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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. 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...

  3. Partial Characterization of Maize Rayado Fino Virus Isolates From Ecuador: Phylogenetic Analysis Supports A Central American Origin of the Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  4. Presence of a polyA tail at the 3’-end of Maize rayado fino virus RNA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV) is the type member of the genus Marafivirus in the family Tymoviridae, yet is distinct from other members of the genus in that its genome reportedly lacks a poly(A) tail at the 3’-terminus. Using naïve and targeted PCR-based approaches, we now show that the MRFV genom...

  5. 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...

  6. Transmission of Switchgrass mosaic virus by Graminella aureovitatta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass mosaic virus (SwMV) was identified in switchgrass (Panicum virgatum) and was proposed as a new marafivirus based on its genome sequence and comparison with its closest relative, Maize rayado fino virus (MRFV), a type member of the genus, Marafivirus. MRFV only infects maize (Zea mays) an...

  7. 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.

  8. 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

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

    SciTech Connect

    Chaulk, S.; Lu, J.; Tan, K.; Arthur, D.; Edwards, R.; Frost, L.; Joachimiak, A.; Glover, J.

    2010-11-01

    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-foot and 3-foot 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.

  10. 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. PMID:18254590

  11. 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.

  12. 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), ...

  13. 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...

  14. Maize: Overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is an important cereal crop that is well-suited to industrial agriculture, both in grain production and in grain utilization. Starch, protein and oil are the three major components of the grain. Several processing methods yield many different food ingredients. In addition, whole grain is pr...

  15. 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

  16. 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...

  17. Comparison of the evolution of low molecular weight phenolic compounds in typical Sherry wines: Fino, Amontillado, and Oloroso.

    PubMed

    García Moreno, M Valme; Barroso, Carmelo García

    2002-12-18

    Changes in the content of low molecular weight phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, aldehydes, and their esterified derivatives, tyrosol and 5-(hydroxymethyl)-2-furaldehyde) during the aging of three different classes of Sherry wine, Fino, Oloroso, and Amontillado, have been studied. The samples studied were taken from each of the scales of the particular aging system applied to the three classes of wine. Clear differences were observed in the behavior of the low molecular weight phenolic in the three classes of wine. The wines subjected to oxidative aging presented a higher phenolic content overall, with the exception of the esterified derivatives of phenolic compounds that are mainly found in the samples that have not undergone any process of oxidation. MANOVA results confirmed that there are significant differences between all of the samples of the three types of wines. Using LDA, a classification of 100% of the samples has been made. PMID:12475270

  18. 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...

  19. 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

  20. 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. PMID:26989411

  1. 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...

  2. 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 ...

  3. 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.

  4. MaizeGDB Community Curation Tools

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. The success of the MaizeGDB project largely can be attributed to the involvement of the community of maize geneticists. Members of the community have (1) made their data available by contributing to MaizeGD...

  5. 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. Genetic, genomic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website...

  6. 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...

  7. Maize rhabdovirus-vector transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    oth of the plant-infecting rhabdovirus genera, Nucleorhabdovirus and Cytorhabdovirus, contain viruses that infect maize (Zea mays L.). The maize infecting rhabdoviruses are transmitted by hemipteran insects in the families Cicadellidae and Delphacidae in a persistent propagative manner. This chapt...

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. The Maize Genetics and Genomics Database. The Community Resource for Access to Diverse Maize Data1

    PubMed Central

    Lawrence, Carolyn J.; Seigfried, Trent E.; Brendel, Volker

    2005-01-01

    The Maize Genetics and Genomics Database (MaizeGDB) serves the maize (Zea mays) research community by making a wealth of genetics and genomics data available through an intuitive Web-based interface. The goals of the MaizeGDB project are 3-fold: to provide a central repository for public maize information; to present the data through the MaizeGDB Web site in a way that recapitulates biological relationships; and to provide an array of computational tools that address biological questions in an easy-to-use manner at the site. In addition to these primary tasks, MaizeGDB team members also serve the community of maize geneticists by lending technical support for community activities, including the annual Maize Genetics Conference and various workshops, teaching researchers to use both the MaizeGDB Web site and Community Curation Tools, and engaging in collaboration with individual research groups to make their unique data types available through MaizeGDB. PMID:15888678

  13. Inbreeding drives maize centromere evolution

    PubMed Central

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

    2016-01-01

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

  14. 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. PMID:26858403

  15. 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...

  16. 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 a larger effort to develop MaizeGDB into a more sequence-centric resource, we recently implemented a genome browser. The GBrowse platform was chosen for this endeavor based on results of a survey...

  17. 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...

  18. 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...

  19. 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.

  20. Induced resistance responses in maize.

    PubMed

    Morris, S W; Vernooij, B; Titatarn, S; Starrett, M; Thomas, S; Wiltse, C C; Frederiksen, R A; Bhandhufalck, A; Hulbert, S; Uknes, S

    1998-07-01

    Systemic acquired resistance (SAR) is a widely distributed plant defense system that confers broad-spectrum disease resistance and is accompanied by coordinate expression of the so-called SAR genes. This type of resistance and SAR gene expression can be mimicked with chemical inducers of resistance. Here, we report that chemical inducers of resistance are active in maize. Chemical induction increases resistance to downy mildew and activates expression of the maize PR-1 and PR-5 genes. These genes are also coordinately activated by pathogen infection and function as indicators of the defense reaction. Specifically, after pathogen infection, the PR-1 and PR-5 genes are induced more rapidly and more strongly in an incompatible than in a compatible interaction. In addition, we show that monocot lesion mimic plants also express these defense-related genes and that they have increased levels of salicylic acid after lesions develop, similar to pathogeninfected maize plants. The existence of chemically inducible disease resistance and PR-1 and PR-5 gene expression in maize indicates that maize is similar to dicots in many aspects of induced resistance. This reinforces the notion of an ancient plant-inducible defense pathway against pathogen attack that is shared between monocots and dicots.

  1. Zmspds2 maize gene

    PubMed Central

    Rodríguez-Kessler, Margarita

    2008-01-01

    During the last decade, growing evidence has arisen referring the importance of the proper regulation of plant polyamine metabolism in the response to stress conditions. Being the activation of signaling pathways, the stabilization of anionic molecules and prevention of their degradation, as well as the free radical scavenger properties of polyamines some possible mechanisms exerted by these amines. Accumulation of polyamines (putrescine, spermidine and spermine) has been associated to plant tolerance to a wide array of environmental stresses. The synthesis of spermidine and spermine is mediated by aminopropyltransferases (spermidine and spermine synthases) which constitute a class of widely distributed enzymes that use decarboxylated S-adenosylmethionine as an aminopropyl donor, and putrescine or spermidine as an amino acceptor. We recently reported the effect of salt stress on the expression of aminopropyltransferase genes in maize seedlings. Our data revealed a time and NaCl dependent regulation of the Zmspds2 and Zmspds1 genes, possibly mediated by abscisic acid, since these genes were regulated at the transcriptional level by this plant hormone. In this addendum, we show that the Zmspds2 gene initially classified as spermidine synthase might encode a spermine synthase based on an in silico analysis. This is discussed in terms of protein homologies and specific amino acid substitutions between aminopropyltransferase enzymes. PMID:19704464

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  5. 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.

  6. 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. PMID:24650320

  7. 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.

  8. 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

  9. Enantioselective Phytotoxicity of Imazamox Against Maize Seedlings.

    PubMed

    Wei, Jing; Zhang, Xiaoxiao; Li, Xuesheng; Zeng, Dongqiang; Tan, Huihua

    2016-02-01

    There is increasing concern about the enantioselective effects of chiral herbicides. To study the enantioselective toxicity of the chiral herbicide imazamox on maize, maize seedlings (Zhengda 619, Zea mays L.) were exposed to imazamox racemate and enantiomers in hydroponic experiments. The results showed that imazamox enantiomers selectively affected maize. The effective concentration of Rac-, S- and R-imazamox that caused 50 % inhibition after 5 days treatments (EC50,5d) were 0.4212, 1.2142 and 0.2460 mg L(-1), respectively, for maize root length; 0.0002, 0.1005, 0.0032 mg L(-1), respectively, for maize root fresh weight; 0.7114, 1.4056 and 0.4530 mg L(-1), respectively, for maize shoot height; 0.6220, 1.5418, 0.2286 mg L(-1), respectively, for maize shoot fresh weight; and 0.1100, 0.3306, 0.0307 mg L(-1), respectively, for the total chlorophyll content of leaves. The root morphological parameters and root activity reflected the toxicity effects in the order R-imazamox > Rac-imazamox > S-imazamox. Maize roots were more sensitive to imazamox than maize shoots. The chiral herbicide imazamox poses enantioselective phytotoxicity on maize seedlings: the order of toxicity is R-imazamox > Rac-imazamox > S-imazamox. PMID:26508428

  10. 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...

  11. Kernel Composition, Starch Structure, and Enzyme Digestibility of Opaque-2 Maize and Quality Protein Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives of this study were to understand how opaque-2 (o2) mutation and quality protein maize (QPM) affect maize kernel composition and starch structure, property, and enzyme digestibility. Kernels of o2 maize contained less protein (9.6−12.5%) than those of the wild-type (WT) counterparts (12...

  12. MaizeGDB becomes 'sequence-centric'.

    PubMed

    Sen, Taner Z; Andorf, Carson M; Schaeffer, Mary L; Harper, Lisa C; Sparks, Michael E; Duvick, Jon; Brendel, Volker P; Cannon, Ethalinda; Campbell, Darwin A; Lawrence, Carolyn J

    2009-01-01

    MaizeGDB is the maize research community's central repository for genetic and genomic information about the crop plant and research model Zea mays ssp. mays. The MaizeGDB team endeavors to meet research needs as they evolve based on researcher feedback and guidance. Recent work has focused on better integrating existing data with sequence information as it becomes available for the B73, Mo17 and Palomero Toluqueño genomes. Major endeavors along these lines include the implementation of a genome browser to graphically represent genome sequences; implementation of POPcorn, a portal ancillary to MaizeGDB that offers access to independent maize projects and will allow BLAST similarity searches of participating projects' data sets from a single point; and a joint MaizeGDB/PlantGDB project to involve the maize community in genome annotation. In addition to summarizing recent achievements and future plans, this article also discusses specific examples of community involvement in setting priorities and design aspects of MaizeGDB, which should be of interest to other database and resource providers seeking to better engage their users. MaizeGDB is accessible online at http://www.maizegdb.org.Database URL:http://www.maizegdb.org.

  13. 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.

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

    PubMed

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

    2012-11-01

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

  15. 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...

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. Comparative genomics of Arabidopsis and maize: prospects and limitations

    PubMed Central

    Brendel, Volker; Kurtz, Stefan; Walbot, Virginia

    2002-01-01

    The completed Arabidopsis genome seems to be of limited value as a model for maize genomics. In addition to the expansion of repetitive sequences in maize and the lack of genomic micro-colinearity, maize-specific or highly-diverged proteins contribute to a predicted maize proteome of about 50,000 proteins, twice the size of that of Arabidopsis. PMID:11897028

  1. 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.

  2. 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. PMID:27145588

  3. 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%.

  4. 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. PMID:27507481

  5. Nutrient absorbtion of weeds in maize.

    PubMed

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

    2008-01-01

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

  6. Reshaping of the maize transcriptome by domestication.

    PubMed

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

    2012-07-17

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

  7. Photophobic behavior of maize roots.

    PubMed

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-07-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed "crawling" behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize.

  8. Photophobic behavior of maize roots

    PubMed Central

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-01-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed “crawling” behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize. PMID:22751294

  9. Photophobic behavior of maize roots.

    PubMed

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-07-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed "crawling" behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize. PMID:22751294

  10. 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

  11. [Effects of intercropping different crops with maize on the Cd uptake by maize].

    PubMed

    Li, Ning-Yu; Li, Zhi-An; Ding, Yong-Zhen; Zou, Bi; Zhuang, Ping

    2008-06-01

    A greenhouse experiment was conducted to investigate the effects of intercropping 7 kinds of crops on the Cd uptake by maize (Zea mays L.). The results showed that most intercrops had no significant effects on the growth of maize, only with purple haricot reduced the maize biomass by 32.2% of the control. Legume crops enhanced the total quantity of Cd in maize in a great magnitude, and chickpea worked most efficiently, which doubled the Cd quantity in maize. The 7 intercrops showed different capability of Cd uptake, among which, rape and amaranth absorbed larger amount of Cd, with a Cd level of 53.9 mg x kg(-1) and 51.0 mg x kg(-1) in their aboveground parts, respectively, and of 91.8 mg x kg(-1) in amaranth root when the soil Cd content was 3 mg x kg(-1) soil. There was an interaction between maize and intercrops in Cd uptake. Legumes absorbed smaller amount of Cd but significantly increased the Cd uptake by maize, while amaranth was in adverse. Rape had a higher level of Cd concentration in its shoot, but reduced the Cd in aboveground part of maize. It was indicated that if maize was used for phytoremediation of Cd-contaminated soil, a higher efficiency of Cd removal could be achieved by intercropping it with legumes. Rape and amaranth could be the two promising plants for phytoremediation because of their high Cd accumulation. PMID:18808034

  12. 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 ...

  13. 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.

  14. 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

  15. [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

  16. Control of virus diseases in maize.

    PubMed

    Redinbaugh, Margaret G; Zambrano, José L

    2014-01-01

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

  17. Can transgenic maize affect soil microbial communities?

    PubMed

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

    2006-09-29

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

  18. 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

  19. Climate change and maize yield in Iowa

    DOE PAGESBeta

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

    2016-05-24

    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 frommore » 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. Lastly, 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.« less

  20. 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.

  1. 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, ...

  2. 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...

  3. 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 ...

  4. 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...

  5. 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. PMID:27192406

  6. 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.

  7. Transcriptional activity of transposable elements in maize

    PubMed Central

    2010-01-01

    Background Mobile genetic elements represent a high proportion of the Eukaryote genomes. In maize, 85% of genome is composed by transposable elements of several families. First step in transposable element life cycle is the synthesis of an RNA, but few is known about the regulation of transcription for most of the maize transposable element families. Maize is the plant from which more ESTs have been sequenced (more than two million) and the third species in total only after human and mice. This allowed us to analyze the transcriptional activity of the maize transposable elements based on EST databases. Results We have investigated the transcriptional activity of 56 families of transposable elements in different maize organs based on the systematic search of more than two million expressed sequence tags. At least 1.5% maize ESTs show sequence similarity with transposable elements. According to these data, the patterns of expression of each transposable element family is variable, even within the same class of elements. In general, transcriptional activity of the gypsy-like retrotransposons is higher compared to other classes. Transcriptional activity of several transposable elements is specially high in shoot apical meristem and sperm cells. Sequence comparisons between genomic and transcribed sequences suggest that only a few copies are transcriptionally active. Conclusions The use of powerful high-throughput sequencing methodologies allowed us to elucidate the extent and character of repetitive element transcription in maize cells. The finding that some families of transposable elements have a considerable transcriptional activity in some tissues suggests that, either transposition is more frequent than previously expected, or cells can control transposition at a post-transcriptional level. PMID:20973992

  8. 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.

  9. 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.

  10. 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...

  11. 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...

  12. Transmission of maize chromosome 9 rearrangements in oat-maize radiation hybrids.

    PubMed

    Vales, M Isabel; Riera-Lizarazu, Oscar; Rines, Howard W; Phillips, Ronald L

    2004-12-01

    Oat-maize radiation hybrids are oat (Avena sativa L.) plants carrying radiation-induced subchromosome fragments of a given maize (Zea mays L.) chromosome. Since first-generation radiation hybrids contain various maize chromosome rearrangements in a hemizygous condition, variation might be expected in the transmission of these rearrangements to subsequent generations. The transmission and integrity of maize chromosome 9 rearrangements were evaluated in progenies of 30 oat-maize radiation hybrids by using a series of DNA-based markers and by genomic in situ hybridization. Maize chromosome 9 rearrangements were reisolated by self-fertilization in 24 of the 30 radiation hybrid lineages. Normal and deleted versions of maize chromosome 9 were transmitted at similar frequencies of 9.1% and 7.6%, respectively, while intergenomic translocations were transmitted at a significantly higher frequency of 47.6%. Most lines (93%) that inherited a rearrangement had it in the hemizygous condition. Lines with a rearrangement in the homozygous state (7%) were only identified in lineages with intergenomic translocations. Homozygous lines are more desirable from the perspective of stock maintenance, since they may stably transmit a given rearrangement to a subsequent generation. However, their isolation is not strictly required, since hemizygous lines can also be used for genome mapping studies.

  13. 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.

  14. 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.

  15. 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...

  16. Getting domestication straight: ramosa1 in maize.

    PubMed

    Dempewolf, Hannes

    2010-04-01

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

  17. 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.

  18. 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...

  19. [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.

  20. Rapid decomposition of maize detritus in agricultural headwater streams.

    PubMed

    Griffiths, Natalie A; Tank, Jennifer L; Royer, Todd V; Rosi-Marshall, Emma J; Whiles, Matt R; Chambers, Catherine P; Frauendorf, Therese C; Evans-White, Michelle A

    2009-01-01

    Headwater streams draining agricultural landscapes receive maize leaves (Zea mays L.) via wind and surface runoff, yet the contribution of maize detritus to organic-matter processing in agricultural streams is largely unknown. We quantified decomposition and microbial respiration rates on conventional (non-Bt) and genetically engineered (Bt) maize in three low-order agricultural streams in northwestern Indiana, USA. We also examined how substrate quality and in-stream nutrient concentrations influenced microbial respiration on maize by comparing respiration on maize and red maple leaves (Acer rubrum) in three nutrient-rich agricultural streams and three low-nutrient forested streams. We found significantly higher rates of microbial respiration on maize vs. red maple leaves and higher rates in agricultural vs. forested streams. Thus both the elevated nutrient status of agricultural streams and the lability of maize detritus (e.g., low carbon-to-nitrogen ratio and low lignin content) result in a rapid incorporation of maize leaves into the aquatic microbial food web. We found that Bt maize had a faster decomposition rate than non-Bt maize, while microbial respiration rates did not differ between Bt and non-Bt maize. Decomposition rates were not negatively affected by genetic engineering, perhaps because the Bt toxin does not adversely affect the aquatic microbial assemblage involved in maize decomposition. Additionally, shredding caddisflies, which are known to have suppressed growth rates when fed Bt maize, were depauperate in these agricultural streams, and likely did not play a major role in maize decomposition. Overall, the conversion of native vegetation to row-crop agriculture appears to have altered the quantity, quality, and predictability of allochthonous carbon inputs to headwater streams, with unexplored effects on stream ecosystem structure and function. PMID:19323178

  1. 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.

  2. 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. PMID:18298063

  3. 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

  4. Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers.

    PubMed

    Hutchison, W D; Burkness, E C; Mitchell, P D; Moon, R D; Leslie, T W; Fleischer, S J; Abrahamson, M; Hamilton, K L; Steffey, K L; Gray, M E; Hellmich, R L; Kaster, L V; Hunt, T E; Wright, R J; Pecinovsky, K; Rabaey, T L; Flood, B R; Raun, E S

    2010-10-01

    Transgenic maize engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become widely adopted in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million hectares, constituting 63% of the U.S. crop. Using statistical analysis of per capita growth rate estimates, we found that areawide suppression of the primary pest Ostrinia nubilalis (European corn borer) is associated with Bt maize use. Cumulative benefits over 14 years are an estimated $3.2 billion for maize growers in Illinois, Minnesota, and Wisconsin, with more than $2.4 billion of this total accruing to non-Bt maize growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion for non-Bt maize growers. These results affirm theoretical predictions of pest population suppression and highlight economic incentives for growers to maintain non-Bt maize refugia for sustainable insect resistance management.

  5. 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...

  6. MGFD: the maize gene families database

    PubMed Central

    Sheng, Lei; Jiang, Haiyang; Yan, Hanwei; Li, Xiaoyu; Lin, Yongxiang; Ye, Hui; Cheng, Beijiu

    2016-01-01

    Most gene families are transcription factor (TF) families, which have fundamental roles in almost all biological processes (development, growth and response to environmental factors) and have been employed to manipulate various types of metabolic, developmental and stress response pathways in plants. Maize (Zea mays) is one of the most important cereal crops in the world due its importance to human nutrition and health. Thus, identifying and annotating all the gene families in maize is an important primary step in defining their functions and understanding their roles in the regulation of diverse biological processes. In this study, we identified 96 predicted maize gene families and systematically characterized all 5826 of the genes in those families. We have also developed a comprehensive database of maize gene families (the MGFD). To further explore the functions of these gene families, we extensively annotated the genes, including such basic information as protein sequence features, gene structure, Gene Ontology classifications, phylogenetic relationships and expression profiles. The MGFD has a user-friendly web interface with multiple browse and search functions, as well as data downloading. The MGFD is freely available to users at http://mgfd.ahau.edu.cn/. Database URL: http://mgfd.ahau.edu.cn/ PMID:26896848

  7. 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...

  8. Interaction between maize seed and Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. 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...

  10. 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 ...

  11. 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...

  12. 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...

  13. 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.

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

    PubMed Central

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

    2013-01-01

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

  15. 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

  16. 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

  17. Processing maize flour and corn meal food products.

    PubMed

    Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

    2014-04-01

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

  18. Gene flow scenarios with transgenic maize in Mexico.

    PubMed

    Serratos-Hernández, José-Antonio; Islas-Gutiérrez, Fabián; Buendía-Rodríguez, Enrique; Berthaud, Julien

    2004-01-01

    Maize diversity is widespread in Mexico and it has been stewarded by campesinos in small communities until the present. With the arrival of transgenic maize, the objective of this study is to analyze possible scenarios that could result if genetically modified maize were not regulated and openly available in Mexico. By applying a simple logistic model based on the conditions of maize production in Mexico, the dispersion of transgenic maize in different situations within fields of farmers is described. In traditional open systems of freely exchanged seed within communities it is concluded that the most likely outcome of GM maize release is the incorporation of transgenes in the genome of Mexican germplasm and possibly in that of teosinte.

  19. 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.

  20. 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.

  1. On the Tetraploid Origin of the Maize Genome

    PubMed Central

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

    2004-01-01

    Data from cytological and genetic mapping studies suggest that maize arose as a tetraploid. Two previous studies investigating the most likely mode of maize origin arrived at different conclusions. Gaut and Doebley [7] proposed a segmental allotetraploid origin of the maize genome and estimated that the two maize progenitors diverged at 20.5 million years ago (mya). In a similar study, using larger data set, Brendel and colleagues (quoted in [8]) suggested a single genome duplication at 16 mya. One of the key components of such analyses is to examine sequence divergence among strictly orthologous genes. In order to identify such genes, Lai and colleagues [10] sequenced five duplicated chromosomal regions from the maize genome and the orthologous counterparts from the sorghum genome. They also identified the orthologous regions in rice. Using positional information of genetic components, they identified 11 orthologous genes across the two duplicated regions of maize, and the sorghum and rice regions. Swigonova et al. [12] analyzed the 11 orthologues, and showed that all five maize chromosomal regions duplicated at the same time, supporting a tetraploid origin of maize, and that the two maize progenitors diverged from each other at about the same time as each of them diverged from sorghum, about 11.9 mya. PMID:18629160

  2. 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.

  3. 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.

  4. EuGène-maize: a web site for maize gene prediction

    PubMed Central

    Montalent, Pierre; Joets, Johann

    2010-01-01

    Motivation:A large part of the maize B73 genome sequence is now available and emerging sequencing technologies will offer cheap and easy ways to sequence areas of interest from many other maize genotypes. One of the steps required to turn these sequences into valuable information is gene content prediction. To date, there is no publicly available gene predictor specifically trained for maize sequences. To this end, we have chosen to train the EuGène software that can combine several sources of evidence into a consolidated gene model prediction. Availability: http://genome.jouy.inra.fr/eugene/cgi-bin/eugene_form.pl Contact: joets@moulon.inra.fr Supplementary information:Supplementary data are available at Bioinformatics online. PMID:20400755

  5. Tracing transgenic maize as affected by breadmaking process and raw material for the production of a traditional maize bread, broa.

    PubMed

    Fernandes, Telmo J R; Oliveira, M Beatriz P P; Mafra, Isabel

    2013-05-01

    Broa is a maize bread highly consumed and appreciated, especially in the north and central zones of Portugal. In the manufacturing of broa, maize flour and maize semolina might be used, besides other cereals such as wheat and rye. Considering the needs for genetically modified organism (GMO) traceability in highly processed foods, the aim of this work was to assess DNA degradation, DNA amplification and GMO quantification along breadmaking process of broa. DNA degradation was noticed by its decrease of integrity after dough baking and in all parts of bread sampling. The PCR amplification results of extracted DNA from the three distinct maize breads (broa 1, 2 and 3) showed that sequences for maize invertase gene and for events MON810 and TC1507 were easily detected with strong products. Real-time PCR revealed that quantification of GMO was feasible in the three different breads and that sampling location of baked bread might have a limited influence since the average quantitative results of both events after baking were very close to the actual values in the case of broa 1 (prepared with maize semolina). In the other two maize breads subjected to the same baking treatment, the contents of MON810 maize were considerably underestimated, leading to the conclusion that heat-processing was not the responsible parameter for that distortion, but the size of particle and mechanical processing of raw maize play also a major role in GMO quantification. PMID:23265541

  6. Tracing transgenic maize as affected by breadmaking process and raw material for the production of a traditional maize bread, broa.

    PubMed

    Fernandes, Telmo J R; Oliveira, M Beatriz P P; Mafra, Isabel

    2013-05-01

    Broa is a maize bread highly consumed and appreciated, especially in the north and central zones of Portugal. In the manufacturing of broa, maize flour and maize semolina might be used, besides other cereals such as wheat and rye. Considering the needs for genetically modified organism (GMO) traceability in highly processed foods, the aim of this work was to assess DNA degradation, DNA amplification and GMO quantification along breadmaking process of broa. DNA degradation was noticed by its decrease of integrity after dough baking and in all parts of bread sampling. The PCR amplification results of extracted DNA from the three distinct maize breads (broa 1, 2 and 3) showed that sequences for maize invertase gene and for events MON810 and TC1507 were easily detected with strong products. Real-time PCR revealed that quantification of GMO was feasible in the three different breads and that sampling location of baked bread might have a limited influence since the average quantitative results of both events after baking were very close to the actual values in the case of broa 1 (prepared with maize semolina). In the other two maize breads subjected to the same baking treatment, the contents of MON810 maize were considerably underestimated, leading to the conclusion that heat-processing was not the responsible parameter for that distortion, but the size of particle and mechanical processing of raw maize play also a major role in GMO quantification.

  7. Intraguild Competition of Three Noctuid Maize Pests.

    PubMed

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

    2016-08-01

    The western bean cutworm Striacosta albicosta (Smith), the fall armyworm Spodoptera frugiperda (J. E. Smith), and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) are among the major lepidopteran pests of maize in the United States, belonging to the same guild and injuring the reproductive tissues of this crop. Here, intraguild competition of these lepidopterans on non-Bt maize was evaluated through survival analysis of each species under laboratory and field conditions. Competition scenarios were carried out in arenas containing maize silk or ear tissue, using larvae on different stadium of development. Fitness cost competition studies were conducted to examine the influence of intraguild competition and cannibalism and predation rates on larval development. The survival of S. albicosta competing with the other species was significantly lower than in intraspecific competition, even when the larvae were more developed than the competitor. For S. frugiperda, survival remained high in the different competition scenarios, except when competing in a smaller stadium with H. zea Larvae of H. zea had a high rate of cannibalism, higher survival when competing against S. albicosta than S. frugiperda, and reduced survival when the H. zea larvae were at the same development stadium or smaller than the competitors. Based on fitness cost results, the absence of a competitor for the feeding source may confer an advantage to the larval development of S. frugiperda and H. zea Our data suggest that S. frugiperda has a competitive advantage against the other species, while S. albicosta has the disadvantage in the intraguild competition on non-Bt maize. PMID:27330146

  8. 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.

  9. 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.

  10. Intraguild Competition of Three Noctuid Maize Pests.

    PubMed

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

    2016-08-01

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

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

    PubMed

    Billeb de Sinibaldi, A C; Bressani, R

    2001-03-01

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

  12. 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

  13. 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

  14. Temperature sensing by primary roots of maize

    SciTech Connect

    Fortin, M.C.A.; Poff, K.L. )

    1990-09-01

    Zea mays L. seedlings, grown on agar plates at 26{degree}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.

  15. 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

  16. 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.

  17. Distribution of expansins in graviresponding maize roots.

    PubMed

    Zhang, N; Hasenstein, K H

    2000-12-01

    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. PMID:11134415

  18. 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

  19. Historical genomics of North American maize

    PubMed Central

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

    2012-01-01

    Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density 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. PMID:22802642

  20. Lipids in Aspergillus flavus-maize interaction

    PubMed Central

    Scarpari, Marzia; Punelli, Marta; Scala, Valeria; Zaccaria, Marco; Nobili, Chiara; Ludovici, Matteo; Camera, Emanuela; Fabbri, Anna A.; Reverberi, Massimo; Fanelli, Corrado

    2014-01-01

    In some filamentous fungi, the pathways related to the oxidative stress and oxylipins production are involved both in the process of host-recognition and in the pathogenic phase. In fact, recent studies have shown that the production of oxylipins in filamentous fungi, yeasts and chromists is also related to the development of the organism itself and to mechanisms of communication with the host at the cellular level. The oxylipins, also produced by the host during defense reactions, are able to induce sporulation and to regulate the biosynthesis of mycotoxins in several pathogenic fungi. In A. flavus, the oxylipins play a crucial role as signals for regulating the biosynthesis of aflatoxins, the conidiogenesis and the formation of sclerotia. To investigate the involvement of an oxylipins based cross-talk into Z. mays and A. flavus interaction, we analyzed the oxylipins profile of the wild type strain and of three mutants of A. flavus that are deleted at the Aflox1 gene level also during maize kernel invasion. A lipidomic approach has been addressed through the use of LC-ToF-MS, followed by a statistical analysis of the principal components (PCA). The results showed the existence of a difference between the oxylipins profile generated by the WT and the mutants onto challenged maize. In relation to this, aflatoxin synthesis which is largely hampered in vitro, is intriguingly restored. These results highlight the important role of maize oxylipin in driving secondary metabolism in A. flavus. PMID:24578700

  1. 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

  2. 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.

  3. 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. PMID:23049773

  4. 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

  5. Maize diversity and ethnolinguistic diversity in Chiapas, Mexico.

    PubMed

    Perales, Hugo R; Benz, Bruce F; Brush, Stephen B

    2005-01-18

    The objective of this study is to investigate whether ethnolinguistic diversity influences crop diversity. Factors suggest a correlation between biological diversity of crops and cultural diversity. Although this correlation has been noted, little systematic research has focused on the role of culture in shaping crop diversity. This paper reports on research in the Maya highlands (altitude >1,800 m) of central Chiapas in southern Mexico that examined the distribution of maize (Zea mays) types among communities of two groups, the Tzeltal and Tzotzil. The findings suggest that maize populations are distinct according to ethnolinguistic group. However, a study of isozymes indicates no clear separation of the region's maize into two distinct populations based on ethnolinguistic origin. A reciprocal garden experiment shows that there is adaptation of maize to its environment but that Tzeltal maize sometimes out-yields Tzotzil maize in Tzotzil environments. Because of the proximity of the two groups and selection for yield, we would expect that the superior maize would dominate both groups' maize populations, but we find that such domination is not the case. The role of ethnolinguistic identity in shaping social networks and information exchange is discussed in relation to landrace differentiation. PMID:15640353

  6. Maize diversity and ethnolinguistic diversity in Chiapas, Mexico

    PubMed Central

    Perales, Hugo R.; Benz, Bruce F.; Brush, Stephen B.

    2005-01-01

    The objective of this study is to investigate whether ethnolinguistic diversity influences crop diversity. Factors suggest a correlation between biological diversity of crops and cultural diversity. Although this correlation has been noted, little systematic research has focused on the role of culture in shaping crop diversity. This paper reports on research in the Maya highlands (altitude > 1,800 m) of central Chiapas in southern Mexico that examined the distribution of maize (Zea mays) types among communities of two groups, the Tzeltal and Tzotzil. The findings suggest that maize populations are distinct according to ethnolinguistic group. However, a study of isozymes indicates no clear separation of the region's maize into two distinct populations based on ethnolin-guistic origin. A reciprocal garden experiment shows that there is adaptation of maize to its environment but that Tzeltal maize sometimes out-yields Tzotzil maize in Tzotzil environments. Because of the proximity of the two groups and selection for yield, we would expect that the superior maize would dominate both groups' maize populations, but we find that such domination is not the case. The role of ethnolinguistic identity in shaping social networks and information exchange is discussed in relation to landrace differentiation. PMID:15640353

  7. 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...

  8. 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...

  9. Photosynthetic response of field-grown maize to fertilizer N

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While N supply has a large effect on growth and productivity of field-grown maize, its impact on leaf and canopy photosynthesis is less clear. Our objective was to characterize how N supply, and use of N by the maize plant impacts photosynthesis under field conditions. The N supply/N use was altered...

  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. 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.

  12. Breeding for Improved Resistance to Fumonisin Contamination in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize grain infected by Fusarium verticillioides may contain the mycotoxin fumonisin, which is associated with livestock and human diseases. To reduce levels of fumonisin in grain, efforts are underway to identify sources of maize with increased resistance to fungal infection and fumonisin contamin...

  13. 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...

  14. 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...

  15. Development of maize host resistance to aflatoxigenic fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aims of this chapter are to review the various aspects/components that are involved in developing aflatoxin-resistant maize germplasm that can lead to breeding commercial resistant lines available to growers. The beginning of the chapter reviewed the initial discoveries of resistant maize lines....

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  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. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. Diversity in global maize germplasm: characterization and utilization.

    PubMed

    Prasanna, B M

    2012-11-01

    Maize (Zea mays L.) is not only of worldwide importance as a food, feed and as a source of diverse industrially important products, but is also a model genetic organism with immense genetic diversity. Although it was first domesticated in Mexico, maize landraces are widely found across the continents. Several studies in Mexico and other countries highlighted the genetic variability in the maize germplasm. Applications of molecular markers, particularly in the last two decades, have led to new insights into the patterns of genetic diversity in maize globally, including landraces as well as wild relatives (especially teosintes) in Latin America, helping in tracking the migration routes of maize from the centers of origin, and understanding the fate of genetic diversity during maize domestication. The genome sequencing of B73 (a highly popular US Corn Belt inbred) and Palomero (a popcorn landrace in Mexico) in the recent years are important landmarks in maize research, with significant implications to our understanding of the maize genome organization and evolution. Next-generation sequencing and high-throughput genotyping platforms promise to further revolutionize our understanding of genetic diversity and for designing strategies to utilize the genomic information for maize improvement. However, the major limiting factor to exploit the genetic diversity in crops like maize is no longer genotyping, but high-throughput and precision phenotyping. There is an urgent need to establish a global phenotyping network for comprehensive and efficient characterization of maize germplasm for an array of target traits, particularly for biotic and abiotic stress tolerance and nutritional quality. 'Seeds of Discovery' (SeeD), a novel initiative by CIMMYT with financial support from the Mexican Government for generating international public goods, has initiated intensive exploration of phenotypic and molecular diversity of maize germplasm conserved in the CIMMYT Gene Bank; this is

  12. 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.

  13. Comparative population genomics of maize domestication and improvement.

    PubMed

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

    2012-06-03

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

  14. 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

  15. 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

  16. Genomic variation in maize: Annual and summary report, 1988

    SciTech Connect

    Rivin, C.J.

    1988-01-01

    We are interested in the molecular basis and biological significance of genomic diversity. Our laboratory has been studying genomic variation in maize and examples of rapidly occurring changes in maize DNA. To understand the mechanisms that generate and maintain variation, the author's lab has followed the reproducibility and stability of new repeated sequence multiplicities in succeeding generations, during plant development and in regenerated plants. We have also initiated studies of the Robertson's Mutator transposon system. These transposons have been shown to be quite variable in copy number in Mutator stocks of maize, but were reported to be absent in normal maize lines. We showed that sequences homologous to the transposon exist in a variety of forms in normal maize, including complete transposon structures. Results are discussed. 3 figs., 1 tab.

  17. Tissue localization of maize acetylcholinesterase associated with heat tolerance in plants

    PubMed Central

    Yamamoto, Kosuke; Momonoki, Yoshie S.

    2012-01-01

    Our recent study reported that maize acetylcholinesterase (AChE) activity in the coleoptile node is enhanced through a post-translational modification response to heat stress and transgenic plants overexpressing maize AChE gene had an elevated heat tolerance, which strongly suggests that maize AChE plays a positive, important role in maize heat tolerance. Here we present (1) maize AChE activity in the mesocotyl also enhances during heat stress and (2) maize AChE mainly localizes in vascular bundles including endodermis and epidermis in coleoptile nodes and mesocotyls of maize seedlings. PMID:22476469

  18. 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

  19. 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.

  20. 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

    2015-08-01

    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

  1. 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

  2. Biofuel, land and water: maize, switchgrass or Miscanthus?

    NASA Astrophysics Data System (ADS)

    Zhuang, Qianlai; Qin, Zhangcai; Chen, Min

    2013-03-01

    The productive cellulosic crops switchgrass and Miscanthus are considered as viable biofuel sources. To meet the 2022 national biofuel target mandate, actions must be taken, e.g., maize cultivation must be intensified and expanded, and other biofuel crops (switchgrass and Miscanthus) must be cultivated. This raises questions on the use efficiencies of land and water; to date, the demand on these resources to meet the national biofuel target has rarely been analyzed. Here, we present a data-model assimilation analysis, assuming that maize, switchgrass and Miscanthus will be grown on currently available croplands in the US. Model simulations suggest that maize can produce 3.0-5.4 kiloliters (kl) of ethanol for every hectare of land, depending on the feedstock to ethanol conversion efficiency; Miscanthus has more than twice the biofuel production capacity relative to maize, and switchgrass is the least productive of the three potential sources of ethanol. To meet the biofuel target, about 26.5 million hectares of land and over 90 km3 of water (of evapotranspiration) are needed if maize grain alone is used. If Miscanthus was substituted for maize, the process would save half of the land and one third of the water. With more advanced biofuel conversion technology for Miscanthus, only nine million hectares of land and 45 km3 of water would probably meet the national target. Miscanthus could be a good alternative biofuel crop to maize due to its significantly lower demand for land and water on a per unit of ethanol basis.

  3. Unconventional P-35S sequence identified in genetically modified maize.

    PubMed

    Al-Hmoud, Nisreen; Al-Husseini, Nawar; Ibrahim-Alobaide, Mohammed A; Kübler, Eric; Farfoura, Mahmoud; Alobydi, Hytham; Al-Rousan, Hiyam

    2014-01-01

    The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan's markets during the period 2009 and 2012. PMID:24495911

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

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

    PubMed

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

    2013-09-01

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

  6. 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. PMID:25629083

  7. 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

    2016-01-01

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem. PMID:26804136

  8. Unconventional P-35S sequence identified in genetically modified maize

    PubMed Central

    Al-Hmoud, Nisreen; Al-Husseini, Nawar; Ibrahim-Alobaide, Mohammed A; Kübler, Eric; Farfoura, Mahmoud; Alobydi, Hytham; Al-Rousan, Hiyam

    2014-01-01

    The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan’s markets during the period 2009 and 2012. PMID:24495911

  9. 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.

  10. Structure and expression of maize phytochrome family homeologs.

    PubMed

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

    2004-07-01

    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

  11. 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

  12. 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.

  13. 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.

  14. Unconventional P-35S sequence identified in genetically modified maize.

    PubMed

    Al-Hmoud, Nisreen; Al-Husseini, Nawar; Ibrahim-Alobaide, Mohammed A; Kübler, Eric; Farfoura, Mahmoud; Alobydi, Hytham; Al-Rousan, Hiyam

    2014-01-01

    The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan's markets during the period 2009 and 2012.

  15. From many, one: genetic control of prolificacy during maize domestication.

    PubMed

    Wills, David M; Whipple, Clinton J; Takuno, Shohei; Kursel, Lisa E; Shannon, Laura M; Ross-Ibarra, Jeffrey; Doebley, John F

    2013-06-01

    A reduction in number and an increase in size of inflorescences is a common aspect of plant domestication. When maize was domesticated from teosinte, the number and arrangement of ears changed dramatically. Teosinte has long lateral branches that bear multiple small ears at their nodes and tassels at their tips. Maize has much shorter lateral branches that are tipped by a single large ear with no additional ears at the branch nodes. To investigate the genetic basis of this difference in prolificacy (the number of ears on a plant), we performed a genome-wide QTL scan. A large effect QTL for prolificacy (prol1.1) was detected on the short arm of chromosome 1 in a location that has previously been shown to influence multiple domestication traits. We fine-mapped prol1.1 to a 2.7 kb "causative region" upstream of the grassy tillers1 (gt1) gene, which encodes a homeodomain leucine zipper transcription factor. Tissue in situ hybridizations reveal that the maize allele of prol1.1 is associated with up-regulation of gt1 expression in the nodal plexus. Given that maize does not initiate secondary ear buds, the expression of gt1 in the nodal plexus in maize may suppress their initiation. Population genetic analyses indicate positive selection on the maize allele of prol1.1, causing a partial sweep that fixed the maize allele throughout most of domesticated maize. This work shows how a subtle cis-regulatory change in tissue specific gene expression altered plant architecture in a way that improved the harvestability of maize.

  16. Comparison of milk and maize based diets in kwashiorkor

    PubMed Central

    Brewster, D; Manary, M; Menzies, I; Henry, R; O'Loughlin, E

    1997-01-01

    Accepted 16 September 1996
 The dual sugar test of intestinal permeability is a reliable non-invasive way of assessing the response of the small intestinal mucosa to nutritional rehabilitation.
AIM—To compare a local mix of maize-soya-egg to the standard milk diet in the treatment of kwashiorkor.
DESIGN—The diets were alternated three monthly in the sequence milk-maize-milk. There were a total of 533 kwashiorkor admissions of at least five days during the study who received either milk or maize. Intestinal permeability was assessed at weekly intervals by the lactulose-rhamnose test in 100 kwashiorkor cases, including 55 on milk and 45 on the maize diet.
RESULTS—Permeability ratios (95% confidence interval) on the milk diet improved by a mean of 6.4 (1.7 to 11.1) compared with −6.8 (−16.8 to 5.0) in the maize group. The improved permeability on milk occurred despite more diarrhoea, which constituted 34.8% of hospital days (29.8 to 39.8) compared with 24.3% (17.8 to 30.8) in the maize group. Case fatality rates for all 533 kwashiorkor admissions were 13.6% v 20.9%, respectively, giving a relative risk of death in the maize group of 1.54 (1.04 to 2.28). The maize group also had more clinical sepsis (60% v 31%) and less weight gain (2.9 v 4.4 g/kg/day) than the milk group.
IMPLICATIONS—Milk is superior to a local maize based diet in the treatment of kwashiorkor in terms of mortality, weight gain, clinical sepsis, and improvement in intestinal permeability.

 PMID:9135266

  17. The transcriptome landscape of early maize meiosis

    PubMed Central

    2014-01-01

    Background A major step in the higher plant life cycle is the decision to leave the mitotic cell cycle and begin the progression through the meiotic cell cycle that leads to the formation of gametes. The molecular mechanisms that regulate this transition and early meiosis remain largely unknown. To gain insight into gene expression features during the initiation of meiotic recombination, we profiled early prophase I meiocytes from maize (Zea mays) using capillary collection to isolate meiocytes, followed by RNA-seq. Results We detected ~2,000 genes as preferentially expressed during early meiotic prophase, most of them uncharacterized. Functional analysis uncovered the importance of several cellular processes in early meiosis. Processes significantly enriched in isolated meiocytes included proteolysis, protein targeting, chromatin modification and the regulation of redox homeostasis. The most significantly up-regulated processes in meiocytes were processes involved in carbohydrate metabolism. Consistent with this, many mitochondrial genes were up-regulated in meiocytes, including nuclear- and mitochondrial-encoded genes. The data were validated with real-time PCR and in situ hybridization and also used to generate a candidate maize homologue list of known meiotic genes from Arabidopsis. Conclusions Taken together, we present a high-resolution analysis of the transcriptome landscape in early meiosis of an important crop plant, providing support for choosing genes for detailed characterization of recombination initiation and regulation of early meiosis. Our data also reveal an important connection between meiotic processes and altered/increased energy production. PMID:24885405

  18. Chlordecone Transfer and Distribution in Maize Shoots.

    PubMed

    Pascal-Lorber, Sophie; Létondor, Clarisse; Liber, Yohan; Jamin, Emilien L; Laurent, François

    2016-01-20

    Chlordecone (CLD) is a persistent organic pollutant (POP) that was mainly used as an insecticide against banana weevils in the French West Indies (1972-1993). Transfer of CLD via the food chain is now the major mechanism for exposure of the population to CLD. The uptake and the transfer of CLD were investigated in shoots of maize, a C4 model plant growing under tropical climates, to estimate the exposure of livestock via feed. Maize plants were grown on soils contaminated with [(14)C]CLD under controlled conditions. The greatest part of the radioactivity was associated with roots, nearly 95%, but CLD was detected in whole shoots, concentrations in old leaves being higher than those in young ones. CLD was thus transferred from the base toward the plant top, forming an acropetal gradient of contaminant. In contrast, results evidenced the existence of a basipetal gradient of CLD concentration within leaves whose extremities accumulated larger amounts of CLD because of evapotranspiration localization. Extractable residues accounted for two-thirds of total residues both in roots and in shoots. This study highlighted the fact that the distribution of CLD contamination within grasses resulted from a conjunction between the age and evapotranspiration rate of tissues. CLD accumulation in fodder may be the main route of exposure for livestock. PMID:26701746

  19. Effect of volunteers on maize gene flow.

    PubMed

    Palaudelmàs, Montserrat; Peñas, Gisela; Melé, Enric; Serra, Joan; Salvia, Jordi; Pla, Maria; Nadal, Anna; Messeguer, Joaquima

    2009-08-01

    Regulatory approvals for deliberate release of GM maize events into the environment have lead to real situations of coexistence between GM and non-GM, with some fields being cultivated with GM and conventional varieties in successive seasons. Given the common presence of volunteer plants in maize fields in temperate areas, we investigated the real impact of GM volunteers on the yield of 12 non-GM agricultural fields. Volunteer density varied from residual to around 10% of plants in the field and was largely reduced using certain cultural practices. Plant vigour was low, they rarely had cobs and produced pollen that cross-fertilized neighbour plants only at low--but variable--levels. In the worst-case scenario, the estimated content of GMO was 0.16%. The influence of GM volunteers was not enough to reach the 0.9% adventitious GM threshold but it could potentially contribute to adventitious GM levels, especially at high initial densities (i.e. above 1,000 volunteers/ha). PMID:19225900

  20. Polymerization of Actin from Maize Pollen.

    PubMed Central

    Yen, L. F.; Liu, X.; Cai, S.

    1995-01-01

    Here we describe the in vitro polymerization of actin from maize (Zea mays) pollen. The purified actin from maize pollen reported in our previous paper (X. Liu, L.F. Yen [1992] Plant Physiol 99: 1151-1155) is biologically active. In the presence of ATP, KCl, and MgCl2 the purified pollen actin polymerized into filaments. During polymerization the spectra of absorbance at 232 nm increased gradually. Polymerization of pollen actin was evidently accompanied by an increase in viscosity of the pollen actin solution. Also, the specific viscosity of pollen F-actin increased in a concentration-dependent manner. The ultraviolet difference spectrum of pollen actin is very similar to that of rabbit muscle actin. The activity of myosin ATPase from rabbit muscle was activated 7-fold by the polymerized pollen actin (F-actin). The actin filaments were visualized under the electron microscope as doubly wound strands of 7 nm diameter. If cytochalasin B was added before staining, no actin filaments were observed. When actin filaments were treated with rabbit heavy meromyosin, the actin filaments were decorated with an arrowhead structure. These results imply that there is much similarity between pollen and muscle actin. PMID:12228343

  1. Effect of volunteers on maize gene flow.

    PubMed

    Palaudelmàs, Montserrat; Peñas, Gisela; Melé, Enric; Serra, Joan; Salvia, Jordi; Pla, Maria; Nadal, Anna; Messeguer, Joaquima

    2009-08-01

    Regulatory approvals for deliberate release of GM maize events into the environment have lead to real situations of coexistence between GM and non-GM, with some fields being cultivated with GM and conventional varieties in successive seasons. Given the common presence of volunteer plants in maize fields in temperate areas, we investigated the real impact of GM volunteers on the yield of 12 non-GM agricultural fields. Volunteer density varied from residual to around 10% of plants in the field and was largely reduced using certain cultural practices. Plant vigour was low, they rarely had cobs and produced pollen that cross-fertilized neighbour plants only at low--but variable--levels. In the worst-case scenario, the estimated content of GMO was 0.16%. The influence of GM volunteers was not enough to reach the 0.9% adventitious GM threshold but it could potentially contribute to adventitious GM levels, especially at high initial densities (i.e. above 1,000 volunteers/ha).

  2. Maize Lethal Necrosis (MLN), an Emerging Threat to Maize-Based Food Security in Sub-Saharan Africa.

    PubMed

    Mahuku, George; Lockhart, Benham E; Wanjala, Bramwel; Jones, Mark W; Kimunye, Janet Njeri; Stewart, Lucy R; Cassone, Bryan J; Sevgan, Subramanian; Nyasani, Johnson O; Kusia, Elizabeth; Kumar, P Lava; Niblett, C L; Kiggundu, Andrew; Asea, Godfrey; Pappu, Hanu R; Wangai, Anne; Prasanna, Boddupalli M; Redinbaugh, Margaret G

    2015-07-01

    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 maize in Kenya. The disease has since been confirmed in Rwanda and the Democratic Republic of Congo, and similar symptoms have been reported in Tanzania, Uganda, South Sudan, and Ethiopia. In 2012, yield losses of up to 90% resulted in an estimated grain loss of 126,000 metric tons valued at $52 million in Kenya alone. In eastern Africa, MLN was found to result from coinfection of maize with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), although MCMV alone appears to cause significant crop losses. We summarize here the results of collaborative research undertaken to understand the biology and epidemiology of MLN in East Africa and to develop disease management strategies, including identification of MLN-tolerant maize germplasm. We discuss recent progress, identify major issues requiring further research, and discuss the possible next steps for effective management of MLN.

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

    PubMed

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

    2015-07-01

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

  4. Modeling kinetics of aflatoxin production by Aspergillus flavus in maize-based medium and maize grain.

    PubMed

    Garcia, Daiana; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2013-03-15

    Predictive mycology has dealt mainly with germination, growth and inactivation of fungi while the issue of mycotoxin production remains relatively unexplored. Very few studies provide biomass dry weight/colony size data along with mycotoxin data for the same sample times, thus the ratio mycotoxin accumulation per fungal biomass dry weight/colony size has rarely been reported. For this reason, the objective of the present study was to model the kinetics of mycotoxin production under the assumption of existing both no-growth-associated and growth-associated production. Aspergillus flavus was chosen as a model mycotoxigenic microorganism, and it was grown in maize agar medium and maize grain at 0.90 and 0.99 aw at 25°C. A significant positive correlation (p<0.05) was observed among the biomass responses (colony radius and biomass dry weight) in agar medium and colony radius in maize at both aw levels assayed. The Luedeking-Piret model was used to model AFB1 production and reasonable percentages of variability were explained. Moreover, AFB1 production was in general slightly better predicted through colony area. As conclusion, aflatoxin production may follow a mixed-growth associated trend, confirming that toxin formation does not present a clear delay in relation to growth under certain conditions. PMID:23422844

  5. 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.

  6. 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.

  7. 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

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

    PubMed

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

    2012-06-03

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

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

    PubMed

    Vučetić, V

    2011-04-01

    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 CO(2) 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 CO(2) 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 suggested that

  10. 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

  11. 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

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

    PubMed

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

    2016-09-01

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

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

    PubMed

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

    2014-11-01

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

  14. 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

  15. 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. PMID:26981357

  16. 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.

  17. 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

  18. 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

  19. Developing Resistance to Aflatoxin in Maize and Cottonseed

    PubMed Central

    Cary, Jeffrey W.; Rajasekaran, Kanniah; Brown, Robert L.; Luo, Meng; Chen, Zhi-Yuan; Bhatnagar, Deepak

    2011-01-01

    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 contamination is the development of preharvest host resistance. This is because A. flavus infects and produces aflatoxins in susceptible crops prior to harvest. In maize production, the host resistance strategy has gained prominence because of advances in the identification of natural resistance traits. However, native resistance in maize to aflatoxin contamination is polygenic and complex and, therefore, markers need to be identified to facilitate the transfer of resistance traits into agronomically viable genetic backgrounds while limiting the transfer of undesirable traits. Unlike maize, there are no known cotton varieties that demonstrate enhanced resistance to A. flavus infection and aflatoxin contamination. For this reason, transgenic approaches are being undertaken in cotton that utilize genes encoding antifungal/anti-aflatoxin factors from maize and other sources to counter fungal infection and toxin production. This review will present information on preharvest control strategies that utilize both breeding and native resistance identification approaches in maize as well as transgenic approaches in cotton. PMID:22069734

  20. Developing resistance to aflatoxin in maize and cottonseed.

    PubMed

    Cary, Jeffrey W; Rajasekaran, Kanniah; Brown, Robert L; Luo, Meng; Chen, Zhi-Yuan; Bhatnagar, Deepak

    2011-06-01

    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 contamination is the development of preharvest host resistance. This is because A. flavus infects and produces aflatoxins in susceptible crops prior to harvest. In maize production, the host resistance strategy has gained prominence because of advances in the identification of natural resistance traits. However, native resistance in maize to aflatoxin contamination is polygenic and complex and, therefore, markers need to be identified to facilitate the transfer of resistance traits into agronomically viable genetic backgrounds while limiting the transfer of undesirable traits. Unlike maize, there are no known cotton varieties that demonstrate enhanced resistance to A. flavus infection and aflatoxin contamination. For this reason, transgenic approaches are being undertaken in cotton that utilize genes encoding antifungal/anti-aflatoxin factors from maize and other sources to counter fungal infection and toxin production. This review will present information on preharvest control strategies that utilize both breeding and native resistance identification approaches in maize as well as transgenic approaches in cotton. PMID:22069734

  1. RNA Polymerases of Maize: Nuclear RNA Polymerases*

    PubMed Central

    Strain, Gustave C.; Mullinix, Kathleen P.; Bogorad, Lawrence

    1971-01-01

    Two DNA-dependent RNA polymerases of nuclear origin have been purified from leaves of Zea mays. The two enzymes can be separated on DEAE-cellulose columns. Enzymes I and II are eluted with 0.08 and 0.20 M (NH4)2SO4, respectively. Both enzymes prefer maize nuclear DNA as a template; they are also more active in the presence of Mg++ than Mn++ and are inhibited by (NH4)2-SO4 or KCl. Neither enzyme is inhibited by rifamycin SV. Enzyme II is strongly inhibited by α-amanitin, whereas enzyme I is not significantly affected. Their ability to use native and denatured DNA as templates varies according to the extent and method of purification of the polymerase. Furthermore, enzyme II can be resolved by DEAE-chromatography or glycerol-gradient centrifugation into two components, one of which prefers native DNA, while the other prefers denatured DNA. PMID:5288239

  2. Dynamic epigenetic states of maize centromeres.

    PubMed

    Liu, Yalin; Su, Handong; Zhang, Jing; Liu, Yang; Han, Fangpu; Birchler, James A

    2015-01-01

    The centromere is a specialized chromosomal region identified as the major constriction, upon which the kinetochore complex is formed, ensuring accurate chromosome orientation and segregation during cell division. The rapid evolution of centromere DNA sequence and the conserved centromere function are two contradictory aspects of centromere biology. Indeed, the sole presence of genetic sequence is not sufficient for centromere formation. Various dicentric chromosomes with one inactive centromere have been recognized. It has also been found that de novo centromere formation is common on fragments in which centromeric DNA sequences are lost. Epigenetic factors play important roles in centromeric chromatin assembly and maintenance. Non-disjunction of the supernumerary B chromosome centromere is independent of centromere function, but centromere pairing during early prophase of meiosis I requires an active centromere. This review discusses recent studies in maize about genetic and epigenetic elements regulating formation and maintenance of centromere chromatin, as well as centromere behavior in meiosis. PMID:26579154

  3. 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.

  4. 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.

  5. Safety assessment of Bt 176 maize in broiler nutrition: degradation of maize-DNA and its metabolic fate.

    PubMed

    Tony, M A; Butschke, A; Broll, H; Grohmann, L; Zagon, J; Halle, I; Dänicke, S; Schauzu, M; Hafez, H M; Flachowsky, G

    2003-08-01

    Insect resistant Bt 176 maize has been developed by genetic modification to resist European borer infection. In the present investigation, the experiment was conducted to determine the effect of feeding a new hybrid of Bt 176 maize (NX 6262- Bt 176) on general health condition and performance of broiler chickens. Maize grains and diets were subjected to proximate analysis. Amino and fatty acids investigation were applied for both maize grains before used. To evaluate the degradation of NX 6262- Bt 176 maize DNA and its metabolic fate in broiler blood, muscles and organs. One-day-old male broilers were fed ad libitum on either an experimental diet containing NX 6262- Bt 176 or a control diet containing the non-modified maize grains for 35 days. Feed consumption and body weight were recorded weekly during the experimental period. All chickens were subjected to nutritional evaluation period at day 20 of age for 5 successive days, to calculate the percentage of apparent digestible nutrients in both diets. At day 35 samples were collected at several intervals after feed withdrawal. Prior to slaughter blood samples were collected from all birds by heart puncture to prevent DNA cross contamination. Samples from pectoral and thigh muscles, liver, spleen, kidney, heart muscle, bursa and thymus glands were collected. Digesta from different sections of the gastrointestinal tract (GIT) were collected as well. Packed cell volume (PCV) and some serum parameters were investigated. There were no significant differences between control and experimental group concerning chemical composition of feeds, apparent digestible nutrients, and all performance parameters measured (P > 0.05). Furthermore, there were no differences in the PCV and the analysed serum parameters between the control and experimental group. The results of maize DNA digestibility showed that the new variety takes the normal physiological passage along broiler GIT similar to the conventional line. In addition, Bt 176

  6. Heritable epigenetic variation among maize inbreds.

    PubMed

    Eichten, Steve R; Swanson-Wagner, Ruth A; Schnable, James C; Waters, Amanda J; Hermanson, Peter J; Liu, Sanzhen; Yeh, Cheng-Ting; Jia, Yi; Gendler, Karla; Freeling, Michael; Schnable, Patrick S; Vaughn, Matthew W; Springer, Nathan M

    2011-11-01

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

  7. 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

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

    PubMed

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

    2009-09-01

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

  9. 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.

  10. Heritable transgene expression pattern imposed onto maize ubiquitin promoter by maize adh-1 matrix attachment regions: tissue and developmental specificity in maize transgenic plants.

    PubMed

    Torney, François; Partier, Anne; Says-Lesage, Véronique; Nadaud, Isabelle; Barret, Pierre; Beckert, Michel

    2004-07-01

    Matrix attachment regions (MARs) have been used to enhance transgene expression and to reduce transgene expression instability in various organisms. In plants, contradictory data question the role of MAR sequences. To assess the use of MAR sequences in maize, we have used two well-characterized MARs from the maize adh-1 region. The MARs have been cloned either 5' to or at both sides of a reporter gene expression cassette to reconstitute a MAR-based domain. Histochemical staining revealed a new transgene expression pattern in roots of regenerated plants and their progeny. Furthermore, MARs systematically induced variegation. We show here that maize adh-1 MARs are able to modify transgene expression patterns as a heritable trait, giving a new and complementary outcome following use of MARs in genetic transformation. PMID:15127223

  11. 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

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

    PubMed

    Duvick, J

    2001-05-01

    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

  13. Quality dynamics of maize 'tuwo' (non-fermented maize-based dumpling) as influenced by steaming of maize grits at different resident time.

    PubMed

    Bolade, Mathew K; Adeyemi, Isaac A

    2014-11-01

    This study was aimed at investigating the influence of starch pregelatinisation of maize flour, through grit steaming, on the quality characteristics of maize tuwo (non-fermented food dumpling). Maize grits were variously steamed, batchwise, for a period of 15, 30, 45 and 60 min respectively from which flour was obtained. The damaged starch value (13.4-16.2 %) of the pregelatinised maize flour increased with an increase in the steaming duration while that from 0-min steaming period was 12.2 %. The water absorption capacity (3.2-3.7 g/g) and oil absorption capacity (2.1-2.5 g/g) of the pregelatinised maize flour increased with an increase in the steaming duration while those from 0-min steaming period were 2.1 g/g and 2.0 g/g respectively. The pasting variables were found to decrease with an increase in the steaming duration include the peak viscosity (80.5-106.1 RVU), breakdown viscosity (17.9-23.1 RVU), final viscosity (102.4-136.8 RVU), setback-I (41.9-56.6 RVU) and setback-II (21.9-35.5 RVU) while those from 0-min steaming period were 108.3, 36.9, 147.4, 76.0 and 39.1 RVU respectively. The colour characteristics of maize flours and tuwo showed that the L*-value of the flours (85.2-88.7) and tuwo (65.1-67.2) decreased with an increase in the steaming duration while those from 0-min steaming period were 90.0 and 67.7 respectively. The rheological properties of maize tuwo showed that the strain at peak, taken as the cohesiveness index of the food product, ranged between 18.0 and 21.7 % while that from 0-min steaming period was 15.4 %. The softness index of the food product also ranged between 17.5 mm and 17.9 mm while that from 0-min steaming period was 17.4 mm. The sensory quality rating of maize tuwo prepared from the pregelatinised flour showed that the food product obtained from the 30-min steaming duration was rated the highest in terms of texture (mouldability), taste and overall acceptability. PMID:26396314

  14. Identification of resistance-associated proteins in closely-related maize lines varying in aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus infection of maize and subsequent contamination with carcinogenic aflatoxins poses serious health concerns, especially in developing countries. Maize lines resistant to A. flavus infection have been identified; however, the development of commercially-useful aflatoxin-resistant ma...

  15. 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

  16. 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

  17. 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%, ...

  18. 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

  19. 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...

  20. [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.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. 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...

  7. Provitamin A carotenoids in biofortified maize and their retention during processing and preparation of South African maize foods.

    PubMed

    Pillay, Kirthee; Siwela, Muthulisi; Derera, John; Veldman, Frederick J

    2014-04-01

    Provitamin A-biofortified maize may contribute to alleviating vitamin A deficiency (VAD), in developing countries. However, processing the maize into food products may reduce its provitamin A content. The aims of this study were to determine the composition of provitamin A carotenoids in biofortified maize varieties as well as to assess their retention during processing of popular maize foods consumed in KwaZulu-Natal, South Africa. The non-provitamin A carotenoid, zeaxanthin and the provitamin A carotenoids, β-cryptoxanthin, and trans and cis isomers of β-carotene, and other unidentified trans and cis isomers of β-carotene were detected in varying concentrations in the maize. Milling provitamin A-biofortified maize into mealie meal resulted in a higher retention of carotenoids compared to milling into samp. The highest retention of provitamin A carotenoids was observed in cooked phutu and cooked samp, whilst cooking into thin porridge resulted in the lowest retention of provitamin A carotenoids. In phutu, 96.6 ± 20.3% β-cryptoxanthin and 95.5 ± 13.6% of the β-carotene were retained after cooking. In samp, 91.9 ± 12.0% β-cryptoxanthin and 100.1 ± 8.8% β-carotene; and in thin porridge, 65.8 ± 4.6% β-cryptoxanthin and 74.7 ± 3.0% β-carotene were retained after cooking. This study demonstrates that provitamin A retention in maize is affected by the cooking method (and hence cooked food form) and therefore cooking methods that result in a good retention of provitamin A need to be identified and recommended.

  8. Responses of stream macroinvertebrates to Bt maize leaf detritus.

    PubMed

    Chambers, Catherine P; Whiles, Matt R; Rosi-Marshall, Emma J; Tank, Jennifer L; Royer, Todd V; Griffiths, Natalie A; Evans-White, Michelle A; Stojak, Amber R

    2010-10-01

    In the midwestern United States, maize detritus enters streams draining agricultural land. Genetically modified Bt maize is commonly planted along streams and can possibly affect benthic macroinvertebrates, specifically members of the order Trichoptera, which are closely related to target species of some Bt toxins and are important detritivores in streams. The significance of inputs of Bt maize to aquatic systems has only recently been recognized, and assessments of potential nontarget impacts on aquatic organisms are lacking. We conducted laboratory feeding trials and found that the leaf-shredding trichopteran, Lepidostoma liba, grew significantly slower when fed Bt maize compared to non-Bt maize, while other invertebrate taxa that we examined showed no negative effects. We also used field studies to assess the influence of Bt maize detritus on benthic macroinvertebrate abundance, diversity, biomass, and functional structure in situ in 12 streams adjacent to Bt maize or non-Bt maize fields. We found no significant differences in total abundance or biomass between Bt and non-Bt streams, and trichopterans comprised only a small percentage of invertebrate biomass at all sites (0-15%). Shannon diversity did not differ among Bt and non-Bt streams and was always low (H' range = 0.9-1.9). Highly tolerant taxa, such as oligochaetes and chironomids, were dominant in both Bt and non-Bt streams, and macroinvertebrate community composition was relatively constant across seasons. We used litterbags to examine macroinvertebrate colonization of Bt and non-Bt maize detritus and found no significant differences among litter or stream types. Our in situ findings did not support our laboratory results; this is likely because the streams we studied in this region are highly degraded and subject to multiple, persistent anthropogenic stressors (e.g., channelization, altered flow, nutrient and pesticide inputs). Invertebrate communities in these streams are a product of these degraded

  9. Diversity and evolution of centromere repeats in the maize genome.

    PubMed

    Bilinski, Paul; Distor, Kevin; Gutierrez-Lopez, Jose; Mendoza, Gabriela Mendoza; Shi, Jinghua; Dawe, R Kelly; Ross-Ibarra, Jeffrey

    2015-03-01

    Centromere repeats are found in most eukaryotes and play a critical role in kinetochore formation. Though centromere repeats exhibit considerable diversity both within and among species, little is understood about the mechanisms that drive centromere repeat evolution. Here, we use maize as a model to investigate how a complex history involving polyploidy, fractionation, and recent domestication has impacted the diversity of the maize centromeric repeat CentC. We first validate the existence of long tandem arrays of repeats in maize and other taxa in the genus Zea. Although we find considerable sequence diversity among CentC copies genome-wide, genetic similarity among repeats is highest within these arrays, suggesting that tandem duplications are the primary mechanism for the generation of new copies. Nonetheless, clustering analyses identify similar sequences among distant repeats, and simulations suggest that this pattern may be due to homoplasious mutation. Although the two ancestral subgenomes of maize have contributed nearly equal numbers of centromeres, our analysis shows that the majority of all CentC repeats derive from one of the parental genomes, with an even stronger bias when examining the largest assembled contiguous clusters. Finally, by comparing maize with its wild progenitor teosinte, we find that the abundance of CentC likely decreased after domestication, while the pericentromeric repeat Cent4 has drastically increased. PMID:25190528

  10. Preceramic maize from Paredones and Huaca Prieta, Peru.

    PubMed

    Grobman, Alexander; Bonavia, Duccio; Dillehay, Tom D; Piperno, Dolores R; Iriarte, José; Holst, Irene

    2012-01-31

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, important problems remain. Among them is the paucity of information on maize's early morphological evolution and racial diversification brought about in part by the poor preservation of macrofossils dating to the pre-5000 calibrated years before the present period from obligate dispersal routes located in the tropical forest. We report newly discovered macrobotanical and microbotanical remains of maize that shed significant light on the chronology, land race evolution, and cultural contexts associated with the crop's early movements into South America and adaptation to new environments. The evidence comes from the coastal Peruvian sites of Paredones and Huaca Prieta, Peru; dates from the middle and late preceramic and early ceramic periods (between ca. 6700 and 3000 calibrated years before the present); and constitutes some of the earliest known cobs, husks, stalks, and tassels. The macrobotanical record indicates that a diversity of racial complexes characteristic of the Andean region emerged during the preceramic era. In addition, accelerator mass spectrometry radiocarbon determinations carried out directly on different structures of preserved maize plants strongly suggest that assays on burned cobs are more reliable than those on unburned cobs. Our findings contribute to knowledge of the early diffusion of maize and agriculture and have broader implications for understanding the development of early preindustrial human societies.

  11. 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. PMID:25486121

  12. Incidence of Fusarium Species and Mycotoxins in Silage Maize

    PubMed Central

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

    2011-01-01

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

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

    PubMed

    Scheets, Kay

    2016-08-15

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

  14. Preceramic maize from Paredones and Huaca Prieta, Peru

    PubMed Central

    Grobman, Alexander; Bonavia, Duccio; Dillehay, Tom D.; Piperno, Dolores R.; Iriarte, José; Holst, Irene

    2012-01-01

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, important problems remain. Among them is the paucity of information on maize's early morphological evolution and racial diversification brought about in part by the poor preservation of macrofossils dating to the pre-5000 calibrated years before the present period from obligate dispersal routes located in the tropical forest. We report newly discovered macrobotanical and microbotanical remains of maize that shed significant light on the chronology, land race evolution, and cultural contexts associated with the crop's early movements into South America and adaptation to new environments. The evidence comes from the coastal Peruvian sites of Paredones and Huaca Prieta, Peru; dates from the middle and late preceramic and early ceramic periods (between ca. 6700 and 3000 calibrated years before the present); and constitutes some of the earliest known cobs, husks, stalks, and tassels. The macrobotanical record indicates that a diversity of racial complexes characteristic of the Andean region emerged during the preceramic era. In addition, accelerator mass spectrometry radiocarbon determinations carried out directly on different structures of preserved maize plants strongly suggest that assays on burned cobs are more reliable than those on unburned cobs. Our findings contribute to knowledge of the early diffusion of maize and agriculture and have broader implications for understanding the development of early preindustrial human societies. PMID:22307642

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

    PubMed

    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).

  16. 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.

  17. 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

  18. 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

  19. 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

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

    PubMed

    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

  1. 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...

  2. 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...

  3. 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. PMID:27524979

  4. 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.

  5. The maize pathogenesis-related PRms protein localizes to plasmodesmata in maize radicles.

    PubMed Central

    Murillo, I; Cavallarin, L; San Segundo, B

    1997-01-01

    Pathogenesis-related (PR) proteins are plant proteins induced in response to infection by pathogens. In this study, an antibody raised against the maize PRms protein was used to localize the protein in fungal-infected maize radicles. The PRms protein was found to be localized at the contact areas between parenchyma cells of the differentiating protoxylem elements. By using immunoelectron microscopy, we found that these immunoreactive regions correspond to plasmodesmal regions. This was also true for the parenchyma cells filling the central pith of the vascular cylinder, although PRms mRNA accumulation was not detected in these cells. These findings suggest that for one cell type, the parenchyma cells of the central pith, the protein is imported rather than synthesized. The localization of the PRms protein indicates the possible existence of mechanisms for sorting of plant proteins to plasmodesmata and suggests that this protein may have a specialized function in the plant defense response. These findings are discussed with respect to the structure and function of plasmodesmata in cell-to-cell communication processes in higher plants. PMID:9061947

  6. 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

  7. Supercritical fluid extraction of Beauvericin from maize.

    PubMed

    Ambrosino, P; Galvano, F; Fogliano, V; Logrieco, A; Fresa, R; Ritieni, A

    2004-02-27

    Beauvericin (BEA), a supercritical fluid extraction with supercritical carbon dioxide from maize was investigated. Extraction efficiencies under several different extraction conditions were examined. Pressure, temperature, extraction time, organic modifier and water matrix content (10%) were investigated. The best extraction conditions were at a temperature of 60 degrees C, 3200psi, for 30min static extraction time and methanol as modifier solvent. Extraction recovery of 36% without modifier by adding water to the matrix in the extraction vessel (reproducibility relative standard deviations (R.S.D.)=3-5%) were recorded. Extraction recovery of 76.9% with methanol as co-solvent (reproducibility R.S.D.=3-5%) was obtained. Data shows that SFE gives a lower BEA recovery compared to conventional extraction protocol with organic solvents while SFE with modifier and conventional extraction yields are comparable. BEA extract contents were determined by high pressure liquid chromatography (HPLC) with a diode array detector (DAD) at 205nm and BEA peak confirmed by LC-MS. Acetonitrile-water as mobile phase and column C-18 were both tested. Instrumental and analytical parameters were optimized in the range linear interval from 1 to 500mgkg(-1) and reached a detection limit of 2ng. PMID:18969327

  8. 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

  9. 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.

  10. Phenotyping for abiotic stress tolerance in maize.

    PubMed

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

    2012-04-01

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

  11. 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

  12. 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.

  13. Maize transpiration in response to meteorological conditions

    NASA Astrophysics Data System (ADS)

    Klimešová, Jana; Stŕedová, Hana; Stŕeda, Tomáš

    2013-09-01

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

  14. 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

  15. Molecular genetic basis of pod corn (Tunicate maize)

    PubMed Central

    Wingen, Luzie U.; Münster, Thomas; Faigl, Wolfram; Deleu, Wim; Sommer, Hans; Saedler, Heinz; Theißen, Günter

    2012-01-01

    Pod corn is a classic morphological mutant of maize in which the mature kernels of the cob are covered by glumes, in contrast to generally grown maize varieties in which kernels are naked. Pod corn, known since pre-Columbian times, is the result of a dominant gain-of-function mutation at the Tunicate (Tu) locus. Some classic articles of 20th century maize genetics reported that the mutant Tu locus is complex, but molecular details remained elusive. Here, we show that pod corn is caused by a cis-regulatory mutation and duplication of the ZMM19 MADS-box gene. Although the WT locus contains a single-copy gene that is expressed in vegetative organs only, mutation and duplication of ZMM19 in Tu lead to ectopic expression of the gene in the inflorescences, thus conferring vegetative traits to reproductive organs. PMID:22517751

  16. C4 photosynthetic machinery: insights from maize chloroplast proteomics

    PubMed Central

    Zhao, Qi; Chen, Sixue; Dai, Shaojun

    2013-01-01

    C4 plants exhibit much higher CO2 assimilation rates than C{}3 plants under certain conditions. The specialized differentiation of mesophyll cell and bundle sheath cell type chloroplasts is unique to C4 plants and improves photosynthetic efficiency. Maize (Zea mays) is an important crop and model with C4 photosynthetic machinery. 2DE and high-throughput quantitative proteomics approaches (e.g., isobaric tags for relative and absolute quantitation and shotgun proteomics) have been employed to investigate maize chloroplast structure and function. These proteomics studies have provided valuable information on C4 chloroplast protein components, photosynthesis, and other metabolic mechanisms underlying chloroplast biogenesis, stromal, and membrane differentiation, as well as response to salinity, high/low temperature, and light stress. This review presents an overview of proteomics advances in maize chloroplast biology. PMID:23596450

  17. 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.

  18. Uptake of polycyclic aromatic hydrocarbons by maize plants.

    PubMed

    Lin, H; Tao, S; Zuo, Q; Coveney, R M

    2007-07-01

    Roots and above-ground parts (tops) of maize plants, comprising cuticles, leaves and stems, have been exposed separately to polycyclic aromatic hydrocarbons (PAHs) by means of air-tight bicameral exposure devices. Maize roots and tops of plants directly accumulate PAHs from aqueous solutions and from air in proportion to exposure levels. Root and leaf concentration factors (log RCF and log LCF) are log-linear functions of log-based octanol-water partition coefficient (log Kow) and log-based octanol-air partition coefficient (log Koa). The PAHs' concentrations among cuticles, leaves and stems display good correlations with each other. PAH concentrations in each part of the plant tested correlated positively with atmospheric PAHs' concentrations. Comparisons between PAHs' concentrations of root epidermis and root tissue showed similar correlations. Bulk concentrations of contaminants in various plant tissues differed greatly, but these differences disappeared after normalization to lipid contents suggesting lipid-based partitioning of PAHs among maize tissues.

  19. 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. PMID:25198847

  20. 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.

  1. 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

  2. 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.

  3. 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. PMID:23656551

  4. “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

  5. "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.

  6. 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.

  7. Molecular farming of industrial proteins from transgenic maize.

    PubMed

    Hood, E E; Kusnadi, A; Nikolov, Z; Howard, J A

    1999-01-01

    Recombinant egg white avidin and bacterial B-glucuronidase (GUS) from transgenic maize have been commercially produced. High levels of expression were obtained in seed by employing the ubiquitin promoter from maize. The recombinant proteins had activities that were indistinguishable from their native counterparts. We have illustrated that down-stream activities in the production of these recombinant proteins, such as stabilizing the germplasm and processing for purification, were accomplished without any major obstacles. Avidin (A8706) and GUS (G2035) are currently marketed by Sigma Chemical Co. PMID:10335391

  8. 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.

  9. 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

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

    PubMed

    Gassmann, Aaron J

    2016-06-01

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

  11. 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.

  12. Evaluation of analytical methods for carotenoid extraction from biofortified maize (Zea mays sp.).

    PubMed

    Howe, Julie A; Tanumihardjo, Sherry A

    2006-10-18

    Biofortification of maize with beta-carotene has the potential to improve vitamin A status in vitamin A deficient populations where maize is a staple crop. Accurate assessment of provitamin A carotenoids in maize must be performed to direct breeding efforts. The objective was to evaluate carotenoid extraction methods and determine essential steps for use in countries growing biofortified maize. The most reproducible method based on coefficient of variation and extraction efficiency was a modification of Kurilich and Juvik (1999). Heat and saponification are required to release carotenoids from biofortified maize and remove oils interfering with chromatographic analysis. For maize samples with high oil content, additional base may be added to ensure complete saponification without compromising results. Degradation of internal standard before carotenoids were released from the maize matrix required the addition of internal standard after heating to prevent overestimation of carotenoids. This modified method works well for lutein, zeaxanthin, beta-cryptoxanthin, alpha-carotene, and beta-carotene. PMID:17032000

  13. [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.

  14. Primary structure of maize chloroplast adenylate kinase.

    PubMed

    Schiltz, E; Burger, S; Grafmüller, R; Deppert, W R; Haehnel, W; Wagner, E

    1994-06-15

    This paper describes the sequence of adenylate kinase (Mg-ATP+AMP<-->Mg-ADP+ADP) from maize chloroplasts. This light-inducible enzyme is important for efficient CO2 fixation in the C4 cycle, by removing and recycling AMP produced in the reversible pyruvate phosphate dikinase reaction. The complete sequence was determined by analyzing peptides from cleavages with trypsin, AspN protease and CNBr and subcleavage of a major CNBr peptide with chymotrypsin. N-terminal Edman degradation and carboxypeptidase digestion established the terminal residues. Electrospray mass spectrometry confirmed the final sequence of 222 residues (M(r) = 24867) including one cysteine and one tryptophan. The sequence shows this enzyme to be a long-variant-type adenylate kinase, the nearest relatives being adenylate kinases from Enterobacteriaceae. Alignment of the sequence with the adenylate kinase from Escherichia coli reveals 44% identical residues. Since the E. coli structure has been published recently at 0.19-nm resolution with the inhibitor adenosine(5')pentaphospho(5')adenosine (Ap5A) [Müller, C. W. & Schulz, G. E. (1992) J. Mol. Biol. 224, 159-177], catalytically essential residues could be compared and were found to be mostly conserved. Surprisingly, in the nucleotide-binding Gly-rich loop Gly-Xaa-Pro-Gly-Xaa-Gly-Lys the middle Gly is replaced by Ala. This is, however, compensated by an Ile-->Val exchange in the nearest spatial neighborhood. A Thr-->Ala exchange explains the unusual tolerance of the enzyme for pyrimidine nucleotides in the acceptor site. PMID:8026505

  15. Water Transport in Maize Roots 1

    PubMed Central

    Steudle, Ernst; Oren, Ram; Schulze, Ernst-Detlef

    1987-01-01

    A root pressure probe has been used to measure the root pressure (Pr) exerted by excised main roots of young maize plants (Zea Mays L.). Defined gradients of hydrostatic and osmotic pressure could be set up between root xylem and medium to induce radial water flows across the root cylinder in both directions. The hydraulic conductivity of the root (Lpr) was evaluated from root pressure relaxations. When permeating solutes were added to the medium, biphasic root pressure relaxations were observed with water and solute phases and root pressure minima (maxima) which allowed the estimation of permeability (PSr) and reflection coefficients (σsr) of roots. Reflection coefficients were: ethanol, 0.27; mannitol, 0.74; sucrose, 0.54; PEG 1000, 0.82; NaCl, 0.64; KNO3, 0.67, and permeability coefficients (in 10−8 meters per second): ethanol, 4.7; sucrose, 1.6; and NaCl, 5.7. Lpr was very different for osmotic and hydrostatic gradients. For hydrostatic gradients Lpr was 1·10−7 meters per second per megapascal, whereas in osmotic experiments the hydraulic conductivity was found to be an order of magnitude lower. For hydrostatic gradients, the exosmotic Lpr was about 15% larger than the endosmotic, whereas in osmotic experiments the polarity in the water movement was reversed. These results either suggest effects of unstirred layers at the osmotic barrier in the root, an asymmetrical barrier, and/or mechanical effects. Measurements of the hydraulic conductivity of individual root cortex cells revealed an Lp similar to Lpr (hydrostatic). It is concluded that, in the presence of external hydrostatic gradients, water moves primarily in the apoplast, whereas in the presence of osmotic gradients this component is much smaller in relation to the cell-to-cell component (symplasmic plus transcellular transport). PMID:16665588

  16. Physical characterisation of high amylose maize starch and acylated high amylose maize starches.

    PubMed

    Lim, Ya-Mei; Hoobin, Pamela; Ying, DanYang; Burgar, Iko; Gooley, Paul R; Augustin, Mary Ann

    2015-03-01

    The particle size, water sorption properties and molecular mobility of high amylose maize starch (HAMS) and high amylose maize starch acylated with acetate (HAMSA), propionate (HAMSP) and butyrate (HAMSB) were investigated. Acylation increased the mean particle size (D(4,3)) and lowered the specific gravity (G) of the starch granules with an inverse relationship between the length of the fatty acid chain and particle size. Acylation of HAMS with fatty acids lowered the monolayer moisture content with the trend being HAMSB

  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. PMID:26162097

  19. 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.

  20. 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...

  1. 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.

  2. Identification of immunogenic maize proteins in a casein hydrolysate formula.

    PubMed

    Frisner, H; Rosendal, A; Barkholt, V

    2000-05-01

    Cow's milk-based formulas used for infants with cow's milk allergy are based on hydrolyzed proteins. The formulas that are successful in preventing allergic responses are extensively hydrolyzed. Nevertheless, reactions to such formulas are occasionally reported, and protein material of higher molecular weight than expected has been detected by binding immunoglobulin E (IgE) from patients' sera. This paper presents the identification of high-molecular-weight material in the extensively hydrolyzed casein formula, Nutramigen. The material was concentrated by simple centrifugation. The proteins in the pellet were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein-containing bands were analyzed by protein sequencing after electroblotting. The proteins were identified as maize zeins, which are water-insoluble proteins of apparent M(r) 20,000 and 23,000, presumably originating from the maize starch in Nutramigen. Rabbits immunized with this formula developed antibodies against zeins but not against milk proteins. The maize zeins are probably identical to the recently reported components in Nutramigen (1), detected by binding of IgE from milk allergic patients, but not correlated to clinical allergic reactivity. The clinical relevance of maize proteins in Nutramigen remains to be established. PMID:10893013

  3. 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...

  4. 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...

  5. 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.

  6. Maize kauralexins: insights into structure, function, and biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoalexins are a broad category of pathogen and insect-inducible biochemicals that locally protect plant tissues. Terpenoid phytoalexins have been extensively examined numerous crop plants but until recently were considered absent in maize (Zea mays). We discovered a series of acidic ent-kaurane-r...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. Diallel analysis of corn earworm resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn earworm, Helicoverpa zea Boddie, is a major pest of maize in the United States. Host plant resistance is widely considered a desirable method for reducing losses to this pest. Nine inbred lines were evaluated for resistance to ear damage, larval survival, and weight of larvae. Mp313E and Mp7...

  12. 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 ...

  13. 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.

  14. 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...

  15. 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...

  16. Gene regularity interactions at lateral organ buondaries in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. 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

  18. 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...

  19. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Genetic Perturbation of the Maize Methylome[W

    PubMed Central

    Li, Qing; Hermanson, Peter J.; Zaunbrecher, Virginia M.; Song, Jawon; Wendt, Jennifer; Rosenbaum, Heidi; Madzima, Thelma F.; Sloan, Amy E.; Huang, Ji; Burgess, Daniel L.; Richmond, Todd A.; McGinnis, Karen M.; Meeley, Robert B.; Danilevskaya, Olga N.; Vaughn, Matthew W.; Kaeppler, Shawn M.; Jeddeloh, Jeffrey A.

    2014-01-01

    DNA methylation can play important roles in the regulation of transposable elements and genes. A collection of mutant alleles for 11 maize (Zea mays) genes predicted to play roles in controlling DNA methylation were isolated through forward- or reverse-genetic approaches. Low-coverage whole-genome bisulfite sequencing and high-coverage sequence-capture bisulfite sequencing were applied to mutant lines to determine context- and locus-specific effects of these mutations on DNA methylation profiles. Plants containing mutant alleles for components of the RNA-directed DNA methylation pathway exhibit loss of CHH methylation at many loci as well as CG and CHG methylation at a small number of loci. Plants containing loss-of-function alleles for chromomethylase (CMT) genes exhibit strong genome-wide reductions in CHG methylation and some locus-specific loss of CHH methylation. In an attempt to identify stocks with stronger reductions in DNA methylation levels than provided by single gene mutations, we performed crosses to create double mutants for the maize CMT3 orthologs, Zmet2 and Zmet5, and for the maize DDM1 orthologs, Chr101 and Chr106. While loss-of-function alleles are viable as single gene mutants, the double mutants were not recovered, suggesting that severe perturbations of the maize methylome may have stronger deleterious phenotypic effects than in Arabidopsis thaliana. PMID:25527708

  2. 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...

  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. Interaction of genetic mechanisms regulating methionine concentration in maize grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. Identifying and developing maize germplasm with resistance to aflatoxin contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin, produced by the fungus Aspergillus flavus, occurs naturally in maize, Zea mays L. It is the most potent carcinogen found in nature, and it is toxic to both humans and animals. Although first identified and recognized as a threat to animals when 100,000 turkeys died in England in 1961, afl...

  6. Towards effective resistance to Striga in African maize

    PubMed Central

    Rich, Patrick J

    2008-01-01

    The fascinating biology of Striga parasitism is manifest through a series of signal exchanges between the parasite and its host. As an obligate root hemi-parasite, Striga development is cued to exudates and solutes of host roots but with negative ramifications on host plant health. Striga control in crops, via a variety of biotechnological approaches, needs to be based on increased understanding of this intricate biology. Maize has become the major cereal crop of Africa. However, this New World transplant has shown a paucity of Striga resistance characters relative to native sorghum. In this paper, we review growing evidence for maize genetic defenses against early pre-emergent phases of the Striga life cycle, when the tolls of parasitism are first manifest. Resistance characters first described in maize wild relatives have now been captured in Zea mays. The possible stacking of new and complementary sources of resistance in improved maize varieties targeted for Striga prone areas is discussed. An integrated approach combining genetic with other control measures is advocated with a more realistic view of the resource challenges prevalent in African agriculture. PMID:19513251

  7. 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...

  8. Strategies for the prevention of preharvest aflatoxin contamination of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination of maize by the fungi Aspergillus flavus and A. parasiticus poses serious health hazards to humans and animals worldwide. This alarming fact, along with the institution of regulations in many countries to control the occurrence of aflatoxins in foods and feed, have stimulate...

  9. EXPRESSION OF THE MAIZE MOSAIC VIRUS GLYCOPROTEIN IN INSECT CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize mosaic virus (genus Nucleorhabdovirus, family Rhabdoviridae) is transmitted in a persistent-propagative manner by Peregrinus maidis, the corn planthopper. Like other rhabdoviruses, the MMV genome encodes a surface glycoprotein that is likely involved in virus attachment and entry into host ce...

  10. Evaluation of the nutritive value of maize for honey bees.

    PubMed

    Höcherl, Nicole; Siede, Reinhold; Illies, Ingrid; Gätschenberger, Heike; Tautz, Jürgen

    2012-02-01

    In modern managed agro-ecosystems, the supply of adequate food from blooming crops is limited to brief periods. During periods of pollen deficiencies, bees are forced to forage on alternative crops, such as maize. However, pollen of maize is believed to be a minor food source for bees as it is thought to be lacking in proteins and essential amino acids. This study was conducted to verify this assumption. In maize, a strikingly low concentration of histidine was found, but the amount of all other essential amino acids was greater than that of mixed pollen. The performance and the immunocompetence of bees consuming a pure maize pollen diet (A) was compared to bees feeding on a polyfloral pollen diet (B) and to bees feeding on an artificial substitute of pollen (C). Consumption of diets A and C were linked to a reduction in brood rearing and lifespan. However, no immunological effects were observed based on two parameters of the humoral immunity. PMID:22172382

  11. 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...

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

    PubMed

    Hufford, Matthew B

    2016-01-01

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

  13. Comparative effects of processing methods on the feeding value of maize in feedlot cattle.

    PubMed

    Zinn, R A; Barreras, A; Corona, L; Owens, F N; Plascencia, A

    2011-12-01

    The primary reason for processing maize is to enhance feeding value. Total tract starch digestion is similar for coarsely processed (dry rolled, cracked) dry maize. Enhancements in starch digestion due to dry rolling maize v. feeding maize whole may be greater in light-weight calves than in yearlings, and when DM intake is restricted ( < 1·5 % of body weight). The net energy (NE) maintain (NEm) and NE gain (NEg) values for whole maize are 8·83 and 6·02 MJ (2·11 and 1·44 Mcal)/kg, respectively. Compared with conventional dry processing (i.e. coarse rolled, cracked), finely processing maize may increase the initial rate of digestion, but does not improve total tract starch digestion. Tempering before rolling (without the addition of steam) may enhance the growth performance response and the NE value of maize. Average total tract starch digestion is similar for high-moisture and steam-flaked maize. However, the proportion of starch digested ruminally is greater (about 8 %) for high-moisture maize. The growth performance response of feedlot cattle to the feeding of high-moisture maize is highly variable. Although the NEm and NEg value of whole high-moisture maize was slightly less than that of dry processed maize (averaging 9·04 and 6·44 MJ (2·16 and 1·54 Mcal)/kg, respectively), grinding or rolling high-moisture maize before ensiling increased (6 %) its NE value. Substituting steam-flaked maize for dry processed maize increases average daily gain (6·3 %) and decreases DM intake (5 %). The comparative NEm and NEg values for steam-flaked maize at optimal processing (density = 0·34 kg/l) are 10·04 and 7·07 MJ (2·40 and 1·69 Mcal)/kg, respectively. These NE values are greater (3 %) than current tabular values (National Research Council, 2000), being more consistent with earlier standards (National Research Council, 1984). When maize is the primary or sole source of starch in the diet, concentration of starch in faeces (faecal starch, % of

  14. 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

  15. 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

  16. Choosing a genome browser for a Model Organism Database: surveying the Maize community

    PubMed Central

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

    2010-01-01

    As the B73 maize genome sequencing project neared completion, MaizeGDB began to integrate a graphical genome browser with its existing web interface and database. To ensure that maize researchers would optimally benefit from the potential addition of a genome browser to the existing MaizeGDB resource, personnel at MaizeGDB surveyed researchers’ needs. Collected data indicate that existing genome browsers for maize were inadequate and suggest implementation of a browser with quick interface and intuitive tools would meet most researchers’ needs. Here, we document the survey’s outcomes, review functionalities of available genome browser software platforms and offer our rationale for choosing the GBrowse software suite for MaizeGDB. Because the genome as represented within the MaizeGDB Genome Browser is tied to detailed phenotypic data, molecular marker information, available stocks, etc., the MaizeGDB Genome Browser represents a novel mechanism by which the researchers can leverage maize sequence information toward crop improvement directly. Database URL: http://gbrowse.maizegdb.org/ PMID:20627860

  17. 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.

  18. Identification of Genetic Differentiation between Waxy and Common Maize by SNP Genotyping

    PubMed Central

    Hao, Derong; Zhang, Zhenliang; Cheng, Yujing; Chen, Guoqing; Lu, Huhua; Mao, Yuxiang; Shi, Mingliang; Huang, Xiaolan; Zhou, Guangfei; Xue, Lin

    2015-01-01

    Waxy maize (Zea mays L. var. ceratina) is an important vegetable and economic crop that is thought to have originated from cultivated flint maize and most recently underwent divergence from common maize. In this study, a total of 110 waxy and 110 common maize inbred lines were genotyped with 3072 SNPs to evaluate the genetic diversity, population structure, and linkage disequilibrium decay as well as identify putative loci that are under positive selection. The results revealed abundant genetic diversity in the studied panel and that genetic diversity was much higher in common than in waxy maize germplasms. Principal coordinate analysis and neighbor-joining cluster analysis consistently classified the 220 accessions into two major groups and a mixed group with mixed ancestry. Subpopulation structure in both waxy and common maize sets were associated with the germplasm origin and corresponding heterotic groups. The LD decay distance (1500–2000 kb) in waxy maize was lower than that in common maize. Fourteen candidate loci were identified as under positive selection between waxy and common maize at the 99% confidence level. The information from this study can assist waxy maize breeders by enhancing parental line selection and breeding program design. PMID:26566240

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

    PubMed

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

    2010-01-01

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

  20. Chemical composition and starch digestibility of tortillas prepared with non-conventional commercial nixtamalized maize flours.

    PubMed

    Hernández-Salazar, M; Agama-Acevedo, E; Sáyago-Ayerdi, S G; Tovar, J; Bello-Pérez, L A

    2006-01-01

    Non-conventional nixtamalized maize flours elaborated by a factory in Mexico were used for tortilla preparation. Tortillas were stored at 4 degrees C for up to 72 h and the total starch, available starch, resistant starch and retrograded resistant starch were assessed. The traditional white tortilla, used as a control, showed higher protein and fat contents than blue maize tortilla, whereas a maize-bean mixed tortilla had the highest protein, ash and fat contents. Lower total starch was obtained in the maize-bean tortilla than in white and blue maize tortillas. The available starch content in all tortillas decreased with the cold-storage, although the change was more marked for blue-maize tortillas. The maize-bean mixed tortillas exhibited the lowest in vitro digestibility, which is consistent with the relatively high resistant starch levels in the bean. Differences in resistant starch content were found between the two maize tortillas, which might be related to the softer texture of blue-maize tortilla. The starch digestibility features of these new types of nixtamalized maize flours open up the possibility of producing tortillas with variable nutritional properties.

  1. Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize

    PubMed Central

    Jordaan, Elizabeth M.; De Waele, D.

    1988-01-01

    The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae infestation of subsequently grown maize. When goose grass, khaki weed, and mealie crotalaria were grown in association with maize in soil infested with P. zeae, goose grass and khaki weed severely suppressed maize root development; this resulted in a low number of nematodes per maize root system and a high number of nematodes per maize root unit. Mealie crotalaria did not restrict maize root growth and did not affect nematode densities per maize root system or maize root unit. Special attention should be given to the control of mealie crotalaria, which is a good host for P. zeae, and goose grass, which, in addition to its ability to compete with maize, is also a suitable host for P. zeae. PMID:19290263

  2. Physical and Genetic Structure of the Maize Genome Reflects Its Complex Evolutionary History

    PubMed Central

    Wei, Fusheng; Coe, Ed; Nelson, William; Bharti, Arvind K; Engler, Fred; Butler, Ed; Kim, HyeRan; Goicoechea, Jose Luis; Chen, Mingsheng; Lee, Seunghee; Fuks, Galina; Sanchez-Villeda, Hector; Schroeder, Steven; Fang, Zhiwei; McMullen, Michael; Davis, Georgia; Bowers, John E; Paterson, Andrew H; Schaeffer, Mary; Gardiner, Jack; Cone, Karen; Messing, Joachim; Soderlund, Carol; Wing, Rod A

    2007-01-01

    Maize (Zea mays L.) is one of the most important cereal crops and a model for the study of genetics, evolution, and domestication. To better understand maize genome organization and to build a framework for genome sequencing, we constructed a sequence-ready fingerprinted contig-based physical map that covers 93.5% of the genome, of which 86.1% is aligned to the genetic map. The fingerprinted contig map contains 25,908 genic markers that enabled us to align nearly 73% of the anchored maize genome to the rice genome. The distribution pattern of expressed sequence tags correlates to that of recombination. In collinear regions, 1 kb in rice corresponds to an average of 3.2 kb in maize, yet maize has a 6-fold genome size expansion. This can be explained by the fact that most rice regions correspond to two regions in maize as a result of its recent polyploid origin. Inversions account for the majority of chromosome structural variations during subsequent maize diploidization. We also find clear evidence of ancient genome duplication predating the divergence of the progenitors of maize and rice. Reconstructing the paleoethnobotany of the maize genome indicates that the progenitors of modern maize contained ten chromosomes. PMID:17658954

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

    PubMed

    Schnable, James C; Freeling, Michael

    2011-01-01

    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.

  4. 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.

  5. 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.

  6. Haploid formation in maize, barley, flax, and potato.

    PubMed

    Pret'ová, A; Obert, B; Bartosová, Z

    2006-08-01

    The article is reviewing some significant features and issues in the process of haploid formation in two important monocotyledonous crop plants - maize and barley - and in two dicotyledonous plants - flax and potato. Exotic maize lines with higher androgenic response turned up as a good source for this heritable trait and this valuable trait can be incorporated into elite maize lines via crossing. Lots of attempts were devoted to identifying some cytological and/or morphological markers for androgenic response in maize microspore cultures. The "starlike" organization of the cytoplasm inside the induced maize microspores together with the enlarged size of induced microspores can be considered as morphological markers for androgenic response. In barley, microspores with rich cytoplasm that was of granular appearance with the nucleus located near the cell wall and with no visible vacuole had the largest survival rate and many of these cells continued in development and produced embryos. In flax, a dramatic increase of induction rate in anther cultures (up to 25%) was achieved when flax anthers were pretreated for 3 days at 4 degrees C and afterwards kept for 1 day at 35 degrees C. Also gynogenesis in flax has been reported already and complete plants were obtained. In potato microspore cultures, formation of two dissimilar cells indicated a strong polarization in the system and as a result of this polarization a prominent suspensor developed that persisted until the torpedo stage of the androgenic embryo. This was the first time the formation of a well developed suspensor was described in connection with androgenesis.

  7. 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.

  8. 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...

  9. [Effects of tillage at pre-planting of winter wheat and summer maize on leaf senescence of summer maize].

    PubMed

    Li, Xia; Zhang, Ji-wang; Ren, Bai-zhao; Fan, Xia; Dong, Shu-ting; Liu, Peng; Zhao, Bin

    2015-05-01

    This study explored the effects of different tillage treatments at pre-planting winter wheat and summer maize on leaf senescence physiological characteristics of summer maize in double cropping system. Zhengdan 958 was used as experimental material. Three tillage treatments, including rotary tillage before winter wheat seeding and no-tillage before summer maize seeding (RN), mold- board plow before winter wheat seeding and no-tillage before summer maize seeding (MN), and moldboard plow before winter wheat seeding and rotary tillage before summer maize seeding (MR), were designed to determine the effects of different tillage treatments on leaf area (LA) , leaf area reduction, photosynthetic pigments content, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and malondialdehyde (MDA) content in ear leaves of summer maize after tasselling (VT). LA of MN and MR were higher than that of RN from VT to 40 days after tasseling (VT + 40) and LA reduction of MR was the highest after VT + 40. As for MR, MN and NT, the photosynthetic pigments content got the maximum value at 20 days after tasselling (VT + 20) and then decreased, following the change of unimodal curve. At VT + 20, the contents of chlorophyll a in MR and MN were increased by 11.4% and 9.7%, the contents of chlorophyll b in MR and MN were increased by 14.9% and 15.9%, compared with RN. The soluble protein content in ear leaves decreased following the growth process in all treatments, and that of MR and MN remained 11.5% and 24.4% higher than that of RN from VT to VT + 40. SOD, CAT and POD activities of three treatments got the maximum values at VT + 20 and then decreased, following the change of unimodal curve. MDA content increased following the growth process in all treatments and that of RN always remained at high levels. Grain yields of MN and MR were 24.0% and 30.6% greater than that of RN, respectively. Grain yield of MR was 5.2% higher than that of MN. In conclusion, the ability of

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

    PubMed

    Ton Nu, M A; Blaabjerg, K; Poulsen, H D

    2014-04-01

    The objective of the study was to evaluate the effect of screen size (1, 2 and 3 mm) and microbial phytase (0 and 1000 FTU/kg as-fed) on phytate degradation in maize (100% maize), soybean meal (100% SBM) and maize-SBM (75% maize and 25% SBM) incubated in water for 0, 2, 4, 8 and 24 h at 38°C. Samples were analysed for pH, dry matter and phytate phosphorus (P). Particle size distribution (PSD) and average particle size (APS) of samples were measured by the Laser Diffraction and Bygholm method. PSD differed between the two methods, whereas APS was similar. Decreasing screen size from 3 to 1 mm reduced APS by 48% in maize, 30% in SBM and 26% in maize-SBM. No interaction between screen size and microbial phytase on phytate degradation was observed, but the interaction between microbial phytase and incubation time was significant ( P<0.001). This was because microbial phytase reduced phytate P by 88% in maize, 84% in maize-SBM and 75% in SBM after 2 h of incubation ( P<0.05), whereas the reduction of phytate P was limited (<50%) in the feeds, even after 24 h when no microbial phytase was added. The exponential decay model was fitted to the feeds with microbial phytase to analyse the effect of screen size and feed on microbial phytase efficacy on phytate degradation. The interaction between screen size and feed affected the relative phytate degradation rate ( Rd) of microbial phytase as well as the time to decrease 50% of the phytate P ( t1 =2) ( P<0.001). Thus, changing from 3 to 1 mm screen size increased Rd by 22 and 10%/h and shortened t1 =2 by 0.4 and 0.2 h in maize and maize-SBM, respectively ( P<0.05), but not in SBM. Moreover, the screen size effect was more pronounced in maize and maize-SBM compared with SBM as a higher phytate degradation rate constant (Kd) and Rd, and a shorter t1 =2 was observed in maize compared with SBM in all screen sizes ( P<0.05). However, a higher amount of degraded phytate was achieved in SBM than in maize because of the higher

  11. 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. PMID:26781035

  12. 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.

  13. Soil Type and Maize Cultivar Affect the Genetic Diversity of Maize Root-Associated Burkholderia cepacia Populations.

    PubMed

    Dalmastri; Chiarini; Cantale; Bevivino; Tabacchioni

    1999-10-01

    Abstract Burkholderia cepacia populations associated with the Zea mays root system were investigated to assess the influence of soil type, maize cultivar, and root localization on the degree of their genetic diversity. A total of 180 B. cepacia isolates were identified by restriction analysis of the amplified 16S rDNA (ARDRA technique). The genetic diversity among B. cepacia isolates was analyzed by the random amplified polymorphic DNA (RAPD) technique, using the 10-mer primer AP5. The analysis of molecular variance (AMOVA) method was applied to estimate the variance components for the RAPD patterns. The results indicated that, among the factors studied, the soil was clearly the dominant one in affecting the genetic diversity of maize root-associated B. cepacia populations. In fact, the percentage of variation among populations was significantly higher between B. cepacia populations recovered from maize planted in different soils than between B. cepacia populations isolated from different maize cultivars and from distinct root compartments such as rhizoplane and rhizosphere. The analysis of the genetic relationships among B. cepacia isolates resulted in dendrograms showing bacterial populations with frequent recombinations and a nonclonal genetic structure. The dendrograms were also in agreement with the AMOVA results. We were able to group strains obtained from distinct soils on the basis of their origin, confirming that soil type had the major effect on the degree of genetic diversity of the maize root-associated B. cepacia populations analyzed. On the other hand, strains isolated from distinct root compartments exhibited a random distribution which confirmed that the rhizosphere and rhizoplane populations analyzed did not significantly differ in their genetic structure.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p273.html

  14. Analysis of Maize Seed Germs by Photoacoustic Microscopy and Photopyroelectric Technique

    NASA Astrophysics Data System (ADS)

    Pacheco, A. Domínguez; Aguilar, C. Hernández; Cruz-Orea, A.

    2013-05-01

    A knowledge about thermal parameters of structural components of maize seed is of great relevance in the seed technology practice. The objective of the present study was to determine the thermal effusivity of germs of maize ( Zea mays L.) of different genotypes by means of the photopyroelectric technique (PPE) in the inverse configuration and obtaining the thermal imaging of these samples by photoacoustic microscopy (PAM). Germs from crystalline maize (white pigment), semi-crystalline maize (yellow pigment), and floury maize (blue pigment) were used in this investigation. The results show differences between germs of maize seeds mainly in the values of their thermal effusivities. The thermal images showed minimum inhomogeneity of these seed germs. Characterizations of thermal parameters in seeds are important in agriculture and food production and could be particularly useful to define their quality and determine their utility. PPE and PAM can be considered as potential diagnostic tools for the characterization of agriculture seeds.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  17. 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

  18. 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

  19. [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. PMID:26955715

  20. [Identification for genetically modified maize T14/T25 with real time fluorescent PCR method].

    PubMed

    Cao, Ji-Juan; Qin, Wen; Zhu, Shui-Fang; Cao, Yuan-Yin

    2004-09-01

    To identify genetically modified (GM) maize T14/T25 lines, a real-time fluorescent PCR (RTF PCR) assay was performed in this study. Primers and Taqman probes specific for inserted genes in the T14/T25 were used to conduct the real-time fluorescent (RTF) PCR and PCR assays. The RTF PCR method was established to detect and identify GM maize lines. The results show that the TaqMan probe could identify T14/T25 maize used, while other GM and NO-GM maize didn't be detected. The RTF PCR could be a new method for detecting other genetically modified organism.

  1. 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.

  2. Maize IgE binding proteins: each plant a different profile?

    PubMed Central

    2014-01-01

    Background Allergies are nearly always triggered by protein molecules and the majority of individuals with documented immunologic reactions to foods exhibit IgE hypersensitivity reactions. In this study we aimed to understand if natural differences, at proteomic level, between maize populations, may induce different IgE binding proteins profiles among maize-allergic individuals. We also intended to deepen our knowledge on maize IgE binding proteins. Results In order to accomplish this goal we have used proteomic tools (SDS-PAGE and 2-D gel electrophoresis followed by western blot) and tested plasma IgE reactivity from four maize-allergic individuals against four different protein fractions (albumins, globulins, glutelins and prolamins) of three different maize cultivars. We have observed that maize cultivars have different proteomes that result in different IgE binding proteins profiles when tested against plasma from maize-allergic individuals. We could identify 19 different maize IgE binding proteins, 11 of which were unknown to date. Moreover, we found that most (89.5%) of the 19 identified potential maize allergens could be related to plant stress. Conclusions These results lead us to conclude that, within each species, plant allergenic potential varies with genotype. Moreover, considering the stress-related IgE binding proteins identified, we hypothesise that the environment, particularly stress conditions, may alter IgE binding protein profiles of plant components. PMID:24650160

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

    PubMed

    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. PMID:25807085

  4. 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

  5. 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. PMID:24329721

  6. The MaizeGDB Genome Browser tutorial: one example of database outreach to biologists via video

    PubMed Central

    Harper, Lisa C.; Schaeffer, Mary L.; Thistle, Jordan; Gardiner, Jack M.; Andorf, Carson M.; Campbell, Darwin A.; Cannon, Ethalinda K.S.; Braun, Bremen L.; Birkett, Scott M.; Lawrence, Carolyn J.; Sen, Taner Z.

    2011-01-01

    Video tutorials are an effective way for researchers to quickly learn how to use online tools offered by biological databases. At MaizeGDB, we have developed a number of video tutorials that demonstrate how to use various tools and explicitly outline the caveats researchers should know to interpret the information available to them. One such popular video currently available is ‘Using the MaizeGDB Genome Browser’, which describes how the maize genome was sequenced and assembled as well as how the sequence can be visualized and interacted with via the MaizeGDB Genome Browser. Database URL: http://www.maizegdb.org/ PMID:21565781

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

    PubMed

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

    2005-02-01

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

  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. Maize proteomics: an insight into the biology of an important cereal crop.

    PubMed

    Pechanova, Olga; Takáč, Tomáš; Samaj, Jozef; Pechan, Tibor

    2013-02-01

    Maize (Zea mays L.) is the most grown cereal crop in the world (839 million tons in 2012). According to its agro-economical importance, maize has received tremendous attention from research communities of academic, state, and industry origin. In this manuscript, we aspire to provide readers with the first comprehensive review of proteomics studies performed on maize within a 1987-2012 time period. The following topics are presented here: maize proteome profiling, developmental proteomics, response to abiotic and biotic stress, maize phosphoproteomics, tissue-specific wild-type versus mutant analyses, heterosis, seed viability, maize allergens, and safety assessment of genetically modified maize. Tissues, organelles, subcellular compartments, secretomes, methods, phenomena, and pertinent proteins were summarized and referenced in tables and figures to provide readers with expediently accessible information in the context of up-to-date achievements. This review illustrates maize proteomics as a firmly established research area with laboratories around the world diligently advancing our knowledge of diverse aspects of maize biology.

  10. 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.

  11. 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

  12. 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. PMID:26566847

  13. 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.

  14. Survey of aflatoxins in maize tortillas from Mexico City.

    PubMed

    Castillo-Urueta, Pável; Carvajal, Magda; Méndez, Ignacio; Meza, Florencia; Gálvez, Amanda

    2011-01-01

    In Mexico, maize tortillas are consumed on a daily basis, leading to possible aflatoxin exposure. In a survey of 396 2-kg samples, taken over four sampling days in 2006 and 2007 from tortilla shops and supermarkets in Mexico City, aflatoxin levels were quantified by HPLC. In Mexico, the regulatory limit is 12 µg kg⁻¹ total aflatoxins for maize tortillas. In this survey, 17% of tortillas contained aflatoxins at levels of 3-385 µg kg⁻¹ or values below the limit of quantification (12 µg kg⁻¹ and 87% were below the regulatory limit. Average aflatoxin concentrations in 56 contaminated samples were: AFB1 (12.1 µg kg⁻¹); AFB2 (2.7 µg kg⁻¹); AFG1 (64.1 µg kg⁻¹) and AFG2 (3.7 µg kg⁻¹), and total AF (20.3 µg kg⁻¹).

  15. Molecular biology of maize Ac/Ds elements: an overview.

    PubMed

    Lazarow, Katina; Doll, My-Linh; Kunze, Reinhard

    2013-01-01

    Maize Activator (Ac) is one of the prototype transposable elements of the hAT transposon superfamily, members of which were identified in plants, fungi, and animals. The autonomous Ac and nonautonomous Dissociation (Ds) elements are mobilized by the single transposase protein encoded by Ac. To date Ac/Ds transposons were shown to be functional in approximately 20 plant species and have become the most widely used transposable elements for gene tagging and functional genomics approaches in plants. In this chapter we review the biology, regulation, and transposition mechanism of Ac/Ds elements in maize and heterologous plants. We discuss the parameters that are known to influence the functionality and transposition efficiency of Ac/Ds transposons and need to be considered when designing Ac transposase expression constructs and Ds elements for application in heterologous plant species.

  16. Determining density of maize canopy. 2: Airborne multispectral scanner data

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Cipra, J. E.

    1971-01-01

    Multispectral scanner data were collected in two flights over a light colored soil background cover plot at an altitude of 305 m. Energy in eleven reflective wavelength band from 0.45 to 2.6 microns was recorded. Four growth stages of maize (Zea mays L.) gave a wide range of canopy densities for each flight date. Leaf area index measurements were taken from the twelve subplots and were used as a measure of canopy density. Ratio techniques were used to relate uncalibrated scanner response to leaf area index. The ratios of scanner data values for the 0.72 to 0.92 micron wavelength band over the 0.61 to 0.70 micron wavelength band were calculated for each plot. The ratios related very well to leaf area index for a given flight date. The results indicated that spectral data from maize canopies could be of value in determining canopy density.

  17. The maize cystatin CC9 interacts with apoplastic cysteine proteases.

    PubMed

    van der Linde, Karina; Mueller, André N; Hemetsberger, Christoph; Kashani, Farnusch; van der Hoorn, Renier A L; Doehlemann, Gunther

    2012-11-01

    In a recent study we identified corn cystain9 (CC9) as a novel compatibility factor for the interaction of the biotrophic smut fungus Ustilago maydis with its host plant maize. CC9 is transcriptionally induced during the compatible interaction with U. maydis and localizes in the maize apoplast where it inhibits apoplastic papain-like cysteine proteases. The proteases are activated during incompatible interaction and salicylic acid (SA) treatment and, in turn, are sufficient to induce SA signaling including PR-gene expression. Therefore the inhibition of apoplastic papain-like cysteine proteases by CC9 is essential to suppress host immunity during U. maydis infection. Here were present new experimental data on the cysteine protease-cystatin interaction and provide an in silco analysis of plant cystatins and the identified apoplastic cysteine proteases.

  18. 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.

  19. The developmental dynamics of the maize leaf transcriptome.

    PubMed

    Li, Pinghua; Ponnala, Lalit; Gandotra, Neeru; Wang, Lin; Si, Yaqing; Tausta, S Lori; Kebrom, Tesfamichael H; Provart, Nicholas; Patel, Rohan; Myers, Christopher R; Reidel, Edwin J; Turgeon, Robert; Liu, Peng; Sun, Qi; Nelson, Timothy; Brutnell, Thomas P

    2010-12-01

    We have analyzed the maize leaf transcriptome using Illumina sequencing. We mapped more than 120 million reads to define gene structure and alternative splicing events and to quantify transcript abundance along a leaf developmental gradient and in mature bundle sheath and mesophyll cells. We detected differential mRNA processing events for most maize genes. We found that 64% and 21% of genes were differentially expressed along the developmental gradient and between bundle sheath and mesophyll cells, respectively. We implemented Gbrowse, an electronic fluorescent pictograph browser, and created a two-cell biochemical pathway viewer to visualize datasets. Cluster analysis of the data revealed a dynamic transcriptome, with transcripts for primary cell wall and basic cellular metabolism at the leaf base transitioning to transcripts for secondary cell wall biosynthesis and C(4) photosynthetic development toward the tip. This dataset will serve as the foundation for a systems biology approach to the understanding of photosynthetic development.

  20. Recent advances in maize nuclear proteomic studies reveal histone modifications.

    PubMed

    Casati, Paula

    2012-01-01

    The nucleus of eukaryotic organisms is highly dynamic and complex, containing different types of macromolecules including DNA, RNA, and a wide range of proteins. Novel proteomic applications have led to a better overall determination of nucleus protein content. Although nuclear plant proteomics is only at the initial phase, several studies have been reported and are summarized in this review using different plants species, such as Arabidopsis thaliana, rice, cowpea, onion, garden cress, and barrel clover. These include the description of the total nuclear or phospho-proteome (i.e., Arabidopsis, cowpea, onion), or the analysis of the differential nuclear proteome under different growth environments (i.e., Arabidopsis, rice, cowpea, onion, garden cress, and barrel clover). However, only few reports exist on the analysis of the maize nuclear proteome or its changes under various conditions. This review will present recent data on the study of the nuclear maize proteome, including the analysis of changes in posttranslational modifications in histone proteins. PMID:23248634

  1. Evidence for Agrobacterium-induced apoptosis in maize cells.

    PubMed

    Hansen, G

    2000-06-01

    Agrobacterium spp. can genetically transform most dicotyledonous plant cells whereas many monocot species are recalcitrant to Agrobacterium-mediated transformation. One major obstacle is that co-cultivation of Agrobacterium spp. with plant tissues often results in cell death. Report here is that, in maize tissues, this process resembles apoptosis, with characteristic DNA cleavage into oligonucleosomal fragments and morphological changes. Two anti-apoptotic genes from baculovirus, p35 and iap, had the ability to prevent the onset of apoptosis triggered by Agrobacterium spp. in maize tissues. p35 is reported to act as a direct inhibitor of a certain class of proteases (caspase) whereas i.a.p. may act upstream to prevent their activation. This evidence raises the possibility that caspase-like proteases may also be involved in the apoptotic pathway in plant cells.

  2. 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.

  3. Trans-Homolog Interactions Facilitating Paramutation in Maize

    PubMed Central

    Giacopelli, Brian John; Hollick, Jay Brian

    2015-01-01

    Paramutations represent locus-specific trans-homolog interactions affecting the heritable silencing properties of endogenous alleles. Although examples of paramutation are well studied in maize (Zea mays), the responsible mechanisms remain unclear. Genetic analyses indicate roles for plant-specific DNA-dependent RNA polymerases that generate small RNAs, and current working models hypothesize that these small RNAs direct heritable changes at sequences often acting as transcriptional enhancers. Several studies have defined specific sequences that mediate paramutation behaviors, and recent results identify a diversity of DNA-dependent RNA polymerase complexes operating in maize. Other reports ascribe broader roles for some of these complexes in normal genome function. This review highlights recent research to understand the molecular mechanisms of paramutation and examines evidence relevant to small RNA-based modes of transgenerational epigenetic inheritance. PMID:26149572

  4. 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. PMID:26919987

  5. 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.

  6. DNA sequence of the maize transposable element Dissociation.

    PubMed

    Döring, H P; Tillmann, E; Starlinger, P

    The DNA sequence of the terminal 4.2 kilobases (kb) of the 30-kb insertion in the endosperm sucrose synthase gene of maize mutant sh-m5933 shows that it comprises two identical 2,040-base pair (bp) segments, one inserted in the reverse direction into the other. We suggest that the 2,040-bp sequence is an example of the transposable element Dissociation described by Barbara McClintock. PMID:6318121

  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. Characterization of a Novel Polerovirus Infecting Maize in China

    PubMed Central

    Chen, Sha; Jiang, Guangzhuang; Wu, Jianxiang; Liu, Yong; Qian, Yajuan; Zhou, Xueping

    2016-01-01

    A novel virus, tentatively named Maize Yellow Mosaic Virus (MaYMV), was identified from the field-grown maize plants showing yellow mosaic symptoms on the leaves collected from the Yunnan Province of China by the deep sequencing of small RNAs. The complete 5642 nucleotide (nt)-long genome of the MaYMV shared the highest nucleotide sequence identity (73%) to Maize Yellow Dwarf Virus-RMV. Sequence comparisons and phylogenetic analyses suggested that MaYMV represents a new member of the genus Polerovirus in the family Luteoviridae. Furthermore, the P0 protein encoded by MaYMV was demonstrated to inhibit both local and systemic RNA silencing by co-infiltration assays using transgenic Nicotiana benthamiana line 16c carrying the GFP reporter gene, which further supported the identification of a new polerovirus. The biologically-active cDNA clone of MaYMV was generated by inserting the full-length cDNA of MaYMV into the binary vector pCB301. RT-PCR and Northern blot analyses showed that this clone was systemically infectious upon agro-inoculation into N. benthamiana. Subsequently, 13 different isolates of MaYMV from field-grown maize plants in different geographical locations of Yunnan and Guizhou provinces of China were sequenced. Analyses of their molecular variation indicate that the 3′ half of P3–P5 read-through protein coding region was the most variable, whereas the coat protein- (CP-) and movement protein- (MP-)coding regions were the most conserved. PMID:27136578

  9. DNA sequence of the maize transposable element Dissociation.

    PubMed

    Döring, H P; Tillmann, E; Starlinger, P

    The DNA sequence of the terminal 4.2 kilobases (kb) of the 30-kb insertion in the endosperm sucrose synthase gene of maize mutant sh-m5933 shows that it comprises two identical 2,040-base pair (bp) segments, one inserted in the reverse direction into the other. We suggest that the 2,040-bp sequence is an example of the transposable element Dissociation described by Barbara McClintock.

  10. 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.

  11. Heterogeneity of Maize Cytoplasmic Genomes among Male-Sterile Cytoplasms

    PubMed Central

    Pring, D. R.; Levings, C. S.

    1978-01-01

    Maize mitochondrial and chloroplast DNA's were prepared from normal (fertile) lines or single crosses and from members of the T, C, and S groups of male-sterile cytoplasms. Restriction endonucleases HindIII, BamI, EcoRI, and SalI were used to restrict the DNA, and the resultant fragments were electrophoresed in agarose gels. The results show that the N (fertile), T, C, and S cytoplasms each contained distinct mitochondrial DNA (mtDNA). These distinctive patterns were unaffected by nuclear genotype. No evidence of paternal inheritance of mtDNA was observed. Chloroplast DNA (ctDNA) from the N, C, and T cytoplasms was indistinguishable by HindIII, SalI, or EcoRI endonuclease digestion. The S cytoplasm ctDNA, however, was slightly different from that of other cytoplasms, as indicated by a slight displacement of one band in HindIII digests. The molecular weight of maize ctDNA was estimated to be as high as 88 x 106. Estimates of the minimum molecular weight of maize mtDNA ranged from 116–131 x 106, but the patterns were to complex for an unambiguous determination. Based on HindIII data, a comparison of the molecular weight of mtDNA bands common to the N, T. C, and S cytoplasms suggests that C cytoplasm most closely resembles N cytoplasm. The T and S sources are more divergent from the C and N cytoplasms. These results indicate a possible gradation of relatedness among male-sterile cytoplasms. The marked variation in mtDNA, with apparently less variation in ctDNA, represents circumstantial, but compelling, evidence that mtDNA may be involved in the male sterility and disease susceptibility traits in maize. PMID:17248823

  12. Maize cytokinin dehydrogenase isozymes are localized predominantly to the vacuoles.

    PubMed

    Zalabák, David; Johnová, Patricie; Plíhal, Ondřej; Šenková, Karolina; Šamajová, Olga; Jiskrová, Eva; Novák, Ondřej; Jackson, David; Mohanty, Amitabh; Galuszka, Petr

    2016-07-01

    The maize genome encompasses 13 genes encoding for cytokinin dehydrogenase isozymes (CKXs). These enzymes are responsible for irreversible degradation of cytokinin plant hormones and thus, contribute regulating their levels. Here, we focus on the unique aspect of CKXs: their diverse subcellular distribution, important in regulating cytokinin homeostasis. Maize CKXs were tagged with green fluorescent protein (GFP) and transiently expressed in maize protoplasts. Most of the isoforms, namely ZmCKX1, ZmCKX2, ZmCKX4a, ZmCKX5, ZmCKX6, ZmCKX8, ZmCKX9, and ZmCKX12, were associated with endoplasmic reticulum (ER) several hours after transformation. GFP-fused CKXs were observed to accumulate in putative prevacuolar compartments. To gain more information about the spatiotemporal localization of the above isoforms, we prepared stable expression lines of all ZmCKX-GFP fusions in Arabidopsis thaliana Ler suspension culture. All the ER-associated isoforms except ZmCKX1 and ZmCKX9 were found to be targeted primarily to vacuoles, suggesting that ER-localization is a transition point in the intracellular secretory pathway and vacuoles serve as these isoforms' final destination. ZmCKX9 showed an ER-like localization pattern similar to those observed in the transient maize assay. Apoplastic localization of ZmCKX1 was further confirmed and ZmCKX10 showed cytosolic/nuclear localization due to the absence of the signal peptide sequence as previously reported. Additionally, we prepared GFP-fused N-terminal signal deletion mutants of ZmCKX2 and ZmCKX9 and clearly demonstrated that the localization pattern of these mutant forms was cytosolic/nuclear. This study provides the first complex model for spatiotemporal localization of the key enzymes of the cytokinin degradation/catabolism in monocotyledonous plants. PMID:27031423

  13. Gene flow in maize fields with different local pollen densities

    NASA Astrophysics Data System (ADS)

    Goggi, A. Susana; Lopez-Sanchez, Higinio; Caragea, Petrutza; Westgate, Mark; Arritt, Raymond; Clark, Craig A.

    2007-08-01

    The development of maize ( Zea mays L.) varieties as factories of pharmaceutical and industrial compounds has renewed interest in controlling pollen dispersal. The objective of this study was to compare gene flow into maize fields of different local pollen densities under the same environmental conditions. Two fields of approximately 36 ha were planted with a nontransgenic, white hybrid, in Ankeny, Iowa, USA. In the center of both fields, a 1-ha plot of a yellow-seeded stacked RR/Bt transgenic hybrid was planted as a pollen source. Before flowering, the white receiver maize of one field was detasseled in a 4:1 ratio to reduce the local pollen density (RPD). The percentage of outcross in the field with RPD was 42.2%, 6.3%, and 1.3% at 1, 10, and 35 m from the central plot, respectively. The percentage of outcross in the white maize with normal pollen density (NPD) was 30.1%, 2.7%, and 0.4%, respectively, at these distances. At distances greater than 100 m, the outcross frequency decreased below 0.1 and 0.03% in the field with RPD and NPD, respectively. A statistical model was used to compare pollen dispersal based on observed outcross percentages. The likelihood ratio test confirmed that the models of outcrossing in the two fields were significantly different ( P is practically 0). Results indicated that when local pollen is low, the incoming pollen has a competitive advantage and the level of outcross is significantly greater than when the local pollen is abundant.

  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. 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. PMID:25473513

  16. 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.

  17. Intraplant communication in maize contributes to defense against insects.

    PubMed

    Varsani, Suresh; Basu, Saumik; Williams, W Paul; Felton, Gary W; Luthe, Dawn S; Louis, Joe

    2016-08-01

    The vasculature of plants act as a channel for transport of signal(s) that facilitate long-distance intraplant communication. In maize, Maize insect resistance1-Cysteine Protease (Mir1-CP), which has homology to papain-like proteases, provides defense to different feeding guilds of insect pests. Furthermore, accumulation of Mir1-CP in the vasculature suggests that Mir1-CP can potentially function as a phloem-mobile protein. In a recent study, we provided evidence that Mir1-CP can curtail the growth of phloem-sap sucking insect, corn leaf aphid (CLA; Rhopalosiphum maidis). Our current study further examined whether aboveground feeding by CLA can induce resistance to subsequent herbivory by belowground feeding western corn rootworm (WCR; Diabrotica virgifera virgifera). Aboveground feeding by CLA systemically induced the accumulation of Mir1-CP in the roots. Furthermore, foliage feeding by CLA provided enhanced resistance to subsequent herbivory by belowground feeding of WCR. Taken together, our previous findings and results presented here indicate that long-distance transport of Mir1-CP is critical for providing enhanced resistance to insect attack in maize. PMID:27467304

  18. 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

  19. Asymmetric distribution of acetylcholinesterase in gravistimulated maize seedlings.

    PubMed

    Momonoki, Y S

    1997-05-01

    Acetylcholinesterase (AChE) activity has previously been studied by this laboratory and shown to occur at the interface between the stele and cortex of the mesocotyl of maize (Zea mays L.) seedlings. In this work we studied the distribution of AChE activity in 5-d-old maize seedlings following a gravity stimulus. After the stimulus, we found an asymmetric distribution of the enzyme in the coleoptile, the coleoptile node, and the mesocotyl of the stimulated seedlings using both histochemical and colorimetric methods for measuring the hydrolysis of acetylthiocholine. The hydrolytic capability of the esterase was greater on the lower side of the horizontally placed seedlings. Using the histochemical method, we localized the hydrolytic capability in the cortical cells around the vascular stele of the tissues. The hydrolytic activity was inhibited 80 to 90% by neostigmine, an inhibitor of AChE. When neostigmine was applied to the corn kernel, the gravity response of the seedling was inhibited and no enzyme-positive spots appeared in the gravity-stimulated seedlings. We believe these results indicate a role for AChE in the gravity response of maize seedlings. PMID:11536808

  20. 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.

  1. Stability of the MON 810 transgene in maize.

    PubMed

    La Paz, Jose Luis; Pla, Maria; Papazova, Nina; Puigdomènech, Pere; Vicient, Carlos M

    2010-12-01

    We analysed the DNA variability of the transgene insert and its flanking regions in maize MON 810 commercial varieties. Southern analysis demonstrates that breeding, since the initial transformation event more than 10 years ago, has not resulted in any rearrangements. A detailed analysis on the DNA variability at the nucleotide level, using DNA mismatch endonuclease assays, showed the lack of polymorphisms in the transgene insert. We conclude that the mutation rate of the transgene is not significantly different from that observed in the maize endogenous genes. Six SNPs were observed in the 5'flanking region, corresponding to a Zeon1 retrotransposon long terminal repeat. All six SNPs are more than 500 bp upstream of the point of insertion of the transgene and do not affect the reliability of the established PCR-based transgene detection and quantification methods. The mutation rate of the flanking region is similar to that expected for a maize repetitive sequence. We detected low levels of cytosine methylation in leaves of different transgenic varieties, with no significant differences on comparing different transgenic varieties, and minor differences in cytosine methylation when comparing leaves at different developmental stages. There was also a reduction in cryIAb mRNA accumulation during leaf development. PMID:20936423

  2. 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.

  3. Regulation of phytochrome message abundance in root caps of maize

    NASA Technical Reports Server (NTRS)

    Johnson, E. M.; Pao, L. I.; Feldman, L. J.

    1991-01-01

    In many cultivars of maize (Zea mays L.) red light affects root development via the photomorphogenetic pigment phytochrome. The site of perception for the light is the root cap. In the maize cultivar Merit, we investigated phytochrome-mediated events in the cap. We established that the message encoded by the phyA1 gene was most abundant in dark-grown tissue and was asymmetrically distributed in the root cap, with greatest expression in the cells which make up the central columella core of the cap. Phytochrome message was negatively autoregulated in a specific region within the root cap. This autoregulation was sensitive to very-low-fluence red light, and thus was characterized as a phytochrome-mediated, very-low-fluence event. The kinetics of message reaccumulation in the dark were also examined and compared to the kinetics of the light requirement for root gravitropism in this cultivar. Similarly, the degree of autoregulation present in two other maize cultivars with different light requirements for gravitropic sensitivity was investigated. It appears that the Merit cultivar expresses a condition of hypersensitivity to phytochrome-mediated light regulation in root tissues. We conclude that phytochrome regulates many activities within the cap, but the degree to which these activities share common phytochrome-mediated steps is not known.

  4. 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.

  5. Intraplant communication in maize contributes to defense against insects.

    PubMed

    Varsani, Suresh; Basu, Saumik; Williams, W Paul; Felton, Gary W; Luthe, Dawn S; Louis, Joe

    2016-08-01

    The vasculature of plants act as a channel for transport of signal(s) that facilitate long-distance intraplant communication. In maize, Maize insect resistance1-Cysteine Protease (Mir1-CP), which has homology to papain-like proteases, provides defense to different feeding guilds of insect pests. Furthermore, accumulation of Mir1-CP in the vasculature suggests that Mir1-CP can potentially function as a phloem-mobile protein. In a recent study, we provided evidence that Mir1-CP can curtail the growth of phloem-sap sucking insect, corn leaf aphid (CLA; Rhopalosiphum maidis). Our current study further examined whether aboveground feeding by CLA can induce resistance to subsequent herbivory by belowground feeding western corn rootworm (WCR; Diabrotica virgifera virgifera). Aboveground feeding by CLA systemically induced the accumulation of Mir1-CP in the roots. Furthermore, foliage feeding by CLA provided enhanced resistance to subsequent herbivory by belowground feeding of WCR. Taken together, our previous findings and results presented here indicate that long-distance transport of Mir1-CP is critical for providing enhanced resistance to insect attack in maize.

  6. 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

  7. 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

  8. 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. PMID:26714286

  9. 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.

  10. Functional Potential of Soil Microbial Communities in the Maize Rhizosphere

    PubMed Central

    Xiong, Jingbo; Li, Jiabao; He, Zhili; Zhou, Jizhong; Yannarell, Anthony C.; Mackie, Roderick I.

    2014-01-01

    Microbial communities in the rhizosphere make significant contributions to crop health and nutrient cycling. However, their ability to perform important biogeochemical processes remains uncharacterized. Here, we identified important functional genes that characterize the rhizosphere microbial community to understand metabolic capabilities in the maize rhizosphere using the GeoChip-based functional gene array method. Significant differences in functional gene structure were apparent between rhizosphere and bulk soil microbial communities. Approximately half of the detected gene families were significantly (p<0.05) increased in the rhizosphere. Based on the detected gyrB genes, Gammaproteobacteria, Betaproteobacteria, Firmicutes, Bacteroidetes and Cyanobacteria were most enriched in the rhizosphere compared to those in the bulk soil. The rhizosphere niche also supported greater functional diversity in catabolic pathways. The maize rhizosphere had significantly enriched genes involved in carbon fixation and degradation (especially for hemicelluloses, aromatics and lignin), nitrogen fixation, ammonification, denitrification, polyphosphate biosynthesis and degradation, sulfur reduction and oxidation. This research demonstrates that the maize rhizosphere is a hotspot of genes, mostly originating from dominant soil microbial groups such as Proteobacteria, providing functional capacity for the transformation of labile and recalcitrant organic C, N, P and S compounds. PMID:25383887

  11. Lactobacillus rhamnosus as additive for maize and sorghum ensiling.

    PubMed

    Salimei, Elisabetta; Capilongo, Valeria; Simoni, Andrea; Peiretti, Pier Giorgio; Maglieri, Cristina; Romano, Cristina A; Mannina, Luisa; Coppola, Raffaele; Sorrentino, Elena

    2007-11-14

    The effects of Lactobacillus rhamnosus AT195, a potential probiotic microorganism cultured in buffalo "scotta" whey, on chemical and microbiological composition in maize and sorghum ensiling were evaluated. Both crops were harvested, chopped, and treated or not with the selected strain prior to ensiling in fiberglass vertical silos; 90 days after ensiling, silages were sensorially evaluated and sampled. Different chemical components were evaluated both on fresh crops and silages: in particular, the water-soluble carbohydrates content was investigated by high-field NMR spectroscopy and the carbohydrate fermentation profile was performed by GC. Besides phenotypic identification and typing, microbiological studies included Lb. rhamnosus genotype typing by RAPD-PCR. All silages, inoculated or not, were well preserved, as their chemical and microbiological data along with the fermentation profiles showed. The selected strain used as inoculum influenced the lactic acid population of silages and evidenced a good survival performance during the ensiling process of both maize and sorghum. Moreover, the use of Lb. rhamnosus strain efficiently improved the quality of the multifactorial ensiling process by significantly reducing the ammonia nitrogen content of both maize and sorghum silages.

  12. Field-evolved resistance by western corn rootworm to multiple Bacillus thuringiensis toxins in transgenic maize.

    PubMed

    Gassmann, Aaron J; Petzold-Maxwell, Jennifer L; Clifton, Eric H; Dunbar, Mike W; Hoffmann, Amanda M; Ingber, David A; Keweshan, Ryan S

    2014-04-01

    The widespread planting of crops genetically engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) places intense selective pressure on pest populations to evolve resistance. Western corn rootworm is a key pest of maize, and in continuous maize fields it is often managed through planting of Bt maize. During 2009 and 2010, fields were identified in Iowa in which western corn rootworm imposed severe injury to maize producing Bt toxin Cry3Bb1. Subsequent bioassays revealed Cry3Bb1 resistance in these populations. Here, we report that, during 2011, injury to Bt maize in the field expanded to include mCry3A maize in addition to Cry3Bb1 maize and that laboratory analysis of western corn rootworm from these fields found resistance to Cry3Bb1 and mCry3A and cross-resistance between these toxins. Resistance to Bt maize has persisted in Iowa, with both the number of Bt fields identified with severe root injury and the ability western corn rootworm populations to survive on Cry3Bb1 maize increasing between 2009 and 2011. Additionally, Bt maize targeting western corn rootworm does not produce a high dose of Bt toxin, and the magnitude of resistance associated with feeding injury was less than that seen in a high-dose Bt crop. These first cases of resistance by western corn rootworm highlight the vulnerability of Bt maize to further evolution of resistance from this pest and, more broadly, point to the potential of insects to develop resistance rapidly when Bt crops do not achieve a high dose of Bt toxin.

  13. 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

  14. Field-evolved resistance by western corn rootworm to multiple Bacillus thuringiensis toxins in transgenic maize

    PubMed Central

    Gassmann, Aaron J.; Petzold-Maxwell, Jennifer L.; Clifton, Eric H.; Dunbar, Mike W.; Hoffmann, Amanda M.; Ingber, David A.; Keweshan, Ryan S.

    2014-01-01

    The widespread planting of crops genetically engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) places intense selective pressure on pest populations to evolve resistance. Western corn rootworm is a key pest of maize, and in continuous maize fields it is often managed through planting of Bt maize. During 2009 and 2010, fields were identified in Iowa in which western corn rootworm imposed severe injury to maize producing Bt toxin Cry3Bb1. Subsequent bioassays revealed Cry3Bb1 resistance in these populations. Here, we report that, during 2011, injury to Bt maize in the field expanded to include mCry3A maize in addition to Cry3Bb1 maize and that laboratory analysis of western corn rootworm from these fields found resistance to Cry3Bb1 and mCry3A and cross-resistance between these toxins. Resistance to Bt maize has persisted in Iowa, with both the number of Bt fields identified with severe root injury and the ability western corn rootworm populations to survive on Cry3Bb1 maize increasing between 2009 and 2011. Additionally, Bt maize targeting western corn rootworm does not produce a high dose of Bt toxin, and the magnitude of resistance associated with feeding injury was less than that seen in a high-dose Bt crop. These first cases of resistance by western corn rootworm highlight the vulnerability of Bt maize to further evolution of resistance from this pest and, more broadly, point to the potential of insects to develop resistance rapidly when Bt crops do not achieve a high dose of Bt toxin. PMID:24639498

  15. A rapid and efficient method for assessing pathogenicity of ustilago maydis on maize and teosinte lines.

    PubMed

    Chavan, Suchitra; Smith, Shavannor M

    2014-01-03

    Maize is a major cereal crop worldwide. However, susceptibility to biotrophic pathogens is the primary constraint to increasing productivity. U. maydis is a biotrophic fungal pathogen and the causal agent of corn smut on maize. This disease is responsible for significant yield losses of approximately $1.0 billion annually in the U.S.(1) Several methods including crop rotation, fungicide application and seed treatments are currently used to control corn smut(2). However, host resistance is the only practical method for managing corn smut. Identification of crop plants including maize, wheat, and rice that are resistant to various biotrophic pathogens has significantly decreased yield losses annually(3-5). Therefore, the use of a pathogen inoculation method that efficiently and reproducibly delivers the pathogen in between the plant leaves, would facilitate the rapid identification of maize lines that are resistant to U. maydis. As, a first step toward indentifying maize lines that are resistant to U. maydis, a needle injection inoculation method and a resistance reaction screening method was utilized to inoculate maize, teosinte, and maize x teosinte introgression lines with a U. maydis strain and to select resistant plants. Maize, teosinte and maize x teosinte introgression lines, consisting of about 700 plants, were planted, inoculated with a strain of U. maydis, and screened for resistance. The inoculation and screening methods successfully identified three teosinte lines resistant to U. maydis. Here a detailed needle injection inoculation and resistance reaction screening protocol for maize, teosinte, and maize x teosinte introgression lines is presented. This study demonstrates that needle injection inoculation is an invaluable tool in agriculture that can efficiently deliver U. maydis in between the plant leaves and has provided plant lines that are resistant to U. maydis that can now be combined and tested in breeding programs for improved disease resistance.

  16. 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.

  17. Field trials to evaluate the effects of transgenic cry1Ie maize on the community characteristics of arthropod natural enemies

    PubMed Central

    Guo, Jingfei; He, Kanglai; Hellmich, Richard L.; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Ahmed, Tofael; Wang, Zhenying

    2016-01-01

    Possible non-target effect of transgenic cry1Ie maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr comparison of transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community biodiversity were compared with whole plant inspections, pitfall traps and suction sampler. Natural enemy diversity indices (Shannon-Wiener’, Simpson’s and Pielou’s index) and abundance suggested there were no significant differences between the two types of maize. The only exceptions were the Pielou’s index for whole plant inspections in 2013 and abundance for pitfall traps in 2012, which were significantly higher in Bt maize than those of non-Bt maize. The main species of natural enemies were identical in Bt and non-Bt maize plots for each method and the three methods combined. For whole plant inspections, Bt maize had no time-dependent effect on the entire arthropod natural enemy community, and also no effect on community dissimilarities between Bt and non-Bt maize plots. These results suggested that despite the presence of a relatively minor difference in natural enemy communities between Bt and non-Bt maize, transgenic cry1Ie maize had little, if any, effect on natural enemy community biodiversity. PMID:26915985

  18. Whole genome association study for drought, aflatoxin resistance, and important agronomic traits in maize in a sub-tropical environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world, where most maize breeding is focused. Important but lower yielding maize growing regions, such as the sub-tropics, experience unique challenges the greatest of which are drought stress and aflatoxin conta...

  19. 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...

  20. 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...

  1. Interactions among Bt maize, entomopathogens, and rootworm species (Coleoptera: Chrysomelidae) in the field: effects on survival, yield and root injury

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two year field study was conducted to determine how a blend of entomopathogens interacts with Bt maize to affect survival of corn rootworm (Diabrotica spp.) species and performance of maize (Zea maize L.). The blend of entomopathogens included two entomopathogenic nematodes, Steinernema carpocaps...

  2. 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...

  3. Field trials to evaluate the effects of transgenic cry1Ie maize on the community characteristics of arthropod natural enemies.

    PubMed

    Guo, Jingfei; He, Kanglai; Hellmich, Richard L; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Ahmed, Tofael; Wang, Zhenying

    2016-02-26

    Possible non-target effect of transgenic cry1Ie maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr comparison of transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community biodiversity were compared with whole plant inspections, pitfall traps and suction sampler. Natural enemy diversity indices (Shannon-Wiener', Simpson's and Pielou's index) and abundance suggested there were no significant differences between the two types of maize. The only exceptions were the Pielou's index for whole plant inspections in 2013 and abundance for pitfall traps in 2012, which were significantly higher in Bt maize than those of non-Bt maize. The main species of natural enemies were identical in Bt and non-Bt maize plots for each method and the three methods combined. For whole plant inspections, Bt maize had no time-dependent effect on the entire arthropod natural enemy community, and also no effect on community dissimilarities between Bt and non-Bt maize plots. These results suggested that despite the presence of a relatively minor difference in natural enemy communities between Bt and non-Bt maize, transgenic cry1Ie maize had little, if any, effect on natural enemy community biodiversity.

  4. A 90-day toxicology study of transgenic lysine-rich maize grain (Y642) in Sprague-Dawley rats.

    PubMed

    He, Xiao Yun; Tang, Mao Zhi; Luo, Yun Bo; Li, Xin; Cao, Si Shuo; Yu, Jing Juan; Delaney, Bryan; Huang, Kun Lun

    2009-02-01

    The gene for a lysine-rich protein (sb401) obtained from potatoes (Solanum berthaultii) was inserted into maize seed to produce Y642 transgenic maize. Compositional analysis of Y642 grain demonstrated that the concentrations of lysine and total protein were higher than those observed in maize grain from a near-isogenic non-genetically modified (non-GM) commercially available control quality protein maize (Nongda 108). The safety of Y642 maize grain was assessed by comparison of toxicology response variables in Sprague-Dawley (SD) rats consuming diets containing Y642 maize grain with those containing Nongda 108 maize grain. Maize grains from Y642 or Nongda 108 were incorporated into rodent diets at low (30%) or high concentrations (76%) and administered to SD rats (n=10/sex/group) for 90 days. An additional group of negative control group of rats (n=10/sex/group) were fed AIN93G diets. No adverse diet-related differences in body weights, feed consumption/utilization, clinical chemistry, hematology, absolute and relative organ weights were observed. Further, no differences in gross or microscopic pathology were observed between rats consuming diets with Y642 maize grain compared with rats consuming diets containing Nongda 108 maize grain. These results demonstrated that Y642 lysine-rich maize is as safe and nutritious as conventional quality protein maize.

  5. 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

  6. 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. PMID:22639639

  7. 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.

  8. Different effects of transgenic maize and nontransgenic maize on nitrogen-transforming archaea and bacteria in tropical soils.

    PubMed

    Cotta, Simone Raposo; Dias, Armando Cavalcante Franco; Marriel, Ivanildo Evódio; Andreote, Fernando Dini; Seldin, Lucy; van Elsas, Jan Dirk

    2014-10-01

    The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCR-denaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants. PMID:25107970

  9. The products of a single maize sesquiterpene synthase form a volatile defense signal that attracts natural enemies of maize herbivores

    PubMed Central

    Schnee, Christiane; Köllner, Tobias G.; Held, Matthias; Turlings, Ted C. J.; Gershenzon, Jonathan; Degenhardt, Jörg

    2006-01-01

    Plants can defend themselves against herbivores by attracting natural enemies of the herbivores. The cues for attraction are often complex mixtures of herbivore-induced plant volatiles, making it difficult to demonstrate the role of specific compounds. After herbivory by lepidopteran larvae, maize releases a mixture of volatiles that is highly attractive to females of various parasitic wasp species. We identified the terpene synthase TPS10 that forms (E)-β-farnesene, (E)-α-bergamotene, and other herbivory-induced sesquiterpene hydrocarbons from the substrate farnesyl diphosphate. The corresponding gene is expressed in response to herbivore attack and is regulated at the transcript level. Overexpression of tps10 in Arabidopsis thaliana resulted in plants emitting high quantities of TPS10 sesquiterpene products identical to those released by maize. Using these transgenic Arabidopsis plants as odor sources in olfactometer assays showed that females of the parasitoid Cotesia marginiventris learn to exploit the TPS10 sesquiterpenes to locate their lepidopteran hosts after prior exposure to these volatiles in association with hosts. This dissection of the herbivore-induced volatile blend demonstrates that a single gene such as tps10 can be sufficient to mediate the indirect defense of maize against herbivore attack. PMID:16418295

  10. Molecular, mesoscopic and microscopic structure evolution during amylase digestion of extruded maize and high amylose maize starches.

    PubMed

    Shrestha, Ashok K; Blazek, Jaroslav; Flanagan, Bernadine M; Dhital, Sushil; Larroque, Oscar; Morell, Matthew K; Gilbert, Elliot P; Gidley, Michael J

    2015-03-15

    Extrusion processing of cereal starch granules with high (>50%) amylose content is a promising approach to create nutritionally desirable resistant starch, i.e. starch that escapes digestion in the small intestine. Whilst high amylose content seems to be required, the structural features responsible for the slow digestion of extrudates are not fully understood. We report the effects of partial enzyme digestion of extruded maize starches on amylopectin branch length profiles, double and single helix contents, crystallinity and lamellar periodicity. Comparing results for three extruded maize starches (27, 57, and 84% apparent amylose) that differ in amylase-sensitivity allows conclusions to be drawn concerning the rate-determining features operating under the digestion conditions used. Enzyme resistance is shown to originate from a combination of molecular and mesoscopic factors, including both recrystallization and an increase in very short branches during the digestion process. This is in contrast to the behaviour of the same starches in the granular form (Shrestha et al., 2012) where molecular and mesoscopic factors are secondary to microscopic structures in determining enzyme susceptibility. Based on the structure of residual material after long-time digestion (>8h), a model for resistant starch from processed high amylose maize starches is proposed based on a fringed micelle structure with lateral aggregation and enzyme susceptibility both limited by attached clusters of branch points.

  11. 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...

  12. Pre- and Post-Harvest Management of Aflatoxin in Maize: An African Perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pre- and post-harvest contamination of aflatoxin in maize is a major health deterrent of people in Africa where increase in production of the crop has been dramatic. This paper discusses management options to manage pre- and post-harvest toxin contamination in maize. Sound crop management practice...

  13. Physiological Workload of Women Agricultural Labourers in Selected Activities in Maize Cultivation

    NASA Astrophysics Data System (ADS)

    Singh, Shiv Pratap

    2015-03-01

    Experiments were conducted to know the physiological workload of farm women in plucking of maize cobs from standing and harvested plants, harvesting, dehusking and shelling the maize cobs. Participating farm women (subjects) were physically fit for the experiments. Average force required in plucking the cobs from standing plant was 7.3 N that varied from 3 to 15 N. Force required in removing a layer from un-dehusked cob was 2.94 N while it was 19.7 N when 3-4 layers had to be removed. Physiological workload of subjects was of light category for the activities of maize cob plucking from harvested plants, dehusking, and shelling the cobs while it was of moderate category for the activities of maize cob plucking from standing plants, and harvesting the maize plants in the field. Protective gear was needed for plucking the maize cobs and harvesting the maize plants. Higher heart beat consumption and drudgery in dehusking and shelling tasks suggested using improved maize dehusker-sheller.

  14. Intercropping Tropical Vine Legumes and Maize for Silage in Temperate Climates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize silage is used extensively in American dairy rations. Increasing protein content would enhance maize silage quality. This study examined nine forage legume species (Austrian winter pea, common bean, cowpea, lablab, scarlet runner bean, sesbania, sunn hemp, tropical kudzu, and velvet bean) gr...

  15. 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...

  16. 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...

  17. 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...

  18. Genetic, Genomic, and Breeding Approaches to Further Explore Kernel Composition Traits and Grain Yield in Maize

    ERIC Educational Resources Information Center

    Da Silva, Helena Sofia Pereira

    2009-01-01

    Maize ("Zea mays L.") is a model species well suited for the dissection of complex traits which are often of commercial value. The purpose of this research was to gain a deeper understanding of the genetic control of maize kernel composition traits starch, protein, and oil concentration, and also kernel weight and grain yield. Germplasm with…

  19. 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...

  20. Crop Rotation and N Input Effects on Soil Fertility, Maize Mineral Nutrition, Yield, and Seed Composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield of maize (Zea mays L.) rotated annually with soybean (Glycine max merr.) is better than its yield in monoculture. To determine how maize would respond to rotations that includes wheat (Triticum aestivum L.) and alfalfa (Medicago sativa L.) under different levels of N input, we evaluated N fer...

  1. 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...

  2. 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...

  3. 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.

  4. Field screening of maize germplasm lines for whorl-feeding fall armyworm resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new set of 13 maize germplasm lines from the Germplasm Enhancement of Maize (GEM) Program was examined with 5 controls that have different degrees of insect resistance. Significant difference in fall armyworm damage ratings was detected among the GEM inbred lines. In addition, the total number of ...

  5. 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-...

  6. Complete Genomic Sequence of Maize Rough Dwarf Virus, a Fijivirus Transmitted by the Small Brown Planthopper

    PubMed Central

    Lv, Mingfang; Xie, Li; Yang, Jian

    2016-01-01

    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. PMID:26847903

  7. Metabolic response of maize plants to multi-factorial abiotic stresses.

    PubMed

    Sun, C X; Li, M Q; Gao, X X; Liu, L N; Wu, X F; Zhou, J H

    2016-01-01

    Clarification of the metabolic mechanisms underlying multi-stress responses in plants will allow further optimisation of crop breeding and cultivation to obtain high yields in an increasingly variable environment. Using NMR metabolomic techniques, we examined the metabolic responses of maize plants grown under different conditions: soil drought, soil salinity, heat and multiple concurrent stresses. A detailed time-course metabolic profile was also performed on maize plants sampled 1, 3 and 7 days after initiation of soil drought and heat stress. The metabolic profile of maize plants subjected to soil drought was more similar to plants exposed to salt stress than to heat-stressed plants. Drought-stressed maize plants subjected to salt or heat stress showed distinct integrated metabolic profiles compared with those exposed to either stressor individually. These differences show the considerable metabolic plasticity of maize in response to different growth conditions. Moreover, glucose, fructose, malate, citrate, proline, alanine, aspartate, asparagine, threonine and one unknown compound fluctuated obviously between maize plants grown in controlled growth cabinet and a natural regime. These changes were associated with the TCA cycle and core nitrogen metabolism, and could be related to their multiple functions during plant growth. The evident stress-induced trajectory of metabolic changes in maize indicated that the primary metabolic responses to soil drought, heat and combined drought and heat stresses occurred in a time-dependent manner. Plasticity at the metabolic level may allow maize plants to acclimatise their metabolic ranges in response to changing environmental conditions. PMID:25622534

  8. 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

    2016-01-01

    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. PMID:26847903

  9. Influence of genetic background on anthocyanin and copigment composition and behavior during thermoalkaline processing of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visual color is a primary factor for foods purchase; identifying factors that influence in-situ color quality of pigmented maize during processing is important. We used 24 genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) to investigate the effect of pigment and copigme...

  10. 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...

  11. 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 (...

  12. Physicochemical and pasting properties of maize as affected by storage temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize grains are used as raw material in various food products. In countries where the production is seasonal, the grains must be stored during all the year in order to provide maize supply for food industries and consumers. During storage, the temperature is known as one of the most critical variab...

  13. 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...

  14. Plant host range and leafhopper transmission of Maize fine streak virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize fine streak virus (MFSV), an emerging rhabdovirus species in the genus Nucleorhabdovirus, is persistently transmitted by the black-faced leafhopper, Graminella nigrifrons (Forbes). MFSV was transmitted to maize, wheat, oats, rye, barley, foxtail, annual ryegrass and quackgrass by G. nigrifron...

  15. Effects of elevated [CO2 ] on maize defence against mycotoxigenic Fusarium verticillioides.

    PubMed

    Vaughan, Martha M; Huffaker, Alisa; Schmelz, Eric A; Dafoe, Nicole J; Christensen, Shawn; Sims, James; Martins, Vitor F; Swerbilow, Jay; Romero, Maritza; Alborn, Hans T; Allen, Leon Hartwell; Teal, Peter E A

    2014-12-01

    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 aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2 ] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2 ] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F. verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2 ]. Following F. verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2 ]. The attenuation of maize 13-LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2 ]. Our findings suggest that elevated [CO2 ] will compromise maize LOX-dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi. PMID:24689748

  16. 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...

  17. 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...

  18. Comparison of nine PCR primer sets designed to detect Pantoea stewartii subsp. stewartii in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea stewartii subsp. stewartii, the causal agent of Stewart's bacterial wilt of maize, is a major quarantine pest in maize seed. Verifying freedom from P. stewartii remains a significant hurdle in exporting corn seed from the U.S. Several PCR primer sets have been developed and suggested as bein...

  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. 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...

  1. Identification of gene markers in aflatoxin-resistant maize germplasm for marker-assisted breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The discovery of maize lines with natural resistance to Aspergillus flavus infection and/or aflatoxin production has aided host resistance in becoming a viable approach for the elimination of aflatoxin contamination of maize. Further breeding involving resistant lines is developing sources of resist...

  2. Drought Responses of Foliar Metabolites in Three Maize Hybrids Differing in Water Stress Tolerance

    PubMed Central

    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. PMID:24143208

  3. Soil carbon sequestration by switchgrass and no-till maize grown for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Net environmental benefits of bioenergy crops including maize and perennial grasses such as switchgrass, are a function of several factors including the soil organic carbon (SOC) sequestered by these crops. In 1998, a long-term SOC study was established in eastern Nebraska for switchgrass and maize ...

  4. 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.

  5. 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...

  6. 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...

  7. 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 ...

  8. 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...

  9. Molecular characterization of Fusarium globosum strains from South African maize and Japanese wheat.

    PubMed

    Moses, Lorraine M; Marasas, Walter F O; Vismer, Hester F; De Vos, Lieschen; Rheeder, John P; Proctor, Robert H; Wingfield, Brenda D

    2010-10-01

    The fungus Fusarium globosum was first isolated from maize in South Africa and subsequently from wheat in Japan. Here, multiple analyses revealed that, despite morphological similarities, South African maize and Japanese wheat isolates of the fungus exhibit multiple differences. An amplified fragment length polymorphism-based similarity index for the two groups of isolates was only 45%. Most maize isolates produced relatively high levels of fumonisins, whereas wheat isolates produced little or no fumonisins. The fumonisin biosynthetic gene FUM1 was detected in maize isolates by Southern blot analysis but not in the wheat isolates. In addition, most of the maize isolates produced sclerotia, and all of them produced large orange to dark purple sporodochia in carrot agar culture, whereas wheat isolates did not produce either structure. In contrast, individual isolates from both maize and wheat carried markers for both mating type idiomorphs, which indicates that the fungus may be homothallic. However, a sexual stage of F. globosum was not formed under standard self-fertilization conditions developed for other homothallic species of Fusarium. The inability to produce the sexual stage is consistent with the high similarity of 87-100% and G (ST) index of 1.72 for the maize isolates, which suggests that these isolates are undergoing asexual but not sexual reproduction. Together, the results suggest that the South African maize and Japanese wheat isolates of F. globosum are distinct populations and could be different species.

  10. 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...

  11. A maize lectin-like protein with antifungal activity against Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The filamentous fungus, Aspergillus flavus, causes an ear rot on maize and produces a mycotoxin, aflatoxin, in colonized maize kernels. Aflatoxins are carcinogenic to humans and animals upon ingestion. The presence of aflatoxins in food and feed is strictly regulated by several governmental agenci...

  12. Charles W. Stuber: Maize geneticist and pioneer of marker-assisted selection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charles W. Stuber is considered a pioneer of quantitative genetic mapping and marker-assisted selection in maize. The achievements of his four decade career in research include the development of genetic marker systems used in maize and adapted in many other crops, the first methods and studies to i...

  13. 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...

  14. 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...

  15. Charge, size, and cellular selectivity for multiwall carbon nanotubes by maize and soybean.

    PubMed

    Zhai, Guangshu; Gutowski, Sarah M; Walters, Katherine S; Yan, Bing; Schnoor, Jerald L

    2015-06-16

    Maize (Zea mays) and soybean (Glycine max) were used as model food-chain plants to explore vegetative uptake of differently charged multiwall carbon nanotubes (MWCNTs). Three types of MWCNTs, including neutral pristine MWCNT (p-MWCNT), positively charged MWCNT-NH2, and negatively charged MWCNT-COOH, were directly taken-up and translocated from hydroponic solution to roots, stems, and leaves of maize and soybean plants at the MWCNT concentrations ranging from 10.0 to 50.0 mg/L during 18-day exposures. MWCNTs accumulated in the xylem and phloem cells and within specific intracellular sites like the cytoplasm, cell wall, cell membrane, chloroplast, and mitochondria, which was observed by transmission electron microscopy. MWCNTs stimulated the growth of maize and inhibited the growth of soybean at the exposed doses. The cumulative transpiration of water in maize exposed to 50 mg/L of MWCNT-COOHs was almost twice as much as that in the maize control. Dry biomass of maize exposed to MWCNTs was greater than that of maize control. In addition, the uptake and translocation of these MWCNTs clearly exhibited cellular, charge, and size selectivity in maize and soybean, which could be important properties for nanotransporters. This is the first report of cellular, charge, and size selectivity on the uptake by whole food plants for three differently charged MWCNTs. PMID:26010305

  16. [Medical and biological safety assessment of genetically modified maize strain MIR604].

    PubMed

    Tutel'ian, V A; Gapparov, M M G; Avren'eva, L I; Aksiuk, I N; Guseva, G V; Kravchenko, L V; L'vova, L S; Saprykin, V P; Tyshko, N V; Chernysheva, O N

    2009-01-01

    The results of toxicologo-hygienic examinations, which were conducted within the framework of integrated medical and biological assessment of genetically modified rootworm Diabrotica spp.-protected maize event MIR604, are presented. Analysis of morphological, hematological, biochemical parameters and system (sensitive) biomarkers has not confirmed any toxic effect of maize event MIR604.

  17. A sorghum MYB transcription factor induces 3-deoxyanthocyanidins and enhances resistance against leaf blights in maize.

    PubMed

    Ibraheem, Farag; Gaffoor, Iffa; Tan, Qixian; Shyu, Chi-Ren; Chopra, Surinder

    2015-01-01

    Sorghum responds to the ingress of the fungal pathogen Colletotrichum sublineolum through the biosynthesis of 3-deoxyanthocyanidin phytoalexins at the site of primary infection. Biosynthesis of 3-deoxyanthocyanidins in sorghum requires a MYB transcription factor encoded by yellow seed1 (y1), an orthologue of the maize gene pericarp color1 (p1). Maize lines with a functional p1 and flavonoid structural genes do not produce foliar 3-deoxyanthocyanidins in response to fungal ingress. To perform a comparative metabolic analysis of sorghum and maize 3-deoxyanthocyanidin biosynthetic pathways, we developed transgenic maize lines expressing the sorghum y1 gene. In maize, the y1 transgene phenocopied p1-regulated pigment accumulation in the pericarp and cob glumes. LC-MS profiling of fungus-challenged Y1-maize leaves showed induction of 3-deoxyanthocyanidins, specifically luteolinidin. Y1-maize plants also induced constitutive and higher levels of flavonoids in leaves. In response to Colletotrichum graminicola, Y1-maize showed a resistance response. PMID:25647576

  18. Life-History Traits of Spodoptera frugiperda Populations Exposed to Low-Dose Bt Maize

    PubMed Central

    Sousa, Fernanda F.; Mendes, Simone M.; Santos-Amaya, Oscar F.; Araújo, Octávio G.; Oliveira, Eugenio E.

    2016-01-01

    Exposure to Bacillus thuringiensis (Bt) toxins in low- and moderate-dose transgenic crops may induce sublethal effects and increase the rate of Bt resistance evolution, potentially compromising control efficacy against target pests. We tested this hypothesis using the fall armyworm Spodoptera frugiperda, a major polyphagous lepidopteran pest relatively tolerant to Bt notorious for evolving field-relevant resistance to single-gene Bt maize. Late-instar larvae were collected from Bt Cry1Ab and non-Bt maize fields in five locations in Brazil, and their offspring was compared for survival, development, and population growth in rearing environment without and with Cry1Ab throughout larval development. Larval survival on Cry1Ab maize leaves varied from 20 to 80% among the populations. Larvae reared on Cry1Ab maize had seven-day delay in development time in relation to control larvae, and such delay was shorter in offspring of armyworms from Cry1Ab maize. Population growth rates were 50–70% lower for insects continuously exposed to Cry1Ab maize relative to controls, showing the population-level effect of Cry1Ab, which varied among the populations and prior exposure to Cry1Ab maize in the field. In three out of five populations, armyworms derived from Bt maize reared on Cry1Ab maize showed higher larval weight, faster larval development and better reproductive performance than the armyworms derived from non-Bt maize, and one of these populations showed better performance on both Cry1Ab and control diets, indicating no fitness cost of the resistance trait. Altogether, these results indicate that offspring of armyworms that developed on field-grown, single-gene Bt Cry1Ab maize had reduced performance on Cry1Ab maize foliage in two populations studied, but in other three populations, these offspring had better overall performance on the Bt maize foliage than that of the armyworms from non-Bt maize fields, possibly because of Cry1Ab resistance alleles in these populations

  19. The origin and evolution of maize in the Southwestern United States.

    PubMed

    da Fonseca, Rute R; Smith, Bruce D; Wales, Nathan; Cappellini, Enrico; Skoglund, Pontus; Fumagalli, Matteo; Samaniego, José Alfredo; Carøe, Christian; Ávila-Arcos, María C; Hufnagel, David E; Korneliussen, Thorfinn Sand; Vieira, Filipe Garrett; Jakobsson, Mattias; Arriaza, Bernardo; Willerslev, Eske; Nielsen, Rasmus; Hufford, Matthew B; Albrechtsen, Anders; Ross-Ibarra, Jeffrey; Gilbert, M Thomas P

    2015-01-01

    The origin of maize (Zea mays mays) in the US Southwest remains contentious, with conflicting archaeological data supporting either coastal(1-4) or highland(5,6) routes of diffusion of maize into the United States. Furthermore, the genetics of adaptation to the new environmental and cultural context of the Southwest is largely uncharacterized(7). To address these issues, we compared nuclear DNA from 32 archaeological maize samples spanning 6,000 years of evolution to modern landraces. We found that the initial diffusion of maize into the Southwest about 4,000 years ago is likely to have occurred along a highland route, followed by gene flow from a lowland coastal maize beginning at least 2,000 years ago. Our population genetic analysis also enabled us to differentiate selection during domestication for adaptation to the climatic and cultural environment of the Southwest, identifying adaptation loci relevant to drought tolerance and sugar content. PMID:27246050

  20. Characteristics of starch isolated from maize as a function of grain storage temperature.

    PubMed

    Paraginski, Ricardo Tadeu; Vanier, Nathan Levien; Moomand, Khalid; de Oliveira, Maurício; Zavareze, Elessandra da Rosa; Marques e Silva, Ricardo; Ferreira, Cristiano Dietrich; Elias, Moacir Cardoso

    2014-02-15

    Considering the importance of maize starch and the lack of knowledge about the effects of storage temperature on the isolated starch properties; maize grains were stored during 12 months at different temperatures (5, 15, 25 and 35 °C). The extraction yield and the physicochemical, thermal, pasting, crystallinity and morphological properties of starches were determined. The starch isolated from grains stored at 35 °C was yellowish and showed a 22.1% decrease in starch extraction yield compared to freshly harvested maize grains. At 35 °C, a reduction in crystallinity was observed by the end of 12 months, despite a parallel rearrangement of the starch chains which resulted in an increase in X-ray peak intensities, gelatinisation temperatures and enthalpy. The starch isolated from maize grains stored at 35 °C appears to have smaller granules, which presents some points in their surface, potentially attributed to the protein matrix compressing the granules within maize grains.

  1. Molecular rearrangement of waxy and normal maize starch granules during in vitro digestion.

    PubMed

    Teng, Anju; Witt, Torsten; Wang, Kai; Li, Ming; Hasjim, Jovin

    2016-03-30

    The objective of the present study is to understand the changes in starch structures during digestion and the structures contributing to slow digestion properties. The molecular, crystalline, and granular structures of native waxy maize, normal maize, high-amylose maize, and normal potato starch granules were monitored using SEC, XRD, DSC, and SEM. The amylose and amylopectin molecules of all four starches were hydrolyzed to smaller dextrins, with some having linear molecular structure. Neither the A- nor B-type crystallinity was resistant to enzyme hydrolysis. Starch crystallites with melting temperature above 120°C appeared in waxy and normal maize starches after digestion, suggesting that the linear dextrins retrograded into thermally stable crystalline structure. These crystallites were also observed for high-amylose maize starch before and after digestion, contributing to its low enzyme digestibility. On the contrary, the enzyme-resistant granular structure of native normal potato starch was responsible for its low susceptibility to enzyme hydrolysis. PMID:26794941

  2. Accumulation potentials of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays).

    PubMed

    Krippner, Johanna; Falk, Sandy; Brunn, Hubertus; Georgii, Sebastian; Schubert, Sven; Stahl, Thorsten

    2015-04-15

    Uptake of perfluoroalkyl acids (PFAAs) by maize represents a potential source of exposure for humans, either directly or indirectly via feed for animals raised for human consumption. The aim of the following study was, therefore, to determine the accumulation potential of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays). Two different concentrations of PFAAs were applied as aqueous solution to the soil to attain target concentrations of 0.25 mg or 1.00 mg of PFAA per kg of soil. Maize was grown in pots, and after harvesting, PFAA concentrations were measured in the straw and kernels of maize. PFCA and PFSA concentrations of straw decreased significantly with increasing chain length. In maize kernels, only PFCAs with a chain length ≤ C8 as well as perfluorobutanesulfonic acid (PFBS) were detected. The highest soil-to-plant transfer for both straw and kernels was determined for short-chained PFCAs and PFSAs.

  3. Aspergillus flavus infection induces transcriptional and physical changes in developing maize kernels

    PubMed Central

    Dolezal, Andrea L.; Shu, Xiaomei; OBrian, Gregory R.; Nielsen, Dahlia M.; Woloshuk, Charles P.; Boston, Rebecca S.; Payne, Gary A.

    2014-01-01

    Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understanding host response to infection by the fungus, transcription of approximately 9000 maize genes were monitored during the host-pathogen interaction with a custom designed Affymetrix GeneChip® DNA array. More than 4000 maize genes were found differentially expressed at a FDR of 0.05. This included the up regulation of defense related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel by A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development. PMID:25132833

  4. Molecular rearrangement of waxy and normal maize starch granules during in vitro digestion.

    PubMed

    Teng, Anju; Witt, Torsten; Wang, Kai; Li, Ming; Hasjim, Jovin

    2016-03-30

    The objective of the present study is to understand the changes in starch structures during digestion and the structures contributing to slow digestion properties. The molecular, crystalline, and granular structures of native waxy maize, normal maize, high-amylose maize, and normal potato starch granules were monitored using SEC, XRD, DSC, and SEM. The amylose and amylopectin molecules of all four starches were hydrolyzed to smaller dextrins, with some having linear molecular structure. Neither the A- nor B-type crystallinity was resistant to enzyme hydrolysis. Starch crystallites with melting temperature above 120°C appeared in waxy and normal maize starches after digestion, suggesting that the linear dextrins retrograded into thermally stable crystalline structure. These crystallites were also observed for high-amylose maize starch before and after digestion, contributing to its low enzyme digestibility. On the contrary, the enzyme-resistant granular structure of native normal potato starch was responsible for its low susceptibility to enzyme hydrolysis.

  5. Comparison of the efficiency between two sampling plans for aflatoxins analysis in maize.

    PubMed

    Mallmann, Adriano Olnei; Marchioro, Alexandro; Oliveira, Maurício Schneider; Rauber, Ricardo Hummes; Dilkin, Paulo; Mallmann, Carlos Augusto

    2014-01-01

    Variance and performance of two sampling plans for aflatoxins quantification in maize were evaluated. Eight lots of maize were sampled using two plans: manual, using sampling spear for kernels; and automatic, using a continuous flow to collect milled maize. Total variance and sampling, preparation, and analysis variance were determined and compared between plans through multifactor analysis of variance. Four theoretical distribution models were used to compare aflatoxins quantification distributions in eight maize lots. The acceptance and rejection probabilities for a lot under certain aflatoxin concentration were determined using variance and the information on the selected distribution model to build the operational characteristic curves (OC). Sampling and total variance were lower at the automatic plan. The OC curve from the automatic plan reduced both consumer and producer risks in comparison to the manual plan. The automatic plan is more efficient than the manual one because it expresses more accurately the real aflatoxin contamination in maize.

  6. Comparison of the efficiency between two sampling plans for aflatoxins analysis in maize

    PubMed Central

    Mallmann, Adriano Olnei; Marchioro, Alexandro; Oliveira, Maurício Schneider; Rauber, Ricardo Hummes; Dilkin, Paulo; Mallmann, Carlos Augusto

    2014-01-01

    Variance and performance of two sampling plans for aflatoxins quantification in maize were evaluated. Eight lots of maize were sampled using two plans: manual, using sampling spear for kernels; and automatic, using a continuous flow to collect milled maize. Total variance and sampling, preparation, and analysis variance were determined and compared between plans through multifactor analysis of variance. Four theoretical distribution models were used to compare aflatoxins quantification distributions in eight maize lots. The acceptance and rejection probabilities for a lot under certain aflatoxin concentration were determined using variance and the information on the selected distribution model to build the operational characteristic curves (OC). Sampling and total variance were lower at the automatic plan. The OC curve from the automatic plan reduced both consumer and producer risks in comparison to the manual plan. The automatic plan is more efficient than the manual one because it expresses more accurately the real aflatoxin contamination in maize. PMID:24948911

  7. The allotetraploidization of maize : Part 2: The theoretical basis - the cytogenetics of segmental allotetraploids.

    PubMed

    Doyle, G G

    1979-07-01

    Allotetraploidization is the creation of artifical allotetraploids from a normally diploid species. The possible value of allotetraploid maize has been discussed in Section I of this series. Allotetraploidization of maize can be achieved by restructuring a maize genome so that its chromosomes will not pair with those of the standard maize genome. This restructuring can be done by concentrating differential pairing affinity (DPA) factors into a single line by a recurrent selection type of breeding program. Because the divergence of the maize genome is a gradual process, it is necessary to devise a model for chromosome pairing and gene segregation in segmental allotetraploids. This has been done by considering pairing in each arm separately and then combining paired arms to form pairing configurations for whole chromosomes. The chromosome disjunction patterns are hypothesized and genetic ratios in relation to different levels of DPA are suggested. PMID:24310338

  8. Metabolizable energy, nitrogen balance, and ileal digestibility of amino acids in quality protein maize for pigs

    PubMed Central

    2014-01-01

    Background To compare the nutritional value and digestibility of five quality protein maize (QPM) hybrids to that of white and yellow maize, two experiments were carried out in growing pigs. In experiment 1, the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize. In experiment 2, the apparent and standardized ileal digestibility (AID and SID, respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize. In both experiments, the comparisons were conducted using contrasts. Results The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids (P < 0.05) than in the pigs fed white or yellow maize. Energy digestibility (P < 0.001) and metabolizability (P < 0.01) were higher in the pigs fed the white and yellow maize diets than in those fed the QPM diets. The AID of lysine was higher (P < 0.01) in the QPM diets than in the white and yellow maize. The AIDs of leucine, isoleucine, valine, phenylalanine, and methionine were lower in the QPM diets than those of maize (white and yellow) (all P < 0.05). Maize (white and yellow) had greater SIDs of leucine, isoleucine, valine, phenylalanine, glutamic acid, serine, alanine, tyrosine, and proline (P < 0.05). Conclusions Based on these results, it was concluded that QPM had a lower metabolizable energy content and a higher amount of digestible lysine than normal maize. PMID:25045520

  9. Effects of elevated [CO2] on maize defence against mycotoxigenic Fusarium verticillioides

    PubMed Central

    Vaughan, Martha M; Huffaker, Alisa; Schmelz, Eric A; Dafoe, Nicole J; Christensen, Shawn; Sims, James; Martins, Vitor F; Swerbilow, Jay; Romero, Maritza; Alborn, Hans T; Allen, Leon HARTWELL; Teal, Peter EA

    2014-01-01

    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 aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F. verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2]. Following F. verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2]. The attenuation of maize 13-LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2]. Our findings suggest that elevated [CO2] will compromise maize LOX-dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi. Elevated [CO2] increases maize susceptibility to Fusarium verticillioides proliferation but mycotoxin levels are unaltered. The attenuation of maize 13-LOXs and JA production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2]. PMID:24689748

  10. Performance of broiler chickens fed event DAS-40278-9 maize containing the aryloxyalkanoate dioxygenase-1 protein.

    PubMed

    Herman, Rod A; Dunville, Christina M; Juberg, Daland R; Fletcher, Dale W; Cromwell, Gary L

    2011-08-01

    Event DAS-40278-9 maize grain (containing the aryloxyalkanoate dioxygenase-1 protein), a non-transgenic near-isogenic maize grain, or one of three commercial maize grains were included in the diets of broiler chickens for six weeks. Growth, feed conversion, and carcass measurements indicated no significant difference between the groups fed the diets containing the DAS-40278-9 maize grain and those fed diets containing the matched control grain. The absence of adverse effects in this study supports the dietary safety of the AAD-1 protein expressed in event DAS-40278-9 maize.

  11. Relative contribution of maize and external manure amendment to soil carbon sequestration in a long-term intensive maize cropping system.

    PubMed

    Zhang, Wenju; Liu, Kailou; Wang, Jinzhou; Shao, Xingfang; Xu, Minggang; Li, Jianwei; Wang, Xiujun; Murphy, Daniel V

    2015-06-03

    We aimed to quantify the relative contributions of plant residue and organic manure to soil carbon sequestration. Using a 27-year-long inorganic fertilizer and manure amendment experiment in a maize (Zea mays L.) double-cropping system, we quantified changes in harvestable maize biomass and soil organic carbon stocks (0-20 cm depth) between 1986-2012. By employing natural (13)C tracing techniques, we derived the proportional contributions of below-ground crop biomass return (maize-derived carbon) and external manure amendment (manure-derived carbon) to the total soil organic carbon stock. The average retention of maize-derived carbon plus manure-derived carbon during the early period of the trial (up to 11 years) was relatively high (10%) compared to the later period (22 to 27 years, 5.1-6.3%). About 11% of maize-derived carbon was converted to soil organic carbon, which was double the retention of manure-derived carbon (4.4-5.1%). This result emphasized that organic amendments were necessary to a win-win strategy for both SOC sequestration and maize production.

  12. Relative contribution of maize and external manure amendment to soil carbon sequestration in a long-term intensive maize cropping system

    PubMed Central

    Zhang, Wenju; Liu, Kailou; Wang, Jinzhou; Shao, Xingfang; Xu, Minggang; Li, Jianwei; Wang, Xiujun; Murphy, Daniel V.

    2015-01-01

    We aimed to quantify the relative contributions of plant residue and organic manure to soil carbon sequestration. Using a 27-year-long inorganic fertilizer and manure amendment experiment in a maize (Zea mays L.) double-cropping system, we quantified changes in harvestable maize biomass and soil organic carbon stocks (0–20 cm depth) between 1986-2012. By employing natural 13C tracing techniques, we derived the proportional contributions of below-ground crop biomass return (maize-derived carbon) and external manure amendment (manure-derived carbon) to the total soil organic carbon stock. The average retention of maize-derived carbon plus manure-derived carbon during the early period of the trial (up to 11 years) was relatively high (10%) compared to the later period (22 to 27 years, 5.1–6.3%). About 11% of maize-derived carbon was converted to soil organic carbon, which was double the retention of manure-derived carbon (4.4–5.1%). This result emphasized that organic amendments were necessary to a win-win strategy for both SOC sequestration and maize production. PMID:26039186

  13. Population structure of the African Clawed Frog (Xenopus laevis) in maize-growing areas with atrazine application versus non-maize-growing areas in South Africa

    USGS Publications Warehouse

    Du Preez, L.H.; Solomon, K.R.; Carr, J.A.; Giesy, J.P.; Gross, T.S.; Kendall, R.J.; Smith, E.E.; Van Der Kraak, G. L.; Weldon, C.

    2005-01-01

    The herbicide atrazine has been suggested to cause gonadal deformities in frogs and could possibly impact on reproduction. Since the early 1960s, atrazine has been used in large amounts in maize production areas of South Africa. These areas overlap with populations of the African Clawed Frog (Xenopus laevis) that has a wide distribution in southern Africa and is found in most water-bodies including those where atrazine residues are detected. The aim of this study was to compare various attributes of individual- and population-level responses of X. laevis from maize-growing and non-maize-growing areas. Xenopus laevis were studied in three reference and five maize-growing sites. Sex ratio, snout-vent length, body-mass and age profiles were found to be similar for populations in maize-growing and non-maize-growing areas. Our mark-recapture data indicated that all sites had robust populations. There were no significant relationships between exposure to atrazine and any of the parameters investigated in populations of X. laevis.

  14. Quantification and identification of genetically modified maize events in non-identity preserved maize samples in 2009 using an individual kernel detection system.

    PubMed

    Akiyama, Hiroshi; Minegishi, Yasutaka; Makiyama, Daiki; Mano, Junichi; Sakata, Kozue; Nakamura, Kosuke; Noguchi, Akio; Takabatake, Reona; Futo, Satoshi; Kondo, Kazunari; Kitta, Kazumi; Kato, Yasuo; Teshima, Reiko

    2012-01-01

    We investigated the GM maize grain content of non-identity preserved (non-IP) maize samples produced in 2009 in the USA using our individual kernel detection system, involving two multiplex qualitative PCR methods coupled to microchip electrophoresis and partially real-time PCR array analysis, to clarify how many GM event maize grains were present in the samples and which GM events frequently appeared in 2009. The average percentage and standard deviation of GM maize grains on a kernel basis in five non-IP sample lots were 81.9%±2.8%, the average percentage of single GM event grains was 46.9%, and the average percentage of stacked GM event grains was 35.0%. MON88017 grains and NK603 grains were the most frequently observed as single GM event grains. The most frequent stacked GM event grains were MON88017×MON810 grains. This study shows that our method can provide information about GM maize events present in imported maize samples on a kernel basis. PMID:23132354

  15. Higher order chromatin structures in maize and Arabidopsis.

    PubMed Central

    Paul, A L; Ferl, R J

    1998-01-01

    We are investigating the nature of plant genome domain organization by using DNase I- and topoisomerase II-mediated cleavage to produce domains reflecting higher order chromatin structures. Limited digestion of nuclei with DNase I results in the conversion of the >800 kb genomic DNA to an accumulation of fragments that represents a collection of individual domains of the genome created by preferential cleavage at super-hypersensitive regions. The median size of these fragments is approximately 45 kb in maize and approximately 25 kb in Arabidopsis. Hybridization analyses with specific gene probes revealed that individual genes occupy discrete domains within the distribution created by DNase I. The maize alcohol dehydrogenase Adh1 gene occupies a domain of 90 kb, and the maize general regulatory factor GRF1 gene occupies a domain of 100 kb in length. Arabidopsis Adh was found within two distinct domains of 8.3 and 6.1 kb, whereas an Arabidopsis GRF gene occupies a single domain of 27 kb. The domains created by topoisomerase II-mediated cleavage are identical in size to those created by DNase I. These results imply that the genome is not packaged by means of a random gathering of the genome into domains of indiscriminate length but rather that the genome is gathered into specific domains and that a gene consistently occupies a discrete physical section of the genome. Our proposed model is that these large organizational domains represent the fundamental structural loop domains created by attachment of chromatin to the nuclear matrix at loop basements. These loop domains may be distinct from the domains created by the matrix attachment regions that typically flank smaller, often functionally distinct sections of the genome. PMID:9707534

  16. Proteome balancing of the maize seed for higher nutritional value

    PubMed Central

    Wu, Yongrui; Messing, Joachim

    2014-01-01

    Most flowering plant seeds are composed of the embryo and endosperm, which are surrounded by maternal tissue, in particular the seed coat. Whereas the embryo is the dormant progeny, the endosperm is a terminal organ for storage of sugars and amino acids in proteins and carbohydrates, respectively. Produced in maternal leaves during photosynthesis, sugars, and amino acids are transported to developing seeds after flowering, and during germination they nourish early seedlings growth. Maize endosperm usually contains around 10% protein and 70% starch, and their composition ratio is rather stable, because it is strictly regulated through a pre-set genetic program that is woven by networks of many interacting or counteracting genes and pathways. Endosperm protein, however, is of low nutritional value due mainly to the high expression of the α-zein gene family, which encodes lysine-free proteins. Reduced levels of these proteins in the opaque 2 (o2) mutant and α-zein RNAi (RNA interference) transgenic seed is compensated by an increase of non-zein proteins, leading to the rebalancing of the nitrogen sink and producing more or less constant levels of total proteins in the seed. The same rebalancing of zeins and non-zeins has been observed for maize seeds bred for 30% protein. In contrast to the nitrogen sink, storage of sulfur is controlled through the accumulation of specialized sulfur-rich proteins in maize endosperm. Silencing the synthesis of α-zeins through RNAi fails to raise sulfur-rich proteins. Although overexpression of the methionine-rich δ-zein can increase the methionine level in seeds, it occurs at least in part at the expense of the cysteine-rich β- and γ-zeins, demonstrating a balance between cysteine and methionine in sulfur storage. Therefore, we propose that the throttle for the flow of sulfur is placed before the synthesis of sulfur amino acids when sulfur is taken up and reduced during photosynthesis. PMID:24910639

  17. Gene-expression profile comparisons distinguish seven organs of maize

    PubMed Central

    Cho, Yangrae; Fernandes, John; Kim, Soo-Hwan; Walbot, Virginia

    2002-01-01

    Background A maize array was fabricated with 5,376 unique expressed sequence tag (EST) clones sequenced from 4-day-old roots, immature ears and adult organ cDNA libraries. To elucidate organ relationships, relative mRNA levels were quantified by hybridization with embryos, three maize vegetative organs (leaf blades, leaf sheaths and roots) from multiple developmental stages, husk leaves and two types of floral organs (immature ears and silks). Results Clustering analyses of the hybridization data suggest that maize utilizes both the PEPCK and NADP-ME C4 photosynthetic routes as genes in these pathways are co-regulated. Husk RNA has a gene-expression profile more similar to floral organs than to vegetative leaves. Only 7% of the genes were highly organ specific, showing over a fourfold difference in at least one of 12 comparisons and 37% showed a two- to fourfold difference. The majority of genes were expressed in diverse organs with little difference in transcript levels. Cross-hybridization among closely related genes within multigene families could obscure tissue specificity. As a first step in elucidating individual gene-expression patterns, we show that 45-nucleotide oligo probes produce signal intensities and signal ratios comparable to PCR probes on the same matrix. Conclusions Gene-expression profile studies with cDNA microarrays provide a new molecular tool for defining plant organs and their relationships and for discovering new biological processes in silico. cDNA microarrays are insufficient for differentiating recently duplicated genes. Gene-specific oligo probes printed along with cDNA probes can query individual gene-expression profiles and gene families simultaneously. PMID:12225584

  18. Ecophysiology of Fusarium temperatum isolated from maize in Argentina.

    PubMed

    Fumero, María Verónica; Sulyok, Michael; Chulze, Sofía

    2016-01-01

    The effect of water activity (aw = 0.95, 0.98 and 0.995), temperature (15, 25 and 30°C), incubation time (7, 14, 21 and 28 days), and their interactions on growth and moniliformin (MON), beauvericin (BEA), fusaproliferin (FUS) and fumonisin B1 (FB1) production by two strains of Fusarium temperatum isolated from Argentinean maize were determined in vitro on sterile layers of maize grains. The results showed that there was a wide range of conditions for growth and mycotoxins production by F. temperatum. Both strains were found to grow faster with increasing aw and at 30°C. In relation to mycotoxin production, the two strains produced more FUS than the other mycotoxins regardless of aw or temperature evaluated (maximum = 50,000 μg g(-1)). For FUS, MON and BEA, the maximum levels were observed at 0.98 aw and 30°C (50,000, 5000 and 2000 μg g(-1) respectively). The lowest levels for these three mycotoxins were detected at 15°C and 0.95 aw (1700 and 100 μg g(-1) for FUS and MON respectively), and at 0.98 aw (400 μg g(-1) for BEA). The maximum levels of FB1 were produced at 15°C and 0.98 aw (1000 μg g(-1)). At all aw and temperatures combinations evaluated there was an increase in toxin concentrations with time incubation. The maximum levels were detected at 21 days. Statistical analyses of aw, temperature, incubation time, and the two- and three-way interactions between them showed significant effects on mycotoxins production by F. temperatum. For its versatility on growth and mycotoxin production, F. temperatum represents a toxicological risk for maize in the field and also during grain storage.

  19. Binding of iron by fiber of wheat and maize.

    PubMed

    Reinhold, J G; Garcia, J S; Garzon, P

    1981-07-01

    Iron II is firmly bound by neutral detergent fiber (NDF) prepared from wheat or maize and NDF accounts for nearly all of the iron binding capability of these cereals. The amount of iron bound depends upon iron concentration, pH, quantity of fiber, and the presence or absence and quantities of inhibitors of binding. Binding is minimal, although appreciable, below pH 4.0, but rises rapidly above pH 5.0 to a maximum near pH 7.0, the limit of stability of iron in the system used. The NDF of wheat binds about 0.38 mg of iron per gram of NDF; that of maize somewhat more than 0.3 mg/g at pH 6.45. Binding of iron by acid detergent fiber (cellulose and lignin) is largely accounted for by its cellulose, and it also is pH dependent but less so than NDF. Iron binding by fiber is strongly inhibited by ascorbic, citric, and phytic acids and by EDTA in low concentrations. Various amino acids produce inhibition, especially cysteine, which inhibits strongly, but others are inactive. Phosphate and calcium are strong inhibitors; taurocholic acid is moderately inhibitory. It appears that a high proportion of ingested nonheme iron combines with fiber of wheat or maize and becomes unavailable for absorption when intake of these cereals are high unless it is released by surges of gastric acid or inhibitors of binding. The promotion of iron absorption by adjuvants such as ascorbic acid, fruit juices, and EDTA may depend in part upon their ability to release iron from its combination with dietary fiber.

  20. Growth and development of maize that contains mutant tubulin genes

    SciTech Connect

    Susan M. Wick

    2004-07-23

    Mutant maize plants containing a Mu transposon disrupting one of the five beta tubulin genes of interest were followed for several generations and hybridized with each other to produce plants containing disruptions in both copies of a single gene or disruption of more than one tubulin gene. Seedlings of some of these plants were grown under chilling conditions for a few weeks. After DOE funding ended, plants have been assessed to see whether mutant are more or less tolerant to chilling. Other mutant plants will be assessed for their male and female fertility relative to non-mutant siblings or other close relatives.