.

    PubMed

    Galli, Mary; Liu, Qiujie; Moss, Britney L; Malcomber, Simon; Li, Wei; Gaines, Craig; Federici, Silvia; Roshkovan, Jessica; Meeley, Robert; Nemhauser, Jennifer L; Gallavotti, Andrea

    2015-10-27

    In plants, small groups of pluripotent stem cells called axillary meristems are required for the formation of the branches and flowers that eventually establish shoot architecture and drive reproductive success. To ensure the proper formation of new axillary meristems, the specification of boundary regions is required for coordinating their development. We have identified two maize genes, BARREN INFLORESCENCE1 and BARREN INFLORESCENCE4 (BIF1 and BIF4), that regulate the early steps required for inflorescence formation. BIF1 and BIF4 encode AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins, which are key components of the auxin hormone signaling pathway that is essential for organogenesis. Here we show that BIF1 and BIF4 are integral to auxin signaling modules that dynamically regulate the expression of BARREN STALK1 (BA1), a basic helix-loop-helix (bHLH) transcriptional regulator necessary for axillary meristem formation that shows a striking boundary expression pattern. These findings suggest that auxin signaling directly controls boundary domains during axillary meristem formation and define a fundamental mechanism that regulates inflorescence architecture in one of the most widely grown crop species.

  5. Maize leaves turn away from neighbors.

    PubMed

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

    2002-11-01

    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.

  6. Biological control of Fusarium moniliforme in maize.

    PubMed Central

    Bacon, C W; Yates, I E; Hinton, D M; Meredith, F

    2001-01-01

    Fusarium moniliforme Sheldon, a biological species of the mating populations within the (italic)Gibberella fujikuroi species complex, i.e., population A [= G. moniliformis (Sheld.) Wineland], is an example of a facultative fungal endophyte. During the biotrophic endophytic association with maize, as well as during saprophytic growth, F. moniliforme produces the fumonisins. The fungus is transmitted vertically and horizontally to the next generation of plants via clonal infection of seeds and plant debris. Horizontal infection is the manner by which this fungus is spread contagiously and through which infection occurs from the outside that can be reduced by application of certain fungicides. The endophytic phase is vertically transmitted. This type infection is important because it is not controlled by seed applications of fungicides, and it remains the reservoir from which infection and toxin biosynthesis takes place in each generation of plants. Thus, vertical transmission of this fungus is just as important as horizontal transmission. A biological control system using an endophytic bacterium, Bacillus subtilis, has been developed that shows great promise for reducing mycotoxin accumulation during the endophytic (vertical transmission) growth phase. Because this bacterium occupies the identical ecological niche within the plant, it is considered an ecological homologue to F. moniliforme, and the inhibitory mechanism, regardless of the mode of action, operates on the competitive exclusion principle. In addition to this bacterium, an isolate of a species of the fungus Trichoderma shows promise in the postharvest control of the growth and toxin accumulation from F. moniliforme on corn in storage. PMID:11359703

  7. Amyloplast sedimentation kinetics in gravistimulated maize roots

    NASA Technical Reports Server (NTRS)

    Sack, F. D.; Suyemoto, M. M.; Leopold, A. C.

    1985-01-01

    Amyloplast sedimentation in gravistimulated maize (Zea mays L.) roots was measured using the change in angle from the center of the cell to each amyloplast as an index of sedimentation. Using tissue fixed after gravistimulation, the relationship between mean amyloplast angle and the duration of gravistimulation was found to be linear when plotted on a logarithmic time scale. Extrapolated values for the onset of angular change are 5.9 s after the start of gravistimulation for the entire population of amyloplasts and 11.8 s for lead amyloplasts. By multiplying the instantaneous angular velocity (in radians) by the cell center to amyloplast radius, it is possible to calculate the initial sedimentation velocity to be 19.1 micrometers min-1 at 5.9 s. During sedimentation, the mean amyloplast angles surpass the calculated cell corner angle of 123 at 2.2 min for all amyloplasts and at 19 s for lead amyloplasts near the new lower wall. Thus, substantial sedimentation occurs within the presentation time, calculated to be 4.1 min. These kinetics are consistent with several hypotheses of graviperception.

  8. Further characterization of Maize chlorotic mottle virus and its synergistic interaction with Sugarcane mosaic virus in maize

    PubMed Central

    Wang, Qiang; Zhang, Chao; Wang, Chunyan; Qian, Yajuan; Li, Zhenghe; Hong, Jian; Zhou, Xueping

    2017-01-01

    Maize chlorotic mottle virus (MCMV) was first reported in maize in China in 2009. In this study we further analyzed the epidemiology of MCMV and corn lethal necrosis disease (CLND) in China. We determined that CLND observed in China was caused by co-infection of MCMV and sugarcane mosaic virus (SCMV). Phylogenetic analysis using four full-length MCMV cDNA sequences obtained in this study and the available MCMV sequences retrieved from GenBank indicated that Chinese MCMV isolates were derived from the same source. To screen for maize germplasm resistance against MCMV infection, we constructed an infectious clone of MCMV isolate YN2 (pMCMV) and developed an Agrobacterium-mediated injection procedure to allow high throughput inoculations of maize with the MCMV infectious clone. Electron microscopy showed that chloroplast photosynthesis in leaves was significantly impeded by the co-infection of MCMV and SCMV. Mitochondria in the MCMV and SCMV co-infected cells were more severely damaged than in MCMV-infected cells. The results of this study provide further insight into the epidemiology of MCMV in China and shed new light on physiological and cytopathological changes related to CLND in maize. PMID:28059116

  9. Circadian expression of the maize catalase Cat3 gene is highly conserved among diverse maize genotypes with structurally different promoters.

    PubMed Central

    Polidoros, A N; Scandalios, J G

    1998-01-01

    The Cat3 gene of maize exhibits a transcriptionally regulated circadian rhythm. In the present study we examined the following: (1) the extent of the circadian Cat3 expression between maize genotypes of diverse origin; (2) the functional significance of a Tourist transposable element located in the Cat3 promoter of the inbred line W64A, which harbors putative regulatory elements (GATA repeat, CCAAT boxes) shown to be involved in the light induction and circadian regulation of the Arabidopsis CAB2, as well as other plant genes; and (3) aspects of the physiological role of CAT-3 in maize metabolism. Results confirm that the circadian Cat3 expression is a general phenomenon in maize. Regulation of Cat3 gene expression is not dependent on the presence of the Tourist element in the promoter of the gene nor on the presence of motifs similar to those found significant in the circadian expression of the Arabidopsis CAB2 gene. Structural diversity was revealed in the Cat3 promoters of maize genotypes of diverse origins. However, highly conserved regions with putative regulatory motifs were identified. Relevance of the conserved regions to the circadian regulation of the gene is discussed. Possible physiological roles of CAT-3 are suggested. PMID:9584112

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

    PubMed

    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.

  11. Equity in access to fortified maize flour and corn meal

    PubMed Central

    Zamora, Gerardo; De-Regil, Luz Maria

    2014-01-01

    Mass fortification of maize flour and corn meal with a single or multiple micronutrients is a public health intervention that aims to improve vitamin and mineral intake, micronutrient nutritional status, health, and development of the general population. Micronutrient malnutrition is unevenly distributed among population groups and is importantly determined by social factors, such as living conditions, socioeconomic position, gender, cultural norms, health systems, and the socioeconomic and political context in which people access food. Efforts trying to make fortified foods accessible to the population groups that most need them require acknowledgment of the role of these determinants. Using a perspective of social determinants of health, this article presents a conceptual framework to approach equity in access to fortified maize flour and corn meal, and provides nonexhaustive examples that illustrate the different levels included in the framework. Key monitoring areas and issues to consider in order to expand and guarantee a more equitable access to maize flour and corn meal are described. PMID:24329609

  12. Accuracy of genomic selection in European maize elite breeding populations.

    PubMed

    Zhao, Yusheng; Gowda, Manje; Liu, Wenxin; Würschum, Tobias; Maurer, Hans P; Longin, Friedrich H; Ranc, Nicolas; Reif, Jochen C

    2012-03-01

    Genomic selection is a promising breeding strategy for rapid improvement of complex traits. The objective of our study was to investigate the prediction accuracy of genomic breeding values through cross validation. The study was based on experimental data of six segregating populations from a half-diallel mating design with 788 testcross progenies from an elite maize breeding program. The plants were intensively phenotyped in multi-location field trials and fingerprinted with 960 SNP markers. We used random regression best linear unbiased prediction in combination with fivefold cross validation. The prediction accuracy across populations was higher for grain moisture (0.90) than for grain yield (0.58). The accuracy of genomic selection realized for grain yield corresponds to the precision of phenotyping at unreplicated field trials in 3-4 locations. As for maize up to three generations are feasible per year, selection gain per unit time is high and, consequently, genomic selection holds great promise for maize breeding programs.

  13. A first-generation haplotype map of maize.

    PubMed

    Gore, Michael A; Chia, Jer-Ming; Elshire, Robert J; Sun, Qi; Ersoz, Elhan S; Hurwitz, Bonnie L; Peiffer, Jason A; McMullen, Michael D; Grills, George S; Ross-Ibarra, Jeffrey; Ware, Doreen H; Buckler, Edward S

    2009-11-20

    Maize is an important crop species of high genetic diversity. We identified and genotyped several million sequence polymorphisms among 27 diverse maize inbred lines and discovered that the genome was characterized by highly divergent haplotypes and showed 10- to 30-fold variation in recombination rates. Most chromosomes have pericentromeric regions with highly suppressed recombination that appear to have influenced the effectiveness of selection during maize inbred development and may be a major component of heterosis. We found hundreds of selective sweeps and highly differentiated regions that probably contain loci that are key to geographic adaptation. This survey of genetic diversity provides a foundation for uniting breeding efforts across the world and for dissecting complex traits through genome-wide association studies.

  14. Thermoplastic starch-waxy maize starch nanocrystals nanocomposites.

    PubMed

    Angellier, Hélène; Molina-Boisseau, Sonia; Dole, Patrice; Dufresne, Alain

    2006-02-01

    Waxy maize starch nanocrystals obtained by hydrolysis of native granules were used as a reinforcing agent in a thermoplastic waxy maize starch matrix plasticized with glycerol. Compared to our previous studies on starch nanocrystals reinforced natural rubber (NR) [Macromolecules 2005, 38, 3783; 2005, 38, 9161], the present system presents two particularities: (i) thermoplastic starch is a polar matrix, contrarily to NR, and (ii) the chemical structures of the matrix and the filler are similar. The influence of the glycerol content, filler content, and aging on the reinforcing properties of waxy maize starch nanocrystals (tensile tests, DMA) and crystalline structure (X-ray diffraction) of materials were studied. It was shown that the reinforcing effect of starch nanocrystals can be attributed to strong filler/filler and filler/matrix interactions due to the establishment of hydrogen bonding. The presence of starch nanocrystals leads to a slowing down of the recrystallization of the matrix during aging in humid atmosphere.

  15. Agroclimatological suitability mapping for dryland maize production in Lesotho

    NASA Astrophysics Data System (ADS)

    Moeletsi, Mokhele Edmond; Walker, Sue

    2013-10-01

    The climatic potential of maize under dryland farming in Lesotho, southern Africa, was investigated using five suitability indices comprising probability of accumulating heat units of greater than 1,500 growing degree days, probability of a frost-free growing season, probability of seasonal rainfall of more than 500 mm, probability of drought during the flowering to grain-filling stages and the slope of an area. A geographic information system layer was prepared for each of these parameters and the layers overlaid using different weights for each of the climatic suitability indices to obtain an agroclimatic maize suitability map for Lesotho. This analysis yielded different suitability classes. This variability points to prevalence of climatic constraints that need to be acknowledged when attempting to identify management strategies that can optimize the rain-fed maize production in climatically variable environments.

  16. PPIM: A Protein-Protein Interaction Database for Maize1

    PubMed Central

    Wu, Aibo; Xu, Xin-Jian; Lu, Le; Liu, Jingdong; Cao, Yongwei; Chen, Luonan; Wu, Jun; Zhao, Xing-Ming

    2016-01-01

    Maize (Zea mays) is one of the most important crops worldwide. To understand the biological processes underlying various traits of the crop (e.g. yield and response to stress), a detailed protein-protein interaction (PPI) network is highly demanded. Unfortunately, there are very few such PPIs available in the literature. Therefore, in this work, we present the Protein-Protein Interaction Database for Maize (PPIM), which covers 2,762,560 interactions among 14,000 proteins. The PPIM contains not only accurately predicted PPIs but also those molecular interactions collected from the literature. The database is freely available at http://comp-sysbio.org/ppim with a user-friendly powerful interface. We believe that the PPIM resource can help biologists better understand the maize crop. PMID:26620522

  17. Red card for pathogens: phytoalexins in sorghum and maize.

    PubMed

    Poloni, Alana; Schirawski, Jan

    2014-06-30

    Cereal crop plants such as maize and sorghum are constantly being attacked by a great variety of pathogens that cause large economic losses. Plants protect themselves against pathogens by synthesizing antimicrobial compounds, which include phytoalexins. In this review we summarize the current knowledge on phytoalexins produced by sorghum (luteolinidin, apigeninidin) and maize (zealexin, kauralexin, DIMBOA and HDMBOA). For these molecules, we highlight biosynthetic pathways, known intermediates, proposed enzymes, and mechanisms of elicitation. Finally, we discuss the involvement of phytoalexins in plant resistance and their possible application in technology, medicine and agriculture. For those whose world is round we tried to set the scene in the context of a hypothetical football game in which pathogens fight with phytoalexins on the different playing fields provided by maize and sorghum.

  18. Susceptibility to aflatoxin contamination among maize landraces from Mexico.

    PubMed

    Ortega-Beltran, Alejandro; Guerrero-Herrera, Manuel D J; Ortega-Corona, Alejandro; Vidal-Martinez, Victor A; Cotty, Peter J

    2014-09-01

    Maize, the critical staple food for billions of people, was domesticated in Mexico about 9,000 YBP. Today, a great array of maize landraces (MLRs) across rural Mexico is harbored in a living library that has been passed among generations since before the establishment of the modern state. MLRs have been selected over hundreds of generations by ethnic groups for adaptation to diverse environmental settings. The genetic diversity of MLRs in Mexico is an outstanding resource for development of maize cultivars with beneficial traits. Maize is frequently contaminated with aflatoxins by Aspergillus flavus, and resistance to accumulation of these potent carcinogens has been sought for over three decades. However, MLRs from Mexico have not been evaluated as potential sources of resistance. Variation in susceptibility to both A. flavus reproduction and aflatoxin contamination was evaluated on viable maize kernels in laboratory experiments that included 74 MLR accessions collected from 2006 to 2008 in the central west and northwest regions of Mexico. Resistant and susceptible MLR accessions were detected in both regions. The most resistant accessions accumulated over 99 % less aflatoxin B1 than did the commercial hybrid control Pioneer P33B50. Accessions supporting lower aflatoxin accumulation also supported reduced A. flavus sporulation. Sporulation on the MLRs was positively correlated with aflatoxin accumulation (R = 0.5336, P < 0.0001), suggesting that resistance to fungal reproduction is associated with MLR aflatoxin resistance. Results of the current study indicate that MLRs from Mexico are potentially important sources of aflatoxin resistance that may contribute to the breeding of commercially acceptable and safe maize hybrids and/or open pollinated cultivars for human and animal consumption.

  19. The Genomic Signature of Crop-Wild Introgression in Maize

    PubMed Central

    Hufford, Matthew B.; Lubinksy, Pesach; Pyhäjärvi, Tanja; Devengenzo, Michael T.; Ellstrand, Norman C.; Ross-Ibarra, Jeffrey

    2013-01-01

    The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes appeared resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these genomic regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly inform our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies. PMID:23671421

  20. A 90-day toxicity study of GmTMT transgenic maize in Sprague-Dawley rats.

    PubMed

    Fang, Jin; Feng, Yongquan; Zhi, Yuan; Zhang, Lan; Yu, Zhou; Jia, Xudong

    2017-04-01

    GmTMT transgenic maize is a genetically modified maize plant that overexpresses the γ-tocopherol methyltransferase (γ-TMT) from Glycine max (Gm). The γ-TMT gene was introduced into maize line Zhen58 to encode the GmTMT2a protein which can convert γ-tocopherol into α-tocopherol. Overexpression of GmTMT2a significantly increased the α-tocopherol content in transgenic maize. The present study was designed to investigate any potential effects of GmTMT maize grain in a 90-day subchronic rodent feeding study. Maize grains from GmTMT or Zhen58 were incorporated into rodent diets at low (12.5%), medium (25%) or high (50%) concentrations and administered to Sprague-Dawley rats (n = 10/sex/group) for 90 days. The negative control group of rats (n = 10/sex/group) were fed with common maize diets. Results from body weights, feed consumption, clinical chemistry, hematology, absolute and relative organ weights indicated no treatment-related side effects of GmTMT maize grain on rats in comparison with rats consuming diets containing Zhen58 maize grain. In addition, no treatment-related changes were found in necropsy and histopathology examinations. Altogether, our data indicates that GmTMT transgenic maize is as safe and nutritious as its conventional non-transgenic maize.

  1. “Omics” of Maize Stress Response for Sustainable Food Production: Opportunities and Challenges

    PubMed Central

    Gong, Fangping; Yang, Le; Tai, Fuju; Hu, Xiuli

    2014-01-01

    Abstract Maize originated in the highlands of Mexico approximately 8700 years ago and is one of the most commonly grown cereal crops worldwide, followed by wheat and rice. Abiotic stresses (primarily drought, salinity, and high and low temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, and eventually production. To understand the response of maize to abiotic and biotic stresses and its mechanism of stress tolerance, high-throughput omics approaches have been used in maize stress studies. Integrated omics approaches are crucial for dissecting the temporal and spatial system-level changes that occur in maize under various stresses. In this comprehensive analysis, we review the primary types of stresses that threaten sustainable maize production; underscore the recent advances in maize stress omics, especially proteomics; and discuss the opportunities, challenges, and future directions of maize stress omics, with a view to sustainable food production. The knowledge gained from studying maize stress omics is instrumental for improving maize to cope with various stresses and to meet the food demands of the exponentially growing global population. Omics systems science offers actionable potential solutions for sustainable food production, and we present maize as a notable case study. PMID:25401749

  2. Global Maize Trade and Food Security: Implications from a Social Network Model

    PubMed Central

    Wu, Felicia; Guclu, Hasan

    2013-01-01

    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 were decreased due to factors such as diversion to non-food uses, climatic factors, or plant diseases. Using data on imports and exports from the United Nations 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, while Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents US 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 US 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. PMID:23656551

  3. "Omics" of maize stress response for sustainable food production: opportunities and challenges.

    PubMed

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

    2014-12-01

    Maize originated in the highlands of Mexico approximately 8700 years ago and is one of the most commonly grown cereal crops worldwide, followed by wheat and rice. Abiotic stresses (primarily drought, salinity, and high and low temperatures), together with biotic stresses (primarily fungi, viruses, and pests), negatively affect maize growth, development, and eventually production. To understand the response of maize to abiotic and biotic stresses and its mechanism of stress tolerance, high-throughput omics approaches have been used in maize stress studies. Integrated omics approaches are crucial for dissecting the temporal and spatial system-level changes that occur in maize under various stresses. In this comprehensive analysis, we review the primary types of stresses that threaten sustainable maize production; underscore the recent advances in maize stress omics, especially proteomics; and discuss the opportunities, challenges, and future directions of maize stress omics, with a view to sustainable food production. The knowledge gained from studying maize stress omics is instrumental for improving maize to cope with various stresses and to meet the food demands of the exponentially growing global population. Omics systems science offers actionable potential solutions for sustainable food production, and we present maize as a notable case study.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

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

    SciTech Connect

    Bethards, L.A.; Scandalios, J.G.

    1988-01-01

    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 (/sup 32/P)-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.

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

    NASA Astrophysics Data System (ADS)

    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. Surface chemical modification of waxy maize starch nanocrystals.

    PubMed

    Angellier, Hélène; Molina-Boisseau, Sonia; Belgacem, Mohamed Naceur; Dufresne, Alain

    2005-03-15

    The surface of waxy maize starch nanocrystals obtained from sulfuric acid hydrolysis of native waxy maize starch granules was chemically modified using two different reagents, namely, alkenyl succinic anhydride and phenyl isocyanate. The occurrence of chemical modification was evaluated by FTIR and X-ray photoelectron spectroscopies. Contact angle measurements from which the surface energy of the materials under investigation was deduced showed that chemical modification led to more hydrophobic particles. Chemical modification altered the morphology of particles, as shown by observation by transmission electron microscopy, but not their crystallinity (X-ray diffraction analysis).

  10. [Impacts of high temperature on maize production and adaptation measures in Northeast China].

    PubMed

    Yin, Xiao-gang; Wang, Meng; Kong, Qing-xin; Wang, Zhan-biao; Zhang, Hai-lin; Chu, Qing-quan; Wen, Xin-ya; Chen, Fu

    2015-01-01

    Heat stress is one of the major agro-meteorological hazards that affect maize production significantly in the farming region of Northeast China (NFR). This study analyzed the temporal and spatial changes of the accumulated temperature above 30 °C (AT) and the accumulated days with the maximum temperature above 30 °C (AD) in different maize growing phases under global warming. It further evaluated the impacts of extreme heat on maize yield in different regions, and put forward some adaptation measures to cope with heat stress for maize production in NFR. The results showed that during 1961 to 2010, the temperature in the maize growing season increased significantly. The maximum temperature in flowering phase was much larger than that in the other growing phases. Temperature increased at rates of 0. 16, 0. 14, 0.06 and 0.23 °C every ten years in the whole maize growing season, vegetative growth phase (from sowing to 11 days before flowering), flowering phase, and late growth phase (from 11 days after flowering to maturity), respectively. The AT in the whole maize growing season increased in NFR during the last 50 years with the highest in the southwest part of NFR, and that in the vegetative growth phase increased faster than in the other two phases. The AD in the whole maize growing season increased during the last 50 years with the highest in the southwest part of NFR, and that in the late growth phase increased faster than in the other two phases. Heat stress negatively affected maize yield during the maize growing season, particularly in the vegetative growth phase. The heat stress in Songliao Plain was much higher in comparison to the other regions. The adaptation measures of maize production to heat stress in NFR included optimizing crop structure, cultivating high temperature resistant maize varieties, improving maize production management and developing the maize production system that could cope with disasters.

  11. Maize plants infestation by Fusarium spp. and deoxynivalenol in genetically modified corn hybrid and traditional maize cultivars.

    PubMed

    Selwet, Marek

    2011-01-01

    The objective of the performed investigations was to isolate pathogenic fungi from contaminated maize cobs, to assess the appearance of maize cob fusariosis and to determine grain contamination with deoxynivalenol in the cultivation of genetically modified maize containing a gene resistance against European corn borer (Ostrinia nubilalis Hbn) as well as selected non-modified cultivars. The plant material comprised the following genetically modified maize cultivar: DKC 3421 YG (MON 810) and non-modified cultivars obtained from Smolice Plant Breeding Ltd., IHAR Group: Junak (FAO 210-220), Prosna (FAO 220), SMH (FAO 230), Baca (FAO 220). Prior to harvesting, the occurrence of maize cob fusariosis was determined in the 89 (BBCH) developmental ripening stage. Microbiological assessment was carried out on grains selected from cobs characterized by various pathological symptoms. In 2008, a total of 133 isolates was obtained from the examined samples of infected maize plants, of which 51 isolates were species-identified, while in 2009, the total of 123 isolates were determined, of which 63 were species-identified. In both experimental years, the majority of isolates contained fungi from the Fusarium genus. The performed analysis of mean levels of cob contamination by fusarioses revealed that DKC 3421 YG (MON 810) and SMH (FAO 230) cultivars showed the smallest levels of contamination as well as the lowest percent of cob contamination per plant, while Junak (FAO 210-220) and Baca (FAO 220) cultivars were characterized by the highest degree of contamination. The lowest deoxynivalenol concentrations were determined in years 2008 and 2009 in the case of the DKC 3421 YG (MON 810) cultivar, whereas Prosna (FAO 220) cultivar was characterized by the highest deoxynivalenol concentration.

  12. Glycoprotein Synthesis in Maize Endosperm Cells

    PubMed Central

    Riedell, Walter E.; Miernyk, Jan A.

    1988-01-01

    Microsomal membrane preparations from maize (Zea mays L., inbred A636) endosperm cultures contained enzymes that transferred sugar moieties from uridine diphosphate-N-acetylglucosamine, guanosine diphosphate-mannose, and uridine diphosphate-glucose to dolichol-phosphate. These enzyme activities were characterized with respect to detergent and pH optima, substrate kinetic constants, and product and antibiotic inhibition constants. It was demonstrated by mild acid hydrolysis and high performance liquid chromatography that the products of the N-acetylglucosamine transferases were N-acetylglucosamine-pyrophosphoryl-dolichol and N,N′-diacetyl-chitobiosyl-pyrophosphoryl-dolichol and that the product of the mannose transferase was mannosyl-phosphoryl-dolichol. A large proportion of the products of the glucose transferase activity was stable to mild acid hydrolysis. However, the proportion that was labile was identified as glucosyl-phosphoryl-dolichol. Rate zonal sedimentation and isopycnic banding in linear sucrose density gradients in the presence of 1 millimolar ethylenediaminetetraacetic acid indicated that the glycosyltransferase activities were located in the endoplasmic reticulum. The glycosyltransferases were not solubilized by 500 millimolar KCl or by sequential washes with tris-(hydroxymethyl)aminomethane and water, treatments that release peripheral membrane proteins. Solubilization was achieved with low concentrations of Triton X-100. When sealed microsomal vesicles were incubated with trypsin for 30 minutes in absence of detergent, the activity of N-acetylglucosaminyl-transferase was substantially reduced, while the activity of the glucosyl-transferase was somewhat reduced. Activity of the mannosyl-transferase was resistant to inactivation by incubation with trypsin unless Triton was present. PMID:16666157

  13. Glycaemic Response to Quality Protein Maize Grits

    PubMed Central

    Panlasigui, Leonora N.; Bayaga, Cecile L. T.; Barrios, Erniel B.; Cochon, Kim L.

    2010-01-01

    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. PMID:20862364

  14. Genomic Predictability of Interconnected Biparental Maize Populations

    PubMed Central

    Riedelsheimer, Christian; Endelman, Jeffrey B.; Stange, Michael; Sorrells, Mark E.; Jannink, Jean-Luc; Melchinger, Albrecht E.

    2013-01-01

    Intense structuring of plant breeding populations challenges the design of the training set (TS) in genomic selection (GS). An important open question is how the TS should be constructed from multiple related or unrelated small biparental families to predict progeny from individual crosses. Here, we used a set of five interconnected maize (Zea mays L.) populations of doubled-haploid (DH) lines derived from four parents to systematically investigate how the composition of the TS affects the prediction accuracy for lines from individual crosses. A total of 635 DH lines genotyped with 16,741 polymorphic SNPs were evaluated for five traits including Gibberella ear rot severity and three kernel yield component traits. The populations showed a genomic similarity pattern, which reflects the crossing scheme with a clear separation of full sibs, half sibs, and unrelated groups. Prediction accuracies within full-sib families of DH lines followed closely theoretical expectations, accounting for the influence of sample size and heritability of the trait. Prediction accuracies declined by 42% if full-sib DH lines were replaced by half-sib DH lines, but statistically significantly better results could be achieved if half-sib DH lines were available from both instead of only one parent of the validation population. Once both parents of the validation population were represented in the TS, including more crosses with a constant TS size did not increase accuracies. Unrelated crosses showing opposite linkage phases with the validation population resulted in negative or reduced prediction accuracies, if used alone or in combination with related families, respectively. We suggest identifying and excluding such crosses from the TS. Moreover, the observed variability among populations and traits suggests that these uncertainties must be taken into account in models optimizing the allocation of resources in GS. PMID:23535384

  15. Reserve Carbohydrate in Maize Stem 1

    PubMed Central

    Setter, Tim Lloyd; Meller, Victoria H.

    1984-01-01

    Maize (Zea mays L.) stem is thought to function alternately as a net importing and net exporting organ during ontogeny, depending on whole plant photosynthetic source and sink status. The [14C]sucrose and [14C]glucose uptake capacity of stem tissues was investigated to increase our understanding of the transport factors which may influence sink status. Uptake from solutions containing up to 200 millimolar radiolabeled sugar showed that d-glucose uptake consisted of saturable and nonsaturable components, while sucrose uptake was primarily nonsaturable during the kernel-fill stages. l-Glucose uptake lacked the saturable component but both d and l isomers apparently had similar slopes for the nonsaturable component. Uptake was sensitive to inhibitors and temperature, and was increased slightly by lowered pH. The seasonal chronology for saturable uptake by isolated vascular bundles and associated pith revealed highest rates between anthesis and early kernel growth, corresponding with the stage when net sugar accumulation rates were highest. For isolated pith, the rates increased at the final stages of plant development. The rate of labeled l-glucose movement from vascular bundles into pith in isolated stem segments was greater at the silking stage than at later developmental stages, suggesting a lower resistance to diffusive transport from vascular bundles into pith at silking. Studies with stem plus ear explants showed that the capability for sugar transport from pith to vascular bundles and for phloem loading and export from the stem region was present throughout the developmental period from early kernel fill (milk) to late kernel fill (dent). PMID:16663675

  16. [Isolation of the capsid protein gene of maize dwarf mosaic virus and its transformation in maize].

    PubMed

    Liu, Xiao-Hong; Zhang, Hong-Wei; Liu, Xin; Liu, Xin-Jie; Tan, Zhen-Bo; Rong, Ting-Zhao

    2005-01-01

    The MDMV (Maize Dwarf Mosaic Virus, MDMV) CP (Coat Protein, CP) gene was cloned by RT-PCR method and introduced into the embryonic calli derived from immature embryos of elite inbred 18-599hong and 18-599bai via particle bombardment. Bombarded calli were selected on selection medium containing 5-10 mg/L (PPT) Bialaphos. From resistant calli, 79 plantlets were regenerated. 18 of 79 were grown and harvested. The results of Southern blotting and PCR analysis demonstrated that MDMV CP have been integrated into the genome of the transgenic plants. PCR-positive progeny plants were artificially inoculated with MDMV strain B, and the average chlorosis of the functional leaves of each plant was investigated. The typical symptoms were observed from the leaves of the control inbreds. while, the presence of the MDMV CP gene provided resistance to inoculation with MDMV strain B.

  17. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize

    PubMed Central

    Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Horak, Michael J.; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W.; Stojšin, Duška; Uribe Montes, Hugo Raúl

    2015-01-01

    Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives. PMID:26162097

  18. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.

    PubMed

    Baltazar, Baltazar M; Castro Espinoza, Luciano; Espinoza Banda, Armando; de la Fuente Martínez, Juan Manuel; Garzón Tiznado, José Antonio; González García, Juvencio; Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Heredia Díaz, Oscar; Horak, Michael J; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W; Stojšin, Duška; Uribe Montes, Hugo Raúl; Zavala García, Francisco

    2015-01-01

    Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives.

  19. Zinc Absorption from Biofortified Maize Meets the Requirements of Young Rural Zambian Children12

    PubMed Central

    Chomba, Elwyn; Westcott, Claire M; Westcott, Jamie E; Mpabalwani, Evans M; Krebs, Nancy F; Patinkin, Zachary W; Palacios, Natalia; Hambidge, K Michael

    2015-01-01

    Background: The zinc content of maize, a major global food staple, is generally insufficient alone to meet the requirements of young children. Objectives: The primary objective of this study was to determine whether substitution of biofortified maize (34 μg zinc/g grain) for control maize (21 μg zinc/g) was adequate to meet zinc physiologic requirements in young children for whom maize was the major food staple. A secondary objective was to compare total daily zinc absorption when maize flour was fortified with zinc oxide to a total concentration of 60 μg zinc/g. Methods: Participants included 60 rural Zambian children with a mean age of 29 mo who were randomly assigned to receive 1 of 3 maize types (control, biofortified, or fortified) all of which were readily consumed (>100 g on 1 d). Total daily zinc intake (from maize and low-zinc relish) was determined from duplicate diet collections. Multiplication by fractional absorption of zinc, measured by a dual isotope ratio technique, determined the total daily zinc absorption on the day the test meals were given. Results: The mean ± SD total daily zinc intake (milligrams per day) from the biofortified maize (5.0 ± 2.2) was higher (P < 0.0001) than for the control maize (2.3 ± 0.9). Intake of zinc from the fortified maize (6.3 ± 2.6) did not differ from the biofortified maize. Fractional absorption of zinc from control maize (0.28 ± 0.10) did not differ from the biofortified maize (0.22 ± 0.06). Total daily absorption of zinc (milligrams per day) from the biofortified maize (1.1 ± 0.5) was higher (P = 0.0001) than for the control maize (0.6 ± 0.2), but did not differ from the fortified maize (1.2 ± 0.4). Conclusions: These results indicate that feeding biofortified maize can meet zinc requirements and provide an effective dietary alternative to regular maize for this vulnerable population. This trial was registered at clinicaltrials.gov as NCT02208635. PMID:25733467

  20. Genomic prediction in CIMMYT maize and wheat breeding programs

    PubMed Central

    Crossa, J; Pérez, P; Hickey, J; Burgueño, J; Ornella, L; Cerón-Rojas, J; Zhang, X; Dreisigacker, S; Babu, R; Li, Y; Bonnett, D; Mathews, K

    2014-01-01

    Genomic selection (GS) has been implemented in animal and plant species, and is regarded as a useful tool for accelerating genetic gains. Varying levels of genomic prediction accuracy have been obtained in plants, depending on the prediction problem assessed and on several other factors, such as trait heritability, the relationship between the individuals to be predicted and those used to train the models for prediction, number of markers, sample size and genotype × environment interaction (GE). The main objective of this article is to describe the results of genomic prediction in International Maize and Wheat Improvement Center's (CIMMYT's) maize and wheat breeding programs, from the initial assessment of the predictive ability of different models using pedigree and marker information to the present, when methods for implementing GS in practical global maize and wheat breeding programs are being studied and investigated. Results show that pedigree (population structure) accounts for a sizeable proportion of the prediction accuracy when a global population is the prediction problem to be assessed. However, when the prediction uses unrelated populations to train the prediction equations, prediction accuracy becomes negligible. When genomic prediction includes modeling GE, an increase in prediction accuracy can be achieved by borrowing information from correlated environments. Several questions on how to incorporate GS into CIMMYT's maize and wheat programs remain unanswered and subject to further investigation, for example, prediction within and between related bi-parental crosses. Further research on the quantification of breeding value components for GS in plant breeding populations is required. PMID:23572121

  1. USDA-ARS Colorado maize water productivity data set

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-Agricultural Research Service conducted a water productivity field trial for irrigated maize in northeastern Colorado in 2008 through 2011. The dataset, which is available online from the USDA National Agricultural Library, includes measurements of irrigation, precipitation, soil water sto...

  2. Heritable site-specific mutagenesis using TALENs in maize.

    PubMed

    Char, Si Nian; Unger-Wallace, Erica; Frame, Bronwyn; Briggs, Sarah A; Main, Marcy; Spalding, Martin H; Vollbrecht, Erik; Wang, Kan; Yang, Bing

    2015-09-01

    Transcription activator-like effector nuclease (TALEN) technology has been utilized widely for targeted gene mutagenesis, especially for gene inactivation, in many organisms, including agriculturally important plants such as rice, wheat, tomato and barley. This report describes application of this technology to generate heritable genome modifications in maize. TALENs were employed to generate stable, heritable mutations at the maize glossy2 (gl2) locus. Transgenic lines containing mono- or di-allelic mutations were obtained from the maize genotype Hi-II at a frequency of about 10% (nine mutated events in 91 transgenic events). In addition, three of the novel alleles were tested for function in progeny seedlings, where they were able to confer the glossy phenotype. In a majority of the events, the integrated TALEN T-DNA segregated independently from the new loss of function alleles, producing mutated null-segregant progeny in T1 generation. Our results demonstrate that TALENs are an effective tool for genome mutagenesis in maize, empowering the discovery of gene function and the development of trait improvement.

  3. Sugar uptake into kernels of tunicate tassel-seed maize

    SciTech Connect

    Thomas, P.A.; Felker, F.C.; Crawford, C.G. )

    1990-05-01

    A maize (Zea mays L.) strain expressing both the tassel-seed (Ts-5) and tunicate (Tu) characters was developed which produces glume-covered kernels on the tassel, often born on 7-10 mm pedicels. Vigorous plants produce up to 100 such kernels interspersed with additional sessile kernels. This floral unit provides a potentially valuable experimental system for studying sugar uptake into developing maize seeds. When detached kernels (with glumes and pedicel intact) are placed in incubation solution, fluid flows up the pedicel and into the glumes, entering the pedicel apoplast near the kernel base. The unusual anatomical features of this maize strain permit experimental access to the pedicel apoplast with much less possibility of kernel base tissue damage than with kernels excised from the cob. ({sup 14}C)Fructose incorporation into soluble and insoluble fractions of endosperm increased for 8 days. Endosperm uptake of sucrose, fructose, and D-glucose was significantly greater than that of L-glucose. Fructose uptake was significantly inhibited by CCCP, DNP, and PCMBS. These results suggest the presence of an active, non-diffusion component of sugar transport in maize kernels.

  4. Aflatoxin resistance in maize: what have we learned lately?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Genetic characterization of the North Carolina State University maize lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1980, 150 North Carolina State University maize inbreds have been developed and released on the basis of superior performance for topcross yield and other traits of agronomic importance. During this time there has been great emphasis placed on breeding with exotic germplasm, with 86 NCSU inbr...

  6. Heterosis is Prevalent for Multiple Traits in Diverse Maize Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterosis describes the superior phenotypes observed in hybrids relative to their inbred parents. Maize is a model system for studying heterosis due to the high levels of yield heterosis and commercial use of hybrids. The inbred lines from an association mapping panel were crossed to a common inbr...

  7. Ionomics of the Maize Nested Association Mapping Panel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterogeneity in the elemental composition of soils is among the major causes of plant stress worldwide. In order to adapt to these conditions, plants frequently alter their elemental content. We employed mineral nutrient and trace element profiling in diverse maize germplasm, to examine the connect...

  8. Flocculation of Kaolin by Waxy Maize Starch Phosphates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by drying heating of starches and sodium orthophosphates at 140 deg C for 4 h. Native...

  9. Flocculation of Kaolin by Waxy Maize Starch Phosphates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by dry heating of starches and sodium orthophosphates at 140 degrees C for 4 hours. N...

  10. Global Synthesis of Drought Effects on Maize and Wheat Production.

    PubMed

    Daryanto, Stefani; Wang, Lixin; Jacinthe, Pierre-André

    2016-01-01

    Drought has been a major cause of agricultural disaster, yet how it affects the vulnerability of maize and wheat production in combination with several co-varying factors (i.e., phenological phases, agro-climatic regions, soil texture) remains unclear. Using a data synthesis approach, this study aims to better characterize the effects of those co-varying factors with drought and to provide critical information on minimizing yield loss. We collected data from peer-reviewed publications between 1980 and 2015 which examined maize and wheat yield responses to drought using field experiments. We performed unweighted analysis using the log response ratio to calculate the bootstrapped confidence limits of yield responses and calculated drought sensitivities with regards to those co-varying factors. Our results showed that yield reduction varied with species, with wheat having lower yield reduction (20.6%) compared to maize (39.3%) at approximately 40% water reduction. Maize was also more sensitive to drought than wheat, particularly during reproductive phase and equally sensitive in the dryland and non-dryland regions. While no yield difference was observed among regions or different soil texture, wheat cultivation in the dryland was more prone to yield loss than in the non-dryland region. Informed by these results, we discuss potential causes and possible approaches that may minimize drought impacts.

  11. Translocation of the neonicotinoid seed treatment clothianidin in maize

    PubMed Central

    Krupke, Christian H.

    2017-01-01

    Neonicotinoid seed treatments, typically clothianidin or thiamethoxam, are routinely applied to >80% of maize (corn) seed grown in North America where they are marketed as a targeted pesticide delivery system. Despite this widespread use, the amount of compound translocated into plant tissue from the initial seed treatment to provide protection has not been reported. Our two year field study compared concentrations of clothianidin seed treatments in maize to that of maize without neonicotinoid seed treatments and found neonicotinoids present in root tissues up to 34 days post planting. Plant-bound clothianidin concentrations followed an exponential decay pattern with initially high values followed by a rapid decrease within the first ~20 days post planting. A maximum of 1.34% of the initial seed treatment was successfully recovered from plant tissues in both study years and a maximum of 0.26% was recovered from root tissue. Our findings show neonicotinoid seed treatments may provide protection from some early season secondary maize pests. However, the proportion of the neonicotinoid seed treatment clothianidin translocated into plant tissues throughout the growing season is low overall and this observation may provide a mechanism to explain reports of inconsistent efficacy of this pest management approach and increasing detections of environmental neonicotinoids. PMID:28282441

  12. The Relationship between auxin transport and maize branching.

    PubMed

    Gallavotti, Andrea; Yang, Yan; Schmidt, Robert J; Jackson, David

    2008-08-01

    Maize (Zea mays) plants make different types of vegetative or reproductive branches during development. Branches develop from axillary meristems produced on the flanks of the vegetative or inflorescence shoot apical meristem. Among these branches are the spikelets, short grass-specific structures, produced by determinate axillary spikelet-pair and spikelet meristems. We investigated the mechanism of branching in maize by making transgenic plants expressing a native expressed endogenous auxin efflux transporter (ZmPIN1a) fused to yellow fluorescent protein and a synthetic auxin-responsive promoter (DR5rev) driving red fluorescent protein. By imaging these plants, we found that all maize branching events during vegetative and reproductive development appear to be regulated by the creation of auxin response maxima through the activity of polar auxin transporters. We also found that the auxin transporter ZmPIN1a is functional, as it can rescue the polar auxin transport defects of the Arabidopsis (Arabidopsis thaliana) pin1-3 mutant. Based on this and on the groundbreaking analysis in Arabidopsis and other species, we conclude that branching mechanisms are conserved and can, in addition, explain the formation of axillary meristems (spikelet-pair and spikelet meristems) that are unique to grasses. We also found that BARREN STALK1 is required for the creation of auxin response maxima at the flanks of the inflorescence meristem, suggesting a role in the initiation of polar auxin transport for axillary meristem formation. Based on our results, we propose a general model for branching during maize inflorescence development.

  13. Diversity of the Fusarium complex on French maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ear rot caused by Fusarium species is a major threat to maize production worldwide, causing yield reduction and poor grain quality. In addition, various species of the genus Fusarium can produce mycotoxins, which accumulate in the grain. The distribution and predominance of the different Fusarium sp...

  14. Global Synthesis of Drought Effects on Maize and Wheat Production

    PubMed Central

    Daryanto, Stefani; Wang, Lixin; Jacinthe, Pierre-André

    2016-01-01

    Drought has been a major cause of agricultural disaster, yet how it affects the vulnerability of maize and wheat production in combination with several co-varying factors (i.e., phenological phases, agro-climatic regions, soil texture) remains unclear. Using a data synthesis approach, this study aims to better characterize the effects of those co-varying factors with drought and to provide critical information on minimizing yield loss. We collected data from peer-reviewed publications between 1980 and 2015 which examined maize and wheat yield responses to drought using field experiments. We performed unweighted analysis using the log response ratio to calculate the bootstrapped confidence limits of yield responses and calculated drought sensitivities with regards to those co-varying factors. Our results showed that yield reduction varied with species, with wheat having lower yield reduction (20.6%) compared to maize (39.3%) at approximately 40% water reduction. Maize was also more sensitive to drought than wheat, particularly during reproductive phase and equally sensitive in the dryland and non-dryland regions. While no yield difference was observed among regions or different soil texture, wheat cultivation in the dryland was more prone to yield loss than in the non-dryland region. Informed by these results, we discuss potential causes and possible approaches that may minimize drought impacts. PMID:27223810

  15. Translocation of the neonicotinoid seed treatment clothianidin in maize.

    PubMed

    Alford, Adam; Krupke, Christian H

    2017-01-01

    Neonicotinoid seed treatments, typically clothianidin or thiamethoxam, are routinely applied to >80% of maize (corn) seed grown in North America where they are marketed as a targeted pesticide delivery system. Despite this widespread use, the amount of compound translocated into plant tissue from the initial seed treatment to provide protection has not been reported. Our two year field study compared concentrations of clothianidin seed treatments in maize to that of maize without neonicotinoid seed treatments and found neonicotinoids present in root tissues up to 34 days post planting. Plant-bound clothianidin concentrations followed an exponential decay pattern with initially high values followed by a rapid decrease within the first ~20 days post planting. A maximum of 1.34% of the initial seed treatment was successfully recovered from plant tissues in both study years and a maximum of 0.26% was recovered from root tissue. Our findings show neonicotinoid seed treatments may provide protection from some early season secondary maize pests. However, the proportion of the neonicotinoid seed treatment clothianidin translocated into plant tissues throughout the growing season is low overall and this observation may provide a mechanism to explain reports of inconsistent efficacy of this pest management approach and increasing detections of environmental neonicotinoids.

  16. Aflatoxin Accumulation in BT and non-BT Maize Testcrosses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accumulation of aflatoxin, which is produced by the fungus, Aspergillus flavus Link: Fries, in maize is a chronic problem in the southeastern United States. Its presence in grain greatly reduces its value and marketability. Aflatoxin accumulation is frequently associated with high temperatures...

  17. Maize as a New Host for Oat Blue Dwarf Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat blue dwarf virus (OBDV) is distributed throughout the North American Great Plains and is found at low incidence levels in barley, oats, and flax in the upper Midwestern U.S. Cropping patterns in this region have changed considerably in recent years, with much greater acreages devoted to maize i...

  18. Genetic and biochemical analysis of iron bioavailability in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is a major cereal crop widely consumed in developing countries, which have a high prevalence of iron (Fe) deficiency including anemia. The major cause of Fe deficiency in these countries is inadequate intake of bioavailable Fe, of which poverty is a major contributing factor. Therefore, biofor...

  19. Genetic and biochemical analysis of iron bioavailability in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is a major cereal crop widely consumed in developing countries, which have a high prevalence of iron (Fe) deficiency including anemia. The major cause of Fe deficiency in these countries is an inadequate intake of bioavailable Fe, of which poverty is a major contributing factor. Therefore, b...

  20. Transformation of Maize Cells and Regeneration of Fertile Transgenic Plants.

    PubMed Central

    Gordon-Kamm, WJ; Spencer, TM; Mangano, ML; Adams, TR; Daines, RJ; Start, WG; O'Brien, JV; Chambers, SA; Adams, WR; Willetts, NG; Rice, TB; Mackey, CJ; Krueger, RW; Kausch, AP; Lemaux, PG

    1990-01-01

    A reproducible system for the generation of fertile, transgenic maize plants has been developed. Cells from embryogenic maize suspension cultures were transformed with the bacterial gene bar using microprojectile bombardment. Transformed calli were selected from the suspension cultures using the herbicide bialaphos. Integration of bar and activity of the enzyme phosphinothricin acetyltransferase (PAT) encoded by bar were confirmed in all bialaphos-resistant callus lines. Fertile transformed maize plants (R0) were regenerated, and of 53 progeny (R1) tested, 29 had PAT activity. All PAT-positive progeny analyzed contained bar. Localized application of herbicide to leaves of bar-transformed R0 and R1 plants resulted in no necrosis, confirming functional activity of PAT in the transgenic plants. Cotransformation experiments were performed using a mixture of two plasmids, one encoding PAT and one containing the nonselected gene encoding [beta]-glucuronidase. R0 plants regenerated from co-transformed callus expressed both genes. These results describe and confirm the development of a system for introduction of DNA into maize. PMID:12354967

  1. Modelling thermal degradation of zearalenone in maize bread during baking.

    PubMed

    Numanoglu, E; Yener, S; Gökmen, V; Uygun, U; Koksel, H

    2013-01-01

    The thermal degradation of zearalenone (ZEA) was investigated using a crust-like model, representing maize bread, which was prepared with naturally contaminated maize flour. Model samples were heated under isothermal conditions at the temperature range of 100-250°C. No reduction was observed at 100°C. Thermal degradation rate constants (k) were calculated as 0.0017, 0.0143 and 0.0216 min(-1) for 150, 200 and 250°C, respectively. Maize bread baked at 250°C for 70 min was used to test the capability of model kinetic data for the prediction of ZEA reduction. The time-temperature history in the crust and crumb parts was recorded separately. Partial degradation of ZEA at each time interval was calculated by means of the corresponding k-values obtained by using the Arrhenius equation, and the total reduction occurring at the end of the entire baking process was predicted. The reduction in the crumb and crust of bread was also experimentally determined and found to be consistent with the predicted values. It was concluded that the kinetic constants determined by means of the crust-like model could be used to predict the ZEA reduction occurring during baking of maize bread.

  2. Genome-wide association studies in maize: praise and stargaze

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genome-wide association study (GWAS) has appeared as a widespread strategy in decoding genotype-phenotype associations in many species thanks to technical advances in next-generation sequencing (NGS) applications. Maize is an ideal crop for GWAS and significant progress has been made in the last dec...

  3. Developing resistance to aflatoxin in maize and cottonseed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At this time, no “magic bullet” for solving the aflatoxin contamination problem in maize and cottonseed has been identified, so several strategies must be utilized simultaneously to ensure a healthy crop, free of aflatoxins. The most widely explored strategy for the control of aflatoxin contaminatio...

  4. Searching and Mining Visually Observed Phenotypes of Maize Mutants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are thousands of maize mutants, which are invaluable resources for plant research. Geneticists use them to study underlying mechanisms of biochemistry, cell biology, cell development, and cell physiology. To streamline the understanding of such complex processes, researchers need the most curr...

  5. Sites of ozone sensitivity in diverse maize inbred lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone (O3) is an air pollutant that costs ~$14-26 billion in global crop losses and is projected to worsen in the future. Potential sites of O3 sensitivity in maize were tested by growing 200 inbred lines, including the nested association mapping population founder lines, under ambient...

  6. Unraveling the KNOTTED1 regulatory network in maize meristems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We carried out whole genome analysis to determine the genes that are differentially expressed in gain- and loss-of-function mutants and to identify the maize genomic regions that KN1 binds. We performed RNA-seq experiments aimed at identifying the genes differentially expressed between normal and kn...

  7. Maize Genetic Resources Collections – Utilizing a Treasure Trove

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize genetic resource collection managed by the USDA-ARS's National Plant Germplasm System is heavily utilized by researchers and educators. A collection of landraces, inbred lines from public and private sector sources, synthetics and key populations, it serves both as a living snapshot of th...

  8. Analysis of Recombination Sites within the Maize Waxy Locus

    PubMed Central

    Okagaki, R. J.; Weil, C. F.

    1997-01-01

    Genetic fine structure analysis of the maize wx locus has determined that the ratio of genetic to physical distance within wx was one to two orders of magnitude higher than the average for the maize genome. Similar results have been found at other maize loci. In this study, we examined several mechanisms that could account for this pattern. First, crossovers in two other maize genes resolve preferentially at specific sites. By mapping exchanges between wx-B1 and wx-I relative to a polymorphic SstI site, we found no evidence for such a hotspot at wx. Second, deletion of promoter sequences from wx alleles had little effect on recombination frequencies, in contrast to results in yeast where promoter sequences are important for initiating recombination in some genes. Third, high levels of insertion polymorphism may suppress intergenic recombination. However, the presence of a 2-kb Ds element 470 bp upstream of the wx transcription start site did not further suppress recombination between Ds insertions in nearby wx sequences. Thus, none of these mechanisms is sufficient to explain the difference between intergenic and intragenic recombination rates at wx. PMID:9335616

  9. Molecular marker-assisted breeding for maize improvement in Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the most important food and feed crops in Asia, and is a source of income for several million farmers. Despite impressive progress made in the last few decades through conventional breeding in the “Asia-7” (China, India, Indonesia, Nepal, Philippines, Thailand and Vietnam), average m...

  10. Fluorescent protein marker lines in maize: generation and applications.

    PubMed

    Wu, Qingyu; Luo, Anding; Zadrozny, Tara; Sylvester, Anne; Jackson, Dave

    2013-01-01

    Fluorescent proteins (FP) have significantly impacted the way that we study plants in the past two decades. In the post-genomics era, these FP tools are in higher demand by plant scientists for studying the dynamics of protein localization, function, and interactions, and to translate sequence information to biological knowledge that can benefit humans. Although FP tools have been widely used in the model plant Arabidopsis, few FP resources have been developed for maize, one of the most important food crops worldwide, and an ideal species for genetic and developmental biology research. In an effort to provide the maize and cereals research communities with a comprehensive set of FP resources for different purposes of study, we generated more than 100 stable transformed maize FP marker lines, which mark most compartments in maize cells with different FPs. Additionally, we are generating driver and reporter lines, based on the principle of the pOp-LhG4 transactivation system, allowing specific expression or mis-expression of any gene of interest to precisely study protein functions. These marker lines can be used not only for static protein localization studies, but will be useful for studying protein dynamics and interactions using kinetic microscopy methods, such as fluorescence recovery after photobleaching (FRAP), fluorescence correlation spectroscopy (FCS), and fluorescence resonance energy transfer (FRET).

  11. Statistical modeling of correlatively expressed functional amino acids in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern maize breeding and selection for large starchy kernels may have contributed to reduced contents of essential amino acids which represents a serious nutritional problem for humans and animals. A large number (1,348) of germplasm accessions belonging to 13 populations and classified into four h...

  12. Sequence, assembly and annotation of the maize W22 genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since its adoption by Brink and colleagues in the 1950s and 60s, the maize W22 inbred has been utilized extensively to understand fundamental genetic and epigenetic processes such recombination, transposition and paramutation. To maximize the utility of W22 in gene discovery, we have Illumina sequen...

  13. The Genetic Basis of Disease Resistance in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advent of high throughput genomics has accelerated progress in understanding the genetic basis of disease resistance in maize, much as it enhanced discovery in other fields. Here we summarize progress made in recent years using resources such as association mapping and nested association mapping...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  15. Arsenic accumulation in maize crop (Zea mays): a review.

    PubMed

    Rosas-Castor, J M; Guzmán-Mar, J L; Hernández-Ramírez, A; Garza-González, M T; Hinojosa-Reyes, L

    2014-08-01

    Arsenic (As) is a metalloid that may represent a serious environmental threat, due to its wide abundance and the high toxicity particularly of its inorganic forms. The use of arsenic-contaminated groundwater for irrigation purposes in crop fields elevates the arsenic concentration in topsoil and its phytoavailability for crops. The transfer of arsenic through the crops-soil-water system is one of the more important pathways of human exposure. According to the Food and Agriculture Organization of the United Nations, maize (Zea mays L.) is the most cultivated cereal in the world. This cereal constitutes a staple food for humans in the most of the developing countries in Latin America, Africa, and Asia. Thus, this review summarizes the existing literature concerning the conditions involved in agricultural soil that leads to As influx into maize crops and the uptake mechanisms, metabolism and phytotoxicity of As in corn plants. Additionally, the studies of the As accumulation in raw corn grain and corn food are summarized, and the As biotransfer into the human diet is highlighted. Due to high As levels found in editable plant part for livestock and humans, the As uptake by corn crop through water-soil-maize system may represent an important pathway of As exposure in countries with high maize consumption.

  16. [Resource competition in maize/soybean intercropping system].

    PubMed

    Lü, Yue; Wu, Pu-Te; Chen, Xiao-Li; Wang, Yu-Bao; Zhao, Xi-Ning

    2014-01-01

    The soil water storage, growth development, biomass and yield in maize/soybean intercropping system under different separation methods were measured to analyze the resource competition of the intercropping crops. The treatments included no shoot or root separation (T1), shoot and root separation (T2), only root separation (T3), and only shoot separation (T4). Results indicated that compared to others, the average soil moisture content in the 0-120 cm soil layer decreased by 3.1%-12.9% in maize line, and by 2.8%-12.5% in soybean line for T1. Compared to T1, maize growth stage in T2, T3 and T4 came late, and the plant height, leaf area and cumulative total biomass, yield and yield components all decreased, while the trends found for soybean were the opposite. In summary, the changes of crop growth and yield in the maize/soybean intercropping system were driven by the interactions of above- and below-ground parts, and the below-ground part played a more important role.

  17. Storage of Maize in Purdue Improved Crop Storage (PICS) Bags.

    PubMed

    Williams, Scott B; Murdock, Larry L; Baributsa, Dieudonne

    2017-01-01

    Interest in using hermetic technologies as a pest management solution for stored grain has risen in recent years. One hermetic approach, Purdue Improved Crop Storage (PICS) bags, has proven successful in controlling the postharvest pests of cowpea. This success encouraged farmers to use of PICS bags for storing other crops including maize. To assess whether maize can be safely stored in PICS bags without loss of quality, we carried out laboratory studies of maize grain infested with Sitophilus zeamais (Motshulsky) and stored in PICS triple bags or in woven polypropylene bags. Over an eight month observation period, temperatures in the bags correlated with ambient temperature for all treatments. Relative humidity inside PICS bags remained constant over this period despite the large changes that occurred in the surrounding environment. Relative humidity in the woven bags followed ambient humidity closely. PICS bags containing S. zeamais-infested grain saw a significant decline in oxygen compared to the other treatments. Grain moisture content declined in woven bags, but remained high in PICS bags. Seed germination was not significantly affected over the first six months in all treatments, but declined after eight months of storage when infested grain was held in woven bags. Relative damage was low across treatments and not significantly different between treatments. Overall, maize showed no signs of deterioration in PICS bags versus the woven bags and PICS bags were superior to woven bags in terms of specific metrics of grain quality.

  18. Storage of Maize in Purdue Improved Crop Storage (PICS) Bags

    PubMed Central

    2017-01-01

    Interest in using hermetic technologies as a pest management solution for stored grain has risen in recent years. One hermetic approach, Purdue Improved Crop Storage (PICS) bags, has proven successful in controlling the postharvest pests of cowpea. This success encouraged farmers to use of PICS bags for storing other crops including maize. To assess whether maize can be safely stored in PICS bags without loss of quality, we carried out laboratory studies of maize grain infested with Sitophilus zeamais (Motshulsky) and stored in PICS triple bags or in woven polypropylene bags. Over an eight month observation period, temperatures in the bags correlated with ambient temperature for all treatments. Relative humidity inside PICS bags remained constant over this period despite the large changes that occurred in the surrounding environment. Relative humidity in the woven bags followed ambient humidity closely. PICS bags containing S. zeamais-infested grain saw a significant decline in oxygen compared to the other treatments. Grain moisture content declined in woven bags, but remained high in PICS bags. Seed germination was not significantly affected over the first six months in all treatments, but declined after eight months of storage when infested grain was held in woven bags. Relative damage was low across treatments and not significantly different between treatments. Overall, maize showed no signs of deterioration in PICS bags versus the woven bags and PICS bags were superior to woven bags in terms of specific metrics of grain quality. PMID:28072835

  19. Bulk genetic characterization of Ghanaian maize landraces using microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) was first introduced into Ghana over 5 centuries ago and remains the most important cereal staple, grown in all agro-ecologies across the country. Yield from farmers’ fields are low, which is attributed in part to farmer’s preferences and/or reliance on local landraces for cultivati...

  20. Hosts of stolbur phytoplasmas in maize redness affected fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant host range of a phytoplasma is strongly dependent on the host range of its insect vector. Maize redness in Serbia is caused by stolbur phytoplasma (subgroup 16SrXII-A) and is transmitted by the cixiid planthoper, Reptalus panzeri (Löw). R. panzeri was the only potential vector found to be ...

  1. Prevalence of genetically modified rice, maize, and soy in Saudi food products.

    PubMed

    Elsanhoty, Rafaat M; Al-Turki, A I; Ramadan, Mohamed Fawzy

    2013-10-01

    Qualitative and quantitative DNA-based methods were applied to detect genetically modified foods in samples from markets in the Kingdom of Saudi Arabia. Two hundred samples were collected from Al-Qassim, Riyadh, and Mahdina in 2009 and 2010. GMOScreen 35S and NOS test kits for the detection of genetically modified organism varieties in samples were used. The positive results obtained from GMOScreen 35S and NOS were identified using specific primer pairs. The results indicated that all rice samples gave negative results for the presence of 35S and NOS terminator. About 26 % of samples containing soybean were positive for 35S and NOS terminator and 44 % of samples containing maize were positive for the presence of 35S and/or NOS terminator. The results showed that 20.4 % of samples was positive for maize line Bt176, 8.8 % was positive for maize line Bt11, 8.8 % was positive for maize line T25, 5.9 % was positive for maize line MON 810, and 5.9 % was positive for StarLink maize. Twelve samples were shown to contain <3 % of genetically modified (GM) soy and 6 samples >10 % of GM soy. Four samples containing GM maize were shown to contain >5 % of GM maize MON 810. Four samples containing GM maize were shown to contain >1 % of StarLink maize. Establishing strong regulations and certified laboratories to monitor GM foods or crops in Saudi market is recommended.

  2. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths.

    PubMed

    Holst, Irene; Moreno, J Enrique; Piperno, Dolores R

    2007-11-06

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals.

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

    PubMed Central

    Gong, Fangping; Wu, Xiaolin; Zhang, Huiyong; Chen, Yanhui; Wang, Wei

    2015-01-01

    Achieving grain supply security with limited arable land is a major challenge in the twenty-first 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. PMID:26500671

  4. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths

    PubMed Central

    Holst, Irene; Moreno, J. Enrique; Piperno, Dolores R.

    2007-01-01

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals. PMID:17978176

  5. A multiplex PCR method of detecting recombinant DNAs from five lines of genetically modified maize.

    PubMed

    Matsuoka, T; Kuribara, H; Akiyama, H; Miura, H; Goda, Y; Kusakabe, Y; Isshiki, K; Toyoda, M; Hino, A

    2001-02-01

    Seven lines of genetically modified (GM) maize have been authorized in Japan as foods and feeds imported from the USA. We improved a multiplex PCR method described in the previous report in order to distinguish the five lines of GM maize. Genomic DNA was extracted from GM maize with a silica spin column kit, which could reduce experimental time and improve safety in the laboratory and potentially in the environment. We sequenced recombinant DNA (r-DNA) introduced into GM maize, and re-designed new primer pairs to increase the specificity of PCR to distinguish five lines of GM maize by multiplex PCR. A primer pair for the maize intrinsic zein gene (Ze1) was also designed to confirm the presence of amplifiable maize DNA. The lengths of PCR products using these six primer pairs were different. The Ze1 and the r-DNAs from the five lines of GM maize were qualitatively detected in one tube. The specific PCR bands were distinguishable from each other on the basis of the expected length. The r-DNA could be detected from maize samples containing 0.5% of each of the five lines of GM maize. The sensitivity would be acceptable to secure the verification of non-GMO materials and to monitor the reliability of the labeling system.

  6. Genes identified by visible mutant phenotypes show increased bias toward one of two subgenomes of maize.

    PubMed

    Schnable, James C; Freeling, Michael

    2011-03-10

    Not all genes are created equal. Despite being supported by sequence conservation and expression data, knockout homozygotes of many genes show no visible effects, at least under laboratory conditions. We have identified a set of maize (Zea mays L.) genes which have been the subject of a disproportionate share of publications recorded at MaizeGDB. We manually anchored these "classical" maize genes to gene models in the B73 reference genome, and identified syntenic orthologs in other grass genomes. In addition to proofing the most recent version 2 maize gene models, we show that a subset of these genes, those that were identified by morphological phenotype prior to cloning, are retained at syntenic locations throughout the grasses at much higher levels than the average expressed maize gene, and are preferentially found on the maize1 subgenome even with a duplicate copy is still retained on the opposite subgenome. Maize1 is the subgenome that experienced less gene loss following the whole genome duplication in maize lineage 5-12 million years ago and genes located on this subgenome tend to be expressed at higher levels in modern maize. Links to the web based software that supported our syntenic analyses in the grasses should empower further research and support teaching involving the history of maize genetic research. Our findings exemplify the concept of "grasses as a single genetic system," where what is learned in one grass may be applied to another.

  7. Effects of inoculation with arbuscular mycorrhizal fungi on maize grown in multi-metal contaminated soils.

    PubMed

    Liang, Chang-Cong; Li, Tao; Xiao, Yan-ping; Liu, Mao-Jun; Zhang, Han-Bo; Zhao, Zhi-Wei

    2009-01-01

    Pot culture experiments were established to determine the effects of colonization by arbuscular mycorrhizal fungi (AMF) (Glomus mosseae and G. sp) on maize (Zea mays L.) grown in Pb, Zn, and Cd complex contaminated soils. AMF and non-AMF inoculated maize were grown in sterilized substrates and subjected to different soil heavy metal (Pb, Zn, Cd) concentrations. The root and shoot biomasses of inoculated maize were significantly higher than those of non-inoculated maize. Pb, Zn, and Cd concentrations in roots were significantly higher than those in shoots in both the inoculated and non-inoculated maize, indicating the heavy metals mostly accumulated in the roots of maize. The translocation rates of Pb, Zn, and Cd from roots to shoots were not significantly difference between inoculated and non-inoculated maize. However, at high soil heavy metal concentrations, Pb, Zn, and Cd in the shoots and Pb in the roots of inoculated maize were significantly reduced by about 50% compared to the non-inoculated maize. These results indicated that AMF could promote maize growth and decrease the uptake of these heavy metals at higher soil concentrations, thus protecting their hosts from the toxicity of heavy metals in Pb, Zn, and Cd complex contaminated soils.

  8. Effects of airborne black carbon pollution on maize

    NASA Astrophysics Data System (ADS)

    Illes, Bernadett; Anda, Angela; Soos, Gabor

    2013-04-01

    The black carbon (BC) changes the radiation balance of the Earth and contributes to global warming. The airborne BC deposited on the surface of plant, changing the radiation balance, water balance and the total dry matter (TDM) content of plant. The objective of our study was to investigate the impact of soot originated from motor vehicle exhaust on maize. The field experiment was carried out in Keszthely Agrometeorological Research Station (Hungary) in three consecutive years (2010, 2011, 2012) of growing season. The test plant was the maize hybrid Sperlona (FAO 340) with short growing season. The BC was chemically "pure", which means that it is free any contaminants (e.g. heavy metals). The BC was coming from the Hankook Tyre Company (Dunaújváros, Hungary), where used that for improve the wear resistance of tires. We used a motorised sprayer of SP 415 type to spray the BC onto the leaf surface. The leaf area index (LAI) was measured each week on the same 12 sample maize in each treatment using an LI 3000A automatic planimeter (LI-COR, Lincoln, NE). Albedo was measured by pyranometers of the CMA-11 type (Kipp & Zonen, Vaisala), what we placed the middle of the plot of 0.3 ha. The effects of BC were studied under two different water supplies: evapotranspirometers of Thornthwaite type were used for "ad libitum" treatment and rainfed treatment in field plots. In 2010 and 2012, a big difference was not observed in the case of LAI in the effects of BC. However, in 2011 there was a significant difference. The LAI of the BC polluted maize was higher (10-15%, P<0.05), than the LAI of the control maize in the rainfed plot and in the ET chambers, respectively. The albedo of the BC contaminated maize decreased (15-30%, P<0.05) in all three years. We also detected that the green plant surface of maize increased on BC contaminated treatment. These results may suggest that the plant is able to absorb the additional carbon source through the leaves. The albedo decreased

  9. Quality protein maize for Africa: closing the protein inadequacy gap in vulnerable populations.

    PubMed

    Nuss, Emily T; Tanumihardjo, Sherry A

    2011-05-01

    Africa shares a unique relationship with maize (Zea mays). After its introduction from New World explorers, maize was quickly adopted as the cornerstone of local cuisine, especially in sub-Saharan countries. Although maize provides macro- and micronutrients required for humans, it lacks adequate amounts of the essential amino acids lysine and tryptophan. For those consuming >50% of their daily energy from maize, pandemic protein malnutrition may exist. Severe protein and energy malnutrition increases susceptibility to life-threatening diseases such as tuberculosis and gastroenteritis. A nutritionally superior maize cultivar named quality protein maize (QPM) represents nearly one-half century of research dedicated to malnutrition eradication. Compared with traditional maize types, QPM has twice the amount of lysine and tryptophan, as well as protein bioavailability that rivals milk casein. Animal and human studies suggest that substituting QPM for common maize results in improved health. However, QPM's practical contribution to maize-subsisting populations remains unresolved. Herein, total protein and essential amino acid requirements recommended by the WHO and the Institute of Medicine were applied to estimate QPM target intake levels for young children and adults, and these were compared with mean daily maize intakes by African country. The comparisons revealed that ~100 g QPM is required for children to maintain adequacy of lysine, the most limiting amino acid, and nearly 500 g is required for adults. This represents a 40% reduction in maize intake relative to common maize to meet protein requirements. The importance of maize in Africa underlines the potential for QPM to assist in closing the protein inadequacy gap.

  10. Quality Protein Maize for Africa: Closing the Protein Inadequacy Gap in Vulnerable Populations12

    PubMed Central

    Nuss, Emily T.; Tanumihardjo, Sherry A.

    2011-01-01

    Africa shares a unique relationship with maize (Zea mays). After its introduction from New World explorers, maize was quickly adopted as the cornerstone of local cuisine, especially in sub-Saharan countries. Although maize provides macro- and micronutrients required for humans, it lacks adequate amounts of the essential amino acids lysine and tryptophan. For those consuming >50% of their daily energy from maize, pandemic protein malnutrition may exist. Severe protein and energy malnutrition increases susceptibility to life-threatening diseases such as tuberculosis and gastroenteritis. A nutritionally superior maize cultivar named quality protein maize (QPM) represents nearly one-half century of research dedicated to malnutrition eradication. Compared with traditional maize types, QPM has twice the amount of lysine and tryptophan, as well as protein bioavailability that rivals milk casein. Animal and human studies suggest that substituting QPM for common maize results in improved health. However, QPM’s practical contribution to maize-subsisting populations remains unresolved. Herein, total protein and essential amino acid requirements recommended by the WHO and the Institute of Medicine were applied to estimate QPM target intake levels for young children and adults, and these were compared with mean daily maize intakes by African country. The comparisons revealed that ∼100 g QPM is required for children to maintain adequacy of lysine, the most limiting amino acid, and nearly 500 g is required for adults. This represents a 40% reduction in maize intake relative to common maize to meet protein requirements. The importance of maize in Africa underlines the potential for QPM to assist in closing the protein inadequacy gap. PMID:22332054

  11. Increased soil phosphorus availability induced by faba bean root exudation stimulates root growth and phosphorus uptake in neighbouring maize.

    PubMed

    Zhang, Deshan; Zhang, Chaochun; Tang, Xiaoyan; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R; Davies, William J; Shen, Jianbo

    2016-01-01

    Root growth is influenced by soil nutrients and neighbouring plants, but how these two drivers affect root interactions and regulate plant growth dynamics is poorly understood. Here, interactions between the roots of maize (Zea mays) and faba bean (Vicia faba) are characterized. Maize was grown alone (maize) or with maize (maize/maize) or faba bean (maize/faba bean) as competitors under five levels of phosphorus (P) supply, and with homogeneous or heterogeneous P distribution. Maize had longer root length and greater shoot biomass and P content when grown with faba bean than with maize. At each P supply rate, faba bean had a smaller root system than maize but greater exudation of citrate and acid phosphatase, suggesting a greater capacity to mobilize P in the rhizosphere. Heterogeneous P availability enhanced the root-length density of maize but not faba bean. Maize root proliferation in the P-rich patches was associated with increased shoot P uptake. Increased P availability by localized P application or by the presence of faba bean exudation stimulated root morphological plasticity and increased shoot growth in maize in the maize/faba bean mixture, suggesting that root interactions of neighbouring plants can be modified by increased P availability.

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

    PubMed

    Schmelz, Eric A; Kaplan, Fatma; Huffaker, Alisa; Dafoe, Nicole J; Vaughan, Martha M; Ni, Xinzhi; Rocca, James R; Alborn, Hans T; Teal, Peter E

    2011-03-29

    Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 μg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 μg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function.

  13. Evolution and Expression of Tandem Duplicated Maize Flavonol Synthase Genes

    PubMed Central

    Falcone Ferreyra, María Lorena; Casas, María Isabel; Questa, Julia Irene; Herrera, Andrea Lorena; DeBlasio, Stacy; Wang, Jing; Jackson, David; Grotewold, Erich; Casati, Paula

    2012-01-01

    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 electrophoretic mobility shift 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. PMID:22654889

  14. Association and Linkage Analysis of Aluminum Tolerance Genes in Maize

    PubMed Central

    Krill, Allison M.; Kirst, Matias; Kochian, Leon V.; Buckler, Edward S.; Hoekenga, Owen A.

    2010-01-01

    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. PMID:20376361

  15. Stolbur Phytoplasma Transmission to Maize by Reptalus panzeri and the Disease Cycle of Maize Redness in Serbia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 4...

  16. The Germplasm Enhancement of Maize (GEM) project: A Public-Private Partnership (PPP) to increase genetic diversity in US maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize (GEM) Project is a mission-oriented, cooperative research effort of the United States Department of Agriculture – Agricultural Research Service (USDA-ARS), land grant universities, private industry, and international agricultural research centers to broaden the ger...

  17. One-step reverse transcription loop-mediated isothermal amplification for the detection of Maize chlorotic mottle virus in maize.

    PubMed

    Chen, Ling; Jiao, Zhiyuan; Liu, Dongmei; Liu, Xingliang; Xia, Zihao; Deng, Congliang; Zhou, Tao; Fan, Zaifeng

    2017-02-01

    Maize chlorotic mottle virus (MCMV) is spreading in many regions worldwide, causing maize lethal necrosis when co-infected with a potyvirid. In this study, one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect MCMV in maize. A set of four specific primers was designed based on the conserved coat protein gene sequences of MCMV. The RT-LAMP could be completed within 60min under isothermal condition at 63°C. The sensitivity test showed that the RT-LAMP was about 10-fold more sensitive than RT-PCR and no cross-reactivity was detected with other viral pathogens infecting maize in China. Moreover, the results of RT-LAMP could be visually inspected by SYBR Green I staining in a closed-tube, facilitating high-throughput application of MCMV detection. This method was further verified by testing field-collected samples. These results suggested that the developed MCMV RT-LAMP technique is a rapid, efficient and sensitive method which could be used as a routine screen for MCMV infection.

  18. Constitutive Expression of the Maize Genes B1 and C1 in Transgenic Hi II Maize Results in Differential Tissue Pigmentation and Generates Resistance to Helicoverpa zea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthocyanin biosynthesis in maize protects tissues from biotic and abiotic stresses. Constitutive expression of the maize B1 and C1 genes, which induces anthocyanin biosynthesis, resulted in transgenic plants with varied phenotypes. Some colored leaves were substantially resistant to thrips damage...

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

    PubMed

    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.

  20. Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

    PubMed Central

    Mathur, Chandni; Kathuria, Pooran C.; Dahiya, Pushpa; Singh, Anand B.

    2015-01-01

    Background 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. Objective To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize. Methods 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. Results 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. Conclusion 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. PMID:25706412

  1. [Development of transgenic maize with anti-rough dwarf virus artificial miRNA vector and their disease resistance].

    PubMed

    Xuan, Ning; Zhao, Chuanzhi; Peng, Zhenying; Chen, Gao; Bian, Fei; Lian, Mingzheng; Liu, Guoxia; Wang, Xingjun; Bi, Yuping

    2015-09-01

    Maize is one of the most important food crops. Rice black-streaked dwarf virus is a maize rough dwarf disease pathogen. The occurrence and transmission of maize rough dwarf disease brings great damage to maize production. The technology of using artificial miRNA to build antiviral plant has been proven effective in a variety of plants. However, such trials in maize have not been reported. We designed primers based on the sequence of maize zea-miR159a precursor and sequence of function protein genes and silencing RBSDV coding genes in RBSDV genome. We constructed amiRNA (artificial miRNA) gene for silencing RBSDV coding gene and gene silencing suppressor. We constructed pCAMBIA3301-121-amiRNA plant expression vector for transforming maize inbred lines Z31 by using agrobacterium mediated method. After molecular analysis of transgenic maize, homozygous lines with high miRNA expression were selected by molecular detection for a subsequent natural infection experiment. We studied the severity of maize rough dwarf disease according to a grading standard (grade 0 to 4). The experiment results showed that the disease resistance of transgenic homozygous maize with the anti-rough dwarf virus amiRNA vector was better than that of wild type. Among the transgenic maize, S6-miR159 transgenic maize had high disease resistance. It is feasible to create new maize variety by the use of artificial miRNA.

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

    NASA Astrophysics Data System (ADS)

    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

  3. Maize acetylcholinesterase is a positive regulator of heat tolerance in plants.

    PubMed

    Yamamoto, Kosuke; Sakamoto, Hikaru; Momonoki, Yoshie S

    2011-11-01

    We previously reported that native tropical zone plants showed high acetylcholinesterase (AChE) activity during heat stress, and that AChE activity in endodermal cells of maize seedlings was increased by heat treatment. However, the physiological role of AChE in heat stressed plants is still unclear. Here we report (1) tissue-specific expression and subcellular localization of maize AChE, (2) elevation of AChE activity and possible post-translational modifications of this enzyme under heat stress, and (3) involvement of AChE in plant heat stress tolerance. Maize AChE was mainly expressed in coleoptile nodes and seeds. Maize AChE fused with green fluorescent protein (GFP) was localized in extracellular spaces of transgenic rice plants. Therefore, in maize coleoptile nodes and seeds AChE mainly functions in the cell wall matrix. After heat treatment, enhanced maize AChE activity was observed by in vitro activity measurement and by in situ cytochemical staining; transcript and protein levels, however, were not changed. Protein gel blot analysis revealed two AChE isoforms (upper and lower); the upper-form gradually disappeared after heat treatment. Thus, maize AChE activity might be enhanced through a post-translational modification response to heat stress. Finally, we found that overexpression of maize AChE in transgenic tobacco plants enhanced heat tolerance relative to that of non-transgenic plants, suggesting AChE plays a positive role in maize heat tolerance.

  4. An insight into the sensitivity of maize to photoperiod changes under controlled conditions.

    PubMed

    Chen, Qiang; Zhong, Hao; Fan, Xian-Wei; Li, You-Zhi

    2015-08-01

    Response of maize to photoperiods affects adaption of this crop to environments. We characterize the phenotypes of four temperate-adapted maize foundation parents, Huangzao 4, Chang 7-2, Ye 478 and Zheng 58, and two tropically adapted maize foundation parents, M9 and Shuang M9 throughout the growth stage under three constant photoperiod regimes in a daily cycle of 24 h at 28 °C, and analysed expression of 48 photoperiod response-associated genes. Consequently, long photoperiod (LP) repressed development of the tassels of photoperiod-sensitive maize lines at V9 stage, and caused subsequent failure in flowering; failure of photoperiod-sensitive maize lines in flowering under LP was associated with lower expression of flowering-related genes; photoperiod changes could make a marked impact on spatial layout of maize inflorescence. The larger oscillation amplitude of expression of photoperiod-responsive genes occurred in LP-sensitive maize lines. In conclusion, failure in development of tassels at V9 stage under LP is an early indicator for judging photoperiod sensitivity. The adaptation of temperate-adapted maize lines to LP is due to the better coordination of expression among photoperiod-sensing genes instead of the loss of the genes. High photoperiod sensitivity of maize is due to high expression of circadian rhythm-responding genes improperly early in the light.

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

    PubMed

    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.

  6. Stability of key micronutrients added to fortified maize flours and corn meal.

    PubMed

    Dunn, Michael L; Jain, Vijaya; Klein, Barbara P

    2014-04-01

    Maize is a dietary staple in many countries. Although nutritious in many ways and a good source of energy, typical maize lacks several key micronutrients (MNs) that are often added to maize meals or flours to enhance nutritional value. Many factors affect MN stability in maize products, including uncontrolled conditions during distribution, long storage times, and MN premix composition. Consumer preparation also affects the final MN content of food. This review summarizes research relating to MN stability during processing, transport, storage, and meal preparation, focusing on those MNs most often added to maize and maize-based foods. Significant losses in B vitamins (B1, B2, B3, B6, B9, and B12) occur during manufacturing, distribution, and cooking. Added minerals (e.g., iron, zinc, calcium) are generally retained, although phytates in corn may affect bioavailability. Vitamins A and D3 are recent additions to fortification premixes for maize and are not well studied. Although there have been numerous studies of MN fortification in wheat flour, maize has not been as thoroughly examined, so recommendations are not as well supported. Future investigations should include well-designed and executed studies of the most labile MNs added to maize flours and meals, and their fate during all steps of processing, shipping, and preparation.

  7. A Selfish Gene Governing Pollen-Pistil Compatibility Confers Reproductive Isolation Between Maize Relatives

    PubMed Central

    Kermicle, Jerry L.

    2006-01-01

    Some populations of maize's closest relatives, the annual teosintes of Mexico, are unreceptive to maize pollen. When present in the pistil (silk and ovary) a number of maize genes discriminate against or exclude pollen not carrying the same allele. An analogous gene Tcb1-s was found in some teosinte populations but not in sympatric or parapatric maize. It was polymorphic among populations of teosinte growing wild, but regularly present in populations growing in intimate association with maize as a weed. Introduction of Tcb1-s into maize substantially to fully restored compatibility with Tcb1-s carrying teosintes. Although Tcb1-s pollen can fertilize tcb1 tcb1 maize, it is at a competitive disadvantage relative to tcb1 pollen. Hence, the influence of Tcb1-s on crossability is bidirectional. In the absence of maize, Tcb1-s can increase in teosinte populations without improving their fitness. In the presence of maize, Tcb1-s appears to have been co-opted to provide reproductive isolation for adaptation to a cultivated habitat. PMID:16157680

  8. Genetic, evolutionary and plant breeding insights from the domestication of maize

    PubMed Central

    Hake, Sarah; Ross-Ibarra, Jeffrey

    2015-01-01

    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 part by its large chromosomes, ease of pollination and growing agricultural importance. Genome comparisons between varieties of maize, teosinte and other grasses are beginning to identify the genes responsible for the domestication of modern maize and are also providing ideas for the breeding of more hardy varieties. DOI: http://dx.doi.org/10.7554/eLife.05861.001 PMID:25807085

  9. Nutritive value of maize silage in relation to dairy cow performance and milk quality.

    PubMed

    Khan, Nazir A; Yu, Peiqiang; Ali, Mubarak; Cone, John W; Hendriks, Wouter H

    2015-01-01

    Maize silage has become the major forage component in the ration of dairy cows over the last few decades. This review provides information on the mean content and variability in chemical composition, fatty acid (FA) profile and ensiling quality of maize silages, and discusses the major factors which cause these variations. In addition, the effect of the broad range in chemical composition of maize silages on the total tract digestibility of dietary nutrients, milk production and milk composition of dairy cows is quantified and discussed. Finally, the optimum inclusion level of maize silage in the ration of dairy cows for milk production and composition is reviewed. The data showed that the nutritive value of maize silages is highly variable and that most of this variation is caused by large differences in maturity at harvest. Maize silages ensiled at a very early stage (dry matter (DM) < 250 g kg(-1)) were particularly low in starch content and starch/neutral detergent fibre (NDF) ratio, and resulted in a lower DM intake (DMI), milk yield and milk protein content. The DMI, milk yield and milk protein content increased with advancing maturity, reaching an optimum level for maize silages ensiled at DM contents of 300-350 g kg(-1), and then declined slightly at further maturity beyond 350 g kg(-1). The increases in milk (R(2) = 0.599) and protein (R(2) = 0.605) yields with maturity of maize silages were positively related to the increase in starch/NDF ratio of the maize silages. On average, the inclusion of maize silage in grass silage-based diets improved the forage DMI by 2 kg d(-1), milk yield by 1.9 kg d(-1) and milk protein content by 1.2 g kg(-1). Further comparisons showed that, in terms of milk and milk constituent yields, the optimum grass/maize silage ratio depends on the quality of both the grass and maize silages. Replacement of grass silage with maize silage in the ration, as well as an increasing maturity of the maize silages, altered the milk FA profile

  10. Genetic signals of origin, spread, and introgression in a large sample of maize landraces

    PubMed Central

    van Heerwaarden, Joost; Doebley, John; Briggs, William H.; Glaubitz, Jeffrey C.; Goodman, Major M.; de Jesus Sanchez Gonzalez, Jose; Ross-Ibarra, Jeffrey

    2011-01-01

    The last two decades have seen important advances in our knowledge of maize domestication, thanks in part to the contributions of genetic data. Genetic studies have provided firm evidence that maize was domesticated from Balsas teosinte (Zea mays subspecies parviglumis), a wild relative that is endemic to the mid- to lowland regions of southwestern Mexico. An interesting paradox remains, however: Maize cultivars that are most closely related to Balsas teosinte are found mainly in the Mexican highlands where subspecies parviglumis does not grow. Genetic data thus point to primary diffusion of domesticated maize from the highlands rather than from the region of initial domestication. Recent archeological evidence for early lowland cultivation has been consistent with the genetics of domestication, leaving the issue of the ancestral position of highland maize unresolved. We used a new SNP dataset scored in a large number of accessions of both teosinte and maize to take a second look at the geography of the earliest cultivated maize. We found that gene flow between maize and its wild relatives meaningfully impacts our inference of geographic origins. By analyzing differentiation from inferred ancestral gene frequencies, we obtained results that are fully consistent with current ecological, archeological, and genetic data concerning the geography of early maize cultivation. PMID:21189301

  11. The maize d2003, a novel allele of VP8, is required for maize internode elongation.

    PubMed

    Lv, Hongkun; Zheng, Jun; Wang, Tianyu; Fu, Junjie; Huai, Junling; Min, Haowei; Zhang, Xiang; Tian, Baohua; Shi, Yunsu; Wang, Guoying

    2014-02-01

    The d2003 is a natural dwarf mutant from maize inbred line K36 and has less than one-third of K36 plant height with severely shortened internodes. In this study, we reported the cloning of d2003 gene using positional cloning. The results showed that there was a single-base insertion in the coding region of Viviparous8 (VP8) in d2003 mutant, which resulted in a premature stop codon. Further genetic allelism tests confirmed that d2003 mutation is a novel allele of VP8. VP8 is mainly expressed in the stem apex, young leaves, and developing vascular tissues, and its expression levels in nodes are significantly higher than that in internodes at 12-leaf stage. Subcellular localization demonstrated that the VP8 protein is localized to the endoplasmic reticulum and the N-terminal 26 amino acids (aa) of VP8 protein are essential to its localization in ER. Further transgenic experiments showed that lack of the 26 aa leads to loss of VP8 function in Arabidopsis amp1 phenotype rescue. These results strongly suggested that the N-terminal 26 aa is critical for VP8 protein localization, and the correct protein localization of VP8 in ER is necessary for its function.

  12. Maize ARGOS1 (ZAR1) transgenic alleles increase hybrid maize yield

    PubMed Central

    Guo, Mei

    2014-01-01

    Crop improvement for yield and drought tolerance is challenging due to the complex genetic nature of these traits and environmental dependencies. This study reports that transgenic over-expression of Zea mays ARGOS1 (ZAR1) enhanced maize organ growth, grain yield, and drought-stress tolerance. The ZAR1 transgene exhibited environmental interactions, with yield increase under Temperate Dry and yield reduction under Temperate Humid or High Latitude environments. Native ZAR1 allele variation associated with drought-stress tolerance. Two founder alleles identified in the mid-maturity germplasm of North America now predominate in Pioneer’s modern breeding programme, and have distinct proteins, promoters and expression patterns. These two major alleles show heterotic group partitioning, with one predominant in Pioneer’s female and the other in the male heterotic groups, respectively. These two alleles also associate with favourable crop performance when heterozygous. Allele-specific transgene testing showed that, of the two alleles discussed here, each allele differed in their impact on yield and environmental interactions. Moreover, when transgenically stacked together the allelic pair showed yield and environmental performance advantages over either single allele, resembling heterosis effects. This work demonstrates differences in transgenic efficacy of native alleles and the differences reflect their association with hybrid breeding performance. PMID:24218327

  13. Maize ARGOS1 (ZAR1) transgenic alleles increase hybrid maize yield.

    PubMed

    Guo, Mei; Rupe, Mary A; Wei, Jun; Winkler, Chris; Goncalves-Butruille, Marymar; Weers, Ben P; Cerwick, Sharon F; Dieter, Jo Ann; Duncan, Keith E; Howard, Richard J; Hou, Zhenglin; Löffler, Carlos M; Cooper, Mark; Simmons, Carl R

    2014-01-01

    Crop improvement for yield and drought tolerance is challenging due to the complex genetic nature of these traits and environmental dependencies. This study reports that transgenic over-expression of Zea mays AR GOS1 (ZAR1) enhanced maize organ growth, grain yield, and drought-stress tolerance. The ZAR1 transgene exhibited environmental interactions, with yield increase under Temperate Dry and yield reduction under Temperate Humid or High Latitude environments. Native ZAR1 allele variation associated with drought-stress tolerance. Two founder alleles identified in the mid-maturity germplasm of North America now predominate in Pioneer's modern breeding programme, and have distinct proteins, promoters and expression patterns. These two major alleles show heterotic group partitioning, with one predominant in Pioneer's female and the other in the male heterotic groups, respectively. These two alleles also associate with favourable crop performance when heterozygous. Allele-specific transgene testing showed that, of the two alleles discussed here, each allele differed in their impact on yield and environmental interactions. Moreover, when transgenically stacked together the allelic pair showed yield and environmental performance advantages over either single allele, resembling heterosis effects. This work demonstrates differences in transgenic efficacy of native alleles and the differences reflect their association with hybrid breeding performance.

  14. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    PubMed

    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. Aspergillus flavus and Fusariumverticillioides Induce Tissue Specific Gene Expression of PRms and UGT in Maize Seed before Fungal Colonization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus and Fusariumverticillioides are fungal pathogens that colonize maize seeds and contaminate them with mycotoxins. To investigate the plant microbe interactions, we conducted histological and molecular studies to characterize the internal colonization of maize seed by the two fungal...

  16. Aflatoxins and ochratoxin A in maize of Punjab, Pakistan.

    PubMed

    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.

  17. Replicative intermediates of maize streak virus found during leaf development.

    PubMed

    Erdmann, Julia B; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind; Rybicki, Edward P; Jeske, Holger

    2010-04-01

    Geminiviruses of the genera Begomovirus and Curtovirus utilize three replication modes: complementary-strand replication (CSR), rolling-circle replication (RCR) and recombination-dependent replication (RDR). Using two-dimensional gel electrophoresis, we now show for the first time that maize streak virus (MSV), the type member of the most divergent geminivirus genus, Mastrevirus, does the same. Although mastreviruses have fewer regulatory genes than other geminiviruses and uniquely express their replication-associated protein (Rep) from a spliced transcript, the replicative intermediates of CSR, RCR and RDR could be detected unequivocally within infected maize tissues. All replicative intermediates accumulated early and, to varying degrees, were already present in the shoot apex and leaves at different maturation stages. Relative to other replicative intermediates, those associated with RCR increased in prevalence during leaf maturation. Interestingly, in addition to RCR-associated DNA forms seen in other geminiviruses, MSV also apparently uses dimeric open circular DNA as a template for RCR.

  18. Using observed warming to identify hazards to Mozambique maize production

    USGS Publications Warehouse

    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.

  19. Effect and localization of phenanthrene in maize roots.

    PubMed

    Dupuy, Joan; Leglize, Pierre; Vincent, Quentin; Zelko, Ivan; Mustin, Christian; Ouvrard, Stéphanie; Sterckeman, Thibault

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) have a toxic effect on plants, which limits the efficiency of phytomanagement of contaminated soils. The mechanisms underlying their toxicity are not fully understood. A cultivation experiment was carried out with maize, used as model plant, exposed to sand spiked with phenanthrene (50 or 150 mg kg(-1) dw). Epi-fluorescence microscopic observation of root sections was used to assess suberization of exodermis and endodermis and phenanthrene localization along the primary root length. For 10 days of cultivation, exodermis and endodermis suberization of exposed maize was more extensive. However, after 20 days of exposure, exodermis and endodermis of non-exposed roots were totally suberized, whilst PHE-exposed roots where less suberized. Early extensive suberization may act as barrier against PHE penetration, however longer exposure inhibits root maturation. Phenanthrene patches were located only near suberized exodermis and endodermis, which may therefore act as retention zones, where the hydrophobic phenanthrene accumulates during its radial transport.

  20. The B73 maize genome: complexity, diversity, and dynamics.

    PubMed

    Schnable, Patrick S; Ware, Doreen; Fulton, Robert S; Stein, Joshua C; Wei, Fusheng; Pasternak, Shiran; Liang, Chengzhi; Zhang, Jianwei; Fulton, Lucinda; Graves, Tina A; Minx, Patrick; Reily, Amy Denise; Courtney, Laura; Kruchowski, Scott S; Tomlinson, Chad; Strong, Cindy; Delehaunty, Kim; Fronick, Catrina; Courtney, Bill; Rock, Susan M; Belter, Eddie; Du, Feiyu; Kim, Kyung; Abbott, Rachel M; Cotton, Marc; Levy, Andy; Marchetto, Pamela; Ochoa, Kerri; Jackson, Stephanie M; Gillam, Barbara; Chen, Weizu; Yan, Le; Higginbotham, Jamey; Cardenas, Marco; Waligorski, Jason; Applebaum, Elizabeth; Phelps, Lindsey; Falcone, Jason; Kanchi, Krishna; Thane, Thynn; Scimone, Adam; Thane, Nay; Henke, Jessica; Wang, Tom; Ruppert, Jessica; Shah, Neha; Rotter, Kelsi; Hodges, Jennifer; Ingenthron, Elizabeth; Cordes, Matt; Kohlberg, Sara; Sgro, Jennifer; Delgado, Brandon; Mead, Kelly; Chinwalla, Asif; Leonard, Shawn; Crouse, Kevin; Collura, Kristi; Kudrna, Dave; Currie, Jennifer; He, Ruifeng; Angelova, Angelina; Rajasekar, Shanmugam; Mueller, Teri; Lomeli, Rene; Scara, Gabriel; Ko, Ara; Delaney, Krista; Wissotski, Marina; Lopez, Georgina; Campos, David; Braidotti, Michele; Ashley, Elizabeth; Golser, Wolfgang; Kim, HyeRan; Lee, Seunghee; Lin, Jinke; Dujmic, Zeljko; Kim, Woojin; Talag, Jayson; Zuccolo, Andrea; Fan, Chuanzhu; Sebastian, Aswathy; Kramer, Melissa; Spiegel, Lori; Nascimento, Lidia; Zutavern, Theresa; Miller, Beth; Ambroise, Claude; Muller, Stephanie; Spooner, Will; Narechania, Apurva; Ren, Liya; Wei, Sharon; Kumari, Sunita; Faga, Ben; Levy, Michael J; McMahan, Linda; Van Buren, Peter; Vaughn, Matthew W; Ying, Kai; Yeh, Cheng-Ting; Emrich, Scott J; Jia, Yi; Kalyanaraman, Ananth; Hsia, An-Ping; Barbazuk, W Brad; Baucom, Regina S; Brutnell, Thomas P; Carpita, Nicholas C; Chaparro, Cristian; Chia, Jer-Ming; Deragon, Jean-Marc; Estill, James C; Fu, Yan; Jeddeloh, Jeffrey A; Han, Yujun; Lee, Hyeran; Li, Pinghua; Lisch, Damon R; Liu, Sanzhen; Liu, Zhijie; Nagel, Dawn Holligan; McCann, Maureen C; SanMiguel, Phillip; Myers, Alan M; Nettleton, Dan; Nguyen, John; Penning, Bryan W; Ponnala, Lalit; Schneider, Kevin L; Schwartz, David C; Sharma, Anupma; Soderlund, Carol; Springer, Nathan M; Sun, Qi; Wang, Hao; Waterman, Michael; Westerman, Richard; Wolfgruber, Thomas K; Yang, Lixing; Yu, Yeisoo; Zhang, Lifang; Zhou, Shiguo; Zhu, Qihui; Bennetzen, Jeffrey L; Dawe, R Kelly; Jiang, Jiming; Jiang, Ning; Presting, Gernot G; Wessler, Susan R; Aluru, Srinivas; Martienssen, Robert A; Clifton, Sandra W; McCombie, W Richard; Wing, Rod A; Wilson, Richard K

    2009-11-20

    We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize.

  1. Properties of Proteoliposomes Containing Fusicoccin Receptors from Maize 1

    PubMed Central

    Aducci, Patrizia; Fullone, Maria Rosaria; Ballio, Alessandro

    1989-01-01

    We have recently described a fusicoccin (FC)-sensitive system reconstituted by inserting into liposomes FC-receptors and H+-ATPase-enriched preparations from maize tissues. While the proteoliposomes of maize H+-ATPase had been already investigated, those of FC-receptors required a careful characterization before use in the dual system. In particular, the influence of the phospholipid environment on time-course, reversibility, and pH-dependence of the FC-binding reaction has been studied by comparing these properties in microsome-bound, solubilized, and liposome-entrapped receptors. Similarities and differences between the results of this investigation and those previously obtained with FC-receptors from spinach leaves suggest that functionally similar binding proteins from monocot and dicot plants have distinct structural features. PMID:16667192

  2. Molecular Characterization of a Maize B Chromosome Centric Sequence

    PubMed Central

    Alfenito, M. R.; Birchler, J. A.

    1993-01-01

    Supernumerary chromosomes are widespread in the plant kingdom but little is known of their molecular nature or mechanism of origin. We report here the initial cloning of sequences from the maize B chromosome. Our analysis suggests that many sequences are highly repetitive and shared with the normal A chromosomes. However, all clones selected for B-specificity contain at least one copy of a particular repeat. Cytological mapping using B chromosome derivatives and in situ hybridization show that the B specific repeats are derived from the centric region of the chromosome. Sequence analysis of this repeat shows homology to motifs mapped to various plant and animal centromeres and to the maize neocentromere. A precise localization of these sequences among breakpoints within the B centromere and an homology to a facultative centromere, suggest a role for this sequence in centromere function. PMID:8244015

  3. Ultrastructural studies on pollen embryogenesis in maize (Zea mays L.).

    PubMed

    Barnabas, B; Fransz, P F; Schel, J H

    1987-06-01

    Maize anthers have been induced on modified N6 medium to produce embryoids. Different stages from the cultures were sampled and prepared for microscopical examination. The microspores at the onset of culture were in an early developmental stage, with the nucleus and numerous organelles centred in the middle, surrounded by many small vacuoles with a lipid content. The binuclear pollen grains contained small vesicles and much starch. The partially condensed vegetative nucleus indicated participation of the vegetative component in the formation of multicellular pollen grains (MPGs). Several MPGs have been observed which differed in morphology. We suggest, on the basis of these ultrastructural observations, that in maize mainly the vegetative cell contributes to the MPG which further develops directly into embryoids.

  4. Yield QTLome distribution correlates with gene density in maize.

    PubMed

    Martinez, Ana Karine; Soriano, Jose Miguel; Tuberosa, Roberto; Koumproglou, Rachil; Jahrmann, Torben; Salvi, Silvio

    2016-01-01

    The genetic control of yield and related traits in maize has been addressed by many quantitative trait locus (QTL) studies, which have produced a wealth of QTL information, also known as QTLome. In this study, we assembled a yield QTLome database and carried out QTL meta-analysis based on 44 published studies, representing 32 independent mapping populations and 49 parental lines. A total of 808 unique QTLs were condensed to 84 meta-QTLs and were projected on the 10 maize chromosomes. Seventy-four percent of QTLs showed a proportion of phenotypic variance explained (PVE) smaller than 10% confirming the high genetic complexity of grain yield. Yield QTLome projection on the genetic map suggested pericentromeric enrichment of QTLs. Conversely, pericentromeric depletion of QTLs was observed when the physical map was considered, suggesting gene density as the main driver of yield QTL distribution on chromosomes. Dominant and overdominant yield QTLs did not distribute differently from additive effect QTLs.

  5. Somatically segregating clone of apomictic maize-tripsacum hybrid

    SciTech Connect

    Yudin, B.F.; Lukina, L.A.

    1988-11-01

    The results of further study on clone AM-5, isolated in the progeny of /gamma/-irradiated plants of the apomictic hybrid of maize with tripsacum (2n = 38) are reported. The variegated-leaf seedlings of the clone segregate somatically and produce variegated, mottled, green (phenotypically normal) plants in different ratios in the apomictic progenies. The variegated, and to a lesser degree, green segregants segregate further. The mottled apomictics as well as mottled branches of variegated seedlings maintain their phenotype on transplantation, however, these is a progressive enhancement of the characters of vegetative lethality. Lethals of two extra maize genomes to the AM-5 nucleus does not affect significantly the scope and nature of segregation. At the same time, the loss of tripsacum genome restores normal phenotype. Clone AM-5 is an example of hybrid apomictic form causing significant morphological variability, which is, nevertheless, not related with apomictic and reversion to the sexual process.

  6. Genetic properties of the maize nested association mapping population.

    PubMed

    McMullen, Michael D; Kresovich, Stephen; Villeda, Hector Sanchez; Bradbury, Peter; Li, Huihui; Sun, Qi; Flint-Garcia, Sherry; Thornsberry, Jeffry; Acharya, Charlotte; Bottoms, Christopher; Brown, Patrick; Browne, Chris; Eller, Magen; Guill, Kate; Harjes, Carlos; Kroon, Dallas; Lepak, Nick; Mitchell, Sharon E; Peterson, Brooke; Pressoir, Gael; Romero, Susan; Oropeza Rosas, Marco; Salvo, Stella; Yates, Heather; Hanson, Mark; Jones, Elizabeth; Smith, Stephen; Glaubitz, Jeffrey C; Goodman, Major; Ware, Doreen; Holland, James B; Buckler, Edward S

    2009-08-07

    Maize genetic diversity has been used to understand the molecular basis of phenotypic variation and to improve agricultural efficiency and sustainability. We crossed 25 diverse inbred maize lines to the B73 reference line, capturing a total of 136,000 recombination events. Variation for recombination frequencies was observed among families, influenced by local (cis) genetic variation. We identified evidence for numerous minor single-locus effects but little two-locus linkage disequilibrium or segregation distortion, which indicated a limited role for genes with large effects and epistatic interactions on fitness. We observed excess residual heterozygosity in pericentromeric regions, which suggested that selection in inbred lines has been less efficient in these regions because of reduced recombination frequency. This implies that pericentromeric regions may contribute disproportionally to heterosis.

  7. The electrical network of maize root apex is gravity dependent.

    PubMed

    Masi, Elisa; Ciszak, Marzena; Comparini, Diego; Monetti, Emanuela; Pandolfi, Camilla; Azzarello, Elisa; Mugnai, Sergio; Baluška, Frantisek; Mancuso, Stefano

    2015-01-15

    Investigations carried out on maize roots under microgravity and hypergravity revealed that gravity conditions have strong effects on the network of plant electrical activity. Both the duration of action potentials (APs) and their propagation velocities were significantly affected by gravity. Similarly to what was reported for animals, increased gravity forces speed-up APs and enhance synchronized electrical events also in plants. The root apex transition zone emerges as the most active, as well as the most sensitive, root region in this respect.

  8. Monitoring of maize chlorophyll content based on multispectral vegetation indices

    NASA Astrophysics Data System (ADS)

    Sun, Hong; Li, Minzan; Zheng, Lihua; Zhang, Yane; Zhang, Yajing

    2012-11-01

    In order to estimate the nutrient status of maize, the multi-spectral image was used to monitor the chlorophyll content in the field. The experiments were conducted under three different fertilizer treatments (High, Normal and Low). A multispectral CCD camera was used to collect ground-based images of maize canopy in green (G, 520~600nm), red (R, 630~690nm) and near-infrared (NIR, 760~900nm) band. Leaves of maize were randomly sampled to detect the chlorophyll content by UV-Vis spectrophotometer. The images were processed following image preprocessing, canopy segmentation and parameter calculation: Firstly, the median filtering was used to improve the visual contrast of image. Secondly, the leaves of maize canopy were segmented in NIR image. Thirdly, the average gray value (GIA, RIA and NIRIA) and the vegetation indices (DVI, RVI, NDVI, et al.) widely used in remote sensing were calculated. A new vegetation index, combination of normalized difference vegetation index (CNDVI), was developed. After the correlation analysis between image parameter and chlorophyll content, six parameters (GIA, RIA, NIRIA, GRVI, GNDVI and CNDVI) were selected to estimate chlorophyll content at shooting and trumpet stages respectively. The results of MLR predicting models showed that the R2 was 0.88 and the adjust R2 was 0.64 at shooting stage; the R2 was 0.77 and the adjust R2 was 0.31 at trumpet stage. It was indicated that vegetation indices derived from multispectral image could be used to monitor the chlorophyll content. It provided a feasible method for the chlorophyll content detection.

  9. Genomewide predictions from maize single-cross data.

    PubMed

    Massman, Jon M; Gordillo, Andres; Lorenzana, Robenzon E; Bernardo, Rex

    2013-01-01

    Maize (Zea mays L.) breeders evaluate many single-cross hybrids each year in multiple environments. Our objective was to determine the usefulness of genomewide predictions, based on marker effects from maize single-cross data, for identifying the best untested single crosses and the best inbreds within a biparental cross. We considered 479 experimental maize single crosses between 59 Iowa Stiff Stalk Synthetic (BSSS) inbreds and 44 non-BSSS inbreds. The single crosses were evaluated in multilocation experiments from 2001 to 2009 and the BSSS and non-BSSS inbreds had genotypic data for 669 single nucleotide polymorphism (SNP) markers. Single-cross performance was predicted by a previous best linear unbiased prediction (BLUP) approach that utilized marker-based relatedness and information on relatives, and from genomewide marker effects calculated by ridge-regression BLUP (RR-BLUP). With BLUP, the mean prediction accuracy (r(MG)) of single-cross performance was 0.87 for grain yield, 0.90 for grain moisture, 0.69 for stalk lodging, and 0.84 for root lodging. The BLUP and RR-BLUP models did not lead to r(MG) values that differed significantly. We then used the RR-BLUP model, developed from single-cross data, to predict the performance of testcrosses within 14 biparental populations. The r(MG) values within each testcross population were generally low and were often negative. These results were obtained despite the above-average level of linkage disequilibrium, i.e., r(2) between adjacent markers of 0.35 in the BSSS inbreds and 0.26 in the non-BSSS inbreds. Overall, our results suggested that genomewide marker effects estimated from maize single crosses are not advantageous (cofmpared with BLUP) for predicting single-cross performance and have erratic usefulness for predicting testcross performance within a biparental cross.

  10. Characterization of a Maize Wip1 Promoter in Transgenic Plants

    PubMed Central

    Zhang, Shengxue; Lian, Yun; Liu, Yan; Wang, Xiaoqing; Liu, Yunjun; Wang, Guoying

    2013-01-01

    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. PMID:24322445

  11. Modeling the Morphometric Evolution of the Maize Shoot Apical Meristem

    PubMed Central

    Leiboff, Samuel; DeAllie, Christopher K.; Scanlon, Michael J.

    2016-01-01

    The maize (Zea mays subsp. mays L.) shoot apical meristem (SAM) is a self-replenishing pool of stem cells that produces all above-ground plant tissues. Improvements in image acquisition and processing techniques have allowed high-throughput, quantitative genetic analyses of SAM morphology. As with other large-scale phenotyping efforts, meaningful descriptions of genetic architecture depend on the collection of relevant measures. In this study, we tested two quantitative image processing methods to describe SAM morphology within the genus Zea, represented by 33 wild relatives of maize and 841 lines from a domesticated maize by wild teosinte progenitor (MxT) backcross population, along with previously reported data from several hundred diverse maize inbred lines. Approximating the MxT SAM as a paraboloid derived eight parabolic estimators of SAM morphology that identified highly overlapping quantitative trait loci (QTL) on eight chromosomes, which implicated previously identified SAM morphology candidate genes along with new QTL for SAM morphological variation. Using a Fourier-transform related method of comprehensive shape analysis, we detected cryptic SAM shape variation that identified QTL on six chromosomes. We found that Fourier transform shape descriptors and parabolic estimation measures are highly correlated and identified similar QTL. Analysis of shoot apex contours from 73 anciently diverged plant taxa further suggested that parabolic shape may be a universal feature of plant SAMs, regardless of evolutionary clade. Future high-throughput examinations of SAM morphology may benefit from the ease of acquisition and phenotypic fidelity of modeling the SAM as a paraboloid. PMID:27867389

  12. Maize Plants Recognize Herbivore-Associated Cues from Caterpillar Frass.

    PubMed

    Ray, Swayamjit; Gaffor, Iffa; Acevedo, Flor E; Helms, Anjel; Chuang, Wen-Po; Tooker, John; Felton, Gary W; Luthe, Dawn S

    2015-09-01

    Caterpillar behaviors such as feeding, crawling, and oviposition are known to induce defenses in maize and other plant species. We examined plant defense responses to another important caterpillar behavior, their defecation. Fall armyworms (FAW, Spodoptera frugiperda), a major threat to maize (Zea mays), are voracious eaters and deposit copious amounts of frass in the enclosed whorl tissue surrounding their feeding site, where it remains for long periods of time. FAW frass is composed of molecules derived from the host plant, the insect itself, and associated microbes, and hence provides abundant cues that may alter plant defense responses. We observed that proteins from FAW frass initially induced wound-responsive defense genes in maize; however, a pathogenesis-related (pr) defense gene was induced as the time after application increased. Elicitation of pathogen defenses by frass proteins was correlated with increased herbivore performance and reduced fungal pathogen performance over time. These responses differ from the typical plant response to oral secretions of the FAW. The results pave the way for identification of protein molecule(s) from the excretion of an herbivore that elicits pathogen defense responses while attenuating herbivore defenses in plants.

  13. Investigating lignin key features in maize lignocelluloses using infrared spectroscopy.

    PubMed

    Chazal, Richard; Robert, Paul; Durand, Sylvie; Devaux, Marie-Françoise; Saulnier, Luc; Lapierre, Catherine; Guillon, Fabienne

    2014-01-01

    Lignins and their cross-linking to hemicelluloses detrimentally affect the cellulose-to-ethanol conversion of grass lignocelluloses. Screening appropriate grass cell walls and their compositional changes during the various steps of the process calls for a high-throughput analytical technique. Such a performance can be fulfilled by Fourier transform mid-infrared (FT-MIR) spectroscopy. In the present paper, a set of maize cell walls from mature stems were selected, including brown midrib samples. Lignin fractions were isolated by mild acidolysis to obtain a set of purified maize lignin standards. The lignin content and the percentage of lignin-derived p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) thioacidolysis monomers were determined. In addition, the composition of cell wall polysaccharides, as well as the amount of ester-linked p-coumaric (CA) and ferulic (FA) acids, was measured by wet chemistry. Partial least square (PLS) analyses were applied to infrared and chemical data of cell walls. The resulting models showed a good predictive ability with regard to the lignin content, to the frequency of S (or G) thioacidolysis monomers, and to the level of ester-linked CA of maize cell walls. The loading plots and regression coefficients revealed relevant infrared absorption bands.

  14. Dry Priming of Maize Seeds Reduces Aluminum Stress

    PubMed Central

    Alcântara, Berenice Kussumoto; Machemer-Noonan, Katja; Silva Júnior, Francides Gomes; Azevedo, Ricardo Antunes

    2015-01-01

    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. PMID:26714286

  15. Early maize agriculture and interzonal interaction in southern Peru.

    PubMed

    Perry, Linda; Sandweiss, Daniel H; Piperno, Dolores R; Rademaker, Kurt; Malpass, Michael A; Umire, Adán; de la Vera, Pablo

    2006-03-02

    Over the past decade, increasing attention to the recovery and identification of plant microfossil remains from archaeological sites located in lowland South America has significantly increased knowledge of pre-Columbian plant domestication and crop plant dispersals in tropical forests and other regions. Along the Andean mountain chain, however, the chronology and trajectory of plant domestication are still poorly understood for both important indigenous staple crops such as the potato (Solanum sp.) and others exogenous to the region, for example, maize (Zea mays). Here we report the analyses of plant microremains from a late preceramic house (3,431 +/- 45 to 3,745 +/- 65 14C bp or approximately 3,600 to 4,000 calibrated years bp) in the highland southern Peruvian site of Waynuna. Our results extend the record of maize by at least a millennium in the southern Andes, show on-site processing of maize into flour, provide direct evidence for the deliberate movement of plant foods by humans from the tropical forest to the highlands, and confirm the potential of plant microfossil analysis in understanding ancient plant use and migration in this region.

  16. Reduced Lateral Root Branching Density Improves Drought Tolerance in Maize.

    PubMed

    Zhan, Ai; Schneider, Hannah; Lynch, Jonathan P

    2015-08-01

    An emerging paradigm is that root traits that reduce the metabolic costs of soil exploration improve the acquisition of limiting soil resources. Here, we test the hypothesis that reduced lateral root branching density will improve drought tolerance in maize (Zea mays) by reducing the metabolic costs of soil exploration, permitting greater axial root elongation, greater rooting depth, and thereby greater water acquisition from drying soil. Maize recombinant inbred lines with contrasting lateral root number and length (few but long [FL] and many but short [MS]) were grown under water stress in greenhouse mesocosms, in field rainout shelters, and in a second field environment with natural drought. Under water stress in mesocosms, lines with the FL phenotype had substantially less lateral root respiration per unit of axial root length, deeper rooting, greater leaf relative water content, greater stomatal conductance, and 50% greater shoot biomass than lines with the MS phenotype. Under water stress in the two field sites, lines with the FL phenotype had deeper rooting, much lighter stem water isotopic signature, signifying deeper water capture, 51% to 67% greater shoot biomass at flowering, and 144% greater yield than lines with the MS phenotype. These results entirely support the hypothesis that reduced lateral root branching density improves drought tolerance. The FL lateral root phenotype merits consideration as a selection target to improve the drought tolerance of maize and possibly other cereal crops.

  17. Cyclins D, phytoregulators and cell cycle onset in germinating maize.

    PubMed

    Vázquez-Ramos, Jorge M; Lara-Nuñez, Aurora

    2008-08-01

    Several different D-type cyclins can be found in plants and in maize, four of these have been characterized: CycD2;1, CycD4;1, CycD5;1 and CycD5;2. These cyclins appear to form complexes with Cdks, with PCNA and also with KRP proteins and in these kinase activity can be measured. The expression of the corresponding genes during maize germination is highly stimulated by phytohormones like auxin and cytokinin, however this is not followed by an equivalent increase in the amount of the corresponding proteins; nonetheless, auxins do stimulate the associated kinase activity, particularly at early germination times. Thus, auxins appear to stimulate the cell cycle during germination at two levels, transcription and kinase activation. Both auxins and cytokinins appear to shorten the G1 phase during germination and stimulate DNA synthesis, but apparently they do it in different ways as the simultaneous addition of both to germinating maize axes eliminates DNA synthesis stimulation. Therefore, similar actions may be achieved by different paths.

  18. Cyclins D, phytoregulators and cell cycle onset in germinating maize

    PubMed Central

    Lara-Nuñez, Aurora

    2008-01-01

    Several different D-type cyclins can be found in plants and in maize, four of these have been characterized: CycD2;1, CycD4;1, CycD5;1 and CycD5;2. These cyclins appear to form complexes with Cdks, with PCNA and also with KRP proteins and in these kinase activity can be measured. The expression of the corresponding genes during maize germination is highly stimulated by phytohormones like auxin and cytokinin, however this is not followed by an equivalent increase in the amount of the corresponding proteins; nonetheless, auxins do stimulate the associated kinase activity, particularly at early germination times. Thus, auxins appear to stimulate the cell cycle during germination at two levels, transcription and kinase activation. Both auxins and cytokinins appear to shorten the G1 phase during germination and stimulate DNA synthesis, but apparently they do it in different ways as the simultaneous addition of both to germinating maize axes eliminates DNA synthesis stimulation. Therefore, similar actions may be achieved by different paths. PMID:19704474

  19. Dry Priming of Maize Seeds Reduces Aluminum Stress.

    PubMed

    Alcântara, Berenice Kussumoto; Machemer-Noonan, Katja; Silva Júnior, Francides Gomes; Azevedo, Ricardo Antunes

    2015-01-01

    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.

  20. Heterosis for carotenoid concentration and profile in maize hybrids.

    PubMed

    Burt, Andrew J; Grainger, Christopher M; Shelp, Barry J; Lee, Elizabeth A

    2011-12-01

    Production of high-lutein maize grain is of particular interest as a value-added feed source to produce high-lutein eggs. In this paper, it is demonstrated that heterosis for total carotenoid concentration and for the ratio of lutein to zeaxanthin (L:Z ratio), or profile type, exists infrequently in yellow dent crosses. However, yellow dent inbred maize lines A619 and CG102, both possessing high-lutein profiles, produce F1 seed with a classic overdominant expression of lutein levels (i.e., 49 µg/g dry weight (DW) above the high-parent value). Reciprocal crosses of A619 and CG102 with one another and with two high-zeaxanthin (i.e., low lutein), high-carotenoid lines both suggest that the A619 and CG102 high-lutein phenotypes are achieved by different and complementary genotypes. The contribution of CG102 to the heterotic response was examined using a QTL-based approach that involved phenotyping the mapping population in a testcross to A619. Significant QTL were found at loci known to be involved in the carotenoid pathway but also at loci proximate to, but separate from, known carotenoid pathway steps. Exploiting an overdominant heterotic response for lutein and total carotenoids should be given strong consideration as a viable method of producing high-carotenoid hybrid maize lines.

  1. Role of Dehydrodiferulates in Maize Resistance to Pests and Diseases

    PubMed Central

    Santiago, Rogelio; Malvar, Rosa A.

    2010-01-01

    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. PMID:20386661

  2. Genetic analysis of arsenic accumulation in maize using QTL mapping

    NASA Astrophysics Data System (ADS)

    Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

    2016-02-01

    Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars.

  3. Independent Molecular Basis of Convergent Highland Adaptation in Maize.

    PubMed

    Takuno, Shohei; Ralph, Peter; Swarts, Kelly; Elshire, Rob J; Glaubitz, Jeffrey C; Buckler, Edward S; Hufford, Matthew B; Ross-Ibarra, Jeffrey

    2015-08-01

    Convergent evolution is the independent evolution of similar traits in different species or lineages of the same species; this often is a result of adaptation to similar environments, a process referred to as convergent adaptation. We investigate here the molecular basis of convergent adaptation in maize to highland climates in Mesoamerica and South America, using genome-wide SNP data. Taking advantage of archaeological data on the arrival of maize to the highlands, we infer demographic models for both populations, identifying evidence of a strong bottleneck and rapid expansion in South America. We use these models to then identify loci showing an excess of differentiation as a means of identifying putative targets of natural selection and compare our results to expectations from recently developed theory on convergent adaptation. Consistent with predictions across a wide parameter space, we see limited evidence for convergent evolution at the nucleotide level in spite of strong similarities in overall phenotypes. Instead, we show that selection appears to have predominantly acted on standing genetic variation and that introgression from wild teosinte populations appears to have played a role in highland adaptation in Mexican maize.

  4. Genetic analysis of arsenic accumulation in maize using QTL mapping

    PubMed Central

    Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

    2016-01-01

    Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars. PMID:26880701

  5. Uncultured bacterial diversity in tropical maize (Zea mays L.) rhizosphere.

    PubMed

    Chauhan, Puneet Singh; Chaudhry, Vasvi; Mishra, Sandhya; Nautiyal, Chandra Shekhar

    2011-02-01

    Structure of maize (Zea mays L.) rhizosphere bacteria was evaluated to explore the feasibility of identifying novel rhizosphere bacteria using culture-independent method based on direct amplification and analysis of 16S rRNA gene (rRNA) sequences and especially to obtain a better understanding of bacterial community structure and diversity from maize. A total of 274 sequences were analyzed and assigned 48.00% Proteobacteria, 10.30% Actinobacteria, 9.90% Bacteroidetes, 6.60% Verrucomicrobia, 4.80% Acidobacteria, 1.80% Firmicutes, 1.50% Chloroflexi, 1.50% TM7, 1.10% Deinococcus-Thermus, 0.70% Planctomycetes, 0.70% Gemmatimonadetes and 0.40% Cyanobacteria. Economically important phyla Actinobacteria was second most dominant group after Proteobacteria, in our clone library. It would be interesting to hypothesize that root exudates from maize rhizosphere favors growth of Actinobacteria like microbes to eliminate pathogenic bacteria and decompose plant matter, for enhanced plant and soil health. An additional 12.8% of clone library (35 operational taxonomical units (OTUs) from 43 clones) with less than 94% similarity to any GenBank sequence could not be assigned to any known phylum and may represent unidentified bacterial lineages and suggests that a large amount of the rhizobacterial diversity remains to be characterized by culturing.

  6. Determination of maize hardness by biospeckle and fuzzy granularity

    PubMed Central

    Weber, Christian; Dai Pra, Ana L; Passoni, Lucía I; Rabal, Héctor J; Trivi, Marcelo; Poggio Aguerre, Guillermo J

    2014-01-01

    In recent years there has been renewed interest in the development of novel grain classification methods that could complement traditional empirical tests. A speckle pattern occurs when a laser beam illuminates an optically rough surface that flickers when the object is active and is called biospeckle. In this work, we use laser biospeckle to classify maize (Zea mays L.) kernel hardness. A series of grains of three types of maize were cut and illuminated by a laser. A series of images were then registered, stored, and processed. These were compared with results obtained by floating test. The laser speckle technique was effective in discriminating the grains based on the presence of floury or vitreous endosperm and could be considered a feasible alternative to traditional floating methods. The results indicate that this methodology can distinguish floury and vitreous grains. Moreover, the assay showed higher discrimination capability than traditional tests. It could be potentially useful for maize classification and to increase the efficiency of processing dry milling corn. PMID:25473513

  7. Comparative transcriptomics of early meiosis in Arabidopsis and maize.

    PubMed

    Dukowic-Schulze, Stefanie; Harris, Anthony; Li, Junhua; Sundararajan, Anitha; Mudge, Joann; Retzel, Ernest F; Pawlowski, Wojciech P; Chen, Changbin

    2014-03-20

    Though sexually reproductive plants share the same principle and most processes in meiosis, there are distinct features detectable. To address the similarities and differences of early meiosis transcriptomes from the dicot model system Arabidopsis and monocot model system maize, we performed comparative analyses of RNA-seq data of isolated meiocytes, anthers and seedlings from both species separately and via orthologous genes. Overall gene expression showed similarities, such as an increased number of reads mapping to unannotated features, and differences, such as the amount of differentially expressed genes. We detected major similarities and differences in functional annotations of genes up-regulated in meiocytes, which point to conserved features as well as unique features. Transcriptional regulation seems to be quite similar in Arabidopsis and maize, and we could reveal known and novel transcription factors and cis-regulatory elements acting in early meiosis. Taken together, meiosis between Arabidopsis and maize is conserved in many ways, but displays key distinctions that lie in the patterns of gene expression.

  8. Determination of maize hardness by biospeckle and fuzzy granularity.

    PubMed

    Weber, Christian; Dai Pra, Ana L; Passoni, Lucía I; Rabal, Héctor J; Trivi, Marcelo; Poggio Aguerre, Guillermo J

    2014-09-01

    In recent years there has been renewed interest in the development of novel grain classification methods that could complement traditional empirical tests. A speckle pattern occurs when a laser beam illuminates an optically rough surface that flickers when the object is active and is called biospeckle. In this work, we use laser biospeckle to classify maize (Zea mays L.) kernel hardness. A series of grains of three types of maize were cut and illuminated by a laser. A series of images were then registered, stored, and processed. These were compared with results obtained by floating test. The laser speckle technique was effective in discriminating the grains based on the presence of floury or vitreous endosperm and could be considered a feasible alternative to traditional floating methods. The results indicate that this methodology can distinguish floury and vitreous grains. Moreover, the assay showed higher discrimination capability than traditional tests. It could be potentially useful for maize classification and to increase the efficiency of processing dry milling corn.

  9. Maize mono-digestion efficiency: results from laboratory tests.

    PubMed

    Ficara, Elena; Malpei, Francesca

    2011-01-01

    A laboratory experimental campaign was carried out in order to assess the optimal configuration for the anaerobic digestion of a mixture of sweet corn and ensiled maize. Batch hydrolysis tests were conducted at 35 and 55 °C and at four different particle sizes (2, 5, 20 and 50 mm) obtained by manual chopping and sieving. Chemical pre-treatment by 24 h incubation at various acid and alkaline pH was also considered for its potential to increase the maize methane yield. Results suggest that the hydrolytic phase proceeds significantly faster under thermophilic conditions. Significant differences in the solubilization rate were also observed when comparing coarse (20-50 mm) with fine (2-5 mm) particles, while 2 and 5 mm particles were solubilized at similar rates. No advantages from the chemical pre-treatment, in terms of solubilization efficiency and biomethanization potential were observed. According to these preliminary results, a two-stage semi-continuous laboratory plant consisting of a thermophilic hydrolytic reactor followed by a mesophilic methanogenic reactor was operated for 110 days. Steady state loading parameters were: influent concentration (maize mixture diluted in tap water) of 46 g VS/L, hydraulic retention time of 31 d, organic loading rate of 1.5 g VS/L/d. Alkalinity was dosed to the methanogenic reactor to avoid pH drops. Collected data allowed the average biodegradation efficiency to be estimated at around 60-65%.

  10. The water budget of rainfed maize and bean intercrop

    NASA Astrophysics Data System (ADS)

    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.

  11. Independent Molecular Basis of Convergent Highland Adaptation in Maize

    PubMed Central

    Takuno, Shohei; Ralph, Peter; Swarts, Kelly; Elshire, Rob J.; Glaubitz, Jeffrey C.; Buckler, Edward S.; Hufford, Matthew B.; Ross-Ibarra, Jeffrey

    2015-01-01

    Convergent evolution is the independent evolution of similar traits in different species or lineages of the same species; this often is a result of adaptation to similar environments, a process referred to as convergent adaptation. We investigate here the molecular basis of convergent adaptation in maize to highland climates in Mesoamerica and South America, using genome-wide SNP data. Taking advantage of archaeological data on the arrival of maize to the highlands, we infer demographic models for both populations, identifying evidence of a strong bottleneck and rapid expansion in South America. We use these models to then identify loci showing an excess of differentiation as a means of identifying putative targets of natural selection and compare our results to expectations from recently developed theory on convergent adaptation. Consistent with predictions across a wide parameter space, we see limited evidence for convergent evolution at the nucleotide level in spite of strong similarities in overall phenotypes. Instead, we show that selection appears to have predominantly acted on standing genetic variation and that introgression from wild teosinte populations appears to have played a role in highland adaptation in Mexican maize. PMID:26078279

  12. Maize somatic embryogenesis: recent features to improve plant regeneration.

    PubMed

    Garrocho-Villegas, Verónica; de Jesús-Olivera, María Teresa; Quintanar, Estela Sánchez

    2012-01-01

    Plant regeneration capacity is maintained through the life of a plant by the stem cell niche present in the meristems. Stem cells are capable of differentiating into any plant organ, allowing propagation of new plants by different techniques. Among them, somatic embryogenesis is a widely used technique characterized by a complex process that involves coordinated expression of genes, mediated by the influence of specific hormones, nutrients, stress, and/or environmental signals. This tool is particularly relevant in the propagation of genetically improved crops. The intrinsic embryogenic potential of the explant used as starting material for plant in vitro cultures varies depending on the genotype of each plant species. Particularly in maize, the regeneration capacity is lost during the course of tissue maturation, since embryogenic callus (E) is almost exclusively obtained from immature zygotic embryos. In this chapter, the latest advances in the literature for maize somatic embryogenesis process are reviewed. Further, a detailed procedure for maize plant regeneration from E callus is described. The callus obtained from immature zygotic embryos is capable to generate somatic embryos that germinate and develop into fertile normal plants.

  13. Feasibility of hydrothermal pretreatment on maize silage for bioethanol production.

    PubMed

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-09-01

    The potential of maize silage as a feedstock to produce bioethanol was evaluated in the present study. The hydrothermal pretreatment with five different pretreatment severity factors (PSF) was employed to pretreat the maize silage and compared in terms of sugar recovery, toxic test, and ethanol production by prehydrolysis and simultaneous saccharification and fermentation. After pretreatment, most of the cellulose remained in the residue, ranging between 85.87% by the highest PSF (185 degrees C, 15 min) and 92.90% obtained at the lowest PSF (185 degrees C, 3 min). A larger part of starch, varying from 71.64% by the highest PSF to 78.28% by the lowest, was liberated into liquor part, leaving 8.05-11.74% in the residues. Xylan recovery in the residues increased from 44.25% at the highest PSF to 82.95% at the lowest. The recovery of xylan in liquor changed from 20.13% to 50.33%. Toxic test indicated that all the liquors from the five conditions were not toxic to the Baker's yeast. Pretreatment under 195 degrees C for 7 min had the similar PSF with that of 185 degrees 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 7.67 g/L.

  14. Growth characteristics of maize seeds exposed to magnetic field.

    PubMed

    Vashisth, Ananta; Joshi, Devendra Kumar

    2017-02-01

    Standardization of magnetic field was done for maximum enhancement in germination characteristics of maize seeds. Seeds of maize were exposed to static magnetic fields of strength 50, 100, 150, 200, and 250 for 1, 2, 3, and 4 h for all field strengths. Results indicate that magnetic field application enhanced seed performance in terms of percentage germination, speed of germination, seedling length, and seedling dry weight significantly compared to unexposed control. Among the various combinations of field strength and duration, 200 mT for 1 h exposure gave best results. Exposure of seeds to magnetic fields improved seed coat membrane integrity as it reduced cellular leakage and, consequently, electrical conductivity. Experiments conducted at a research farm as well as farmer's field showed that plants raised from seeds exposed to 200 mT for 1 h had higher values of leaf area index, shoot length, number of leaves, chlorophyll content, shoot/root dry weight, and root characteristics as compared to corresponding values in untreated control. From the studies, it may be concluded that exposure of dry seeds to static magnetic field of 200 mT for 1 h improved shoot and root growth. Improved root system and biomass led to increased seed yield. Improved functional root parameters suggested that magnetically treated maize seeds could be used under moisture stress conditions. Bioelectromagnetics. 38:151-157, 2017. © 2016 Wiley Periodicals, Inc.

  15. Carbon monoxide photoproduction from rice and maize leaves

    NASA Astrophysics Data System (ADS)

    Yonemura, S.; Morokuma, M.; Kawashima, S.; Tsuruta, H.

    We investigated CO photoproduction from intact leaves of rice ( Oryza sativa L.) and maize ( Zea mays L.) by laboratory experiments. CO photoproduction showed positive correlation with light intensity and was positively dependent on oxygen concentration. The average CO photoproduction was 2.6±0.3×10 10 molecules cm -2 s -1 from rice leaves and 2.2±0.1×10 10 molecules cm -2 s -1 from maize leaves ( n=5) at a radiation intensity of 49 mW cm -2. CO photoproduction from senescent rice leaves was 9 times greater (25.7±1.5×10 10 molecules cm -2 s -1, n=2) at the same radiation intensity than from live leaves, and responded slowly to changes in oxygen concentration and light intensity. CO photoproduction showed no correlation with CO 2 concentration or humidity. This indicates that CO photoproduction in leaves is not directly controlled by carbon metabolism or stomatal conductance. The lack of dependence on stomatal conductance leads to the conclusion that the diffusion of CO from inside the leaves to the atmosphere is not a controlling factor for CO photoproduction from rice and maize leaves.

  16. Placing bounds on extreme temperature response of maize

    NASA Astrophysics Data System (ADS)

    Anderson, Christopher J.; Babcock, Bruce A.; Peng, Yixing; Gassman, Philip W.; Campbell, Todd D.

    2015-12-01

    Plant water availability is a key factor that determines maize yield response to excess heat. Lack of available data has limited researchers’ ability to estimate this relationship at regional and global scales. Using a new soil moisture data set developed by running a crop growth simulator over historical data we demonstrate how current estimates of maize yield sensitivity to high temperature are misleading. We develop an empirical model relating observed yields to climate variables and soil moisture in a high maize production region in the United States to develop bounds on yield sensitivity to high temperatures. For the portion of the region with a relatively long growing season, yield reduction per °C is 10% for high water availability and 32.5% for low water availability. Where the growing season is shorter, yield reduction per °C is 6% for high water availability and 27% for low water availability. These results indicate the importance of using both water availability and temperature to model crop yield response to explain future climate change on crop yields.

  17. Genetic analysis of arsenic accumulation in maize using QTL mapping.

    PubMed

    Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

    2016-02-16

    Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars.

  18. Tribology of swollen starch granule suspensions from maize and potato.

    PubMed

    Zhang, Bin; Selway, Nichola; Shelat, Kinnari J; Dhital, Sushil; Stokes, Jason R; Gidley, Michael J

    2017-01-02

    The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications.

  19. Molecular Cloning of Complementary DNA Encoding Maize Nitrite Reductase

    PubMed Central

    Lahners, Kristine; Kramer, Vance; Back, Eduard; Privalle, Laura; Rothstein, Steven

    1988-01-01

    Complementary DNA has been isolated that codes for maize nitrite reductase (NiR) by using the corresponding spinach gene (E Back et al. 1988 Mol Gen Genet 212:20-26) as a heterologous probe. The sequences of the complementary DNAs from the two species are 66% homologous while the deduced amino acid sequences are 86% similar when analogous amino acids are included. A high percentage of the differences in the DNA sequences is due to the extremely strong bias in the corn gene to have a G/C base in the third codon position with 559/569 codons ending in a G or C. Using a hydroponic system, maize seedlings grown in the absence of an exogenous nitrogen source were induced with nitrate or nitrite. Nitrate stimulated a rapid induction of the NiR mRNA in both roots and leaves. There is also a considerable induction of this gene in roots upon the addition of nitrite, although under the conditions used the final mRNA level was not as high as when nitrate was the inducer. There is a small but detectable level of NiR mRNA in leaves prior to induction, but no constitutive NiR mRNA can be seen in the roots. Analysis of genomic DNA supports the notion that there are at least two NiR genes in maize. Images Fig. 3 Fig. 4 Fig. 5 PMID:16666376

  20. Early competition shapes maize whole-plant development in mixed stands

    PubMed Central

    Evers, Jochem B.

    2014-01-01

    Mixed cropping is practised widely in developing countries and is gaining increasing interest for sustainable agriculture in developed countries. Plants in intercrops grow differently from plants in single crops, due to interspecific plant interactions, but adaptive plant morphological responses to competition in mixed stands have not been studied in detail. Here the maize (Zea mays) response to mixed cultivation with wheat (Triticum aestivum) is described. Evidence is provided that early responses of maize to the modified light environment in mixed stands propagate throughout maize development, resulting in different phenotypes compared with pure stands. Photosynthetically active radiation (PAR), red:far-red ratio (R:FR), leaf development, and final organ sizes of maize grown in three cultivation systems were compared: pure maize, an intercrop with a small distance (25cm) between maize and wheat plants, and an intercop with a large distance (44cm) between the maize and the wheat. Compared with maize in pure stands, maize in the mixed stands had lower leaf and collar appearance rates, increased blade and sheath lengths at low ranks and smaller sizes at high ranks, increased blade elongation duration, and decreased R:FR and PAR at the plant base during early development. Effects were strongest in the treatment with a short distance between wheat and maize strips. The data suggest a feedback between leaf initiation and leaf emergence at the plant level and coordination between blade and sheath growth at the phytomer level. A conceptual model, based on coordination rules, is proposed to explain the development of the maize plant in pure and mixed stands. PMID:24307719

  1. Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production

    PubMed Central

    Okeke, Chiamaka A.; Ezekiel, Chibundu N.; Nwangburuka, Cyril C.; Sulyok, Michael; Ezeamagu, Cajethan O.; Adeleke, Rasheed A.; Dike, Stanley K.; Krska, Rudolf

    2015-01-01

    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 24–96 h 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 24–72 h. 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. PMID:26697001

  2. Early competition shapes maize whole-plant development in mixed stands.

    PubMed

    Zhu, Junqi; Vos, Jan; van der Werf, Wopke; van der Putten, Peter E L; Evers, Jochem B

    2014-02-01

    Mixed cropping is practised widely in developing countries and is gaining increasing interest for sustainable agriculture in developed countries. Plants in intercrops grow differently from plants in single crops, due to interspecific plant interactions, but adaptive plant morphological responses to competition in mixed stands have not been studied in detail. Here the maize (Zea mays) response to mixed cultivation with wheat (Triticum aestivum) is described. Evidence is provided that early responses of maize to the modified light environment in mixed stands propagate throughout maize development, resulting in different phenotypes compared with pure stands. Photosynthetically active radiation (PAR), red:far-red ratio (R:FR), leaf development, and final organ sizes of maize grown in three cultivation systems were compared: pure maize, an intercrop with a small distance (25cm) between maize and wheat plants, and an intercop with a large distance (44cm) between the maize and the wheat. Compared with maize in pure stands, maize in the mixed stands had lower leaf and collar appearance rates, increased blade and sheath lengths at low ranks and smaller sizes at high ranks, increased blade elongation duration, and decreased R:FR and PAR at the plant base during early development. Effects were strongest in the treatment with a short distance between wheat and maize strips. The data suggest a feedback between leaf initiation and leaf emergence at the plant level and coordination between blade and sheath growth at the phytomer level. A conceptual model, based on coordination rules, is proposed to explain the development of the maize plant in pure and mixed stands.

  3. Effect of harvest maturity on carbohydrates for ethanol production from sugar enhanced temperate x tropical maize hybrid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A northern adapted sugar maize (Zea mays L.) hybrid was bred by crossing temperate x tropical maize for bioethanol production. Temperate x tropical maize (TTM) has a prolonged vegetative growth and accumulates more sugar in the stalk compared to its respective tropical and temperature parents. In th...

  4. Identification of maize genes associated with host plant resistance and susceptibility to Aspergillus flavus infection and aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus infection and aflatoxin contamination of maize pose negative impacts in agriculture and health. Commercial maize hybrids are generally susceptible to this fungus. Significant levels of host plant resistance have been observed in certain maize inbred lines. This study was conducted...

  5. Effects of transgenic cry1Ie maize on non-lepidopteran pest abundance, diversity and community composition.

    PubMed

    Guo, Jingfei; He, Kanglai; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Wang, Fuxin; Wang, Zhenying

    2016-12-01

    Non-lepidopteran pests are exposed to, and may be influenced by, Bt toxins when feeding on Bt maize that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt). In order to assess the potential effects of transgenic cry1Ie maize on non-lepidopteran pest species and ecological communities, a 2-year field study was conducted to compare the non-lepidopteran pest abundance, diversity and community composition between transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) by whole plant inspections. Results showed that Bt maize had no effects on non-lepidopteran pest abundance and diversity (Shannon-Wiener diversity index, Simpson's diversity index, species richness, and Pielou's index). There was a significant effect of year and sampling time on those indices analyzed. Redundancy analysis indicated maize type, sampling time and year totally explained 20.43 % of the variance in the non-lepidopteran pest community composition, but no association was presented between maize type (Bt maize and non-Bt maize) and the variance. Nonmetric multidimensional scaling analysis showed that sampling time and year, rather than maize type had close relationship with the non-lepidopteran pest community composition. These results corroborated the hypothesis that, at least in the short-term, the transgenic cry1Ie maize had negligible effects on the non-lepidopteran pest abundance, diversity and community composition.

  6. Yellow maize with high beta-carotene is an effective source of vitamin A in healthy Zimbabwean men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bioconversion efficiency of yellow maize beta-carotene to retinol in humans is unknown. Thus, the objective of this study was to determine the vitamin A value of yellow maize beta-carotene in humans. A high beta-carotene containing yellow maize was grown in a hydroponic medium with 23 atom% 2H2O...

  7. Yellow maize with high (beta)-carotene is an effective source of vitamin A in healthy Zimbabwean men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: The bioconversion efficiency of yellow maize Beta-carotene to retinol in humans is unknown. OBJECTIVE: The objective of this study was to determine the vitamin A value of yellow maize Beta-carotene in humans. DESIGN: High Beta-carotene-containing yellow maize was grown in a hydroponic...

  8. The Maize PIN Gene Family of Auxin Transporters.

    PubMed

    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.

  9. The Maize PIN Gene Family of Auxin Transporters

    PubMed Central

    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

  10. Competition of three species of Sitophilus on rice and maize

    PubMed Central

    Athanassiou, Christos G.; Kavallieratos, Nickolas G.; Campbell, James F.

    2017-01-01

    Laboratory tests were carried out in order to examine competition among three congeneric species on rice and maize: the granary weevil, Sitophilus granarius, the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais. For this purpose, a total of 30 adults were placed in vials that contained 50 g or either rice or maize: 30 adults of S. granarius, 30 adults of S. oryzae, 30 adults of S. zeamais, 15 adults of S. granarius+15 adults of S. oryzae, 15 adults of S. granarius+15 adults of S. zeamais, 15 adults of S. oryzae +15 adults of S. zeamais, and 10 adults of S. granarius+10 adults of S. oryzae+10 adults of S. zeamais. After 62 days at 30°C and 65% relative humidity the number of individuals of each species were counted. Insect damaged kernels (IDK), weight of frass and grain weight were measured. When each species was alone, S. granarius had the lowest numbers of adults in both grains, which did not exceed 34 adults/vial, and S. oryzae numbers were always higher than other species. For S. oryzae and S. zeamais, the numbers of adults were considerably higher on rice than on maize. On rice, S. oryzae numbers ranged between 281 and 563 adults per vial, while for S. zeamais between 137 and 372 adults per vial. At the same time, for both species on maize, adult numbers did not exceed 54 adults per vial. The number of S. oryzae adults were constantly higher than the other species in all combinations tested. Moreover, for rice, IDK in the vials that contained S. oryzae, either alone or in combination with other species, was higher than all the other combinations. Similarly, grain weight was lower in the vials that contained S. oryzae compared to the other species combinations. In general, for S. oryzae and S. zeamais progeny production was increased with the increase of the number of the initial adults that had been placed inside the vials. At the same time, progeny production of all three species was not affected by the presence of another species

  11. Mycorrhiza and PGPB modulate maize biomass, nutrient uptake and metabolic pathways in maize grown in mining-impacted soil.

    PubMed

    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.

  12. Predicting maize phenology: Intercomparison of functions for developmental response to temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate prediction of phenological development in maize is fundamental to determining crop adaptation and yield potential. A number of thermal functions are used in crop models, but their relative precision in predicting maize development has not been quantified. The objectives of this study were t...

  13. Genotypic and phenotypic characterization of isogenic doubled haploid exotic introgression lines in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We characterized the genotypic and phenotypic variation for cell wall digestibility (CWD) and other agronomic traits of 50 backcross 1 generation doubled haploids (BC1DH) lines developed from the Germplasm Enhancement of Maize (GEM) project. These lines consisted of 31 exotic, unadapted maize race...

  14. Screening for insect and disease resistance and aflatoxin accumulation in experimental maize hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to develop new maize germplasm lines with resistance to multiple insect pests, disease, and aflatoxin accumulation in temperate region, a set of new experimental hybrids was made using exotic tropical and subtropical maize inbred lines. The evaluation of these breeding crosses for insect a...

  15. Toward Cost-Effective Fingerprinting Methodology to Distinguish Maize Open-Pollinated Varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Africa, many smallholder farmers grow open pollinated maize varieties (OPVs), as they allow seed recycling and out-yield traditional farmer’s (unimproved) landraces. One popular OPV, ZM521 released by the International Maize and Wheat Improvement Center (CIMMYT), has been provided to farmers, o...

  16. The genetics of leaf flecking in maize and its relationship to plant defense and disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physiological/genetic leaf spotting, or flecking, is a mild lesion phenotype observed on the leaves of several commonly used maize inbred lines and has been anecdotally linked to enhanced broad-spectrum disease resistance. Flecking was assessed in the maize nested association mapping (NAM) populati...

  17. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) production, which is of global agro-economic importance, is largely limited by herbivore pests, pathogens, and environmental conditions, such as drought. Zealexins and kauralexins belong to two recently identified families of acidic terpenoid phytoalexins in maize that mediate defen...

  18. Drought responses of foliar metabolites in three maize hybrids differing in water stress tolerance.

    PubMed

    Barnaby, Jinyoung Y; Kim, Moon; Bauchan, Gary; Bunce, James; Reddy, Vangimalla; Sicher, Richard Charles

    2013-01-01

    Maize (Zea mays L.) hybrids varying in drought tolerance were treated with water stress in controlled environments. Experiments were performed during vegetative growth and water was withheld for 19 days beginning 17 days after sowing. Genotypic comparisons used measured changes of leaf water potential or results were expressed by time of treatment. Total dry matter of the drought tolerant hybrid on the final harvest was 53% less than that of the intermediate and susceptible maize hybrids when plants were water sufficient. This showed that maize hybrids selected for extreme drought tolerance possessed a dwarf phenotype that affected soil water contents and leaf water potentials. Changes of shoot and root growth, leaf water potential, net photosynthesis and stomatal conductance in response to the time of water stress treatment were diminished when comparing the drought tolerant to the intermediate or susceptible maize hybrids. Genotypic differences were observed in 26 of 40 total foliar metabolites during water stress treatments. Hierarchical clustering revealed that the tolerant maize hybrid initiated the accumulation of stress related metabolites at higher leaf water potentials than either the susceptible or intermediate hybrids. Opposite results occurred when changes of metabolites in maize leaves were expressed temporally. The above results demonstrated that genotypic differences were readily observed by comparing maize hybrids differing in drought tolerance based on either time of treatment or measured leaf water potential. Current findings provided new and potentially important insights into the mechanisms of drought tolerance in maize.

  19. Using High-Throughput Genotyping Information for Management of a Large Maize Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Plant Germplasm System's collection of maize inbred lines is curated by the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) personnel in Ames, Iowa. The collection offers a rich set of genetic resources including key historical inbreds relevant to maize breeding hist...

  20. [Transposition of the maize transposable element dSpm in transgenic sugar beets].

    PubMed

    Kishchenko, E M; Komarnitskiĭ, I K; Kuchuk, N V

    2010-01-01

    Transgenic sugar beet plants carrying maize Spmn/dSpm transposable elements system have been constructed. Heterologous system of maize transposable elements Spm/dSpm was active in transgenic sugar beets that permits transposon-based gene tagging and obtaining of marker-free transgenic sugar beet.

  1. Investigation of false-positive reactions for CBH351 maize in screening PCR analysis.

    PubMed

    Monma, Kimio; Moriuchi, Rie; Sagi, Naoki; Ichikawa, Hisatsugu; Satoh, Kazue; Tobe, Takashi; Kamata, Kunihiro

    2006-02-01

    Examination for CBH351 maize was conducted by the qualitative polymerase chain reaction (PCR) method in maize grain and maize processed foods obtained in the Tokyo area. The numbers of samples possibly positive in the screening test were 7 of 22 (31.8%) for maize grain samples, 4 of 14 (28.6%) for semi-processed foods, 11 of 30 (36.7%) for canned products, 3 of 30 (10.0%) for maize snacks, 3 of 4 (75%) for tacos and 1 of 3 (33.3%) for tortillas. However, CBH351 maize was not detected in the confirmation test. Therefore, the results of the screening test were false-positive. Since the reaction might have been caused by the base sequences of the 3'-end of primers CaM03-5' and CBH02-3' used in the screening test, a new primer pair was designed. The PCR products obtained with the new primer pair TMC2-5'--TMS2-3' were specific for CBH351 and were not obtained with barley, wheat, rice, RRS, Bt11, or Event176. Thus, the new primer pair shows high specificity. CBH351 maize was detected from samples containing at least 0.05% CBH 351 maize DNA by using this primer pair.

  2. The MaizeGDB Genome Browser Tutorial: One example of database outreach to biologists via video

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Video tutorials are an effective way for researchers to quickly learn how to use online tools offered by biological databases. At the Maize Genetics and Genomics Database (MaizeGDB), we have developed a number of video tutorials that aim to demonstrate how to use various tools as well as to explici...

  3. Effects of elevated [CO2] on maize defense against mycotoxigenic Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is by quantity the most important C4 cereal crop; 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, which aggrava...

  4. The proteome and phosphoproteome of maize pollen uncovers fertility candidate proteins.

    PubMed

    Chao, Qing; Gao, Zhi-Fang; Wang, Yue-Feng; Li, Zhe; Huang, Xia-He; Wang, Ying-Chun; Mei, Ying-Chang; Zhao, Biligen-Gaowa; Li, Liang; Jiang, Yu-Bo; Wang, Bai-Chen

    2016-06-01

    Maize is unique since it is both monoecious and diclinous (separate male and female flowers on the same plant). We investigated the proteome and phosphoproteome of maize pollen containing modified proteins and here we provide a comprehensive pollen proteome and phosphoproteome which contain 100,990 peptides from 6750 proteins and 5292 phosphorylated sites corresponding to 2257 maize phosphoproteins, respectively. Interestingly, among the total 27 overrepresented phosphosite motifs we identified here, 11 were novel motifs, which suggested different modification mechanisms in plants compared to those of animals. Enrichment analysis of pollen phosphoproteins showed that pathways including DNA synthesis/chromatin structure, regulation of RNA transcription, protein modification, cell organization, signal transduction, cell cycle, vesicle transport, transport of ions and metabolisms, which were involved in pollen development, the following germination and pollen tube growth, were regulated by phosphorylation. In this study, we also found 430 kinases and 105 phosphatases in the maize pollen phosphoproteome, among which calcium dependent protein kinases (CDPKs), leucine rich repeat kinase, SNF1 related protein kinases and MAPK family proteins were heavily enriched and further analyzed. From our research, we also uncovered hundreds of male sterility-associated proteins and phosphoproteins that might influence maize productivity and serve as targets for hybrid maize seed production. At last, a putative complex signaling pathway involving CDPKs, MAPKs, ubiquitin ligases and multiple fertility proteins was constructed. Overall, our data provides new insight for further investigation of protein phosphorylation status in mature maize pollen and construction of maize male sterile mutants in the future.

  5. Ear leaf photosynthesis and related parameters of transgenic and non-GMO maize hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Using Live-Cell Markers in Maize to Analyze Cell Division Orientation and Timing.

    PubMed

    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.

  7. Comparative transcriptomes between viviparous1 and wildtype maize developing endosperms in response to water deficit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize kernel development is particularly sensitive to water stress at the early post-pollination phase. Endosperm plays an essential role in support of embryo development. In the present study, we compared transcriptomes of developing maize endosperms between an ABA-insensitive mutant, viviparous1 (...

  8. Isolation, characterization, and expression analyses of tryptophan aminotransferase genes in a maize dek18 mutant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Soil, Maize Crop, and Kernel Composition Responses to Rotation and N Fertilizer Treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize can utilize nitrogen (N) from inorganic fertilizers as well as from mineralized organic sources. We were interested in how maize responds to rotations that contain legumes. The objective of this 2-yr field investigation conducted on a long-term field study (started in 1990) was to measure effe...

  10. QTL controlling masculinization of ear tips in a maize (Zea mays L.) intraspecific cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is unique among cereal grasses because of its monoecious flowering habit. Male flowers are normally restricted to the tassel that terminates the primary shoot, whereas female flowers occur as ears at the terminal nodes of lateral branches. We observed a tropical maize inbred, Ki14, that produc...

  11. Complete Genomic Sequence of Maize Rough Dwarf Virus, a Fijivirus Transmitted by the Small Brown Planthopper.

    PubMed

    Lv, Mingfang; Xie, Li; Yang, Jian; Chen, Jianping; Zhang, Heng-Mu

    2016-02-04

    The nucleotide sequences of the 10 genomic segments of an Italian isolate of maize rough dwarf virus (MRDV) were determined. This first complete genomic sequence of MRDV will help understand the phylogenetic relationships among group 2 fijiviruses and especially the closely related rice black-streaked dwarf virus, which is also found to naturally infect maize.

  12. Comparative analysis of maize (Zea mays) crop performance: natural variation, incremental improvements and economic impacts.

    PubMed

    Leibman, Mark; Shryock, Jereme J; Clements, Michael J; Hall, Michael A; Loida, Paul J; McClerren, Amanda L; McKiness, Zoe P; Phillips, Jonathan R; Rice, Elena A; Stark, Steven B

    2014-09-01

    Grain yield from maize hybrids continues to improve through advances in breeding and biotechnology. Despite genetic improvements to hybrid maize, grain yield from distinct maize hybrids is expected to vary across growing locations due to numerous environmental factors. In this study, we examine across-location variation in grain yield among maize hybrids in three case studies. The three case studies examine hybrid improvement through breeding, introduction of an insect protection trait or introduction of a transcription factor trait associated with increased yield. In all cases, grain yield from each hybrid population had a Gaussian distribution. Across-location distributions of grain yield from each hybrid partially overlapped. The hybrid with a higher mean grain yield typically outperformed its comparator at most, but not all, of the growing locations (a 'win rate'). These results suggest that a broad set of environmental factors similarly impacts grain yields from both conventional- and biotechnology-derived maize hybrids and that grain yields among two or more hybrids should be compared with consideration given to both mean yield performance and the frequency of locations at which each hybrid 'wins' against its comparators. From an economic standpoint, growers recognize the value of genetically improved maize hybrids that outperform comparators in the majority of locations. Grower adoption of improved maize hybrids drives increases in average U.S. maize grain yields and contributes significant value to the economy.

  13. Genomic, transcriptomic and phenomic variation reveals the complex adaptation to stress response of modern maize breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early maize adaptation to different agricultural environments was an important process associated with the creation of a stable food supply that allowed the evolution of human civilization in the Americas. To explore the mechanisms of maize adaptation, genomic, transcriptomic and phenomic data were ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 sa...

  15. Ear Rot, Aflatoxin Accumulation, and Fungal Biomass in Maize after Inoculation with Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin, a toxin produced by the fungus Aspergillus flavus Link:Fries, occurs naturally in maize (Zea mays L.). Aflatoxin is a potent human carcinogen and is toxic to livestock, pets, and wildlife. When contaminated with aflatoxin, the value of maize grain is markedly reduced. Eight germplasm l...

  16. Maize terpenoid phytoalexins function in resistance against both abiotic and biotic stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) crop production, which is an essential part of the world’s grain supply, is limited by insect pests, pathogen diseases, and unfavorable weather, such as drought. Zealexins and kauralexins belong to recently identified families of terpenoid phytoalexins that function in maize defense...

  17. Influence of maize and pigweed on tarnished plant bug (Hemiptera: Miridae) populations infesting cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize and groundnut, important staples in Zambia, are susceptible to aflatoxin-producing fungi. Aflatoxins are potent human carcinogens also associated with stunting and immunosuppression. Although health and economic burdens of aflatoxins are well known, patterns of contamination in maize and grou...

  19. Molecular breeding for developing drought tolerant and disease resistant maize in sub Saharan Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Maize and Wheat Improvement Center (CIMMYT), in collaboration with public and private partners, is working on developing and disseminating drought tolerant maize for sub Saharan Africa (SSA) using pedigree selection and molecular breeding. In this paper, we provide an overview of ...

  20. Comparison of cellulosic ethanol yields from midwestern maize and reconstructed tallgrass prairie systems managed for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-spe...

  1. Discovery and purification of a fungal protease secreted by Bipolaris zeicola that modifies maize seed endochitinase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Healthy maize seeds have two basic endochitinases, chitA and chitB, with antifungal properties. A comparison of the isoenzyme profiles of symptomatic fungal-infested maize seeds, removed at harvest from ears that we wound inoculated in the late milk stage of maturity with one of several common ear-...

  2. Evaluating the MaizSim model in simulating potential corn growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Models that simply calculate crop growth rate as the product of intercepted light and radiation use efficiency may not be able to adequately simulate plant growth under stress conditions. We developed a new corn model MaizSim. In MaizSim, photosynthesis is mechanistically related to environmental co...

  3. Co-occurence of aflatoxins and fumonisins in maize: guatemala as a case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Investigating the roles of jasmonic acid and cytokinin in maize leaf growth control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant growth is the accumulation of biomass attributed to cell division and cell expansion. In the maize leaf, growth is spatially separated into three distinct growth zones: the division zone, elongation zone, and the maturation zone. This spatial separation makes the maize leaf a useful model for ...

  5. Transcriptional profiles uncover Aspergillus flavus-induced resistance in maize kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and during storage, and also a concern in many other crops, such as peanuts, cottonseed, tree nuts, and rice. Although a number of resistant maize lines with low aflatoxin c...

  6. Enhanced pest resistance of maize leaves expressing monocot crop plant derived ribosome inactivating protein and agglutinin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although many insect resistance genes have been identified, the number of studies examining their effects in combination using transgenic systems is limited. We introduced a construct into maize containing the coding sequence for maize ribosome inactivating protein (MRIP), wheat germ agglutinin (WGA...

  7. Nitric oxide detoxification by Fusarium verticillioides flavohemoglobin and role in pathogenicity of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides is a non-obligate plant pathogen of maize causing a number of specific diseases, including root rot, kernel rot, seed rot, stalk rot, and seedling blight. The saprophytic nature of this fungus, its production of the mycotoxin fumonisin, and complex relationship maize puts t...

  8. Iron bioavailability of maize hemoglobin in a Caco-2 cell culture model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is an important staple crop in many parts of the world but has low iron bioavailability, in part due to its high phytate content. Hemoglobin is a form of iron that is highly bioavailable and its bioavailability is not inhibited by phytate. We hypothesize that maize hemoglobin is a highly bioav...

  9. Fusarium graminearum: an pathogen of maize in Nepal, pathogenic variability and mycotoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is an important pathogen of maize in hills of Nepal. It predominantly occurs on maize grown in cool and humid environment of high hills. The pathogen is also known to infect other cereal crops including wheat and rice causing important diseases. The incidence of ear rot is hi...

  10. Diallel analysis of resistance to fusarium ear rot and fumonisin contamination in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Fusarium verticillioides infects maize ears and kernels, resulting in Fusarium ear rot disease, reduced grain yields, and contamination of grain with the mycotoxin fumonisin. Typical hybrid maize breeding programs involve selection for both favorable inbred and hybrid performance, and the...

  11. Developing maize germplasm lines with multiple insect and disease resistance and low aflatoxin contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield and quality losses caused BY insects, diseases, and mycotoxin contaminations are the critical impediments for maize production under warm climate. In order to develop maize germplasm lines with resistance to multiple insect pests and aflatoxin accumulation, a set of 13 reciprocal breeding cro...

  12. Metabolic effects of ß-glucans addition to corn maize flour

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of ß-glucans to degermed precooked corn maize flour produced favorably low metabolic responses in healthy young subjects. The increase in viscosity in the small intestine during the digestion period is the proposed mechanism for this effect. The addition of ß-glucans to corn maize pro...

  13. Belowground resistance to western corn rootworm in Lepidopteran-resistant maize genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several maize inbred lines developed from an Antiguan maize population have been shown to exhibit resistance to numerous aboveground lepidopteran pests. This study shows that these genotypes are able to significantly reduce the survival of two root feeding pests, western corn rootworm (Diabrotica v...

  14. Novel acidic sesquiterpenoids constitute a dominant class of pathogen-induced phytoalexins in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-volatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterizati...

  15. The circadian clock-associated gene zea mays gigantea1 affects maize developmental transitions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The circadian clock is the internal timing mechanism that allows plants to make developmental decisions in accordance with environmental conditions. The genes of the maize circadian clock are not well defined. Gigantea (gi) genes are conserved across flowering plants, including maize. In model plant...

  16. Microfossil evidence for pre-Columbian maize dispersals in the neotropics from San Andres, Tabasco, Mexico.

    PubMed

    Pohl, Mary E D; Piperno, Dolores R; Pope, Kevin O; Jones, John G

    2007-04-17

    The history of maize (Zea mays L.) is one of the most debated topics in New World archaeology. Molecular and genetic studies indicate that maize domestication took place in tropical southwest Mexico. Although archaeological evidence for the evolution of maize from its wild ancestor teosinte has yet to be found in that poorly studied region, other research combining paleoecology and archaeology is documenting the nature and timing of maize domestication and dispersals. Here we report a phytolith analysis of sediments from San Andrés, Tabasco, that confirms the spread of maize cultivation to the tropical Mexican Gulf Coast >7,000 years ago ( approximately 7,300 calendar years before present). We review the different methods used in sampling, identifying, and dating fossil maize remains and compare their strengths and weaknesses. Finally, we examine how San Andrés amplifies the present evidence for widespread maize dispersals into Central and South America. Multiple data sets from many sites indicate that maize was brought under cultivation and domesticated and had spread rapidly out of its domestication cradle in tropical southwest Mexico by the eighth millennium before the present.

  17. Maize Phenology Affects Establishment, Damage, and Development of the Western Corn Rootworm (Coleoptera:Chrysomelidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of maize (Zea mays L.) phenology on establishment and adult emergence of the western corn rootworm (Diabrotica virgifera virgifera LeConte) as well as plant damage to maize was evaluated in the greenhouse and in field trials in 2001 and 2002. Although neonate western corn rootworm larva...

  18. Genome Browser Survey Results and Browser Selection for MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various platforms for genome browsing exist. Each has strengths and weaknesses, and users often champion their favorites (either based upon use needs or overall impressions). Faced with a need to shift MaizeGDB (http://www.maizegdb.org; the community database for maize genetics and genomics) towar...

  19. Early detection and mitigation of resistance to Bt maize by western corn rootworm (Coleoptera: Chrysomelidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic Bt maize that produces less than a high dose has been widely adopted and presents considerable insect resistance management (IRM) challenges. Western corn rootworm, Diabrotica virgifera virgifera LeConte, has rapidly evolved resistance to Bt maize in the field leading to local loss of eff...

  20. Methane yield through anaerobic digestion for various maize varieties in China.

    PubMed

    Gao, Ruifang; Yuan, Xufeng; Zhu, Wanbin; Wang, Xiaofen; Chen, Shaojiang; Cheng, Xu; Cui, Zongjun

    2012-08-01

    The methane potential of nine varieties of fresh maize harvested at three different times and of maize silage was experimentally determined in batch assays. The ultimate methane productivity in terms of volatile solids (VS) was determined as 213.94-313.63, 195.88-334.81 mL/g VS from several fresh and silage maize in three stages, respectively. The average specific methane yield of wax ripeness stage for fresh maize and full ripeness stage for silage maize were higher than that of other stages, respectively. The high-oil varieties of fresh maize and silage varieties of ensiling maize could produce more methane than general varieties in the same ripeness stage. Methane yield of ensiled materials was higher than fresh material. The methane yields of fresh and silage maize in full ripeness stage were ranged 5656-7956 and 4633-8915 m(3)/ha, respectively. The corresponding maximum of methane yield came from fresh HO5580 and silage CAU No. 4.